From jacob at blindza.co.za  Thu Jan  1 04:10:39 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Thu, 1 Jan 2015 11:10:39 +0200
Subject: Why For Loop Skips the Last element?
In-Reply-To: <CAAmLL-+HJ40OVSST2HhkQfmQbSKX0NfESmiaZh3KUasqjW3PPg@mail.gmail.com>
References: <CAAmLL-+HJ40OVSST2HhkQfmQbSKX0NfESmiaZh3KUasqjW3PPg@mail.gmail.com>
Message-ID: <8ED4CB03BF5A47809A69E43E8C4E5345@JakesPC>

Not sure after quick skim/scan, but, I would generally use either for I in range(len(inlist)): or just for it in inlist, instead of using while, etc.

Stay well

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."

  ----- Original Message ----- 
  From: Thuruv V 
  To: python-list at python.org 
  Sent: Wednesday, December 31, 2014 11:25 PM
  Subject: Why For Loop Skips the Last element?


  Hi all,


  Here's the list. .


  inlist = ["Fossil Women's Natalie Stainless Steel Watch Brown (JR1385)",
  'Balmer Swiss Made Veyron Mens Watch: Black Band/ Black Dial (62625241)',
  'Fortune NYC Ladies Quilted Dial Watch: Brown',
  'Jeanne Collection w/ Swarovski Elements Watch: Dark Purple Band (62623659)',
  'Swiss Legend Commander Chronograph: Watch Orange/Black (SL-10067-01-ORS)',
  'Debussy Ladies Watch: Brown/Gray/Silver 14070 - 62625292',
  '#2 Swiss Legend Commander Chronograph: Green (SL-10067-BB-017)',
  'Auguste Jaccard 3 Timezone Watch: Black Band/ Gray & Black Dial (62625184)'
  ]


  My code :
  i = 0
  while i <= len(inlist):
      if 'watch' in str(inlist[i]).lower() or 'watches' in str(inlist[i]).lower():
          if 'women' in str(inlist[i]).lower() or 'female' in str(inlist[i]).lower() or 'ladies' in str(inlist[i]).lower():
              print 'FEMale Watch', inlist.index(i),str(i)
          elif 'men' in str(inlist[i]).lower() or 'male' in str(inlist[i]).lower() or 'chronograph' in str(inlist[i]).lower():
              print 'Male Watch',inlist.index(i),str(i)
          i = next(inlist)


  When on executing python skips the last element('Auguste Jaccard 3 Timezone Watch: Black Band/ Gray & Black Dial (62625184)') in the list.


  But when accessing through 'print inlist[0]' is possible,i.e it shows the e;lement. but the list skips it. .
  Please enlighten me. .
  Thanks.


------------------------------------------------------------------------------


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From breamoreboy at yahoo.co.uk  Thu Jan  1 04:28:06 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 01 Jan 2015 09:28:06 +0000
Subject: Why For Loop Skips the Last element?
In-Reply-To: <CAAmLL-+HJ40OVSST2HhkQfmQbSKX0NfESmiaZh3KUasqjW3PPg@mail.gmail.com>
References: <CAAmLL-+HJ40OVSST2HhkQfmQbSKX0NfESmiaZh3KUasqjW3PPg@mail.gmail.com>
Message-ID: <m833v8$5dj$1@ger.gmane.org>

On 31/12/2014 21:25, Thuruv V wrote:
> Hi all,
>
> Here's the list. .
>
> inlist = ["Fossil Women's Natalie Stainless Steel Watch Brown (JR1385)",
> 'Balmer Swiss Made Veyron Mens Watch: Black Band/ Black Dial (62625241)',
> 'Fortune NYC Ladies Quilted Dial Watch: Brown',
> 'Jeanne Collection w/ Swarovski Elements Watch: Dark Purple Band
> (62623659)',
> 'Swiss Legend Commander Chronograph: Watch Orange/Black (SL-10067-01-ORS)',
> 'Debussy Ladies Watch: Brown/Gray/Silver 14070 - 62625292',
> '#2 Swiss Legend Commander Chronograph: Green (SL-10067-BB-017)',
> 'Auguste Jaccard 3 Timezone Watch: Black Band/ Gray & Black Dial (62625184)'
> ]
>
> My code :
> i = 0
> while i <= len(inlist):
>      if 'watch' in str(inlist[i]).lower() or 'watches' in
> str(inlist[i]).lower():
>          if 'women' in str(inlist[i]).lower() or 'female' in
> str(inlist[i]).lower() or 'ladies' in str(inlist[i]).lower():
>              print 'FEMale Watch', inlist.index(i),str(i)
>          elif 'men' in str(inlist[i]).lower() or 'male' in
> str(inlist[i]).lower() or 'chronograph' in str(inlist[i]).lower():
>              print 'Male Watch',inlist.index(i),str(i)
>          i = next(inlist)
>
> When on executing python skips the last element('Auguste Jaccard 3
> Timezone Watch: Black Band/ Gray & Black Dial (62625184)') in the list.
>
> But when accessing through 'print inlist[0]' is possible,i.e it shows
> the e;lement. but the list skips it. .
> Please enlighten me. .
> Thanks.
>
>

Why don't you show us your actual code?  There is no for loop above and 
running the actual code gives "ValueError: 0 is not in list" on the 
first pass through the while loop.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From jpiitula at ling.helsinki.fi  Thu Jan  1 04:31:08 2015
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 01 Jan 2015 11:31:08 +0200
Subject: Why For Loop Skips the Last element?
References: <mailman.17302.1420102630.18130.python-list@python.org>
Message-ID: <qotwq56alur.fsf@ruuvi.it.helsinki.fi>

Thuruv V writes:

> Here's the list. .
> 
> inlist = ["Fossil Women's Natalie Stainless Steel Watch Brown (JR1385)",
> 'Balmer Swiss Made Veyron Mens Watch: Black Band/ Black Dial (62625241)',
> 'Fortune NYC Ladies Quilted Dial Watch: Brown',
> 'Jeanne Collection w/ Swarovski Elements Watch: Dark Purple Band
> (62623659)',
> 'Swiss Legend Commander Chronograph: Watch Orange/Black (SL-10067-01-ORS)',
> 'Debussy Ladies Watch: Brown/Gray/Silver 14070 - 62625292',
> '#2 Swiss Legend Commander Chronograph: Green (SL-10067-BB-017)',
> 'Auguste Jaccard 3 Timezone Watch: Black Band/ Gray & Black Dial (62625184)'
> ]
> 
> My code :
> i = 0
> while i <= len(inlist):
>     if 'watch' in str(inlist[i]).lower() or 'watches' in
> str(inlist[i]).lower():
>         if 'women' in str(inlist[i]).lower() or 'female' in
> str(inlist[i]).lower() or 'ladies' in str(inlist[i]).lower():
>             print 'FEMale Watch', inlist.index(i),str(i)
>         elif 'men' in str(inlist[i]).lower() or 'male' in
> str(inlist[i]).lower() or 'chronograph' in str(inlist[i]).lower():
>             print 'Male Watch',inlist.index(i),str(i)
>         i = next(inlist)
> 
> When on executing python skips the last element('Auguste Jaccard 3
> Timezone Watch: Black Band/ Gray & Black Dial (62625184)') in the
> list.

Looks like it should raise an exception at the first element, as soon
as it tries to print inlist.index(0). And looks like you are confusing
the element and the index of the element all the way through.

Also, re subject line, that's not a for loop. That's a while loop. But
since you mean it to go through all elements of the list, a for loop
is indeed preferable:

    for line in inlist:
       print(line)

To walk each line and its index together, use enumerate:

   for i, line in enumerate(inlist):
       print(i, line)

(The "i = next(inlist)" in your while loop wants to be "i += 1", and
it really doesn't want to be inside the if-statement. But since your
while loop wants to be a for loop, the whole update of the index
should go away.)

> But when accessing through 'print inlist[0]' is possible,i.e it
> shows the e;lement. but the list skips it. .
> Please enlighten me. .
> Thanks.

I suspect you didn't post quite the version of the code you ran, but
maybe the above suggestions help you get on track again. Best wishes.


From steve+comp.lang.python at pearwood.info  Thu Jan  1 05:15:20 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 01 Jan 2015 21:15:20 +1100
Subject: Why For Loop Skips the Last element?
References: <mailman.17302.1420102630.18130.python-list@python.org>
Message-ID: <54a51e39$0$12998$c3e8da3$5496439d@news.astraweb.com>

Thuruv V wrote:

> Hi all,
> 
> Here's the list. .

The exact details of the list are not important. Please simplify your code
to something easier to handle than this:

> inlist = ["Fossil Women's Natalie Stainless Steel Watch Brown (JR1385)",
> 'Balmer Swiss Made Veyron Mens Watch: Black Band/ Black Dial (62625241)',
> 'Fortune NYC Ladies Quilted Dial Watch: Brown',
> 'Jeanne Collection w/ Swarovski Elements Watch: Dark Purple Band
> (62623659)',
> 'Swiss Legend Commander Chronograph: Watch Orange/Black
> (SL-10067-01-ORS)', 'Debussy Ladies Watch: Brown/Gray/Silver 14070 -
> 62625292', '#2 Swiss Legend Commander Chronograph: Green
> (SL-10067-BB-017)', 'Auguste Jaccard 3 Timezone Watch: Black Band/ Gray &
> Black Dial (62625184)' ]

For your testing, try this first:

inlist = ['Female 1', 'male 1', 'Male 2', 'ladies 2']


When you have your code working with the simple test data, then you can go
on with the more complicated real data.


> My code :

Why are you using a while loop? I don't understand where this comes from. So
many beginners keep doing things the hard way, using a while loop.


Iterate over the list like this:


for item in inlist:
    item = item.lower()
    if "female" in item or "ladies" in item:
        print("Female")
    elif "man" in item or "male" in item:
        print("Male")




> i = 0
> while i <= len(inlist):
>     if 'watch' in str(inlist[i]).lower() or 'watches' in
> str(inlist[i]).lower():
>         if 'women' in str(inlist[i]).lower() or 'female' in
> str(inlist[i]).lower() or 'ladies' in str(inlist[i]).lower():
>             print 'FEMale Watch', inlist.index(i),str(i)
>         elif 'men' in str(inlist[i]).lower() or 'male' in
> str(inlist[i]).lower() or 'chronograph' in str(inlist[i]).lower():
>             print 'Male Watch',inlist.index(i),str(i)
>         i = next(inlist)
> 
> When on executing python skips the last element('Auguste Jaccard 3
> Timezone Watch: Black Band/ Gray & Black Dial (62625184)') in the list.

Your code skips that last item because the second-last item doesn't have the
word "watch" in it, so the loop never advances and it just loops forever.

But really, the code you show us is not the code you are actually using. Why
do you show us something different from what you actually use?

I know that the code you show cannot possibly be the code you are using,
because the code you show fails. If you ran this code, it would raise
TypeError.




-- 
Steven



From breamoreboy at yahoo.co.uk  Thu Jan  1 05:34:10 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 01 Jan 2015 10:34:10 +0000
Subject: Why For Loop Skips the Last element?
In-Reply-To: <54a51e39$0$12998$c3e8da3$5496439d@news.astraweb.com>
References: <mailman.17302.1420102630.18130.python-list@python.org>
 <54a51e39$0$12998$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <m837r4$ob1$1@ger.gmane.org>

On 01/01/2015 10:15, Steven D'Aprano wrote:
>
> I know that the code you show cannot possibly be the code you are using,
> because the code you show fails. If you ran this code, it would raise
> TypeError.
>

Traceback (most recent call last):
   File "C:\Users\Mark\Documents\MyPython\mytest.py", line 16, in <module>
     print('FEMale Watch', inlist.index(i),str(i))
ValueError: 0 is not in list

Sinner, but as it's New Year's Day I'll let you off :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From wxjmfauth at gmail.com  Thu Jan  1 05:39:42 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Thu, 1 Jan 2015 02:39:42 -0800 (PST)
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
Message-ID: <1c8ee08b-f60c-4482-9176-3537f3b7956a@googlegroups.com>

Le mercredi 31 d?cembre 2014 23:24:50 UTC+1, Andr? Roberge a ?crit?:
> EasyGUI_Qt version 0.9 has been released.  This is the first announcement about EasyGUI_Qt on this list.
> 
> Like the original EasyGUI (which used Tkinter), 
> EasyGUI_Qt seeks to provide simple GUI widgets
> that can be called in a procedural program. 
> 
> EasyGUI_Qt is NOT event-driven: all GUI interactions are invoked by simple function calls.
> 
> The archetype is get_string(message)
> which pops a box whose purpose is exactly the same as Python's input(prompt),
> that is, present the user with a question/prompt, have the user enter an
> answer, and return the provided answer as a string.  Thus
> easygui_qt.get_string() can be used as a drop-in replacement for
> input().
> 
> Similarly, instead of using a print() function to display a message,
> show_message() is used which pops a message window.
> 
> EasyGUI_Qt requires PyQt4 and is really targeted for Python 3.3+ - although it can work (possibly with some unicode problems ...) using Python 2.7.
> 
> More information can be found at 
> http://easygui-qt.readthedocs.org/en/latest/index.html
> 
> Feedback is most welcome, including reporting bugs to 
> https://github.com/aroberge/easygui_qt/issues
> 
> Happy 2015 everyone,
> 
> Andr? Roberge

If it works like eric6, I quickly tested yesterday
morning, it will not work.

jmf


From breamoreboy at yahoo.co.uk  Thu Jan  1 06:01:25 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 01 Jan 2015 11:01:25 +0000
Subject: Why For Loop Skips the Last element?
In-Reply-To: <8ED4CB03BF5A47809A69E43E8C4E5345@JakesPC>
References: <CAAmLL-+HJ40OVSST2HhkQfmQbSKX0NfESmiaZh3KUasqjW3PPg@mail.gmail.com>
 <8ED4CB03BF5A47809A69E43E8C4E5345@JakesPC>
Message-ID: <m839e7$ecm$1@ger.gmane.org>

On 01/01/2015 09:10, Jacob Kruger wrote:
> Not sure after quick skim/scan, but, I would generally use either for I
> in range(len(inlist)): or just for it in inlist, instead of using while,
> etc.
> Stay well
>

As a rule of thumb if you're writing range(len(inlist)) you're doing it 
wrong.  For an example of how to do things correctly see the pairwise 
recipe here 
https://docs.python.org/3/library/itertools.html#itertools-recipes. 
This is available in more-itertools here 
https://pythonhosted.org/more-itertools/api.html

As an aside would you please not top post on this list, thanks.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From steve+comp.lang.python at pearwood.info  Thu Jan  1 07:38:17 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 01 Jan 2015 23:38:17 +1100
Subject: Why For Loop Skips the Last element?
References: <mailman.17302.1420102630.18130.python-list@python.org>
 <54a51e39$0$12998$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17305.1420108467.18130.python-list@python.org>
Message-ID: <54a53fba$0$13014$c3e8da3$5496439d@news.astraweb.com>

Mark Lawrence wrote:

> On 01/01/2015 10:15, Steven D'Aprano wrote:
>>
>> I know that the code you show cannot possibly be the code you are using,
>> because the code you show fails. If you ran this code, it would raise
>> TypeError.
>>
> 
> Traceback (most recent call last):
>    File "C:\Users\Mark\Documents\MyPython\mytest.py", line 16, in <module>
>      print('FEMale Watch', inlist.index(i),str(i))
> ValueError: 0 is not in list
> 
> Sinner, but as it's New Year's Day I'll let you off :)


I was thinking of the next(inlist).


 

-- 
Steven



From denismfmcmahon at gmail.com  Thu Jan  1 09:24:37 2015
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Thu, 1 Jan 2015 14:24:37 +0000 (UTC)
Subject: Why For Loop Skips the Last element?
References: <mailman.17302.1420102630.18130.python-list@python.org>
Message-ID: <m83lb4$a4v$1@dont-email.me>

On Thu, 01 Jan 2015 02:55:49 +0530, Thuruv V wrote:

> Hi all,
> 
> Here's the list. .
> 
> inlist = ["Fossil Women's Natalie Stainless Steel Watch Brown (JR1385)",
> 'Balmer Swiss Made Veyron Mens Watch: Black Band/ Black Dial
> (62625241)',
> 'Fortune NYC Ladies Quilted Dial Watch: Brown',
> 'Jeanne Collection w/ Swarovski Elements Watch: Dark Purple Band
> (62623659)',
> 'Swiss Legend Commander Chronograph: Watch Orange/Black
> (SL-10067-01-ORS)',
> 'Debussy Ladies Watch: Brown/Gray/Silver 14070 - 62625292',
> '#2 Swiss Legend Commander Chronograph: Green (SL-10067-BB-017)',
> 'Auguste Jaccard 3 Timezone Watch: Black Band/ Gray & Black Dial
> (62625184)'
> ]
> 
> My code :
> i = 0 while i <= len(inlist):
>     if 'watch' in str(inlist[i]).lower() or 'watches' in
> str(inlist[i]).lower():
>         if 'women' in str(inlist[i]).lower() or 'female' in
> str(inlist[i]).lower() or 'ladies' in str(inlist[i]).lower():
>             print 'FEMale Watch', inlist.index(i),str(i)
>         elif 'men' in str(inlist[i]).lower() or 'male' in
> str(inlist[i]).lower() or 'chronograph' in str(inlist[i]).lower():
>             print 'Male Watch',inlist.index(i),str(i)
>         i = next(inlist)

..........^

If the indents are correct, i will only increment if watch or watches are 
found. Your last but 1 item doesn't match these strings (chronograph 
instead of watch).

It would still be better as others have posted to use a for loop.

-- 
Denis McMahon, denismfmcmahon at gmail.com


From jsf80238 at gmail.com  Thu Jan  1 12:09:13 2015
From: jsf80238 at gmail.com (Jason Friedman)
Date: Thu, 1 Jan 2015 10:09:13 -0700
Subject: Logger not logging
Message-ID: <CANy1k1jvvTAhD7eQV-9id-yB1HA5qQMp9S6HQiGj1OTA2p+aqg@mail.gmail.com>

What am I missing?

I expect logger.info("hello") to emit.

$ python
Python 3.4.0 (default, Apr 18 2014, 19:16:28)
[GCC 4.8.1] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import logging
>>> logger = logging.getLogger()
>>> logger.setLevel(logging.INFO)
>>> logger.info("hello")
>>> logger.warn("hello")
hello
>>>


From dan at tombstonezero.net  Thu Jan  1 12:25:22 2015
From: dan at tombstonezero.net (Dan Sommers)
Date: Thu, 1 Jan 2015 17:25:22 +0000 (UTC)
Subject: Logger not logging
References: <mailman.17307.1420132161.18130.python-list@python.org>
Message-ID: <m83vu1$5s0$1@dont-email.me>

On Thu, 01 Jan 2015 10:09:13 -0700, Jason Friedman wrote:

> What am I missing?
> 
> I expect logger.info("hello") to emit.
> 
> $ python
> Python 3.4.0 (default, Apr 18 2014, 19:16:28)
> [GCC 4.8.1] on linux
> Type "help", "copyright", "credits" or "license" for more information.
>>>> import logging
>>>> logger = logging.getLogger()
>>>> logger.setLevel(logging.INFO)
>>>> logger.info("hello")
>>>> logger.warn("hello")
> hello
>>>>

By default, loggers only log warnings and errors.  Add this:

    logger.setLevel(logging.INFO)

HTH,
Dan


From joel.goldstick at gmail.com  Thu Jan  1 12:49:15 2015
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Thu, 1 Jan 2015 12:49:15 -0500
Subject: Logger not logging
In-Reply-To: <m83vu1$5s0$1@dont-email.me>
References: <mailman.17307.1420132161.18130.python-list@python.org>
 <m83vu1$5s0$1@dont-email.me>
Message-ID: <CAPM-O+w612N-U5AHFpbER2jgjuCR_0CYuwF6nURVijbSyBckTg@mail.gmail.com>

On Thu, Jan 1, 2015 at 12:25 PM, Dan Sommers <dan at tombstonezero.net> wrote:

> On Thu, 01 Jan 2015 10:09:13 -0700, Jason Friedman wrote:
>
> > What am I missing?
> >
> > I expect logger.info("hello") to emit.
> >
> > $ python
> > Python 3.4.0 (default, Apr 18 2014, 19:16:28)
> > [GCC 4.8.1] on linux
> > Type "help", "copyright", "credits" or "license" for more information.
> >>>> import logging
> >>>> logger = logging.getLogger()
> >>>> logger.setLevel(logging.INFO)
> >>>> logger.info("hello")
> >>>> logger.warn("hello")
> > hello
> >>>>
>
> By default, loggers only log warnings and errors.  Add this:
>
>     logger.setLevel(logging.INFO)
>
> HTH,
> Dan
>

Looks like op did that?

> --
> https://mail.python.org/mailman/listinfo/python-list
>



-- 
Joel Goldstick
http://joelgoldstick.com
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From __peter__ at web.de  Thu Jan  1 12:59:42 2015
From: __peter__ at web.de (Peter Otten)
Date: Thu, 01 Jan 2015 18:59:42 +0100
Subject: Logger not logging
References: <CANy1k1jvvTAhD7eQV-9id-yB1HA5qQMp9S6HQiGj1OTA2p+aqg@mail.gmail.com>
Message-ID: <m841ue$3po$1@ger.gmane.org>

Jason Friedman wrote:


> I expect logger.info("hello") to emit.
> 
> $ python
> Python 3.4.0 (default, Apr 18 2014, 19:16:28)
> [GCC 4.8.1] on linux
> Type "help", "copyright", "credits" or "license" for more information.
>>>> import logging
>>>> logger = logging.getLogger()
>>>> logger.setLevel(logging.INFO)
>>>> logger.info("hello")
>>>> logger.warn("hello")
> hello
>>>>

> What am I missing?

The handler also filters. The easiest way to get one that is configured 
appropriately is to use basicConfig():

>>> import logging
>>> logging.basicConfig(level=logging.INFO)
>>> root = logging.getLogger()
>>> root.info("hello")
INFO:root:hello




From jsf80238 at gmail.com  Thu Jan  1 13:22:41 2015
From: jsf80238 at gmail.com (Jason Friedman)
Date: Thu, 1 Jan 2015 11:22:41 -0700
Subject: Logger not logging
In-Reply-To: <m841ue$3po$1@ger.gmane.org>
References: <CANy1k1jvvTAhD7eQV-9id-yB1HA5qQMp9S6HQiGj1OTA2p+aqg@mail.gmail.com>
 <m841ue$3po$1@ger.gmane.org>
Message-ID: <CANy1k1gcCt+6KmZ1iGo3TS2Eez2DT=Lu20-tm07RcAQ=fWnNJA@mail.gmail.com>

>> Python 3.4.0 (default, Apr 18 2014, 19:16:28)
>> [GCC 4.8.1] on linux
>> Type "help", "copyright", "credits" or "license" for more information.
>>>>> import logging
>>>>> logger = logging.getLogger()
>>>>> logger.setLevel(logging.INFO)
>>>>> logger.info("hello")
>>>>> logger.warn("hello")
>> hello
>>>>>
>
>> What am I missing?
>
> The handler also filters. The easiest way to get one that is configured
> appropriately is to use basicConfig():
>
>>>> import logging
>>>> logging.basicConfig(level=logging.INFO)
>>>> root = logging.getLogger()
>>>> root.info("hello")
> INFO:root:hello


Thank you


From lucasvfxdood at gmail.com  Thu Jan  1 13:43:57 2015
From: lucasvfxdood at gmail.com (lucasvfxdood at gmail.com)
Date: Thu, 1 Jan 2015 10:43:57 -0800 (PST)
Subject: Moving 1 Picture in a Programm - How to?
Message-ID: <ceb5d76c-afd9-4f6d-b725-c86ed82716c3@googlegroups.com>

Hey Guys! I need your help!
So i want to make a programm like the app called "Feed Me"
There are 2 Pictures (I got that) than you can click the food picture and drag it on the boys mouth and than the sad boys face disappears and a happy face shows up.

Heres the code ive wrtiten
from tkinter import * 
f = Tk()
f.title('Give the boy the apple.')
f.geometry('500x500')
c = Canvas(master=f,width=500,height=500,bg='white')
c.place(x=0,y=0)
p = PhotoImage(file='traurigsmiley.png') #sad smiley
i = c.create_image(250,320,image=p) #position
p2 = PhotoImage(file='essen.png') #food
i2 = c.create_image(70,100,image=p2)
f.geometry('500x500')
f.mainloop()


Please Help!


From auriocus at gmx.de  Thu Jan  1 14:36:46 2015
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Thu, 01 Jan 2015 20:36:46 +0100
Subject: Moving 1 Picture in a Programm - How to?
In-Reply-To: <ceb5d76c-afd9-4f6d-b725-c86ed82716c3@googlegroups.com>
References: <ceb5d76c-afd9-4f6d-b725-c86ed82716c3@googlegroups.com>
Message-ID: <m847jm$qfl$1@dont-email.me>

Am 01.01.15 um 19:43 schrieb lucasvfxdood at gmail.com:
> Hey Guys! I need your help! So i want to make a programm like the app
> called "Feed Me" There are 2 Pictures (I got that) than you can click
> the food picture and drag it on the boys mouth and than the sad boys
> face disappears and a happy face shows up.

Have a look at the canvasplot.py demo of the Tk canvas. It shows how to 
do basic drag'n'drop with items on a canvas. Can be downloaded from here:

http://tkinter.unpythonic.net/wiki/A_tour_of_Tkinter_widgets

	Christian


From rantingrickjohnson at gmail.com  Thu Jan  1 14:50:21 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 1 Jan 2015 11:50:21 -0800 (PST)
Subject: Moving 1 Picture in a Programm - How to?
In-Reply-To: <ceb5d76c-afd9-4f6d-b725-c86ed82716c3@googlegroups.com>
References: <ceb5d76c-afd9-4f6d-b725-c86ed82716c3@googlegroups.com>
Message-ID: <b6ef1b9e-595e-4465-ba3b-2b8ccee3ecfb@googlegroups.com>

On Thursday, January 1, 2015 12:44:13 PM UTC-6, lucas mvm wrote:
> Hey Guys! I need your help! So i want to make a program
> like the app called "Feed Me" There are 2 Pictures (I got
> that) than you can click the food picture and drag it on
> the boys mouth and than the sad boys face disappears and a
> happy face shows up.

This interactivity will require mastering a few basic
events. The Tkinter canvas offers a few extra methods of
binding events besides the normal "widget level" event
bindings. Since you are beginning you should focus on the
ubiquitous bindings at the "widget level" -- master those
before moving on to "tag level bindings".

First step: FORGET ABOUT PICTURES, because they will only
get in your way at this time. First step is to create three
events that map mouse clicks, mouse drags, and mouse
releases to print messages to stdout. THEN, and only then
you can move to the next step!

    DIVIDE AND CONQUER... in teeny tiny baby steps!
    
But first allow me to critique your code.

> Heres the code ive wrtiten
> from tkinter import * 

Oh no... I would not suggest importing everything (even
though the library can be) since doing so pollutes your
namespace with many names you'll never use. Instead do:
"import tkinter as tk" and prefix every class with "tk.". For
the constants you do either "from tkinter.constants import
*" or individually import only the names you will use (the
second option is obviously better) But for now, let's just
get this code working, shall we?

> f = Tk()

Why would you use "f" as a variable for a tkinter window? A
better symbol would be "root" or "topwin". Make sure your
symbols are describing succinctly what they reference (THIS
IS VERY IMPORTANT!) Even though Tkinter allows you to use a
"frame" as a "window" (frame.mainloop()), it only works
because there is some "magic" going on behind the scenes.
You must understand that "frames != windows".

> f.title('Give the boy the apple.')
> f.geometry('500x500')
> c = Canvas(master=f,width=500,height=500,bg='white')
> c.place(x=0,y=0)

The "place" geometry manager should only be use in
*extremely* specific circumstances. And since your code does
not require such "needs" i suggest you replace "c.place"
with "c.pack(fill=BOTH, expand=YES)". There are three
geometry managers in Tkinter:

    1. Pack
    2. Grid
    3. Place
    
When your trying to decide which manager to use, start with
the "pack manager" first, if it cannot solve your needs then
contemplate the "grid manager", and only after deciding
that the "pack manager" and "grid manager" won't work, then
you can us the "place manager".

> p = PhotoImage(file='traurigsmiley.png') #sad smiley
> i = c.create_image(250,320,image=p) #position
> p2 = PhotoImage(file='essen.png') #food
> i2 = c.create_image(70,100,image=p2)
> f.geometry('500x500')
> f.mainloop()
>
> Please Help!

First, rewrite your code in the manner i suggest, then
expand it with the following.

1. Bind three events to your canvas object:

    c.bind("<Button>", evtButtonDown)
    c.bind(...) # < -- homework!
    c.bind(...) # < -- homework!

1. Create three functions that act as callback for the events:

    def evtButtonDown(evt):
        # print the number of the button pressd here!
    
    def evtButtonUp(evt):
        # print the number of the button pressd here!
    
    def evtMouseMove(evt):
        # print the x,y location of the cursor here!

============================================================
RESOURCES: 
============================================================
http://effbot.org/tkinterbook/
http://infohost.nmt.edu/tcc/help/pubs/tkinter/web/index.html


From bv4bv4bv4 at gmail.com  Thu Jan  1 16:43:51 2015
From: bv4bv4bv4 at gmail.com (bv4bv4bv4 at gmail.com)
Date: Thu, 1 Jan 2015 13:43:51 -0800 (PST)
Subject: THE SUPERIORITY OF THE MOTHER IN ISLAM
Message-ID: <08ff6e80-f926-4736-b161-a894bac6d792@googlegroups.com>

THE SUPERIORITY OF THE MOTHER IN ISLAM
#1- From Abu Hurairah -radiallaahu anhu- who said: A man came to the Messenger of Allah -sallallaahu alayhi wa sallam- and said: 'O Messenger of Allah who from the people is the most deserving of my good companionship?

The Messenger -sallallaahu alayhi wa sallam- replied:

'Your mother.'

The man said: 'then who?'

The Messenger -sallallaahu alayhi wa sallam- replied:

'Your mother.'

The man said: 'then who?'

The Messenger -sallallaahu alayhi wa sallam- replied:

'Your mother.'

The man said: 'then who?'

The Messenger -sallallaahu alayhi wa sallam- said:

'Your father.'

[In another narration: '. . . . . the next closest relative then those closest after them.']

[Collected in 'Adab al-Mufrad' no.3, Tirmidhi and 'Irwaa al-Ghaleel' 829/2232, declared Hasan by Albaani.]

In another narration: 'A man came to the Prophet of Allah -sallallaahu alayhi wa sallam- and said: 'What do you order me with?' The Messenger -sallallaahu alayhi wa sallam- said:

'Be good to your mother.'

[Collected by 'Adab al-Mufrad' no. 6]

[Collected by Bukhari in 'Kitaab al-Adab' in the second chapter: 'Who from the people is the most deserving of my good companionship?' and also collected by Muslim in 'Kitaab al-Birr wa Silat wal Adab']

Imam Nawawi said in his explanation of this hadeeth:

'The Scholars have said: the reason for the superiority of the mother is due to her becoming tired on your account, her compassion, her serving you, suffering hardship while being pregnant with you, then giving birth to you, then suckling you, then bringing you up, serving you, nursing you and other things.'

[Taken from the 'Sharh Saheeh Muslim' 16/80]

Ibn Hajr quotes Ibn Battaal in the explanation of this hadeeth:

Ibn Battaal said: 'Malik was asked: my father requests me to do something but my mother prevents me from it.'

Imam Malik answered:

'Obey your father and do not disobey your mother.'

['Fath ul Bari'10/402]

#2- 'Asma bint Abu Bakr said: 'My mother came to me and she is a Mushrikah (Non-Muslim) at the time of the Messenger of Allah -sallallaahu alayhi wa sallam-, so I asked the Messenger of Allah -sallallaahu alayhi wa sallam- about this and I said to him: 'My mother has come to me, and she is asking for me to be good to her, should I keep good relations with my mother?

The Messenger of Allah -sallallaahu alayhi wa sallam- said: 'Keep good relations with her.'

[Collected by Bukhari, Muslim and in the wording mentioned by Abu Dawud: 'Asma -radiallaahu anha- said: '... and she hates Islam.' 'Saheeh Targhib wa Tarhib' p.657 no. 2500]

Ibn Uayainah said: Allah -Azza wa Jall- revealed:

<< Allah does not forbid you from dealing justly and kindly with those who did not fight against you on account of religion >>

[al-Mumtahina: 8] regarding her.

[Collected by Bukhari in 'Adab al-Mufrad' no. 25, declared Saheeh by Albaani in 'Saheeh Abu Dawud' (1468)]

#3- It is narrated from Talha bin Muaaweeyah as-Sulamee -radiallaahu anhu- who said: I came to the Prophet -sallallaahu alayhi wa sallam- and said: 'O Messenger of Allah! Indeed I want to participate in Jihad in the path of Allah.'

The Prophet -sallallaahu alayhi wa sallam- said: 'Is your mother alive?'

I said: 'Yes.'

The Prophet -sallallaahu alayhi wa sallam- said:

'Stay at her feet, for there is Paradise.'

[Collected by Tabraani and Albaani declared it Saeeih li Ghayreehi in 'Saheeh Targhib wa Tarhib' 2/2484 p.649]

In a similar narration from Muaaweeyah bin Jaahimah where the Prophet -sallallaahu alayhi wa sallam- said:

'Stick to your mother, since indeed Paradise is at her feet.'

[Collected by Ibn Majah, Nisa'i and Albaani declared it Hasan Saheeh in 'Saheeh Targhib wa Tarhib' 2/2485]

In a similar hadeeth the Prophet -sallallaahu alayhi wa sallam- asked: 'Do you have parents?'

I said: 'Yes.'

The Prophet -sallallaahu alayhi wa sallam- said:

'Stick to them, since indeed Paradise is under their feet.'

[Collected by Tabrani and Albaani declared it Hasan Saheeh in 'Saheeh Targhib wa Tarhib' no. 2485]

#4 - From Ibn Umar -radiallaahu anhu- who said: 'A man came to the Prophet -sallallaahu alayhi wa sallam- and said: 'Indeed I have committed a major sin, is there any repentance for me?'

The Prophet -sallallaahu alayhi wa sallam- said: 'Do you have a mother?'

He answered: 'No.'

The Prophet -sallallaahu alayhi wa sallam- said: 'Do you have an aunt (mother's sister)?'

He answered: 'Yes.'

The Prophet -sallallaahu alayhi wa sallam- said:

'Then be good to her.'

[Collected by Tirmidhi, and declared Saheeh by Albaani and in the wording collected by Ibn Hibban and Hakim: 'Do you have parents?' 'Saheeh Targhib wa Tarhib' p.658 no. 2504]

#5- From al-Mughirah bin Shaybah -radiallaahu anhu- from the Prophet -sallallaahu alayhi wa sallam- who said:

'Indeed Allah has prohibited you from being disobedient to your mothers, and burying your daughters alive, to withhold from what Allah has allowed, claiming something which you do not have the right to claim. And Allah dislikes gossiping and excessive questioning, and wasting wealth.'

[Collected by Bukhari]

#6- From al-Miqdam bin Ma'adi Karb al-Kindi on the authority of the Prophet -sallallaahu alayhi wa sallam- who said:

'Indeed Allah orders you to fulfill the rights of your mothers, then to fulfill the rights of close relatives then those who are after them.'

[Collected in 'Silsilah Sahihah' No.1666]

>From the Athaar of the Salaf

#7- From Sa'id bin Abu Burdah from his father who said: Ibn Umar -radiallaahu anhu- said: he was making Tawaaf and he saw a man making Tawaaf while carrying his mother saying:

Indeed I am like her submissive camel

Even if her ride becomes startled I will not become startled and run away

I carry her since she carried me more, do you think that I have paid her back O Ibn Umar?

He said: No, not even one breath while giving birth.

[Taken from 'Akhbar as-Salaf' p.268, 'Mukarim al-Akhlaaq' p.225, and 'Adab al-Mufrad' No.11and authenticated by Albaani]

#8- From Abu Hazim: that Abu Huraira -radiallaahu anhu- did not perform Hajj until his mother died.

[Collected in 'Mukarim al-Akhlaaq' p.80, taken from 'Akhbar as-Salaf' p.268]

#9- From Muhammad who said: 'There was a date palm which bore one thousand dates, so Usamah bin Zayd -radiallaahu anhu- went to these dates and cut them off the tree due to their beauty. He was asked about it, so he said: Indeed my mother mentioned to me that she would love to have them, and there is nothing from the Dunya that my mother wants and I have the capability of getting except that I will get it for her.'

[Collected in 'Mukarim al-Akhlaaq' p.225, taken from 'Akhbar as-Salaf' p. 268]

#10- From Ibn Abbas -radiallaahu anhu- that a man came to him and said: 'I proposed to a woman but she refused to marry me, someone else proposed to her and she liked him and married him. I became jealous over her and I killed her, can I repent from this?'

Ibn 'Abbas asked: 'Is your mother alive?'

He answered: 'No.'

Then Ibn Abbas said: 'Repent to Allah -Azza wa Jal- and come close to Him as much as you can.'

The narrator said: I went and asked Ibn 'Abbas -radiallaahu anhu-: 'Why did you ask him whether his mother was alive?'

Ibn Abbas -radiallaahu anhu- answered:

'Indeed I do not know of an action closer to Allah -Azza wa Jal- than being good to one's mother.'

[Collected by Bukhari in 'Adab al-Mufrad' no.4, declared Saheeh by Albaani in 'Silsilah as-Sahihah' 2799]

#11- From Abu Hazim that Abu Murrah, the freed slave of Umm Hani the daughter of Abu Taalib informed him that he rode with Abu Hurairah to al-Aqeeq where his land was. When he entered his land he yelled at the top of his voice: 'O my mother Assalamu alaykum wa Rahmatullaahi wa Baraktuhu'

She replied: 'Wa alayka assalam wa Rahmatullaahi wa Baraktuhu'

He said: 'May Allah have mercy upon you as you brought me up when I was small.'

She said: 'O my son, and likewise to you, may Allah reward you with goodness and may He be pleased with you, as you look after me while I am old.'

[Collected by Bukhari in 'Adab al-Mufrad' No.14, and Albaani declared it to have a Hasan Isnad]

#12- From 'Atta that a person's mother took an oath from him that he should not pray except the obligatory prayer and not to fast except Ramadan, 'Atta said:

'Obey her!'

[Collected in 'al-Birr' by Ibn al-Jawzi p.67, taken from 'Akhbar as-Salaf' p.269]

#13- From Humaid who said: When Umm Eyaas bin Muaaweeyah died, Eyaas cried, it was said: 'What makes you cry?' He said: 'I used to have two doors open towards Paradise and one of them has been closed.'

[Collected in 'al-Birr' by Ibn al-Jawzi p.68, taken from 'Akhbar as-Salaf' p.269]

#14- Muhammad bin al-Munkadir said: 'I spent the night massaging my mother's leg and Umar spent the night praying. His night would not make me happier than my night.'

[Collected in 'al-Hileeyah' 3/150, taken from 'Akhbar as-Salaf' p.269]

#15- From Jafar bin Sulayman who said: Muhammad bin al-Munkadir used to place his cheek on the floor, and then say to his mother: 'place your foot upon it!'

[Collected in 'Mukarim al-Akhlaaq' p.226, taken from 'Akhbar as-Salaf' p.270]

#16- From Ibn 'Awn who said: 'Muhammad bin Sireen used to when he was with his mother lower his voice and speak slowly.'

[Collected in 'Mukarim al-Akhlaaq' p.226, taken from 'Akhbar as-Salaf' p.270]

#17- From al-Hasan that a man said to him: 'Indeed I made Hajj and indeed my mother has given me permission to perform another Hajj.' So al-Hasan said: 'To sit with her at her table is more beloved to me than your Hajj [i.e. optional Hajj].'

[Collected in 'Mukarim al-Akhlaaq' p.227, taken from 'Akhbar as-Salaf' p.270]

#18- From Hisham who said: Hafsah bint Sireen used to ask for Allah's mercy upon her son Huthayal and say: He would go and get reed and stalks to make a fire, he would peel them and gather them in the summer time, so when it was lit it would not produce smoke. When it came to winter time he would come and sit behind me while I prayed and he would light a small fire so that I could feel the warmth from it and so that the smoke from it would not bother me. I used to say to him, O my son it is night time go to your wife, and he would say: 'O mother I know what you want.'

She continued: 'If I did not continue saying it to him perhaps he would be there till the morning time!'

[Collected in 'al-Birr' by Ibn al-Jawzi p.53, taken from 'Akhbar as-Salaf' p.270]

#19- From 'Ali bin al-Hussain that it was said to him that you are from the best amongst the people but I do not see you eating with your mother?

He answered: 'I fear that, if I eat with her, my hand might precede her eye upon some food, so I would have been disrespectful to her!!'

[Collected in 'al-Birr wa Silaah' p.82, taken from 'Akhbar as-Salaf' p.270]

#20- From Mansoor who said: 'It has been said that the mother receives three quarters of al-Birr [being good to her].'

[Collected in 'al-Hileeyah' 5/42, taken from 'Akhbar as-Salaf' p.271]

#21- From Abu Bakr bin 'Aeeyash who said: 'I was sitting with Mansoor in his house, and his mother came and she was harsh and said: 'O Mansoor, Ibn Hubayrah wants you to be a judge and you refused!?' Mansoor did not raise his eyes up to look at her and his beard would touch his chest due to lowering his head.'

[Collected in 'al-Birr' by Ibn al-Jawzi p.53, taken from 'Akhbar as-Salaf' p.271]

#22- From al-Hasan bin Nuh who said: 'Khamas used to work using plaster every day for two small coins, and when the evening would approach he would buy a piece of fruit with that and bring it to his mother!'

[Collected in 'al-Hileeyah' 6/212, taken from 'Akhbar as-Salaf' p.271]

#23- From Mughira who said: 'Talq bin Habeeb used to help his mother with her work.'

[Collected in ash-Shuyb/7543, taken from 'Akhbar as-Salaf' p.271]

#24- From Hafsa bint Sireen who said: 'Umm Muhammad bin Sireen was a woman from the Hijjaz, and she loved dyed clothing. When Muhammad would buy her clothing he would buy her the softest material that could be found, and if it was close to Eid he would have her clothing dyed.'

[Collected in 'Tabaqaat' by Ibn Sa'd 7/228 taken from 'Akhbar as-Salaf' p.271]

#25- 'Amr bin Ubayr used to visit Khamas, he would greet him with Salaams and sit with him and his companions. So his mother said to him: 'Indeed I see this person and his companions and I dislike them, and I am not impressed by them so do not sit with them.' 'Amr and his companions came to him and he came close to them, and said: Indeed my mother dislikes you and your companions so do not visit me.'

[Collected in 'al-Hileeyah' 6/212, taken from 'Akhbar as-Salaf' p.272]


From anthony at cajuntechie.org  Thu Jan  1 18:13:31 2015
From: anthony at cajuntechie.org (Anthony Papillion)
Date: Thu, 01 Jan 2015 17:13:31 -0600
Subject: How do I remove/unlink wildcarded files
Message-ID: <54A5D49B.8040900@cajuntechie.org>

Hi Everyone,

I have a function I'm writing to delete wildcarded files in a directory.
I tried this:

def unlinkFiles():
    os.remove("/home/anthony/backup/unix*")

This doesn't seem to work because it's a wildcard filename. What is the
proper way to delete files using wildcards?

Thanks,
Anthony

-- 
Anthony Papillion

Phone:       1.918.631.7331
XMPP Chat:   cypher at chat.cpunk.us
Fingerprint: 65EF73EC 8B57F6B1 8C475BD4 426088AC FE21B251
iNum:        +883510001190960
PGP Key:     http://www.cajuntechie.org/p/my-pgp-key.html


From lucasvfxdood at gmail.com  Thu Jan  1 19:36:19 2015
From: lucasvfxdood at gmail.com (lucas mvm)
Date: Thu, 1 Jan 2015 16:36:19 -0800 (PST)
Subject: Drag and Drop Images in Python (NEED HELP!)
Message-ID: <56266ecf-4778-4ce7-b73f-4e4a9343f403@googlegroups.com>

Hi at all user!

I used Tkinter and canvas to make a window and i added 2 transparent .png images. So when i start my programm it just shows the 2 images.
I want to drag one image above the other image and than it will disappear.
So I need help with "drag and drop images"

heres my code if you want to have a look, its basically just displaying 2 images but i want to drag 1 image above the other one..



#pythonprogramm "feed"
from tkinter import * #importing tkinter
f = Tk()
f.title('Give the boy his apple.')
f.geometry('500x500')
c = Canvas(master=f,width=500,height=500,bg='white')
c.place(x=0,y=0)
p = PhotoImage(file='sadsmiley.png') #sad smiley image
i = c.create_image(250,320,image=p) #genaue position
p2 = PhotoImage(file='food.png') #food image (should be dropped on sadsmiley)
i2 = c.create_image(70,100,image=p2)
f.geometry('500x500')
f.mainloop()





From tjreedy at udel.edu  Thu Jan  1 20:09:50 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Thu, 01 Jan 2015 20:09:50 -0500
Subject: Drag and Drop Images in Python (NEED HELP!)
In-Reply-To: <56266ecf-4778-4ce7-b73f-4e4a9343f403@googlegroups.com>
References: <56266ecf-4778-4ce7-b73f-4e4a9343f403@googlegroups.com>
Message-ID: <m84r57$4dk$1@ger.gmane.org>

On 1/1/2015 7:36 PM, lucas mvm wrote:
a different introduction to the same code posted 6 hours earlier.

Read and study both of the answers already given about an hour after the 
first post.  Ignoring them and reposting, with 'NEED HELP!' no less, is 
rude.  I strongly suggest you do the exercise suggested by Rick.

-- 
Terry Jan Reedy



From emil at fuse.pl  Fri Jan  2 03:52:38 2015
From: emil at fuse.pl (Emil Oppeln-Bronikowski)
Date: Fri, 02 Jan 2015 09:52:38 +0100
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <54A5D49B.8040900@cajuntechie.org>
References: <54A5D49B.8040900@cajuntechie.org>
Message-ID: <54A65C56.4040705@fuse.pl>


> This doesn't seem to work because it's a wildcard filename. What is the
> proper way to delete files using wildcards?

You could try glob[1] and then iterate over collected list (it also 
gives you a chance to handle errors like unreadable/not owned by you files).

[1] https://docs.python.org/2/library/glob.html

-- 

Emil Oppeln-Bronikowski *|* http://fuse.pl
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From airween at gmail.com  Fri Jan  2 04:00:51 2015
From: airween at gmail.com (Ervin =?utf-8?Q?Heged=C3=BCs?=)
Date: Fri, 2 Jan 2015 10:00:51 +0100
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <54A5D49B.8040900@cajuntechie.org>
References: <54A5D49B.8040900@cajuntechie.org>
Message-ID: <20150102090051.GC22372@arxnet.hu>

Hi,

On Thu, Jan 01, 2015 at 05:13:31PM -0600, Anthony Papillion wrote:
> Hi Everyone,
> 
> I have a function I'm writing to delete wildcarded files in a directory.
> I tried this:
> 
> def unlinkFiles():
>     os.remove("/home/anthony/backup/unix*")
> 
> This doesn't seem to work because it's a wildcard filename. What is the
> proper way to delete files using wildcards?

Now I didn't checked, but once I've used some like this:

def unlinkFiles():
    dirname = "/path/to/dir"
    for f in os.listdir(dirname):
        if re.match("^unix*$", f):
            os.remove(os.path.join(dirname, f))


a.


-- 
I ? UTF-8


From ben+python at benfinney.id.au  Fri Jan  2 04:02:38 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Fri, 02 Jan 2015 20:02:38 +1100
Subject: How do I remove/unlink wildcarded files
References: <54A5D49B.8040900@cajuntechie.org>
Message-ID: <85bnmhzhap.fsf@benfinney.id.au>

Anthony Papillion <anthony at cajuntechie.org> writes:

> I have a function I'm writing to delete wildcarded files in a
> directory.

Is the brute-force method (explicit, easy to understand) good enough?

    import os
    import os.path
    import glob

    paths_to_remove = glob.glob(
            os.path.join([
                os.path.expanduser("~anthony"), "backup", "unix*"
                ]))
    for path in paths_to_remove:
        os.remove(path)

-- 
 \           ?In case you haven't noticed, [the USA] are now almost as |
  `\     feared and hated all over the world as the Nazis were.? ?Kurt |
_o__)                                                   Vonnegut, 2004 |
Ben Finney



From cs at zip.com.au  Fri Jan  2 05:21:53 2015
From: cs at zip.com.au (Cameron Simpson)
Date: Fri, 2 Jan 2015 21:21:53 +1100
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <20150102090051.GC22372@arxnet.hu>
References: <20150102090051.GC22372@arxnet.hu>
Message-ID: <20150102102153.GA89926@cskk.homeip.net>

On 02Jan2015 10:00, Ervin Heged?s <airween at gmail.com> wrote:
>On Thu, Jan 01, 2015 at 05:13:31PM -0600, Anthony Papillion wrote:
>> I have a function I'm writing to delete wildcarded files in a directory.
>> I tried this:
>>
>> def unlinkFiles():
>>     os.remove("/home/anthony/backup/unix*")
>>
>> This doesn't seem to work because it's a wildcard filename. What is the
>> proper way to delete files using wildcards?
>
>Now I didn't checked, but once I've used some like this:
>
>def unlinkFiles():
>    dirname = "/path/to/dir"
>    for f in os.listdir(dirname):
>        if re.match("^unix*$", f):
>            os.remove(os.path.join(dirname, f))

That is a very expensive way to check the filename in this particular case.  
Consider:

  if f.startswith('unix'):

instead of using a regular expression.

But generally the OP will probably want to use the glob module to expand the 
shell pattern as suggested by others.

Cheers,
Cameron Simpson <cs at zip.com.au>

Each new user of a new system uncovers a new class of bugs.     - Kernighan


From wxjmfauth at gmail.com  Fri Jan  2 05:29:22 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Fri, 2 Jan 2015 02:29:22 -0800 (PST)
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
Message-ID: <9d2a330f-eaf8-4943-a246-d143b1b773ca@googlegroups.com>

Le mercredi 31 d?cembre 2014 23:24:50 UTC+1, Andr? Roberge a ?crit?:
> EasyGUI_Qt version 0.9 has been released.  This is the first announcement about EasyGUI_Qt on this list.
> 
> Like the original EasyGUI (which used Tkinter), 
> EasyGUI_Qt seeks to provide simple GUI widgets
> that can be called in a procedural program. 
> 
> EasyGUI_Qt is NOT event-driven: all GUI interactions are invoked by simple function calls.
> 
> The archetype is get_string(message)
> which pops a box whose purpose is exactly the same as Python's input(prompt),
> that is, present the user with a question/prompt, have the user enter an
> answer, and return the provided answer as a string.  Thus
> easygui_qt.get_string() can be used as a drop-in replacement for
> input().
> 
> Similarly, instead of using a print() function to display a message,
> show_message() is used which pops a message window.
> 
> EasyGUI_Qt requires PyQt4 and is really targeted for Python 3.3+ - although it can work (possibly with some unicode problems ...) using Python 2.7.
> 
> More information can be found at 
> http://easygui-qt.readthedocs.org/en/latest/index.html
> 
> Feedback is most welcome, including reporting bugs to 
> https://github.com/aroberge/easygui_qt/issues
> 
> Happy 2015 everyone,
> 
> Andr? Roberge

I toyed and I spent a couple of hours with it.
I do not know to much what to say.


From maikwo at gmail.com  Fri Jan  2 05:49:49 2015
From: maikwo at gmail.com (Connor)
Date: Fri, 02 Jan 2015 11:49:49 +0100
Subject: Own network protocol
In-Reply-To: <3633b178-9100-4409-a711-62d872b89b59@googlegroups.com>
References: <3633b178-9100-4409-a711-62d872b89b59@googlegroups.com>
Message-ID: <54A677CD.9050709@gmail.com>

Hi,

You can use the TML/SIDEX SDK to setup a server on a Raspberry_Pi. It 
enables peer to peer communcation beased on the Blocks Extensible 
Exchange protocol. The Python interface is easy to use and you can find 
tutorial videos on youtube, how to install it on a raspberry_py.

Search for "How to install TML/SIDEX on Raspberry Pi" on youtube.

The SDK is available on multiple platforms and it is free for personal 
projects.

Cheers,
Connor

Am 27.12.2014 um 10:56 schrieb pfranken85 at gmail.com:
> Hello!
>
> I am just about setting up a project with an Raspberry Pi that is connected to some hardware via its GPIO pins. Reading the data already works perfectly but now I want to distribute it to clients running in the network. Hence, I have to setup a server in Python.
>
> I do not want to reinvent the wheel, so I am asking myself whether there is a good practice solution. It should basically work such that once value (can be either binary or an analog value) has changed on the server, it should send the update to the connected clients. At the same time, it should be possible for the client to send a particular request to the server as well, i.e., switch on LED X.
>
> What kind of protocol do you recommend for this? UDP or TCP? Do you recommend the use of frameworks such as twisted?
>
> Thanks for your input!



From airween at gmail.com  Fri Jan  2 06:00:00 2015
From: airween at gmail.com (Ervin =?utf-8?Q?Heged=C3=BCs?=)
Date: Fri, 2 Jan 2015 12:00:00 +0100
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <20150102102153.GA89926@cskk.homeip.net>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
Message-ID: <20150102110000.GA23285@arxnet.hu>

Hi,

On Fri, Jan 02, 2015 at 09:21:53PM +1100, Cameron Simpson wrote:
> On 02Jan2015 10:00, Ervin Heged?s <airween at gmail.com> wrote:
> >On Thu, Jan 01, 2015 at 05:13:31PM -0600, Anthony Papillion wrote:
> >>I have a function I'm writing to delete wildcarded files in a directory.
> >>I tried this:
> >>
> >>def unlinkFiles():
> >>    os.remove("/home/anthony/backup/unix*")
> >>
> >>This doesn't seem to work because it's a wildcard filename. What is the
> >>proper way to delete files using wildcards?
> >
> >Now I didn't checked, but once I've used some like this:
> >
> >def unlinkFiles():
> >   dirname = "/path/to/dir"
> >   for f in os.listdir(dirname):
> >       if re.match("^unix*$", f):
> >           os.remove(os.path.join(dirname, f))
> 
> That is a very expensive way to check the filename in this
> particular case.  Consider:
> 
>  if f.startswith('unix'):
> 
> instead of using a regular expression.

well, that's true - but that works only the example above.

> But generally the OP will probably want to use the glob module to
> expand the shell pattern as suggested by others.

I didn't know the glob module before, but yes, that's better
solution for this - but as I see, that also uses os.listdir()
(and fnmatch modue).


Anyway, thanks for the tip.


a.

-- 
I ? UTF-8


From wxjmfauth at gmail.com  Fri Jan  2 06:05:16 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Fri, 2 Jan 2015 03:05:16 -0800 (PST)
Subject: Python in 2015
Message-ID: <3ab9d389-876d-469b-9863-d4ec2ad73ce0@googlegroups.com>

I wonder how many new apps will not work this
year on the side of the "coding of characters".

Should I count Python 3.5?

jmf


From python at mrabarnett.plus.com  Fri Jan  2 06:29:07 2015
From: python at mrabarnett.plus.com (MRAB)
Date: Fri, 02 Jan 2015 11:29:07 +0000
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <20150102102153.GA89926@cskk.homeip.net>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
Message-ID: <54A68103.8020605@mrabarnett.plus.com>

On 2015-01-02 10:21, Cameron Simpson wrote:
> On 02Jan2015 10:00, Ervin Heged?s <airween at gmail.com> wrote:
>>On Thu, Jan 01, 2015 at 05:13:31PM -0600, Anthony Papillion wrote:
>>> I have a function I'm writing to delete wildcarded files in a directory.
>>> I tried this:
>>>
>>> def unlinkFiles():
>>>     os.remove("/home/anthony/backup/unix*")
>>>
>>> This doesn't seem to work because it's a wildcard filename. What is the
>>> proper way to delete files using wildcards?
>>
>>Now I didn't checked, but once I've used some like this:
>>
>>def unlinkFiles():
>>    dirname = "/path/to/dir"
>>    for f in os.listdir(dirname):
>>        if re.match("^unix*$", f):
>>            os.remove(os.path.join(dirname, f))
>
> That is a very expensive way to check the filename in this particular case.

It'll also match "uni".

> Consider:
>
>    if f.startswith('unix'):
>
> instead of using a regular expression.
>
> But generally the OP will probably want to use the glob module to expand the
> shell pattern as suggested by others.
>



From python.list at tim.thechases.com  Fri Jan  2 06:35:52 2015
From: python.list at tim.thechases.com (Tim Chase)
Date: Fri, 2 Jan 2015 05:35:52 -0600
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <20150102102153.GA89926@cskk.homeip.net>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
Message-ID: <20150102053552.6ed449b8@bigbox.christie.dr>

On 2015-01-02 21:21, Cameron Simpson wrote:
> >def unlinkFiles():
> >    dirname = "/path/to/dir"
> >    for f in os.listdir(dirname):
> >        if re.match("^unix*$", f):
> >            os.remove(os.path.join(dirname, f))
> 
> That is a very expensive way to check the filename in this
> particular case. Consider:
> 
>   if f.startswith('unix'):
> 
> instead of using a regular expression.

And worse, the given re would delete a file named "uni" which doesn't
sound ANYTHING like what the OP wanted :-)

-tkc




From airween at gmail.com  Fri Jan  2 07:36:04 2015
From: airween at gmail.com (Ervin =?utf-8?Q?Heged=C3=BCs?=)
Date: Fri, 2 Jan 2015 13:36:04 +0100
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <20150102053552.6ed449b8@bigbox.christie.dr>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
Message-ID: <20150102123604.GB24295@arxnet.hu>

Hi,

On Fri, Jan 02, 2015 at 05:35:52AM -0600, Tim Chase wrote:
> On 2015-01-02 21:21, Cameron Simpson wrote:
> > >def unlinkFiles():
> > >    dirname = "/path/to/dir"
> > >    for f in os.listdir(dirname):
> > >        if re.match("^unix*$", f):
> > >            os.remove(os.path.join(dirname, f))
> > 
> > That is a very expensive way to check the filename in this
> > particular case. Consider:
> > 
> >   if f.startswith('unix'):
> > 
> > instead of using a regular expression.
> 
> And worse, the given re would delete a file named "uni" which doesn't
> sound ANYTHING like what the OP wanted :-)

yes, you're right - I've missed out a "." before the "*". :)



thanks:


a.


-- 
I ? UTF-8


From rosuav at gmail.com  Fri Jan  2 07:59:17 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 2 Jan 2015 23:59:17 +1100
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <20150102123604.GB24295@arxnet.hu>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
Message-ID: <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>

On Fri, Jan 2, 2015 at 11:36 PM, Ervin Heged?s <airween at gmail.com> wrote:
>> And worse, the given re would delete a file named "uni" which doesn't
>> sound ANYTHING like what the OP wanted :-)
>
> yes, you're right - I've missed out a "." before the "*". :)

Another reason to avoid regexps when you don't actually need them.
Globs are simpler, and have fewer obscure failure modes.

ChrisA


From airween at gmail.com  Fri Jan  2 08:51:32 2015
From: airween at gmail.com (Ervin =?utf-8?Q?Heged=C3=BCs?=)
Date: Fri, 2 Jan 2015 14:51:32 +0100
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
Message-ID: <20150102135132.GE24572@arxnet.hu>

Hi,

On Fri, Jan 02, 2015 at 11:59:17PM +1100, Chris Angelico wrote:
> On Fri, Jan 2, 2015 at 11:36 PM, Ervin Heged?s <airween at gmail.com> wrote:
> >> And worse, the given re would delete a file named "uni" which doesn't
> >> sound ANYTHING like what the OP wanted :-)
> >
> > yes, you're right - I've missed out a "." before the "*". :)
> 
> Another reason to avoid regexps when you don't actually need them.
> Globs are simpler, and have fewer obscure failure modes.

it may be at the concrete example in OP is better the glob - but
I think in most cases the re modul gives more flexibility, I mean
the glob modul can handle the upper/lower chars? 


(Anyway, now I checked the fnmatch module, which uses re module :))


Cheers:


a.


-- 
I ? UTF-8


From rosuav at gmail.com  Fri Jan  2 09:01:31 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 3 Jan 2015 01:01:31 +1100
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <20150102135132.GE24572@arxnet.hu>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
 <20150102135132.GE24572@arxnet.hu>
Message-ID: <CAPTjJmoG0ZZSeeRegq3EDFRLpG1OQM_jGRO8ybiPO91=oYwVxw@mail.gmail.com>

On Sat, Jan 3, 2015 at 12:51 AM, Ervin Heged?s <airween at gmail.com> wrote:
> it may be at the concrete example in OP is better the glob - but
> I think in most cases the re modul gives more flexibility, I mean
> the glob modul can handle the upper/lower chars?

I'm not sure that I'd want to. Handling case insensitivity is fine
when you're restricting everything to ASCII, but it's rather harder
when you allow all of Unicode. For instance, U+0069 and U+0049 would
be considered case-insensitively equal in English, but in Turkish,
they're different letters; U+0069 upper-cases to U+0130, and U+0049
lower-cases to U+0131. Much safer, when you're writing generic tools,
to simply require case sensitivity. And you can't easily know whether
the file system is case-sensitive, case-retaining, or case-folding;
you could easily have multiple mounts that differ, so
"/home/rosuav/foo/bar/quux" might be the same as
"/home/rosuav/FOO/bar/quux", but the other four components are all
case sensitive. Yes, it really is possible.

ChrisA


From airween at gmail.com  Fri Jan  2 09:10:09 2015
From: airween at gmail.com (Ervin =?utf-8?Q?Heged=C3=BCs?=)
Date: Fri, 2 Jan 2015 15:10:09 +0100
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <CAPTjJmoG0ZZSeeRegq3EDFRLpG1OQM_jGRO8ybiPO91=oYwVxw@mail.gmail.com>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
 <20150102135132.GE24572@arxnet.hu>
 <CAPTjJmoG0ZZSeeRegq3EDFRLpG1OQM_jGRO8ybiPO91=oYwVxw@mail.gmail.com>
Message-ID: <20150102141009.GA24786@arxnet.hu>

Hi Chris,

On Sat, Jan 03, 2015 at 01:01:31AM +1100, Chris Angelico wrote:
> On Sat, Jan 3, 2015 at 12:51 AM, Ervin Heged?s <airween at gmail.com> wrote:
> > it may be at the concrete example in OP is better the glob - but
> > I think in most cases the re modul gives more flexibility, I mean
> > the glob modul can handle the upper/lower chars?
> 
> I'm not sure that I'd want to. Handling case insensitivity is fine
> when you're restricting everything to ASCII, but it's rather harder
> when you allow all of Unicode. For instance, U+0069 and U+0049 would
> be considered case-insensitively equal in English, but in Turkish,
> they're different letters; U+0069 upper-cases to U+0130, and U+0049
> lower-cases to U+0131. Much safer, when you're writing generic tools,
> to simply require case sensitivity. And you can't easily know whether
> the file system is case-sensitive, case-retaining, or case-folding;
> you could easily have multiple mounts that differ, so
> "/home/rosuav/foo/bar/quux" might be the same as
> "/home/rosuav/FOO/bar/quux", but the other four components are all
> case sensitive. Yes, it really is possible.

I didn't want to solve the OP's problem - I just gave an idea.
Here was another possible solution, I think the OP can choose the
right one :)


Cheers:

a.


-- 
I ? UTF-8


From rosuav at gmail.com  Fri Jan  2 09:14:47 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 3 Jan 2015 01:14:47 +1100
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <20150102141009.GA24786@arxnet.hu>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
 <20150102135132.GE24572@arxnet.hu>
 <CAPTjJmoG0ZZSeeRegq3EDFRLpG1OQM_jGRO8ybiPO91=oYwVxw@mail.gmail.com>
 <20150102141009.GA24786@arxnet.hu>
Message-ID: <CAPTjJmp4T5qH2=mLtkGUK5ugZ+WvnKsn8mJuKGHNm7VRf_Gyww@mail.gmail.com>

On Sat, Jan 3, 2015 at 1:10 AM, Ervin Heged?s <airween at gmail.com> wrote:
> I didn't want to solve the OP's problem - I just gave an idea.
> Here was another possible solution, I think the OP can choose the
> right one :)

Heh. Fortunately, even in cases where the OP can't recognize the right
choice, the rest of python-list will make it pretty clear :)

ChrisA


From breamoreboy at yahoo.co.uk  Fri Jan  2 10:18:45 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Fri, 02 Jan 2015 15:18:45 +0000
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <CAPTjJmoG0ZZSeeRegq3EDFRLpG1OQM_jGRO8ybiPO91=oYwVxw@mail.gmail.com>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
 <20150102135132.GE24572@arxnet.hu>
 <CAPTjJmoG0ZZSeeRegq3EDFRLpG1OQM_jGRO8ybiPO91=oYwVxw@mail.gmail.com>
Message-ID: <m86cso$qve$1@ger.gmane.org>

On 02/01/2015 14:01, Chris Angelico wrote:
> On Sat, Jan 3, 2015 at 12:51 AM, Ervin Heged?s <airween at gmail.com> wrote:
>> it may be at the concrete example in OP is better the glob - but
>> I think in most cases the re modul gives more flexibility, I mean
>> the glob modul can handle the upper/lower chars?
>
> I'm not sure that I'd want to. Handling case insensitivity is fine
> when you're restricting everything to ASCII, but it's rather harder
> when you allow all of Unicode. For instance, U+0069 and U+0049 would
> be considered case-insensitively equal in English, but in Turkish,
> they're different letters; U+0069 upper-cases to U+0130, and U+0049
> lower-cases to U+0131. Much safer, when you're writing generic tools,
> to simply require case sensitivity. And you can't easily know whether
> the file system is case-sensitive, case-retaining, or case-folding;
> you could easily have multiple mounts that differ, so
> "/home/rosuav/foo/bar/quux" might be the same as
> "/home/rosuav/FOO/bar/quux", but the other four components are all
> case sensitive. Yes, it really is possible.
>
> ChrisA
>

Did you have to mention unicode?  Next thing you know it'll be "Is it a 
bird, is it a plane, no, it's our resident unicode expert!!!" :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rantingrickjohnson at gmail.com  Fri Jan  2 12:15:02 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Fri, 2 Jan 2015 09:15:02 -0800 (PST)
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <mailman.17324.1420207299.18130.python-list@python.org>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
 <20150102135132.GE24572@arxnet.hu>
 <mailman.17324.1420207299.18130.python-list@python.org>
Message-ID: <2a5bfb42-c0b4-40dc-ba86-10bb67001350@googlegroups.com>

On Friday, January 2, 2015 8:01:50 AM UTC-6, Chris Angelico wrote:
> I'm not sure that I'd want to. Handling case insensitivity is fine
> when you're restricting everything to ASCII, but it's rather harder
> when you allow all of Unicode. For instance, U+0069 and U+0049 would
> be considered case-insensitively equal in English, but in Turkish,
> they're different letters; U+0069 upper-cases to U+0130, and U+0049
> lower-cases to U+0131. 

So what? If you're going to go out of your way to accomadate
a small regional perversion of language semantics, then your
"fetish of multiculturalism" is even more
dangerous than i have previously thought!

SPECIAL CASES ARE NOT *SPECIAL ENOUGH* TO BREAK THE RULES!
    
This "idea" that software needs to be written to accommodate
every language of the world is complete nonsense. I would
suggest writing software that targets *only* the modern
world. Those who refuse to be a part of the modern world can
suffer the troubles of forking the code into their ancient
systems -- and i will not loose any sleep over the issue.

PROGRESS IS MORE IMPORTANT THAN PROTECTION OF DELICATE SENSIBILITIES!


From rustompmody at gmail.com  Fri Jan  2 12:54:32 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 2 Jan 2015 09:54:32 -0800 (PST)
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <2a5bfb42-c0b4-40dc-ba86-10bb67001350@googlegroups.com>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
 <20150102135132.GE24572@arxnet.hu>
 <mailman.17324.1420207299.18130.python-list@python.org>
 <2a5bfb42-c0b4-40dc-ba86-10bb67001350@googlegroups.com>
Message-ID: <f7a40fa7-18da-40aa-8002-25f2ee7071e9@googlegroups.com>

On Friday, January 2, 2015 10:45:17 PM UTC+5:30, Rick Johnson wrote:
> On Friday, January 2, 2015 8:01:50 AM UTC-6, Chris Angelico wrote:
> > I'm not sure that I'd want to. Handling case insensitivity is fine
> > when you're restricting everything to ASCII, but it's rather harder
> > when you allow all of Unicode. For instance, U+0069 and U+0049 would
> > be considered case-insensitively equal in English, but in Turkish,
> > they're different letters; U+0069 upper-cases to U+0130, and U+0049
> > lower-cases to U+0131. 
> 
> So what? If you're going to go out of your way to accomadate
> a small regional perversion of language semantics, then your
> "fetish of multiculturalism" is even more
> dangerous than i have previously thought!
> 
> SPECIAL CASES ARE NOT *SPECIAL ENOUGH* TO BREAK THE RULES!

And how does this strange language called English fits into your rules 
and (no) special cases scheme?

http://www.omgfacts.com/lists/3989/Did-you-know-that-ough-can-be-pronounced-TEN-DIFFERENT-WAYS


From andre.roberge at gmail.com  Fri Jan  2 14:11:05 2015
From: andre.roberge at gmail.com (=?ISO-8859-1?Q?Andr=E9_Roberge?=)
Date: Fri, 2 Jan 2015 11:11:05 -0800 (PST)
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <9d2a330f-eaf8-4943-a246-d143b1b773ca@googlegroups.com>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
 <9d2a330f-eaf8-4943-a246-d143b1b773ca@googlegroups.com>
Message-ID: <9ade6cb4-6a78-4ebb-8104-83dbf1916482@googlegroups.com>

On Friday, 2 January 2015 06:29:37 UTC-4, wxjm... at gmail.com  wrote:
> Le mercredi 31 d?cembre 2014 23:24:50 UTC+1, Andr? Roberge a ?crit?:
> > EasyGUI_Qt version 0.9 has been released.  This is the first announcement about EasyGUI_Qt on this list.
snip
> I toyed and I spent a couple of hours with it.
> I do not know to much what to say.
Well, this is more positive than your previous comment expressing doubt that it would work. ;-)   So, thank you!


From emil at fuse.pl  Fri Jan  2 14:27:33 2015
From: emil at fuse.pl (Emil Oppeln-Bronikowski)
Date: Fri, 2 Jan 2015 20:27:33 +0100
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <9ade6cb4-6a78-4ebb-8104-83dbf1916482@googlegroups.com>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
 <9d2a330f-eaf8-4943-a246-d143b1b773ca@googlegroups.com>
 <9ade6cb4-6a78-4ebb-8104-83dbf1916482@googlegroups.com>
Message-ID: <20150102192733.GD2035@mikrus>

On Fri, Jan 02, 2015 at 11:11:05AM -0800, Andr? Roberge wrote:

Sorry if this was asked before: have you tried building a portable version using py2exe/Nuitka/etc? I always hit a wall when it comes to building against huge libraries like Python-Qt.

-- 
People are like potatos. They die when you eat them.



From gordon_ken_stewart at msn.com  Fri Jan  2 14:44:55 2015
From: gordon_ken_stewart at msn.com (Ken Stewart)
Date: Fri, 2 Jan 2015 12:44:55 -0700
Subject: Command Line Inputs from Windows
Message-ID: <COL130-DS1607D96864155F77FE9C11C85D0@phx.gbl>

Court of King Arthur,

I?d appreciate any help you can provide.  I?m having problems passing 
command line parameters from Windows 7 into a Python script (using Python 
3.4.2).  It works correctly when I call the interpreter explicitly from the 
Windows command prompt, but it doesn?t work when I enter the script name 
without calling the Python interpreter.

This works:
python myScript.py arg1 arg2 arg3

This doesn?t work:
myScript.py arg1 arg2 arg3

The Windows PATH environment variable contains the path to Python, as well 
as the path to the Script directory.  The PATHEXT environment variable 
contains the Python extension (.py).

There are other anomalies too between the two methods of invoking the script 
depending on whether I include the extension (.py) along with the script 
name.  For now I?m only interested in passing the arguments without 
explicitly calling the Python interpreter.

************************************
Here is the script:

#! python

import sys

def getargs():
    sys.stdout.write("\nHello from Python %s\n\n" % (sys.version,))
    print ('    Number of arguments =', len(sys.argv))
    print ('    Argument List =', str(sys.argv))

if __name__ == '__main__':
    getargs()

************************************
Result_1 (working correctly):

C:\Python34\Scripts> python myScript.py arg1 arg2 arg3

Hello from Python 3.4.2 (v3.4.2:ab2c023a9432, Oct  6 2014, 22:15:05) [MSC 
v.1600 32 bit (Intel)]

    Number of arguments = 4
    Argument List = ['myScript.py', 'arg1', 'arg2', 'arg3']

************************************
Result_ 2 (Fail)

C:\Python34\Scripts> myScript.py arg1 arg2 arg3

Hello from Python 3.4.2 (v3.4.2:ab2c023a9432, Oct  6 2014, 22:15:05) [MSC 
v.1600 32 bit (Intel)]

    Number of arguments = 1
    Argument List = ['C:\\Python34\\Scripts\\myScript.py']

As a beginner I?m probably making a mistake somewhere but I can?t find it. 
I don?t think the shebang does anything in Windows but I?ve tried several 
variations without success.  I?ve tried writing the script using only 
commands, without the accouterments of a full program (without the def 
statement and without the if __name__ == ?__main__? ?) to no avail.  I?m out 
of ideas.  Any suggestions?

Ken Stewart



From andre.roberge at gmail.com  Fri Jan  2 14:53:26 2015
From: andre.roberge at gmail.com (=?ISO-8859-1?Q?Andr=E9_Roberge?=)
Date: Fri, 2 Jan 2015 11:53:26 -0800 (PST)
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <mailman.17329.1420226530.18130.python-list@python.org>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
 <9d2a330f-eaf8-4943-a246-d143b1b773ca@googlegroups.com>
 <9ade6cb4-6a78-4ebb-8104-83dbf1916482@googlegroups.com>
 <mailman.17329.1420226530.18130.python-list@python.org>
Message-ID: <9cb6ea10-0828-4c12-a266-20927e164f30@googlegroups.com>

On Friday, 2 January 2015 15:22:22 UTC-4, Emil Oppeln-Bronikowski  wrote:
> On Fri, Jan 02, 2015 at 11:11:05AM -0800, Andr? Roberge wrote:
> 
> Sorry if this was asked before: have you tried building a portable version using py2exe/Nuitka/etc? I always hit a wall when it comes to building against huge libraries like Python-Qt.
> 
No, this would seem really silly since the widgets created by EasyGUI_Qt need to be used within a Python program, like Python's own "input()" function.  What would happen if you took a simple module containing the following:

def get_string(prompt):
    return input(prompt)

and tried to package it into an exe?  How could it then be used?

> -- 
> People are like potatos. They die when you eat them.



From emil at fuse.pl  Fri Jan  2 15:21:48 2015
From: emil at fuse.pl (Emil Oppeln-Bronikowski)
Date: Fri, 2 Jan 2015 21:21:48 +0100
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <9cb6ea10-0828-4c12-a266-20927e164f30@googlegroups.com>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
 <9d2a330f-eaf8-4943-a246-d143b1b773ca@googlegroups.com>
 <9ade6cb4-6a78-4ebb-8104-83dbf1916482@googlegroups.com>
 <mailman.17329.1420226530.18130.python-list@python.org>
 <9cb6ea10-0828-4c12-a266-20927e164f30@googlegroups.com>
Message-ID: <20150102202147.GF2035@mikrus>

On Fri, Jan 02, 2015 at 11:53:26AM -0800, Andr? Roberge wrote:
> How could it then be used?

Maybe I failed to explain myself fully. What I meant to say is building a distribution-ready program that utilizes your library; not your library being turn into a executable.

Or maybe something is going over my head? Tell you what, once I get to some decent network I'll try it on my own. :)
-- 
People are like potatos. They die when you eat them.



From rosuav at gmail.com  Fri Jan  2 16:08:29 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 3 Jan 2015 08:08:29 +1100
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <f7a40fa7-18da-40aa-8002-25f2ee7071e9@googlegroups.com>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
 <20150102135132.GE24572@arxnet.hu>
 <mailman.17324.1420207299.18130.python-list@python.org>
 <2a5bfb42-c0b4-40dc-ba86-10bb67001350@googlegroups.com>
 <f7a40fa7-18da-40aa-8002-25f2ee7071e9@googlegroups.com>
Message-ID: <CAPTjJmo74ZxQEvLbWuVcvg=yf6rvwJc42qjKeWH9AC-m_cZQtQ@mail.gmail.com>

On Sat, Jan 3, 2015 at 4:54 AM, Rustom Mody <rustompmody at gmail.com> wrote:
> And how does this strange language called English fits into your rules
> and (no) special cases scheme?
>
> http://www.omgfacts.com/lists/3989/Did-you-know-that-ough-can-be-pronounced-TEN-DIFFERENT-WAYS

I learned six, which is no more than there are for the simple vowel
'a' (at least, in British English; American English has a few less
sounds for 'a'). Consider "cat", "bay", "car" (that's the three most
common sounds), "watch", "water", "parent" (these three are less
common, and American English often folds them into the other three).
Now have a look at Norwegian, where the fifth of those sounds
("water") is spelled with a ring above, eg "La den g?" - and the sixth
is (I think) more often spelled with a slashed O - "Den kraften jeg
skjulte f?r". Similarly in Swedish: "Sl? dig loss, sl? dig fri" is
pronounced "Slaw di loss, slaw di free". Or let's look at another of
English's oddities. Put a t and an h together, and you get a
completely different sound... two different sounds, in fact, voiced or
unvoiced. Icelandic uses thorn instead: "?etta er n?g" is pronounced
(roughly) "Thetta air know". And the whole notion of putting a dot on
a lower-case i and not putting one on upper-case I is pretty
illogical, but Turkish, as I mentioned in the previous post, uses the
dots to distinguish between two pronunciations of the vowel, hence
"ald?rma" which would sound somewhat different with a dot on the i.

(You may be able to see a theme in my example texts, but I figured
it's time to see what I can do with full Unicode support. The cold
looks of disapproval never bothered me, anyway.)

ChrisA


From rosuav at gmail.com  Fri Jan  2 16:09:10 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 3 Jan 2015 08:09:10 +1100
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <2a5bfb42-c0b4-40dc-ba86-10bb67001350@googlegroups.com>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
 <20150102135132.GE24572@arxnet.hu>
 <mailman.17324.1420207299.18130.python-list@python.org>
 <2a5bfb42-c0b4-40dc-ba86-10bb67001350@googlegroups.com>
Message-ID: <CAPTjJmqySTxOCKAYA8s638J3gDMYZwB9Es7BLDGjObdfW-ac4A@mail.gmail.com>

On Sat, Jan 3, 2015 at 4:15 AM, Rick Johnson
<rantingrickjohnson at gmail.com> wrote:
> Those who refuse to be a part of the modern world can
> suffer the troubles of forking the code into their ancient
> systems -- and i will not loose any sleep over the issue.

By the way, is this "loose" part of your "modern world", or is that
just a straight-up error?

ChrisA


From rosuav at gmail.com  Fri Jan  2 16:29:05 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 3 Jan 2015 08:29:05 +1100
Subject: Command Line Inputs from Windows
In-Reply-To: <COL130-DS1607D96864155F77FE9C11C85D0@phx.gbl>
References: <COL130-DS1607D96864155F77FE9C11C85D0@phx.gbl>
Message-ID: <CAPTjJmogEyJzGNPe+OEhYmJyhG5nfVOBLChBZbp6NWmjiEXmTw@mail.gmail.com>

On Sat, Jan 3, 2015 at 6:44 AM, Ken Stewart <gordon_ken_stewart at msn.com> wrote:
> This works:
> python myScript.py arg1 arg2 arg3
>
> This doesn?t work:
> myScript.py arg1 arg2 arg3

The latter form is governed by the association. I don't know off-hand
where that's set in the registry, but you should be able to poke
around in folder settings to find it (but, thank you very much
Microsoft, the exact menu path has changed a number of times between
Win2K and Win8). On WinXP, if I have my test-box set up correctly,
it's View, Folder Options, File Types, select the one for .py,
Advanced, select "open", Edit. That'll tell you that the application
used is something like:

"C:\Python27\python.exe" "%1" %*

The %* should mean that arguments get carried through; if that's
missing, you won't get any args.

I may have some details wrong, and it's likely to be a little
different on Win7, but poke around and look for a missing %*. Or,
better still, make sure you have the py.exe launcher; then you can
have Python scripts request a specific interpreter using a PEP 397
compliant shebang, which will also work nicely on Unix systems.

ChrisA


From andre.roberge at gmail.com  Fri Jan  2 16:35:55 2015
From: andre.roberge at gmail.com (=?ISO-8859-1?Q?Andr=E9_Roberge?=)
Date: Fri, 2 Jan 2015 13:35:55 -0800 (PST)
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <mailman.17331.1420230127.18130.python-list@python.org>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
 <9d2a330f-eaf8-4943-a246-d143b1b773ca@googlegroups.com>
 <9ade6cb4-6a78-4ebb-8104-83dbf1916482@googlegroups.com>
 <mailman.17329.1420226530.18130.python-list@python.org>
 <9cb6ea10-0828-4c12-a266-20927e164f30@googlegroups.com>
 <mailman.17331.1420230127.18130.python-list@python.org>
Message-ID: <1455625c-3367-4c09-a2e6-b91d897a99d2@googlegroups.com>

On Friday, 2 January 2015 16:22:21 UTC-4, Emil Oppeln-Bronikowski  wrote:
> On Fri, Jan 02, 2015 at 11:53:26AM -0800, Andr? Roberge wrote:
> > How could it then be used?
> 
> Maybe I failed to explain myself fully. What I meant to say is building a distribution-ready program that utilizes your library; not your library being turn into a executable.

Ah, this makes sense.  But I have not had the need to do so mysefl.
> 
> Or maybe something is going over my head? Tell you what, once I get to some decent network I'll try it on my own. :)
Please, let me know what you think - direct email is probably better.
> -- 
> People are like potatos. They die when you eat them.



From accessnewbie at gmail.com  Fri Jan  2 18:03:23 2015
From: accessnewbie at gmail.com (accessnewbie at gmail.com)
Date: Fri, 2 Jan 2015 15:03:23 -0800 (PST)
Subject: Looking for sample python script using Tkinter
Message-ID: <65275e9b-a1e2-4ab7-981c-c0b1c8587159@googlegroups.com>

I have a script that I trying to go from command line entry to interface entry. I am tinkering with Tkinter and want to review some Tkinter interface building scripts. Really basic stuff covering file selection and making some of the data captured required I am learning how to use Tkinter (Python 2.7) to build a data entry interface where the variables (about 15 data entry fields in all) will be used later in the script to perform some analyses. I have a few requirements when capturing the data:

    Must be able to navigate to a file and capture entire filename and pathname (which may be on a network rather than the C drive)
    Capture date
    Capture text (Some of the data entry fields will have commas)
    Some of the data entry fields are required, some are not.

Is there a sample script out there that I can review to see how these features are accomplished? I am particularly stumped by #1 and 4.

Thanks to any and all help.


From auriocus at gmx.de  Fri Jan  2 18:26:12 2015
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Sat, 03 Jan 2015 00:26:12 +0100
Subject: Looking for sample python script using Tkinter
In-Reply-To: <65275e9b-a1e2-4ab7-981c-c0b1c8587159@googlegroups.com>
References: <65275e9b-a1e2-4ab7-981c-c0b1c8587159@googlegroups.com>
Message-ID: <m879dr$rio$1@dont-email.me>

Am 03.01.15 um 00:03 schrieb accessnewbie at gmail.com:
> I have a script that I trying to go from command line entry to interface entry. I am tinkering with Tkinter and want to review some Tkinter interface building scripts. Really basic stuff covering file selection and making some of the data captured required I am learning how to use Tkinter (Python 2.7) to build a data entry interface where the variables (about 15 data entry fields in all) will be used later in the script to perform some analyses. I have a few requirements when capturing the data:
>
>  1   Must be able to navigate to a file and capture entire filename and pathname (which may be on a network rather than the C drive)
>  2   Capture date
>  3   Capture text (Some of the data entry fields will have commas)
>  4   Some of the data entry fields are required, some are not.
>
> Is there a sample script out there that I can review to see how
> these  features are accomplished? I am particularly stumped by #1 and 4.

1: Does tkFileDialog.askopenfilename() fulfill your needs? On Windows, 
this should open the native file dialog. Usually, one packs a button 
near an entry widget to open the file dialog and the return value is 
placed in the entry

2: There are some date megawidgets. But you might prefer to just have an 
entry and validate the input / convert it to a date

3: The basic entry widget should do. It has no problems with commas. the 
only critical character is a tab, because it switches to the next field

4: GUI widgets don't have the notion of being required or not, that is 
entirely up to your application. Usually, there will be an "Apply" or 
"Submit" button or similar (or the action is bound to the Return key). 
On that occasion, don't accept the data if the required fields are left 
blank.

In general, you need to validate all input fields before you accept 
them. This is specific to your application and can't be handled by the 
toolkit itself. For common tasks like single real numbers, there are 
ready-made validators available that can validate the input already 
during editing. Note this is more difficult to get right than it seems 
at first glance; e.g. copy/pasting can be damaged if the validator is 
too simple. It is much easier to validate only before the data is accepted.

There are also several choices how you react if the validation fails. 
You could show the error in a popup (tkMessageBox). This is the simplest 
approach, but makes the error unavailable to the user after it is 
acknowledged. A better method from a usability perspective is a status 
line that signals the error, possibly in red, and also marks the fields 
with errors in red. All of this can be done in a couple of lines easily, 
but is lots of work to do completely right and capture every possible case.

	Christian


From rantingrickjohnson at gmail.com  Fri Jan  2 18:52:49 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Fri, 2 Jan 2015 15:52:49 -0800 (PST)
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <f7a40fa7-18da-40aa-8002-25f2ee7071e9@googlegroups.com>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
 <20150102135132.GE24572@arxnet.hu>
 <mailman.17324.1420207299.18130.python-list@python.org>
 <2a5bfb42-c0b4-40dc-ba86-10bb67001350@googlegroups.com>
 <f7a40fa7-18da-40aa-8002-25f2ee7071e9@googlegroups.com>
Message-ID: <7bd5dcd3-f6c9-43db-a0a7-6586b2e87160@googlegroups.com>

On Friday, January 2, 2015 11:54:49 AM UTC-6, Rustom Mody wrote:
> And how does this strange language called English fits
> into your rules and (no) special cases scheme?

Oh i'm not blind to the many warts of the English language,
for it has many undesirable qualities indeed, however, it
*is* the "most ubiquitous language spoken" in the world.

    Note that "most ubiquitous spoken" does not mean that
    "the majority of people in the world speak English",
    rather that: "English crosses more cultural divides than
    any language spoken today" -- and because of that fact
    (for better or worse???) our public communications
    should be in English only.

I not suggesting that "supporting" multiple languages is a
sin, merely that, supporting multiple languages is a waste
of valuable time -- time that could be better spent tracking
bugs or adding features.

That is the sole reason why i detest UNICODE. UNICODE's
existence provides "life-support" for natural language
multiplicity, because it acts as a translator for selfish
alias's of ideas. Without this "translator", the technical
society would render these languages obsolete in short time.

    ============================================================
    REGIONAL LANGUAGES REPRESENT "SELFISH SYMBOL TABLES", WHO'S
    KEYS ARE MERELY "SUPERFLUOUS CODIFICATIONS" OF THE UBIQUITOUS
    "IMMUTABLE GLOBAL CONCEPTS" FOR WHICH THEY MAP, AND WE NEED
    AN OPTIMIZER TO FOREVER FREE OUR COMMUNICATIONS OF THESE
    "REDUNDANT BINDINGS"; INJECTED BY EMOTIONAL LITTLE AMATEURS,
    WHO's INTELLECTUAL BOUNDARIES END AT THE BASE OF THEIR OWN
    INSIGNIFICANT LITTLE ANT HILL!

    THE UNIVERSE SHOULD BE THE ONLY LIMIT!
    ============================================================

A tree is a tree, not matter how you spell it. A dog is dog,
velocity/mass/etc... These definitions (an many others) of
both "tangible objects" and "intangible ideas" are not in
dispute, SO WHY PERPETUATE SELFISH CODES TO DESCRIBE THEM?

Relationships such as: "dogs and cats are mammals", are
likewise not disputable, but yet we continue to codify
knowledge behind a multiplicity of selfish regional symbols --
and for what benefit?

Look, i know humans have this "instinctual need" to assemble
in herds, herds which employ unique symbols which "coddle"
their need for "sense of being" within the herd, but
these "needs" are not intellectual, they are but *cheap*
emotional remnants from our primitive days, and whist these
"herd emotions" are invaluable to the survival of primitive
lifeforms, we must realize that they serve no intellectual
purpose, and in fact, are an anchor around the necks of
advanced lifeforms such as ourselves.

    ============================================================
    WE MUST RELY ON LOGIC TO MOVE US INTO THE NEXT EVOLUTIONARY
    STAGE -- BECAUSE EMOTION WILL DESTROY US!
    ============================================================

Logic is not instinctual, neither is reason -- but emotion
*IS*! Emotion is our "basic modality" to fall back on when
the "logical system" fails us. A clear example of this "base
system" in action is the "oft-cited cop-out" of:

    "Oh, that's just semantics!"

Such a remark is nothing more than a weak "ego defense"
employed by an opponent who is either: (1) too lazy to
contemplate the intellectual depths, or (2) lacks the
intellectual *fortitude* to grasp the inherent concepts.

At some point we *ALL* need to realize that most ideas need
to be codified into a stdlib of world-wide natural language,
and then internalized within all public communication. Am i
suggesting that no one would be allowed to speak in regional
tongues...?

OF COURSE NOT!

I'm merely suggesting that only *ONE* official language be
supported for public business and public communication
purposes. You are free to speak or write whatever "slang" or
"regionally selfish code" that you want in any "non-
official" communique.



From rantingrickjohnson at gmail.com  Fri Jan  2 19:32:06 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Fri, 2 Jan 2015 16:32:06 -0800 (PST)
Subject: Looking for sample python script using Tkinter
In-Reply-To: <65275e9b-a1e2-4ab7-981c-c0b1c8587159@googlegroups.com>
References: <65275e9b-a1e2-4ab7-981c-c0b1c8587159@googlegroups.com>
Message-ID: <2c04cbff-c437-4728-a1ee-fd206637f079@googlegroups.com>

On Friday, January 2, 2015 5:03:35 PM UTC-6, access... at gmail.com wrote:
> I have a script that I trying to go from command line
> entry to interface entry. [...] I have a few requirements
> when capturing the data:
>    Must be able to navigate to a file and capture entire
>    filename and pathname (which may be on a network rather
>    than the C drive)

I don't foresee an issue here. Like Christian said, give the
tkFileDialog a spin.

>    Capture date
>
>    Capture text (Some of the data entry fields will have
>    commas)
>
>    Some of the data entry fields are required, some are
>    not.

The "capturing" part has nothing to do with GUI's, and the
code should map "almost unchanged" from your command-line 
code.

> Is there a sample script out there that I can review to
> see how these features are accomplished? I am particularly
> stumped by #1 and 4.

Maybe, but i would not know. I think instead of expecting
that a script in the wild might be a one-to-one mapping of
your current problem, you should break the many problems
within this script into distinct areas of research.  But
first you should research the following prerequisites:

  1. How to: create a blank Tkinter window?
     Hint: tk.Tk()

  2. How to: place "N" input fields on a Tkinter window?
     Hint: tk.Entry(...)

  3. How to: dynamically create "N" input fields on demand?
     Hint: "for" he's a jolly good fellow!

  4. How to: customize and/or restrict the input of an input field?
     Hint: "widget.bind("<SEQUENCE_STRING>", func)"

  5. How to: "validate" a group of input fields?
     Hint: "for" he's a jolly good fellow!

  6. How to: allow the user to locate a file (local or otherwise?)
     Hint: "import tkFileDialog"


  http://effbot.org/tkinterbook/
  http://infohost.nmt.edu/tcc/help/pubs/tkinter/web/index.html

I think you'll catch more informative answers if you
restrict the problem domain a bit.


From stephane at wirtel.be  Fri Jan  2 20:57:15 2015
From: stephane at wirtel.be (=?utf-8?q?St=C3=A9phane?= Wirtel)
Date: Sat, 03 Jan 2015 02:57:15 +0100
Subject: PythonFOSDEM 2015 - Selected Talks
Message-ID: <086A4B54-7ABF-4845-8A2E-50F03A50D822@wirtel.be>

Hi all,

We are really proud to announce the official listing for the selected 
talks of the PythonFOSDEM 2015 (during the FOSDEM 2015 : 
https://fosdem.org/2015/).

This year, it's a real surprise for us, firstly we received 42 proposals 
for this edition 2015
and secondly, we move to a bigger room with 200 seats.

You are cordially invited to this PythonFOSDEM 2015.

The room is H.1301 with a capacity of 200 seats.

The event will start at 09:00 AM (local) and will finish at 06:00 PM.

We think to propose a Ligthning Talk Session of one hour.

Here is the talks of this year.

* 09:00 - TaskFlow: State Management Framework
     by Vishal Yadav

* 09:30 - Lea, a probability engine in Python Probabilities made easy!
     by Pierre Denis

* 10:00 - Dive into Scrapy
     by Juan Riaza

* 10:30 - Mercurial, with real python bites
     by Pierre-Yves David

* 11:00 - python-prompt-toolkit / ptpython
     by Jonathan Slenders

* 11:30 - Federation and Python webapps
     by Christopher Webber

* 12:00 - Let's build a spreadsheet app in Python
     by Harry Percival

* 12:30 - PDB is your friend
     by Raul Cumplido Dominguez

* 14:00 - Customize Gunicorn for your own business.
     by Benoit Chesneau

* 14:30 - Python, WebRTC and you
     by Sa?l Ibarra Corretg?

* 15:00 - When performance matters ...
     by Marc-Andr? Lemburg

* 15:30 - Gradual Typing in Python
     by Alejandro Gomez

* 16:00 - Knowing your garbage collector
     by Francisco Fern?ndez Castano

* 16:30 - RedBaron a bottom up approach to refactoring in python
     by Laurent Peuch

* 17:00 - Extending Python, what is the best option for me?
     by Francisco Fern?ndez Castano

* 17:30 - PyPy and the future of the Python ecosystem
     by Romain Guillebert

You can find this list on the site of FOSDEM: 
https://fosdem.org/2015/schedule/track/python/
and on the site of PythonFOSDEM.

Of course, after the talks, there will be a dinner in a restaurant of 
Brussels with the Python Community, here is the link to the doodle [1] 
for the subscription to the dinner.
We need to know the exact numbers for the restaurant. So, please, could 
you subscribe as soon as possible and try to be present for the dinner.

Thank you a lot for your patience and Thank you for the proposals.

[1] http://doodle.com/ngdeesgbr6dcx3f5


--
St?phane Wirtel - http://wirtel.be - @matrixise


From greg.ewing at canterbury.ac.nz  Fri Jan  2 21:18:02 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sat, 03 Jan 2015 15:18:02 +1300
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <mailman.17333.1420232958.18130.python-list@python.org>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
 <20150102135132.GE24572@arxnet.hu>
 <mailman.17324.1420207299.18130.python-list@python.org>
 <2a5bfb42-c0b4-40dc-ba86-10bb67001350@googlegroups.com>
 <mailman.17333.1420232958.18130.python-list@python.org>
Message-ID: <cgp1qrFbi94U1@mid.individual.net>

Chris Angelico wrote:
> On Sat, Jan 3, 2015 at 4:15 AM, Rick Johnson
> <rantingrickjohnson at gmail.com> wrote:
> 
>>Those who refuse to be a part of the modern world can
>>suffer the troubles of forking the code into their ancient
>>systems -- and i will not loose any sleep over the issue.
> 
> By the way, is this "loose" part of your "modern world", or is that
> just a straight-up error?

I think he's just let slip a clue to his secret
evil plans. Anyone who stands between him and
world domination will be anaesthetised by his
fearsome giant sleep cannon.

-- 
Greg


From james at jls-radio.com  Fri Jan  2 22:41:41 2015
From: james at jls-radio.com (James Scholes)
Date: Sat, 03 Jan 2015 03:41:41 +0000
Subject: Command Line Inputs from Windows
In-Reply-To: <CAPTjJmogEyJzGNPe+OEhYmJyhG5nfVOBLChBZbp6NWmjiEXmTw@mail.gmail.com>
References: <COL130-DS1607D96864155F77FE9C11C85D0@phx.gbl>
 <CAPTjJmogEyJzGNPe+OEhYmJyhG5nfVOBLChBZbp6NWmjiEXmTw@mail.gmail.com>
Message-ID: <54A764F5.1040309@jls-radio.com>

Chris Angelico wrote:
> The latter form is governed by the association. I don't know off-hand
> where that's set in the registry, but you should be able to poke
> around in folder settings to find it (but, thank you very much
> Microsoft, the exact menu path has changed a number of times between
> Win2K and Win8). On WinXP, if I have my test-box set up correctly,
> it's View, Folder Options, File Types, select the one for .py,
> Advanced, select "open", Edit.

As of Windows 7 (possibly Vista although don't quote me on that), this
functionality is no longer available.  You'll need to either edit the
registry directly or use a third party tool to manage filetypes and
their associated actions.
-- 
James Scholes
http://twitter.com/JamesScholes


From rosuav at gmail.com  Fri Jan  2 23:16:39 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 3 Jan 2015 15:16:39 +1100
Subject: Command Line Inputs from Windows
In-Reply-To: <54A764F5.1040309@jls-radio.com>
References: <COL130-DS1607D96864155F77FE9C11C85D0@phx.gbl>
 <CAPTjJmogEyJzGNPe+OEhYmJyhG5nfVOBLChBZbp6NWmjiEXmTw@mail.gmail.com>
 <54A764F5.1040309@jls-radio.com>
Message-ID: <CAPTjJmpA=EHzVnPa6CBqmaVyss=XHsgopwKaiFd0Q4Ra=uNvwA@mail.gmail.com>

On Sat, Jan 3, 2015 at 2:41 PM, James Scholes <james at jls-radio.com> wrote:
> Chris Angelico wrote:
>> The latter form is governed by the association. I don't know off-hand
>> where that's set in the registry, but you should be able to poke
>> around in folder settings to find it (but, thank you very much
>> Microsoft, the exact menu path has changed a number of times between
>> Win2K and Win8). On WinXP, if I have my test-box set up correctly,
>> it's View, Folder Options, File Types, select the one for .py,
>> Advanced, select "open", Edit.
>
> As of Windows 7 (possibly Vista although don't quote me on that), this
> functionality is no longer available.  You'll need to either edit the
> registry directly or use a third party tool to manage filetypes and
> their associated actions.

Blargh. Can you recommend a third-party tool? If not, the best advice
I can give is "poke around on the Google".

ChrisA


From breamoreboy at yahoo.co.uk  Sat Jan  3 02:51:29 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 03 Jan 2015 07:51:29 +0000
Subject: Command Line Inputs from Windows
In-Reply-To: <CAPTjJmogEyJzGNPe+OEhYmJyhG5nfVOBLChBZbp6NWmjiEXmTw@mail.gmail.com>
References: <COL130-DS1607D96864155F77FE9C11C85D0@phx.gbl>
 <CAPTjJmogEyJzGNPe+OEhYmJyhG5nfVOBLChBZbp6NWmjiEXmTw@mail.gmail.com>
Message-ID: <m88724$ad9$1@ger.gmane.org>

On 02/01/2015 21:29, Chris Angelico wrote:
> On Sat, Jan 3, 2015 at 6:44 AM, Ken Stewart <gordon_ken_stewart at msn.com> wrote:
>> This works:
>
> I may have some details wrong, and it's likely to be a little
> different on Win7, but poke around and look for a missing %*. Or,
> better still, make sure you have the py.exe launcher; then you can
> have Python scripts request a specific interpreter using a PEP 397
> compliant shebang, which will also work nicely on Unix systems.
>

The launcher has been included since 3.3 
https://docs.python.org/3/whatsnew/3.3.html#pep-397-python-launcher-for-windows

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From breamoreboy at yahoo.co.uk  Sat Jan  3 02:57:48 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 03 Jan 2015 07:57:48 +0000
Subject: Command Line Inputs from Windows
In-Reply-To: <COL130-DS1607D96864155F77FE9C11C85D0@phx.gbl>
References: <COL130-DS1607D96864155F77FE9C11C85D0@phx.gbl>
Message-ID: <m887e0$fk3$1@ger.gmane.org>

On 02/01/2015 19:44, Ken Stewart wrote:
> Court of King Arthur,

Court of BDFL actually.

>
> I?d appreciate any help you can provide.  I?m having problems passing
> command line parameters from Windows 7 into a Python script (using
> Python 3.4.2).  It works correctly when I call the interpreter
> explicitly from the Windows command prompt, but it doesn?t work when I
> enter the script name without calling the Python interpreter.
>
> This works:
> python myScript.py arg1 arg2 arg3
>
> This doesn?t work:
> myScript.py arg1 arg2 arg3
>
> The Windows PATH environment variable contains the path to Python, as
> well as the path to the Script directory.  The PATHEXT environment
> variable contains the Python extension (.py).
>
> There are other anomalies too between the two methods of invoking the
> script depending on whether I include the extension (.py) along with the
> script name.  For now I?m only interested in passing the arguments
> without explicitly calling the Python interpreter.
>
> ************************************
> Here is the script:
>
> #! python
>
> import sys
>
> def getargs():
>     sys.stdout.write("\nHello from Python %s\n\n" % (sys.version,))
>     print ('    Number of arguments =', len(sys.argv))
>     print ('    Argument List =', str(sys.argv))
>
> if __name__ == '__main__':
>     getargs()
>
> ************************************
> Result_1 (working correctly):
>
> C:\Python34\Scripts> python myScript.py arg1 arg2 arg3
>
> Hello from Python 3.4.2 (v3.4.2:ab2c023a9432, Oct  6 2014, 22:15:05)
> [MSC v.1600 32 bit (Intel)]
>
>     Number of arguments = 4
>     Argument List = ['myScript.py', 'arg1', 'arg2', 'arg3']
>
> ************************************
> Result_ 2 (Fail)
>
> C:\Python34\Scripts> myScript.py arg1 arg2 arg3
>
> Hello from Python 3.4.2 (v3.4.2:ab2c023a9432, Oct  6 2014, 22:15:05)
> [MSC v.1600 32 bit (Intel)]
>
>     Number of arguments = 1
>     Argument List = ['C:\\Python34\\Scripts\\myScript.py']
>
> As a beginner I?m probably making a mistake somewhere but I can?t find
> it. I don?t think the shebang does anything in Windows but I?ve tried
> several variations without success.  I?ve tried writing the script using
> only commands, without the accouterments of a full program (without the
> def statement and without the if __name__ == ?__main__? ?) to no avail.
> I?m out of ideas.  Any suggestions?
>
> Ken Stewart
>

Works fine for me with this:-

c:\Users\Mark\Documents\MyPython>assoc .py
.py=Python.File

c:\Users\Mark\Documents\MyPython>assoc .pyw
.pyw=Python.NoConFile

c:\Users\Mark\Documents\MyPython>ftype Python.File
Python.File="C:\Windows\py.exe" "%1" %*

c:\Users\Mark\Documents\MyPython>ftype Python.NoConFile
Python.NoConFile="C:\Windows\pyw.exe" "%1" %*

c:\Users\Mark\Documents\MyPython>set pathext
PATHEXT=.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC;.PY

This is set up by the Python Launcher for Windows, introduced in 3.3, 
see https://docs.python.org/3/using/windows.html#launcher, noting that 
shebang lines also work.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From gordon_ken_stewart at msn.com  Sat Jan  3 03:03:34 2015
From: gordon_ken_stewart at msn.com (Ken Stewart)
Date: Sat, 3 Jan 2015 01:03:34 -0700
Subject: Command Line Inputs from Windows
In-Reply-To: <CAPTjJmpA=EHzVnPa6CBqmaVyss=XHsgopwKaiFd0Q4Ra=uNvwA@mail.gmail.com>
References: <COL130-DS1607D96864155F77FE9C11C85D0@phx.gbl>
 <CAPTjJmogEyJzGNPe+OEhYmJyhG5nfVOBLChBZbp6NWmjiEXmTw@mail.gmail.com>
 <54A764F5.1040309@jls-radio.com>
 <CAPTjJmpA=EHzVnPa6CBqmaVyss=XHsgopwKaiFd0Q4Ra=uNvwA@mail.gmail.com>
Message-ID: <COL130-DS98295575A8BC2E0BAAF92C85A0@phx.gbl>

Chris, Dennis, James, and Mark:

SUCCESS!  Thanks for your suggestions.  It was the registry.  Kudos to 
Dennis.  The data strings for a lot of different "command" keys in the 
registry were missing the %* (percent star) characters.  Thanks Chris for 
the explanation on why the %* string is needed.

Here is a sample key:
S1-5-21-1560217580-722697556-320042093-1000-Classes
    py_auto_file
        shell
            open
                command

The corrected data for the key looks like this:

"C:\Python34\python.exe" %1 %*

I used the 'find' tool in regedit to search for python in the registry. 
There were many hits on the word python but only a handful had data fields 
similar to the one above.  Every instance was missing the %* string.  I 
modified them all.  My script didn't start working until after I'd modified 
the very last one.  Happily, my computer still boots after mucking around in 
the registry.

I haven't yet investigated the launcher suggested by Chris and Mark.  That 
may well be the proper solution.  At the moment it looks like the Python 
installer didn't create these registry entries properly in Windows 7.

Thanks again

Ken Stewart



From rosuav at gmail.com  Sat Jan  3 03:06:52 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 3 Jan 2015 19:06:52 +1100
Subject: Command Line Inputs from Windows
In-Reply-To: <COL130-DS98295575A8BC2E0BAAF92C85A0@phx.gbl>
References: <COL130-DS1607D96864155F77FE9C11C85D0@phx.gbl>
 <CAPTjJmogEyJzGNPe+OEhYmJyhG5nfVOBLChBZbp6NWmjiEXmTw@mail.gmail.com>
 <54A764F5.1040309@jls-radio.com>
 <CAPTjJmpA=EHzVnPa6CBqmaVyss=XHsgopwKaiFd0Q4Ra=uNvwA@mail.gmail.com>
 <COL130-DS98295575A8BC2E0BAAF92C85A0@phx.gbl>
Message-ID: <CAPTjJmoSpgZzJe7BbX4rWgdk4r5teSeAJQ=dNLiXmLdCC4G=0Q@mail.gmail.com>

On Sat, Jan 3, 2015 at 7:03 PM, Ken Stewart <gordon_ken_stewart at msn.com> wrote:
> I used the 'find' tool in regedit to search for python in the registry.
> There were many hits on the word python but only a handful had data fields
> similar to the one above.  Every instance was missing the %* string.  I
> modified them all.  My script didn't start working until after I'd modified
> the very last one.  Happily, my computer still boots after mucking around in
> the registry.

Excellent!

Fiddling with Python's setup under Windows is unlikely ever to stop
your computer from booting. Unlike on most Linux and Mac OS systems,
there's no "system Python" that's used internally; Windows itself
doesn't make use of Python. So you should have no problems playing
around with things.

ChrisA


From breamoreboy at yahoo.co.uk  Sat Jan  3 03:10:46 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 03 Jan 2015 08:10:46 +0000
Subject: Command Line Inputs from Windows
In-Reply-To: <COL130-DS98295575A8BC2E0BAAF92C85A0@phx.gbl>
References: <COL130-DS1607D96864155F77FE9C11C85D0@phx.gbl>
 <CAPTjJmogEyJzGNPe+OEhYmJyhG5nfVOBLChBZbp6NWmjiEXmTw@mail.gmail.com>
 <54A764F5.1040309@jls-radio.com>
 <CAPTjJmpA=EHzVnPa6CBqmaVyss=XHsgopwKaiFd0Q4Ra=uNvwA@mail.gmail.com>
 <COL130-DS98295575A8BC2E0BAAF92C85A0@phx.gbl>
Message-ID: <m8886a$oq0$1@ger.gmane.org>

On 03/01/2015 08:03, Ken Stewart wrote:
> At the moment it looks like the
> Python installer didn't create these registry entries properly in
> Windows 7.
>

If that is actally the case please raise an issue on the bug tracker at 
bugs.python.org if one doesn't already exist.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From wxjmfauth at gmail.com  Sat Jan  3 03:52:08 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Sat, 3 Jan 2015 00:52:08 -0800 (PST)
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <9ade6cb4-6a78-4ebb-8104-83dbf1916482@googlegroups.com>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
 <9d2a330f-eaf8-4943-a246-d143b1b773ca@googlegroups.com>
 <9ade6cb4-6a78-4ebb-8104-83dbf1916482@googlegroups.com>
Message-ID: <b5c4b11c-068b-4d8f-9fe7-c5eda1b44034@googlegroups.com>

Le vendredi 2 janvier 2015 20:11:25 UTC+1, Andr? Roberge a ?crit?:
> On Friday, 2 January 2015 06:29:37 UTC-4, wxjm... at gmail.com  wrote:
> > Le mercredi 31 d?cembre 2014 23:24:50 UTC+1, Andr? Roberge a ?crit?:
> > > EasyGUI_Qt version 0.9 has been released.  This is the first announcement about EasyGUI_Qt on this list.
> snip
> > I toyed and I spent a couple of hours with it.
> > I do not know to much what to say.
> Well, this is more positive than your previous comment expressing doubt that it would work. ;-)   So, thank you!

Do not get me wrong, I do not wish to be rude.
You are building a tool upon a toolkit which
simply does not work properly.

If for some reason you are not aware of this,
you are not aware of this, it is unfortunately
a simple as this.

(Not only I know why, I'm able to explain the
cause).

jmf


From steve+comp.lang.python at pearwood.info  Sat Jan  3 05:01:41 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 03 Jan 2015 21:01:41 +1100
Subject: How do I remove/unlink wildcarded files
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
 <20150102135132.GE24572@arxnet.hu>
 <mailman.17324.1420207299.18130.python-list@python.org>
 <2a5bfb42-c0b4-40dc-ba86-10bb67001350@googlegroups.com>
 <f7a40fa7-18da-40aa-8002-25f2ee7071e9@googlegroups.com>
 <mailman.17332.1420232918.18130.python-list@python.org>
Message-ID: <54a7be06$0$12989$c3e8da3$5496439d@news.astraweb.com>

Chris Angelico wrote:

> On Sat, Jan 3, 2015 at 4:54 AM, Rustom Mody <rustompmody at gmail.com> wrote:
>> And how does this strange language called English fits into your rules
>> and (no) special cases scheme?
>>
>>
http://www.omgfacts.com/lists/3989/Did-you-know-that-ough-can-be-pronounced-TEN-DIFFERENT-WAYS
> 
> I learned six, which is no more than there are for the simple vowel
> 'a' (at least, in British English; American English has a few less
> sounds for 'a'). 

What is this thing you call "American English"? :-) 

I wouldn't want to put an exact number of distinct accents in the USA, but
it's probably in three figures. And it used to be said that a sufficiently
skilled linguist could tell what side of the street an English person was
born on, that's how fine-grained English accents used to be.


> Consider "cat", "bay", "car" (that's the three most 
> common sounds), "watch", "water", "parent" (these three are less
> common, and American English often folds them into the other three).

There's a joke about how people from certain parts of the US suffer
from "hat attacks" (heart attacks).


> Now have a look at Norwegian, where the fifth of those sounds
> ("water") is spelled with a ring above, eg "La den g?" - and the sixth
> is (I think) more often spelled with a slashed O - "Den kraften jeg
> skjulte f?r". Similarly in Swedish: "Sl? dig loss, sl? dig fri" is
> pronounced "Slaw di loss, slaw di free". Or let's look at another of
> English's oddities. Put a t and an h together, and you get a
> completely different sound... two different sounds, in fact, voiced or
> unvoiced. Icelandic uses thorn instead: "?etta er n?g" is pronounced
> (roughly) "Thetta air know".

English used to include the letter Thorn too. Among others. Little known
fact: at one time, ampersand & (as in "and") used to be included as a
letter of the alphabet

http://mentalfloss.com/article/31904/12-letters-didnt-make-alphabet


> And the whole notion of putting a dot on 
> a lower-case i and not putting one on upper-case I is pretty
> illogical, but Turkish, as I mentioned in the previous post, uses the
> dots to distinguish between two pronunciations of the vowel, hence
> "ald?rma" which would sound somewhat different with a dot on the i.
> 
> (You may be able to see a theme in my example texts, but I figured
> it's time to see what I can do with full Unicode support. The cold
> looks of disapproval never bothered me, anyway.)
> 
> ChrisA

-- 
Steven



From rosuav at gmail.com  Sat Jan  3 05:16:30 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 3 Jan 2015 21:16:30 +1100
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <54a7be06$0$12989$c3e8da3$5496439d@news.astraweb.com>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
 <20150102135132.GE24572@arxnet.hu>
 <mailman.17324.1420207299.18130.python-list@python.org>
 <2a5bfb42-c0b4-40dc-ba86-10bb67001350@googlegroups.com>
 <f7a40fa7-18da-40aa-8002-25f2ee7071e9@googlegroups.com>
 <mailman.17332.1420232918.18130.python-list@python.org>
 <54a7be06$0$12989$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmrTYSEemnpaHRJBLDYq-gp2-wVpht4E_y1SnJmC8X6UVA@mail.gmail.com>

On Sat, Jan 3, 2015 at 9:01 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Chris Angelico wrote:
>
>> On Sat, Jan 3, 2015 at 4:54 AM, Rustom Mody <rustompmody at gmail.com> wrote:
>>> And how does this strange language called English fits into your rules
>>> and (no) special cases scheme?
>>>
>>>
> http://www.omgfacts.com/lists/3989/Did-you-know-that-ough-can-be-pronounced-TEN-DIFFERENT-WAYS
>>
>> I learned six, which is no more than there are for the simple vowel
>> 'a' (at least, in British English; American English has a few less
>> sounds for 'a').
>
> What is this thing you call "American English"? :-)
>
> I wouldn't want to put an exact number of distinct accents in the USA, but
> it's probably in three figures. And it used to be said that a sufficiently
> skilled linguist could tell what side of the street an English person was
> born on, that's how fine-grained English accents used to be.

"American English" is the category compassing all of those accents
common to the USA. There are certain broad similarities between it and
British English, just as there are similarities between Dutch and
German; and there are certain commonalities across all accents of
American English, allowing generalizations about the number of sounds
made by the vowel "a". :)

>> Now have a look at Norwegian, where the fifth of those sounds
>> ("water") is spelled with a ring above, eg "La den g?" - and the sixth
>> is (I think) more often spelled with a slashed O - "Den kraften jeg
>> skjulte f?r". Similarly in Swedish: "Sl? dig loss, sl? dig fri" is
>> pronounced "Slaw di loss, slaw di free". Or let's look at another of
>> English's oddities. Put a t and an h together, and you get a
>> completely different sound... two different sounds, in fact, voiced or
>> unvoiced. Icelandic uses thorn instead: "?etta er n?g" is pronounced
>> (roughly) "Thetta air know".
>
> English used to include the letter Thorn too. Among others.

Yes, but it doesn't any more. Icelandic is the only modern language
I'm aware of that retains thorn and eth (eg in "?a?").

ChrisA


From breamoreboy at yahoo.co.uk  Sat Jan  3 05:38:21 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 03 Jan 2015 10:38:21 +0000
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <CAPTjJmrTYSEemnpaHRJBLDYq-gp2-wVpht4E_y1SnJmC8X6UVA@mail.gmail.com>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
 <20150102135132.GE24572@arxnet.hu>
 <mailman.17324.1420207299.18130.python-list@python.org>
 <2a5bfb42-c0b4-40dc-ba86-10bb67001350@googlegroups.com>
 <f7a40fa7-18da-40aa-8002-25f2ee7071e9@googlegroups.com>
 <mailman.17332.1420232918.18130.python-list@python.org>
 <54a7be06$0$12989$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmrTYSEemnpaHRJBLDYq-gp2-wVpht4E_y1SnJmC8X6UVA@mail.gmail.com>
Message-ID: <m88gr1$cdf$1@ger.gmane.org>

On 03/01/2015 10:16, Chris Angelico wrote:
> On Sat, Jan 3, 2015 at 9:01 PM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> Chris Angelico wrote:
>>
>>> On Sat, Jan 3, 2015 at 4:54 AM, Rustom Mody <rustompmody at gmail.com> wrote:
>>>> And how does this strange language called English fits into your rules
>>>> and (no) special cases scheme?
>>>>
>>>>
>> http://www.omgfacts.com/lists/3989/Did-you-know-that-ough-can-be-pronounced-TEN-DIFFERENT-WAYS
>>>
>>> I learned six, which is no more than there are for the simple vowel
>>> 'a' (at least, in British English; American English has a few less
>>> sounds for 'a').
>>
>> What is this thing you call "American English"? :-)
>>
>> I wouldn't want to put an exact number of distinct accents in the USA, but
>> it's probably in three figures. And it used to be said that a sufficiently
>> skilled linguist could tell what side of the street an English person was
>> born on, that's how fine-grained English accents used to be.
>
> "American English" is the category compassing all of those accents
> common to the USA. There are certain broad similarities between it and
> British English, just as there are similarities between Dutch and
> German; and there are certain commonalities across all accents of
> American English, allowing generalizations about the number of sounds
> made by the vowel "a". :)
>

I used to get very confused watching the old westerns.  The child when 
talking about "more" and "paw" wasn't referring to possibly an 
adjective, noun or adverb and a part of an animal, but what we would 
refer to in the UK as "mum" and "dad" :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From real-not-anti-spam-address at apple-juice.co.uk  Sat Jan  3 05:54:23 2015
From: real-not-anti-spam-address at apple-juice.co.uk (D.M. Procida)
Date: Sat, 3 Jan 2015 10:54:23 +0000
Subject: DjangoCon Europe 2015, in Cardiff, Wales
Message-ID: <1lxo5w9.1ltpb0bgno3h0N%real-not-anti-spam-address@apple-juice.co.uk>

In 2015, DjangoCon Europe is coming to Cardiff:
<http://2015.djangocon.eu/> - the first-ever six-day DjangoCon.

The conference will begin with an open day (as in, open to anyone who
feels like coming) of free talks and tutorials, aimed at introducing new
people to Python and Django and the communities around them.

Registration's now open:
<http://2015.djangocon.eu/news/registration-opens/>

Hope to see you there. Maybe someone can even do a lightning talk about
comp.lang.python to introduce all the young whippersnappers to Usenet...

Daniele
-- 
DjangoCon Europe 2015 in Cardiff, 2nd to 7th June. 
Six days of talks, tutorials and code.

<http://2015.djangocon.eu/>


From pramod.sp78 at gmail.com  Sat Jan  3 06:43:18 2015
From: pramod.sp78 at gmail.com (pramod gowda)
Date: Sat, 3 Jan 2015 03:43:18 -0800 (PST)
Subject: Socket programming
Message-ID: <f8631430-9364-42c8-8b12-daa3da4edf7c@googlegroups.com>

Hi i am learning socket programming,

client code:

import socket

client_socket=socket.socket()
server_address='192.168.2.2'
server_port= 80
print("hello")
client_socket.connect((server_address,server_port))
print("hello")
data=client_socket.recv(1024)
print(data)
client_socket.close()

server code:
import socket

server_socket=socket.socket()
server_name='192.168.2.2'
server_port= 80
server_socket.bind((server_name,server_port))
server_socket.listen(1)

while True:
    print("hello")
    c,address=server_socket.accept()
    print("we got connection from:",address)
    c.send("hello,hw ru")
    c.close()




I am not getting the output, i am using windows 7 OS..
please  check and give me the solution.


From georg.grafendorfer at gmail.com  Sat Jan  3 06:55:49 2015
From: georg.grafendorfer at gmail.com (Georg Grafendorfer)
Date: Sat, 3 Jan 2015 12:55:49 +0100
Subject: pathlib type error
Message-ID: <CAHRCC4=TE7Ep7GPVAw-3pFnzSzopHjkJPLgK-NbmmFkSMqg-eQ@mail.gmail.com>

Hi

I'm using Debian 8 Jessie on an AMD64 machine.
Getting this error:

~$ python3
Python 3.4.2 (default, Oct  8 2014, 10:45:20)
[GCC 4.9.1] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from pathlib import Path
>>> p = Path("/etc")
>>> q = p / "init.d"
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unsupported operand type(s) for /: 'PosixPath' and 'str'
>>>


This also happens if I compile python3.4.2 from scratch:

.../data/Python-3.4.2$ ./python
Python 3.4.2 (default, Jan  3 2015, 12:42:09)
[GCC 4.9.1] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from pathlib import Path
>>> p = Path("/etc")
>>> q = p / "init.d"
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unsupported operand type(s) for /: 'PosixPath' and 'str'
>>>


On the same computer, using rescuecd 4.4.1 (Nov 2014) which ships python
3.4.1 it works as expected.

thanks for help, Georg
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From rosuav at gmail.com  Sat Jan  3 06:56:13 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 3 Jan 2015 22:56:13 +1100
Subject: Socket programming
In-Reply-To: <f8631430-9364-42c8-8b12-daa3da4edf7c@googlegroups.com>
References: <f8631430-9364-42c8-8b12-daa3da4edf7c@googlegroups.com>
Message-ID: <CAPTjJmp7VJQdD1sFv5LU7EfwcfJ=sJ3C98v+9bjh7hL4HOf6Fg@mail.gmail.com>

On Sat, Jan 3, 2015 at 10:43 PM, pramod gowda <pramod.sp78 at gmail.com> wrote:
> I am not getting the output, i am using windows 7 OS..
> please  check and give me the solution.

Windows 7 - that's part of the story. What version of Python are you
using? Is 192.168.2.2 the correct IP address? What happens when you
run these? Do you get exceptions?

ChrisA


From rosuav at gmail.com  Sat Jan  3 07:06:20 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 3 Jan 2015 23:06:20 +1100
Subject: pathlib type error
In-Reply-To: <CAHRCC4=TE7Ep7GPVAw-3pFnzSzopHjkJPLgK-NbmmFkSMqg-eQ@mail.gmail.com>
References: <CAHRCC4=TE7Ep7GPVAw-3pFnzSzopHjkJPLgK-NbmmFkSMqg-eQ@mail.gmail.com>
Message-ID: <CAPTjJmop-+OXkzu6nu4EhW1y5S1p=g-JCdBWhvPtHcennSAV6Q@mail.gmail.com>

On Sat, Jan 3, 2015 at 10:55 PM, Georg Grafendorfer
<georg.grafendorfer at gmail.com> wrote:
> I'm using Debian 8 Jessie on an AMD64 machine.
> Getting this error:
>
> ~$ python3
> Python 3.4.2 (default, Oct  8 2014, 10:45:20)
> [GCC 4.9.1] on linux
> Type "help", "copyright", "credits" or "license" for more information.
>>>> from pathlib import Path
>>>> p = Path("/etc")
>>>> q = p / "init.d"
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> TypeError: unsupported operand type(s) for /: 'PosixPath' and 'str'
>>>>

Unable to reproduce:

rosuav at dewey:~$ python3
Python 3.4.2 (default, Oct  8 2014, 10:45:20)
[GCC 4.9.1] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from pathlib import Path
>>> p = Path("/etc")
>>> q = p / "init.d"
>>> q
PosixPath('/etc/init.d')
>>> pathlib.__file__
'/usr/lib/python3.4/pathlib.py'

Is it possible you have another pathlib installed? It's available on
PyPI, maybe you got it with pip - check 'pip freeze|grep pathlib' on
the off-chance. Is your pathlib.__file__ the same as mine?

ChrisA


From rosuav at gmail.com  Sat Jan  3 07:07:08 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 3 Jan 2015 23:07:08 +1100
Subject: pathlib type error
In-Reply-To: <CAPTjJmop-+OXkzu6nu4EhW1y5S1p=g-JCdBWhvPtHcennSAV6Q@mail.gmail.com>
References: <CAHRCC4=TE7Ep7GPVAw-3pFnzSzopHjkJPLgK-NbmmFkSMqg-eQ@mail.gmail.com>
 <CAPTjJmop-+OXkzu6nu4EhW1y5S1p=g-JCdBWhvPtHcennSAV6Q@mail.gmail.com>
Message-ID: <CAPTjJmprA4NPqywvAaKKD_HUJ-VLYsWDDVXihQPBdQYjbVCMxQ@mail.gmail.com>

On Sat, Jan 3, 2015 at 11:06 PM, Chris Angelico <rosuav at gmail.com> wrote:
> On Sat, Jan 3, 2015 at 10:55 PM, Georg Grafendorfer
> <georg.grafendorfer at gmail.com> wrote:
>> I'm using Debian 8 Jessie on an AMD64 machine.
>> Getting this error:
>>
>> ~$ python3
>> Python 3.4.2 (default, Oct  8 2014, 10:45:20)
>> [GCC 4.9.1] on linux
>
> Unable to reproduce:
>
> rosuav at dewey:~$ python3
> Python 3.4.2 (default, Oct  8 2014, 10:45:20)
> [GCC 4.9.1] on linux

Should have clarified: Dewey is also running Debian Jessie.

ChrisA


From pramod.sp78 at gmail.com  Sat Jan  3 07:25:16 2015
From: pramod.sp78 at gmail.com (pramod gowda)
Date: Sat, 3 Jan 2015 04:25:16 -0800 (PST)
Subject: Socket programming
In-Reply-To: <mailman.17347.1420286176.18130.python-list@python.org>
References: <f8631430-9364-42c8-8b12-daa3da4edf7c@googlegroups.com>
 <mailman.17347.1420286176.18130.python-list@python.org>
Message-ID: <3734210e-5811-4f05-b95d-ceb4c78c1377@googlegroups.com>

On Saturday, January 3, 2015 5:26:27 PM UTC+5:30, Chris Angelico wrote:
> On Sat, Jan 3, 2015 at 10:43 PM, pramod gowda <pramod.sp78 at gmail.com> wrote:
> > I am not getting the output, i am using windows 7 OS..
> > please  check and give me the solution.
> 
> Windows 7 - that's part of the story. What version of Python are you
> using? Is 192.168.2.2 the correct IP address? What happens when you
> run these? Do you get exceptions?
> 
> ChrisA

Hi chris.


I am using python 3.4.2
I don get any exceptions,
but wn i run the code,i don see any connections, IP address is given as my system IP.

 c,address=server_socket.accept() in server.py..if am trying to print something,it fails


From rosuav at gmail.com  Sat Jan  3 07:38:07 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 3 Jan 2015 23:38:07 +1100
Subject: Socket programming
In-Reply-To: <3734210e-5811-4f05-b95d-ceb4c78c1377@googlegroups.com>
References: <f8631430-9364-42c8-8b12-daa3da4edf7c@googlegroups.com>
 <mailman.17347.1420286176.18130.python-list@python.org>
 <3734210e-5811-4f05-b95d-ceb4c78c1377@googlegroups.com>
Message-ID: <CAPTjJmoNtWZvRcPk+ih6hvtduuK+5nDCa4zaWmXovCRauAO1gg@mail.gmail.com>

On Sat, Jan 3, 2015 at 11:25 PM, pramod gowda <pramod.sp78 at gmail.com> wrote:
> I am using python 3.4.2
> I don get any exceptions,
> but wn i run the code,i don see any connections, IP address is given as my system IP.

What does the client say?

ChrisA


From pramod.sp78 at gmail.com  Sat Jan  3 08:22:38 2015
From: pramod.sp78 at gmail.com (pramod gowda)
Date: Sat, 3 Jan 2015 05:22:38 -0800 (PST)
Subject: Socket programming
In-Reply-To: <mailman.17350.1420288695.18130.python-list@python.org>
References: <f8631430-9364-42c8-8b12-daa3da4edf7c@googlegroups.com>
 <mailman.17347.1420286176.18130.python-list@python.org>
 <3734210e-5811-4f05-b95d-ceb4c78c1377@googlegroups.com>
 <mailman.17350.1420288695.18130.python-list@python.org>
Message-ID: <98b75dfe-0077-44b1-9b3d-fc242253b4ee@googlegroups.com>

On Saturday, January 3, 2015 6:08:28 PM UTC+5:30, Chris Angelico wrote:
> On Sat, Jan 3, 2015 at 11:25 PM, pramod gowda <pramod.sp78 at gmail.com> wrote:
> > I am using python 3.4.2
> > I don get any exceptions,
> > but wn i run the code,i don see any connections, IP address is given as my system IP.
> 
> What does the client say?
> 
> ChrisA

After  c,address=server_socket.accept()  ,this line of code,nothing s being executed.

example i am just trying to print "Hello"
thts also not being printed


From gvanem at yahoo.no  Sat Jan  3 09:09:52 2015
From: gvanem at yahoo.no (Gisle Vanem)
Date: Sat, 03 Jan 2015 14:09:52 +0000
Subject: Command Line Inputs from Windows
In-Reply-To: <COL130-DS98295575A8BC2E0BAAF92C85A0@phx.gbl>
References: <COL130-DS1607D96864155F77FE9C11C85D0@phx.gbl>
 <CAPTjJmogEyJzGNPe+OEhYmJyhG5nfVOBLChBZbp6NWmjiEXmTw@mail.gmail.com>
 <54A764F5.1040309@jls-radio.com>
 <CAPTjJmpA=EHzVnPa6CBqmaVyss=XHsgopwKaiFd0Q4Ra=uNvwA@mail.gmail.com>
 <COL130-DS98295575A8BC2E0BAAF92C85A0@phx.gbl>
Message-ID: <54A7F830.8050906@yahoo.no>

Ken Stewart wrote:

> Here is a sample key:
> S1-5-21-1560217580-722697556-320042093-1000-Classes
>     py_auto_file
>         shell
>             open
>                 command
>
> The corrected data for the key looks like this:
>
> "C:\Python34\python.exe" %1 %*


Yikes! You use the awful cmd.exe as the shell don't you?
An advice is to use something like TakeCommand or 4NT (from jpsoft.com)
and create an "executable extension" for .py/.pyw files. Like I've
done:
  set .py=C:\Python34\python.exe
  set .pyw=C:\Python34\pythonw.exe

No need to fiddle with registry settings.

-- 
--gv


From pinoparuzzeddu at gmx.com  Sat Jan  3 09:26:25 2015
From: pinoparuzzeddu at gmx.com (GIANNI)
Date: Sat, 3 Jan 2015 06:26:25 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
References: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
Message-ID: <2402b8ac-4341-4e7f-84b9-7cb9af36f676@googlegroups.com>

-- redacted --


From none at mailinator.com  Sat Jan  3 10:09:07 2015
From: none at mailinator.com (mm0fmf)
Date: Sat, 03 Jan 2015 15:09:07 +0000
Subject: Socket programming
In-Reply-To: <f8631430-9364-42c8-8b12-daa3da4edf7c@googlegroups.com>
References: <f8631430-9364-42c8-8b12-daa3da4edf7c@googlegroups.com>
Message-ID: <uCTpw.281005$P42.33854@fx24.am4>

On 03/01/2015 11:43, pramod gowda wrote:
> server_socket=socket.socket()
> server_name='192.168.2.2'
> server_port= 80
> server_socket.bind((server_name,server_port))
> server_socket.listen(1)

I don't do much Python on Windows but do you have the necessary access 
rights to open a listening socket on port 80? Don't you need to run this 
with Administrator rights?






From pramod.sp78 at gmail.com  Sat Jan  3 10:15:25 2015
From: pramod.sp78 at gmail.com (pramod gowda)
Date: Sat, 3 Jan 2015 07:15:25 -0800 (PST)
Subject: Socket programming
In-Reply-To: <uCTpw.281005$P42.33854@fx24.am4>
References: <f8631430-9364-42c8-8b12-daa3da4edf7c@googlegroups.com>
 <uCTpw.281005$P42.33854@fx24.am4>
Message-ID: <7a67b545-ee20-47c1-b8a9-fa83c4dfa660@googlegroups.com>

On Saturday, January 3, 2015 8:39:26 PM UTC+5:30, mm0fmf wrote:
> On 03/01/2015 11:43, pramod gowda wrote:
> > server_socket=socket.socket()
> > server_name='192.168.2.2'
> > server_port= 80
> > server_socket.bind((server_name,server_port))
> > server_socket.listen(1)
> 
> I don't do much Python on Windows but do you have the necessary access 
> rights to open a listening socket on port 80? Don't you need to run this 
> with Administrator rights?

HI, i m doing n personal laptop.
so i think i ve rights to open a listening socket,could u pls tell me hw can i check it?


From steve+comp.lang.python at pearwood.info  Sat Jan  3 10:57:07 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 04 Jan 2015 02:57:07 +1100
Subject: Socket programming
References: <f8631430-9364-42c8-8b12-daa3da4edf7c@googlegroups.com>
 <uCTpw.281005$P42.33854@fx24.am4>
 <7a67b545-ee20-47c1-b8a9-fa83c4dfa660@googlegroups.com>
Message-ID: <54a81154$0$13000$c3e8da3$5496439d@news.astraweb.com>

pramod gowda wrote:

> HI, i m doing n personal laptop.
> so i think i ve rights to open a listening socket,could u pls tell me hw
> can i check it?

Is your keyboard broken? There are a lot of missing characters in your
sentences. You're going to have a lot of trouble programming with a broken
keyboard.

As far as sockets, this is a Python discussion group, not Windows experts.
Try googling for more information and see if that helps:

https://duckduckgo.com/?q=windows%20permission%20to%20open%20sockets




-- 
Steven



From pramod.sp78 at gmail.com  Sat Jan  3 11:10:48 2015
From: pramod.sp78 at gmail.com (pramod gowda)
Date: Sat, 3 Jan 2015 08:10:48 -0800 (PST)
Subject: Socket programming
In-Reply-To: <54a81154$0$13000$c3e8da3$5496439d@news.astraweb.com>
References: <f8631430-9364-42c8-8b12-daa3da4edf7c@googlegroups.com>
 <uCTpw.281005$P42.33854@fx24.am4>
 <7a67b545-ee20-47c1-b8a9-fa83c4dfa660@googlegroups.com>
 <54a81154$0$13000$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <c481f2b5-a6ac-4fa7-bf29-951a9f17984d@googlegroups.com>

On Saturday, January 3, 2015 9:27:20 PM UTC+5:30, Steven D'Aprano wrote:
> pramod gowda wrote:
> 
> > HI, i m doing n personal laptop.
> > so i think i ve rights to open a listening socket,could u pls tell me hw
> > can i check it?
> 
> Is your keyboard broken? There are a lot of missing characters in your
> sentences. You're going to have a lot of trouble programming with a broken
> keyboard.
> 
> As far as sockets, this is a Python discussion group, not Windows experts.
> Try googling for more information and see if that helps:
> 
> https://duckduckgo.com/?q=windows%20permission%20to%20open%20sockets
> 
> 
> 
> 
> -- 
> Steven

Hi Steven,


Sorry for using short words while posting,I am using python in windows7 with Python ver 3.4.2 for socket program,so i am asking for help.

Thanks
Pramod SP



From andre.roberge at gmail.com  Sat Jan  3 12:11:10 2015
From: andre.roberge at gmail.com (=?ISO-8859-1?Q?Andr=E9_Roberge?=)
Date: Sat, 3 Jan 2015 09:11:10 -0800 (PST)
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <b5c4b11c-068b-4d8f-9fe7-c5eda1b44034@googlegroups.com>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
 <9d2a330f-eaf8-4943-a246-d143b1b773ca@googlegroups.com>
 <9ade6cb4-6a78-4ebb-8104-83dbf1916482@googlegroups.com>
 <b5c4b11c-068b-4d8f-9fe7-c5eda1b44034@googlegroups.com>
Message-ID: <fda3c983-e336-4f81-870f-bd03c7ef15db@googlegroups.com>

On Saturday, 3 January 2015 04:52:21 UTC-4, wxjm... at gmail.com  wrote:
> Le vendredi 2 janvier 2015 20:11:25 UTC+1, Andr? Roberge a ?crit?:
> > On Friday, 2 January 2015 06:29:37 UTC-4, wxjm... at gmail.com  wrote:
> > > Le mercredi 31 d?cembre 2014 23:24:50 UTC+1, Andr? Roberge a ?crit?:
> > > > EasyGUI_Qt version 0.9 has been released.  This is the first announcement about EasyGUI_Qt on this list.
> > snip
> > > I toyed and I spent a couple of hours with it.
> > > I do not know to much what to say.
> > Well, this is more positive than your previous comment expressing doubt that it would work. ;-)   So, thank you!
> 
> Do not get me wrong, I do not wish to be rude.
> You are building a tool upon a toolkit which
> simply does not work properly.
> 
> If for some reason you are not aware of this,
> you are not aware of this, it is unfortunately
> a simple as this.
> 
> (Not only I know why, I'm able to explain the
> cause).

Would you care to elaborate?  All the code I have written works correctly on all the tests I have done.  I do have reports from a user using a Mac with Python 2.7 for which some widgets did not quite work properly ... but that's all I have heard about problems with it. 

I would like to hear about the problems you know about either here, on by filing an issue at https://github.com/aroberge/easygui_qt/issues
> 
> jmf


From drsalists at gmail.com  Sat Jan  3 12:16:57 2015
From: drsalists at gmail.com (Dan Stromberg)
Date: Sat, 3 Jan 2015 09:16:57 -0800
Subject: Socket programming
In-Reply-To: <f8631430-9364-42c8-8b12-daa3da4edf7c@googlegroups.com>
References: <f8631430-9364-42c8-8b12-daa3da4edf7c@googlegroups.com>
Message-ID: <CAGGBd_rFqtU2obvNVV6NcAniGGvXuXAMMbbGUnx2O69ZgqbPzw@mail.gmail.com>

On Sat, Jan 3, 2015 at 3:43 AM, pramod gowda <pramod.sp78 at gmail.com> wrote:
> Hi i am learning socket programming,

This "works" on Linux Mint 17.1.

Server:
#!/usr/local/cpython-3.4/bin/python

import socket

server_socket = socket.socket()
#server_name = '192.168.2.2'
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_name = 'localhost'
server_port = 8080
server_socket.bind((server_name, server_port))
server_socket.listen(1)

while True:
    print("hello")
    c,address = server_socket.accept()
    print("we got connection from:",address)
    c.send(b"hello,hw ru")
    c.close()


client:
#!/usr/local/cpython-3.4/bin/python

import socket

client_socket = socket.socket()
#server_address='192.168.2.2'
server_address = 'localhost'
server_port = 8080
print("hello")
client_socket.connect((server_address,server_port))
print("hello")
data=client_socket.recv(1024)
print(data)
client_socket.close()


But note that if you send 10 bytes into a socket, it could be received
as two chunks of 5, or other strangeness. So you should frame your
data somehow - adding crlf to the end of your send's is one simple
way.  There are multiple ways of dealing with this.  Here's one:
http://stromberg.dnsalias.org/~strombrg/bufsock.html with links to
others.


From breamoreboy at yahoo.co.uk  Sat Jan  3 12:38:51 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 03 Jan 2015 17:38:51 +0000
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <fda3c983-e336-4f81-870f-bd03c7ef15db@googlegroups.com>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
 <9d2a330f-eaf8-4943-a246-d143b1b773ca@googlegroups.com>
 <9ade6cb4-6a78-4ebb-8104-83dbf1916482@googlegroups.com>
 <b5c4b11c-068b-4d8f-9fe7-c5eda1b44034@googlegroups.com>
 <fda3c983-e336-4f81-870f-bd03c7ef15db@googlegroups.com>
Message-ID: <m899fe$ao8$1@ger.gmane.org>

On 03/01/2015 17:11, Andr? Roberge wrote:
> On Saturday, 3 January 2015 04:52:21 UTC-4, wxjm... at gmail.com  wrote:
>> Le vendredi 2 janvier 2015 20:11:25 UTC+1, Andr? Roberge a ?crit :
>>> On Friday, 2 January 2015 06:29:37 UTC-4, wxjm... at gmail.com  wrote:
>>>> Le mercredi 31 d?cembre 2014 23:24:50 UTC+1, Andr? Roberge a ?crit :
>>>>> EasyGUI_Qt version 0.9 has been released.  This is the first announcement about EasyGUI_Qt on this list.
>>> snip
>>>> I toyed and I spent a couple of hours with it.
>>>> I do not know to much what to say.
>>> Well, this is more positive than your previous comment expressing doubt that it would work. ;-)   So, thank you!
>>
>> Do not get me wrong, I do not wish to be rude.
>> You are building a tool upon a toolkit which
>> simply does not work properly.
>>
>> If for some reason you are not aware of this,
>> you are not aware of this, it is unfortunately
>> a simple as this.
>>
>> (Not only I know why, I'm able to explain the
>> cause).
>
> Would you care to elaborate?  All the code I have written works correctly on all the tests I have done.  I do have reports from a user using a Mac with Python 2.7 for which some widgets did not quite work properly ... but that's all I have heard about problems with it.
>
> I would like to hear about the problems you know about either here, on by filing an issue at https://github.com/aroberge/easygui_qt/issues
>>
>> jmf

I hope you know that you're engaging with a person who makes statements 
about the inadequacies of various tools, but when challenged to provide 
evidence to support his claims he can never do so.  He is our "Resident 
Unicode Expert", in other words when it comes to Unicode he hasn't got 
the faintest idea what he's talking about, at least with respect to PEP 
393 and the Flexible String Representation.  Please ignore him as he's 
just not worth the effort.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rantingrickjohnson at gmail.com  Sat Jan  3 12:53:08 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Sat, 3 Jan 2015 09:53:08 -0800 (PST)
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <mailman.17344.1420281519.18130.python-list@python.org>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
 <20150102135132.GE24572@arxnet.hu>
 <mailman.17324.1420207299.18130.python-list@python.org>
 <2a5bfb42-c0b4-40dc-ba86-10bb67001350@googlegroups.com>
 <f7a40fa7-18da-40aa-8002-25f2ee7071e9@googlegroups.com>
 <mailman.17332.1420232918.18130.python-list@python.org>
 <54a7be06$0$12989$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmrTYSEemnpaHRJBLDYq-gp2-wVpht4E_y1SnJmC8X6UVA@mail.gmail.com>
 <mailman.17344.1420281519.18130.python-list@python.org>
Message-ID: <f69874c8-48f6-4696-8678-c2a761f2f18d@googlegroups.com>

On Saturday, January 3, 2015 4:39:25 AM UTC-6, Mark Lawrence wrote:

> I used to get very confused watching the old westerns.  The child when 
> talking about "more" and "paw" wasn't referring to possibly an 
> adjective, noun or adverb and a part of an animal, but what we would 
> refer to in the UK as "mum" and "dad" :)

Early Americans are easy to satirize since most were
schooled at home by illiterate parents. I believe the
"redneck vernacular" substituted "mother" and "father" for
"maw" and "paw" respectively. Which is not surprising since
most uneducated folks tend to favor single syllable
simplifications of words over their multi-syllable
counterparts.

Widespread centralized free schooling did not exists until
almost the 1900's. Heck, looking back at American history,
the world *SHOULD* be in awe. To go from a rag-tag
illiterate bunch of cowboys, to the worlds most powerful and
technically advanced society (in roughly one hundred years!)
has to be the most amazing transformation in the history of
the human society.

Of course with all success stories, timing and luck had a
little to do with it, but it was undoubtedly the rebellious
and self reliant nature of Americans that made them so
successful. So before you go and spouting off about how dumb
Americans are/were, ask yourself, what greatness has *MY*
country achieved in the span of a century?

*school bell rings*

PS: I've recently developed an industrial grade scraper
specially designed for removing dried egg residue from the
human face with a "minimal" amount of collateral damage. If
any of you are interested in volunteering your egg covered
faces for testing i would be thankful! Please send me a
private message as the alpha phase begins soon!




From abaskm at gmail.com  Sat Jan  3 13:30:36 2015
From: abaskm at gmail.com (abaskm at gmail.com)
Date: Sat, 3 Jan 2015 10:30:36 -0800 (PST)
Subject: Python Tk Tix GUI documentation & builder overview and tips
In-Reply-To: <e92d6639-28e4-4b58-83f3-fa1e88a186db@k2g2000yql.googlegroups.com>
References: <e92d6639-28e4-4b58-83f3-fa1e88a186db@k2g2000yql.googlegroups.com>
Message-ID: <5373bac1-9d1b-4468-adb8-361240afef92@googlegroups.com>

Hi,

I have had issues running Tix on python 2.7.6 and 3.4.2:

More details on the issue here.

http://stackoverflow.com/questions/27751923/tix-widgets-installation-issue

Has anyone had similar issues with Tix?

Thanks and Happy New Year.


On Friday, March 27, 2009 5:19:42 PM UTC-4, bal... at googlemail.com wrote:
> I have recently started development for a small video conversion
> project using a GUI. After some research I decided to use Tkinter/Tix
> (Tk/Tix). The reasons are mainly:
> 
> 1. the GUI is rather simple, and
> 
> 2. the end-user is not necessarily technically inclined so I want to
> keep
>   a) required libraries as few as possible, and
>   b) installation as painless as possible.
> 
> 3. Tk/Tix is included with Python. Thus only a Python installation is
> needed. Nothing else.
> 
> 4. Tk itsself misses some rudimentary widgets like meters, multi/colum
> lists, grid and scrolled widgets. Tix provides those. Good enough for
> my little application (more advanced and more modern widgets are
> available in frameworks like Qt, Gtk, or wxWindows).
> 
> 
> Before starting I spent some effort to find
> a) relevant documentation,
> b) GUI Builders which might help me,
> c) answers to non-obvious questions.
> 
> The process took some time and effort so I want to share my findings:
> 
> a) Documentation resources
> 
> Python Docs
>         http://docs.python.org/library/tkinter.html
> Tk Commands
>         http://www.tcl.tk/man/tcl8.5/TkCmd/contents.htm
> Tix Reference
>         http://tix.sourceforge.net/man/html/contents.htm
> Tix demo application
> 	You want to extract the Tix demo application coming with the Tix
> 8.4.3 source distribution. It contains 	examples for many widgets -
> unfortunately none for multi-column HList or the Grid (see below).
> 	https://sourceforge.net/project/showfiles.php?group_id=5649&package_id=5704
> 	Tix8.4.3-src.tar.gz, then look in /Tix8.4.3/Python/Demo/tix
> Thinking in Tkinter
> 	I recommend the "Individual programs online"
> 	http://www.ferg.org/thinking_in_tkinter/index.html
> 
> 
> b) GUI development tools
> 
> ActiveState GUI Builder (using grid layout)
> 	SpecTcl is the predecessor of GUI Builder (by ActivaState).
>         http://spectcl.sourceforge.net/
>         FAQ (where to get source)
>         http://aspn.activestate.com/ASPN/Mail/Message/komodo-announce/3355346
> 
> PAGE v3.0 by Stewart Allen (using placer layout)
>         http://page.sourceforge.net/
> 
> There are many more for other GUI toolkits mentioned in this post:
> 	http://mail.python.org/pipermail/python-list/2004-February/250727.html
> 
> Finally I decided to use the packer layout and create the widgets
> manually. Just the simplest and quickest way for me.
> 
> 
> c) How do I ...?
> 
> How do I use all methods available in the Tix Grid?
> 
> Tix Grid with full implementation of all methods
>         http://klappnase.bubble.org/TixGrid/index.html
> 
> 
> How do I create a multi-column Tix.HList?
> 
> 	import Tkinter as Tk
> 	import Tix
> 
> 	root = Tix.Tk()
> 	# setup HList
>         hl = Tix.HList(root, columns = 5, header = True)
>         hl.header_create(0, text = "File")
>         hl.header_create(1, text = "Date")
>         hl.header_create(1, text = "Size")
> 	# create a multi-column row
> 	hl.add("row1", text = "filename.txt")
> 	hl.item_create(entry_path, 1, text = "2009-03-26 21:07:03")
> 	hl.item_create(entry_path, 2, text = "200MiB")
> 
> I haven't found out how to right-justify individual columns? Anyone?
> 
> 
> How to implement Tk GUI with multiple threads?
> 
> Usually there are two options to make threads wait for an event:
> 
>   * gui thread polling (lame)
>     see here how to use Tk.after() (actually a Tcl command) to poll
>     	http://uucode.com/texts/pylongopgui/pyguiapp.html
> 
>     see here how to imitate the Tk event loop to poll for non-Tk
> events (a socket, for example)
> 	https://sourceforge.net/project/showfiles.php?group_id=5649&package_id=5704
> 	Tix8.4.3-src.tar.gz, then look in /Tix8.4.3/Python/Demo/tix/
> tixwidgets.py, find loop()
> 
> 
>   * multithreaded with events (the option to choose)
>     Basically this uses bind and event_generate to send "Notify"
> messages to the Tk instance.
>     I suspect the following example failed due to not synchronising
> the event_generate call
>         http://coding.derkeiler.com/Archive/Python/comp.lang.python/2006-07/msg01479.html
> 
> For multithreading Python Tk GUI applications the following rules
> apply:
> 1. same thread calling Tk must do all subsequent GUI calls,
> 2. other threads may send events with send_event to the root Tk
> instance,
> 3. with threading problems you might try to synchonise access to
> event_generate(). Using event_generate() with one non-GUI thread seems
> to be safe.


From breamoreboy at yahoo.co.uk  Sat Jan  3 13:35:54 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 03 Jan 2015 18:35:54 +0000
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <f69874c8-48f6-4696-8678-c2a761f2f18d@googlegroups.com>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
 <20150102135132.GE24572@arxnet.hu>
 <mailman.17324.1420207299.18130.python-list@python.org>
 <2a5bfb42-c0b4-40dc-ba86-10bb67001350@googlegroups.com>
 <f7a40fa7-18da-40aa-8002-25f2ee7071e9@googlegroups.com>
 <mailman.17332.1420232918.18130.python-list@python.org>
 <54a7be06$0$12989$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmrTYSEemnpaHRJBLDYq-gp2-wVpht4E_y1SnJmC8X6UVA@mail.gmail.com>
 <mailman.17344.1420281519.18130.python-list@python.org>
 <f69874c8-48f6-4696-8678-c2a761f2f18d@googlegroups.com>
Message-ID: <m89cqd$t28$1@ger.gmane.org>

On 03/01/2015 17:53, Rick Johnson wrote:
> On Saturday, January 3, 2015 4:39:25 AM UTC-6, Mark Lawrence wrote:
>
>> I used to get very confused watching the old westerns.  The child when
>> talking about "more" and "paw" wasn't referring to possibly an
>> adjective, noun or adverb and a part of an animal, but what we would
>> refer to in the UK as "mum" and "dad" :)
>
> Early Americans are easy to satirize since most were
> schooled at home by illiterate parents. I believe the
> "redneck vernacular" substituted "mother" and "father" for
> "maw" and "paw" respectively. Which is not surprising since
> most uneducated folks tend to favor single syllable
> simplifications of words over their multi-syllable
> counterparts.
>
> Widespread centralized free schooling did not exists until
> almost the 1900's. Heck, looking back at American history,
> the world *SHOULD* be in awe. To go from a rag-tag
> illiterate bunch of cowboys, to the worlds most powerful and
> technically advanced society (in roughly one hundred years!)
> has to be the most amazing transformation in the history of
> the human society.

I suspect that the engineers who pushed the railways across North 
America were hardly "a rag-tag illiterate bunch of cowboys".  I won't 
mention that the transformation involved wiping out 99% of the 
indigenous population.

>
> Of course with all success stories, timing and luck had a
> little to do with it, but it was undoubtedly the rebellious
> and self reliant nature of Americans that made them so
> successful. So before you go and spouting off about how dumb
> Americans are/were, ask yourself, what greatness has *MY*
> country achieved in the span of a century?

I'm not entirely sure how a little bit of gentle teasing about accents 
in fictional films translates into "spouting off about how dumb 
Americans are/were" but there you go.  Hardly a century but I believe 
that the British Empire covered 25% of the land surface on the planet. 
Quite an achievement for a tiny patch of islands sitting off the coast 
of Europe.  However I suspect that a large number of people were glad to 
see the back of us, although I still think it audacious for those people 
to actually want to run their own countries.

>
> *school bell rings*
>
> PS: I've recently developed an industrial grade scraper
> specially designed for removing dried egg residue from the
> human face with a "minimal" amount of collateral damage. If
> any of you are interested in volunteering your egg covered
> faces for testing i would be thankful! Please send me a
> private message as the alpha phase begins soon!
>

I believe that this has already been done.  Should I ever need one I'll 
probably get a cheap one, complete with its "Made in China" sticker, 
from one of the many ? stores that are springing up in the UK.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From pvrijlandt at gmail.com  Sat Jan  3 13:50:56 2015
From: pvrijlandt at gmail.com (patrick vrijlandt)
Date: Sat, 03 Jan 2015 19:50:56 +0100
Subject: surprise - byte in set
Message-ID: <54a83a19$0$6953$e4fe514c@dreader36.news.xs4all.nl>

Hello list,

Let me first wish you all the best in 2015!

Today I was trying to test for occurrence of a byte in a set ...

 >>> sys.version
'3.4.2 (v3.4.2:ab2c023a9432, Oct  6 2014, 22:15:05) [MSC v.1600 32 bit 
(Intel)]'
 >>> 'b' in 'abc'
True
 >>> b'b' in b'abc'
True
 >>> 'b' in set('abc')
True
 >>> b'b' in set(b'abc')
False

I was surprised by the last result. What happened?
(Examples simplified; I was planning to manipulate the set)

Patrick

---
Dit e-mailbericht is gecontroleerd op virussen met Avast antivirussoftware.
http://www.avast.com



From am1r.ar3alan at gmail.com  Sat Jan  3 14:08:42 2015
From: am1r.ar3alan at gmail.com (Amir Arsalan)
Date: Sat, 3 Jan 2015 22:38:42 +0330
Subject: surprise - byte in set
In-Reply-To: <CANNmrNZAH0gbk=UQgmXDRpPcs21tD0yVE-eEXSqPjbqpJ573=A@mail.gmail.com>
References: <54a83a19$0$6953$e4fe514c@dreader36.news.xs4all.nl>
 <CANNmrNZAH0gbk=UQgmXDRpPcs21tD0yVE-eEXSqPjbqpJ573=A@mail.gmail.com>
Message-ID: <CANNmrNYzmcyFzPTt+Ps1wGf=JKghSS2_jYtEbuHEROh_pBaEfg@mail.gmail.com>

Hi my friends.

On last result you have  a , b , c  binary.

>> set('abc')
{'a','b','c')
>> set(b'abc')
{97,98,99}
On Jan 3, 2015 10:25 PM, "patrick vrijlandt" <pvrijlandt at gmail.com> wrote:

> Hello list,
>
> Let me first wish you all the best in 2015!
>
> Today I was trying to test for occurrence of a byte in a set ...
>
> >>> sys.version
> '3.4.2 (v3.4.2:ab2c023a9432, Oct  6 2014, 22:15:05) [MSC v.1600 32 bit
> (Intel)]'
> >>> 'b' in 'abc'
> True
> >>> b'b' in b'abc'
> True
> >>> 'b' in set('abc')
> True
> >>> b'b' in set(b'abc')
> False
>
> I was surprised by the last result. What happened?
> (Examples simplified; I was planning to manipulate the set)
>
> Patrick
>
> ---
> Dit e-mailbericht is gecontroleerd op virussen met Avast antivirussoftware.
> http://www.avast.com
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>
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From jsf80238 at gmail.com  Sat Jan  3 14:12:46 2015
From: jsf80238 at gmail.com (Jason Friedman)
Date: Sat, 3 Jan 2015 12:12:46 -0700
Subject: surprise - byte in set
In-Reply-To: <54a83a19$0$6953$e4fe514c@dreader36.news.xs4all.nl>
References: <54a83a19$0$6953$e4fe514c@dreader36.news.xs4all.nl>
Message-ID: <CANy1k1hTf7Rd_NSc5SQgWFHNmsay9SdVtTk7Z+zWVD6maZ_fiA@mail.gmail.com>

>>>> sys.version
> '3.4.2 (v3.4.2:ab2c023a9432, Oct  6 2014, 22:15:05) [MSC v.1600 32 bit
> (Intel)]'
>>>> 'b' in 'abc'
> True
>>>> b'b' in b'abc'
> True
>>>> 'b' in set('abc')
> True
>>>> b'b' in set(b'abc')
> False
>
> I was surprised by the last result. What happened?
> (Examples simplified; I was planning to manipulate the set)

I'm no expert, but I see:

>>> for i in set(b'abc'):
...     print(type(i))
...
<class 'int'>
<class 'int'>
<class 'int'>


From drsalists at gmail.com  Sat Jan  3 14:15:17 2015
From: drsalists at gmail.com (Dan Stromberg)
Date: Sat, 3 Jan 2015 11:15:17 -0800
Subject: surprise - byte in set
In-Reply-To: <54a83a19$0$6953$e4fe514c@dreader36.news.xs4all.nl>
References: <54a83a19$0$6953$e4fe514c@dreader36.news.xs4all.nl>
Message-ID: <CAGGBd_oNvtthbZG7CJ=t=pedvbjhQdi7T6jrTpZdBiOyvQ-NxA@mail.gmail.com>

On Sat, Jan 3, 2015 at 10:50 AM, patrick vrijlandt <pvrijlandt at gmail.com> wrote:
> Hello list,
>
> Let me first wish you all the best in 2015!
>
> Today I was trying to test for occurrence of a byte in a set ...


In the last case, the set has integers in it.

Try:
b'b'[0] in set(b'abc')


From john at wexfordpress.com  Sat Jan  3 14:23:27 2015
From: john at wexfordpress.com (John Culleton)
Date: Sat, 3 Jan 2015 11:23:27 -0800 (PST)
Subject: Put float number in message.
Message-ID: <4e62c96c-aa5f-43fd-ba67-c147c5ef0b96@googlegroups.com>

Here is my last line in a simple program that is a scribus script.
end = scribus.messageBox('Book Spine Width', 'dummy', ICON_WARNING, BUTTON_OK)

This works. Now I want to put a float number called S instead of 'dummy'.
If I just put S in the command I get an error. If I convert S to a string with
SS = str(S)
first and then 
and substitute SS for 'dummy' I get what appears to be the ASCII numbers representing the characters, not the characters I want. 

I am a total newbie with Python. Anyone have a suggestion? Can I use a print command instead?

John Culleton 


From gherron at digipen.edu  Sat Jan  3 15:05:49 2015
From: gherron at digipen.edu (Gary Herron)
Date: Sat, 03 Jan 2015 12:05:49 -0800
Subject: surprise - byte in set
In-Reply-To: <54a83a19$0$6953$e4fe514c@dreader36.news.xs4all.nl>
References: <54a83a19$0$6953$e4fe514c@dreader36.news.xs4all.nl>
Message-ID: <54A84B9D.7050808@digipen.edu>

On 01/03/2015 10:50 AM, patrick vrijlandt wrote:
> Hello list,
>
> Let me first wish you all the best in 2015!
>
> Today I was trying to test for occurrence of a byte in a set ...
>
> >>> sys.version
> '3.4.2 (v3.4.2:ab2c023a9432, Oct  6 2014, 22:15:05) [MSC v.1600 32 bit 
> (Intel)]'
> >>> 'b' in 'abc'
> True
> >>> b'b' in b'abc'
> True
> >>> 'b' in set('abc')
> True
> >>> b'b' in set(b'abc')
> False
>
> I was surprised by the last result. What happened?
> (Examples simplified; I was planning to manipulate the set)

The surprise is really that the 3rd test is True not that the fourth is 
False.

First, as should be expected, a byte string is a sequence of (small) 
ints.  So b'b' is a (short) byte string and the set set(b'abc') is 
composed of three ints.  You should not expect your inclusion test to 
return True when testing for a bytes-type object in a set of int-type 
objects.  And that explains your False result in the 4th test.

 >>> type(b'abc')
<class 'bytes'>
 >>> type(b'abc'[0])
<class 'int'>


But things are different for strings.  You might think a string is a 
sequence of characters, but Python does not have a character type. In 
fact the elements of a string are just 1 char long strings:

 >>> type('abc')
<class 'str'>
 >>> type('abc'[0])
<class 'str'>

You would not logically expect to find a string 'b' in a set of 
characters in, say C++,  where the two types are different.  But that's 
not the Python way.  In Python a set of characters set('abc') is really 
a set of (short) strings, and the character 'b' is really a (short) 
string, so the inclusion test works.

Python's way of returning a 1-byte string when indexing a string 
(instead of returning an element of type character) allows this 
surprising result.

 >>> 'abc'[0]
'a'
 >>> 'abc'[0][0]
'a'
 >>> 'abc'[0][0][0]
'a'
 >>> 'abc'[0][0][0][0]
'a'
...


I've never considered this a problem, but a infinitely indexable object 
*is* a bit of an oddity.




>
> Patrick
>
> ---
> Dit e-mailbericht is gecontroleerd op virussen met Avast 
> antivirussoftware.
> http://www.avast.com
>


-- 
Dr. Gary Herron
Department of Computer Science
DigiPen Institute of Technology
(425) 895-4418



From ravas at outlook.com  Sat Jan  3 15:28:07 2015
From: ravas at outlook.com (ravas)
Date: Sat, 3 Jan 2015 12:28:07 -0800 (PST)
Subject: apostrophe not considered with tkinter's wordstart and wordend
Message-ID: <e6143cd5-3475-431a-b2cf-17fd9659681c@googlegroups.com>

When I place my mouse over a word (and I press something) 
I want the program to analyze the word.
Tkinter almost provides the perfect option:
self.text.get('current wordstart', 'current wordend')

Unfortunately apostrophes are not considered using wordstart and wordend.
http://infohost.nmt.edu/tcc/help/pubs/tkinter/
Says: 
"For the purposes of this operation, a word is either 
a string of consecutive letter, digit, or underbar (_) characters, 
or a single character that is none of these types."

The easy work around is to highlight the word and use:
self.text.get('sel.first', 'sel.last')

However, it seems like it could be an easy improvement 
if we could include the apostrophe in the list of word characters.
Is it possible that this could be added in an upcoming version of Python -- 
or is this a Tk issue?

----
Windows 7 & Python 3.4


From breamoreboy at yahoo.co.uk  Sat Jan  3 15:32:38 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 03 Jan 2015 20:32:38 +0000
Subject: Put float number in message.
In-Reply-To: <4e62c96c-aa5f-43fd-ba67-c147c5ef0b96@googlegroups.com>
References: <4e62c96c-aa5f-43fd-ba67-c147c5ef0b96@googlegroups.com>
Message-ID: <m89jl9$ujv$1@ger.gmane.org>

On 03/01/2015 19:23, John Culleton wrote:
> Here is my last line in a simple program that is a scribus script.
> end = scribus.messageBox('Book Spine Width', 'dummy', ICON_WARNING, BUTTON_OK)
>
> This works. Now I want to put a float number called S instead of 'dummy'.
> If I just put S in the command I get an error. If I convert S to a string with
> SS = str(S)
> first and then
> and substitute SS for 'dummy' I get what appears to be the ASCII numbers representing the characters, not the characters I want.
>
> I am a total newbie with Python. Anyone have a suggestion? Can I use a print command instead?
>
> John Culleton
>

I think you just want some string formatting so (untested) either

end = scribus.messageBox('Book Spine Width', '{}'.format(S), 
ICON_WARNING, BUTTON_OK)

or

end = scribus.messageBox('Book Spine Width', '%f' % S, ICON_WARNING, 
BUTTON_OK)

For all the formatting options see 
https://docs.python.org/3/library/string.html#string-formatting or 
https://docs.python.org/3/library/stdtypes.html#old-string-formatting 
respectively.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From __peter__ at web.de  Sat Jan  3 16:06:22 2015
From: __peter__ at web.de (Peter Otten)
Date: Sat, 03 Jan 2015 22:06:22 +0100
Subject: apostrophe not considered with tkinter's wordstart and wordend
References: <e6143cd5-3475-431a-b2cf-17fd9659681c@googlegroups.com>
Message-ID: <m89lke$nb1$1@ger.gmane.org>

ravas wrote:

> When I place my mouse over a word (and I press something)
> I want the program to analyze the word.
> Tkinter almost provides the perfect option:
> self.text.get('current wordstart', 'current wordend')
> 
> Unfortunately apostrophes are not considered using wordstart and wordend.
> http://infohost.nmt.edu/tcc/help/pubs/tkinter/
> Says:
> "For the purposes of this operation, a word is either
> a string of consecutive letter, digit, or underbar (_) characters,
> or a single character that is none of these types."
> 
> The easy work around is to highlight the word and use:
> self.text.get('sel.first', 'sel.last')
> 
> However, it seems like it could be an easy improvement
> if we could include the apostrophe in the list of word characters.
> Is it possible that this could be added in an upcoming version of Python
> -- or is this a Tk issue?

I think it is.

<http://www.tcl.tk/man/tcl8.6/TkCmd/text.htm#M41> does not mention a way to 
configure the set of word chars either:

"""
?submodifier? wordstart
Adjust the index to refer to the first character of the word containing the 
current index. A word consists of any number of adjacent characters that are 
letters, digits, or underscores, or a single character that is not one of 
these. If the display submodifier is given, this only examines non-elided 
characters, otherwise all characters (elided or not) are examined.
"""




From tjreedy at udel.edu  Sat Jan  3 16:57:34 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Sat, 03 Jan 2015 16:57:34 -0500
Subject: Python Tk Tix GUI documentation & builder overview and tips
In-Reply-To: <5373bac1-9d1b-4468-adb8-361240afef92@googlegroups.com>
References: <e92d6639-28e4-4b58-83f3-fa1e88a186db@k2g2000yql.googlegroups.com>
 <5373bac1-9d1b-4468-adb8-361240afef92@googlegroups.com>
Message-ID: <m89okp$55e$1@ger.gmane.org>

On 1/3/2015 1:30 PM, abaskm at gmail.com wrote:
> Hi,
>
> I have had issues running Tix on python 2.7.6 and 3.4.2:
>
> More details on the issue here.
>
> http://stackoverflow.com/questions/27751923/tix-widgets-installation-issue
>
> Has anyone had similar issues with Tix?

The current doc is wrong in any case.  I opened
http://bugs.python.org/issue23156

-- 
Terry Jan Reedy



From pvrijlandt at gmail.com  Sat Jan  3 17:08:52 2015
From: pvrijlandt at gmail.com (patrick vrijlandt)
Date: Sat, 03 Jan 2015 23:08:52 +0100
Subject: surprise - byte in set
In-Reply-To: <54a83a19$0$6953$e4fe514c@dreader36.news.xs4all.nl>
References: <54a83a19$0$6953$e4fe514c@dreader36.news.xs4all.nl>
Message-ID: <54a8687d$0$15822$e4fe514c@dreader35.news.xs4all.nl>

Dear all,

Many thanks for your responses. I never realised this difference between 
'bytes' and 'string'.

Thanks,

Patrick

---
Dit e-mailbericht is gecontroleerd op virussen met Avast antivirussoftware.
http://www.avast.com



From johnhpote at o2.co.uk  Sat Jan  3 17:54:33 2015
From: johnhpote at o2.co.uk (John Pote)
Date: Sat, 03 Jan 2015 22:54:33 +0000
Subject: Enumerating loggers iin logging module
In-Reply-To: <CAPTjJmqvpr7uR8E8cNuwmPM3owuqs_iddun9OoOFKWNDDaus_Q@mail.gmail.com>
References: <54A2F215.6000409@jptechnical.co.uk>
 <20141230152444.4a82da38@bigbox.christie.dr>
 <CAPTjJmqvpr7uR8E8cNuwmPM3owuqs_iddun9OoOFKWNDDaus_Q@mail.gmail.com>
Message-ID: <54A87329.9070600@o2.co.uk>

Thanks for the replies, thought there'd be a simple answer. Much 
appreciated.
John

On 30/12/2014 22:40, Chris Angelico wrote:
> On Wed, Dec 31, 2014 at 8:24 AM, Tim Chase
> <python.list at tim.thechases.com> wrote:
>> While it may involve reaching into the objects may or may not be
>> blessed, the following seems to work for me in Py2.7:
>>
>>    >>> import logging
>>    >>> # add a bunch of loggers and sub-loggers
>>    >>> print logging.Logger.manager.loggerDict.keys()
> Works in 3.5, too, aside from trivialities:
>
> $ python3
> Python 3.5.0a0 (default:1c51f1650c42+, Dec 29 2014, 02:29:06)
> [GCC 4.7.2] on linux
> Type "help", "copyright", "credits" or "license" for more information.
>>>> import logging
>>>> logging.getLogger("Name")
> <logging.Logger object at 0x7f8dcc339be0>
>>>> logging.getLogger("name.sublogger")
> <logging.Logger object at 0x7f8dcc339ba8>
>>>> logging.Logger.manager.loggerDict
> {'name.sublogger': <logging.Logger object at 0x7f8dcc339ba8>, 'Name':
> <logging.Logger object at 0x7f8dcc339be0>, 'name':
> <logging.PlaceHolder object at 0x7f8dcc33ebe0>}
>
> I'd say this is fine for debugging with.
>
> ChrisA



From torriem at gmail.com  Sat Jan  3 18:06:07 2015
From: torriem at gmail.com (Michael Torrie)
Date: Sat, 03 Jan 2015 16:06:07 -0700
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <fda3c983-e336-4f81-870f-bd03c7ef15db@googlegroups.com>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
 <9d2a330f-eaf8-4943-a246-d143b1b773ca@googlegroups.com>
 <9ade6cb4-6a78-4ebb-8104-83dbf1916482@googlegroups.com>
 <b5c4b11c-068b-4d8f-9fe7-c5eda1b44034@googlegroups.com>
 <fda3c983-e336-4f81-870f-bd03c7ef15db@googlegroups.com>
Message-ID: <54A875DF.2020004@gmail.com>

On 01/03/2015 10:11 AM, Andr? Roberge wrote:
> Would you care to elaborate?  All the code I have written works
> correctly on all the tests I have done.  I do have reports from a
> user using a Mac with Python 2.7 for which some widgets did not quite
> work properly ... but that's all I have heard about problems with it.
> 
> 
> I would like to hear about the problems you know about either here,
> on by filing an issue at
> https://github.com/aroberge/easygui_qt/issues

It's not clear to me that jmf even understands what easygui is intended
to do.  So I wouldn't worry too much about what he says.  So I'd just
ignore what he has to say.  If someone needs a full event-driven GUI,
they can use an appropriate toolkit.  For quick and dirty little
utilities I can see how easygui fits the bill, and being Qt-based is
good news.

By the way, I'm not seeing jmf's emails; I think they are being filtered
at the mailing list level.  I think enough people got tired of his
trolling that they banned him, though on USENET he's still getting through.


From eshikafe at gmail.com  Sat Jan  3 18:19:24 2015
From: eshikafe at gmail.com (austin aigbe)
Date: Sat, 3 Jan 2015 15:19:24 -0800 (PST)
Subject: list comparison vs integer comparison, which is more efficient?
Message-ID: <d27586b9-017a-4519-a6bb-e0a1fac005d0@googlegroups.com>

Hi,

I am currently implementing the LTE physical layer in Python (ver 2.7.7).
For the qpsk, 16qam and 64qam modulation I would like to know which is more efficient to use, between an integer comparison and a list comparison:

Integer comparison: bit_pair as an integer value before comparison

    # QPSK - TS 36.211 V12.2.0, section 7.1.2, Table 7.1.2-1
    def mp_qpsk(self):
        r = []
        for i in range(self.nbits/2):
            bit_pair = (self.sbits[i*2] << 1) | self.sbits[i*2+1] 
            if bit_pair == 0:
                r.append(complex(1/math.sqrt(2),1/math.sqrt(2)))
            elif bit_pair == 1:
                r.append(complex(1/math.sqrt(2),-1/math.sqrt(2)))
            elif bit_pair == 2:
                r.append(complex(-1/math.sqrt(2),1/math.sqrt(2)))
            elif bit_pair == 3:
                r.append(complex(-1/math.sqrt(2),-1/math.sqrt(2)))
        return r

List comparison: bit_pair as a list before comparison

    # QPSK - TS 36.211 V12.2.0, section 7.1.2, Table 7.1.2-1
    def mp_qpsk(self):
        r = []
        for i in range(self.nbits/2):
            bit_pair = self.sbits[i*2:i*2+2] 
            if bit_pair == [0,0]:
                r.append(complex(1/math.sqrt(2),1/math.sqrt(2)))
            elif bit_pair == [0,1]:
                r.append(complex(1/math.sqrt(2),-1/math.sqrt(2)))
            elif bit_pair == [1,0]:
                r.append(complex(-1/math.sqrt(2),1/math.sqrt(2)))
            elif bit_pair == [1,1]:
                r.append(complex(-1/math.sqrt(2),-1/math.sqrt(2)))
        return r

Thanks


From rosuav at gmail.com  Sat Jan  3 18:40:07 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 4 Jan 2015 10:40:07 +1100
Subject: list comparison vs integer comparison, which is more efficient?
In-Reply-To: <d27586b9-017a-4519-a6bb-e0a1fac005d0@googlegroups.com>
References: <d27586b9-017a-4519-a6bb-e0a1fac005d0@googlegroups.com>
Message-ID: <CAPTjJmrXhYq0CXSLzJCX5-y5rtDH7oPYtktzwO2Sr5fSz5v=SQ@mail.gmail.com>

On Sun, Jan 4, 2015 at 10:19 AM, austin aigbe <eshikafe at gmail.com> wrote:
> I would like to know which is more efficient to use, between an integer comparison and a list comparison:

You can test them with the timeit module, but my personal suspicion is
that any difference between them will be utterly and completely
dwarfed by all your sqrt(2) calls in the complex constructors. If you
break those out, and use a tuple instead of a list, you could write
this very simply and tidily:

    bits = {
        (0,0): complex(1/math.sqrt(2),1/math.sqrt(2)),
        (0,1): complex(1/math.sqrt(2),-1/math.sqrt(2)),
        (1,0): complex(-1/math.sqrt(2),1/math.sqrt(2)),
        (1,1): complex(-1/math.sqrt(2),-1/math.sqrt(2)),
    }
    # QPSK - TS 36.211 V12.2.0, section 7.1.2, Table 7.1.2-1
    def mp_qpsk(self):
        r = []
        for i in range(self.nbits/2):
            bit_pair = self.sbits[i*2:i*2+2]
            r.append(bits[tuple(bit_pair)])
        return r

At this point, your loop looks very much like a list comprehension in
full form, so you can make a simple conversion:

# From itertools recipes
# https://docs.python.org/3/library/itertools.html
def pairwise(iterable):
    "s -> (s0,s1), (s1,s2), (s2, s3), ..."
    a, b = tee(iterable)
    next(b, None)
    return zip(a, b)
# Replace zip() with izip() for the Python 2 equivalent.

    def mp_qpsk(self):
        return [bits[pair] for pair in pairwise(self.sbits)]

How's that look? I don't care if it's faster or not, I prefer this form :)

ChrisA


From thomas.f.hahn2 at gmail.com  Sat Jan  3 22:14:47 2015
From: thomas.f.hahn2 at gmail.com (thomas hahn)
Date: Sat, 3 Jan 2015 21:14:47 -0600
Subject: Help with finding tutors for Python, Linux, R, Perl, Octave, MATLAB
 and/or Cytoscape for yeast microarray analysis, next generation sequencing
 and constructing gene interaction networks
Message-ID: <CAKJ67ZVNcSNHY0ors+DGrNBnao4wf8V5fdqe=tXZdgOOt60TXQ@mail.gmail.com>

??

*Help with finding tutors for Python, Linux, R, Perl, Octave, MATLAB and/or
Cytoscape for yeast microarray analysis, next generation sequencing and
constructing gene interaction networks*



Hi



I am a visually impaired bioinformatics graduate student using microarray
data for my master?s thesis aimed at deciphering the mechanism by which the
yeast wild type can suppress the rise of free reactive oxygen species (ROS)
induced by caloric restriction (CR) but the Atg15 and Erg6 knockout mutant
cannot.



Since my remaining vision is very limited I need very high magnification.
But that makes my visual field very small.  Therefore I need somebody to
teach me how to use these programming environments, especially for
microarray analysis, next generation sequencing and constructing gene and
pathway interaction networks.  This is very difficult for me to figure out
without assistance because Zoomtext, my magnification and text to speech
software, on which I am depending because I am almost blind, has problems
reading out aloud many programming related websites to me.  And even those
websites it can read, it can only read sequentially from left to right and
then from top to bottom.  Unfortunately, this way of acquiring, finding,
selecting and processing new information and answering questions is too
tiresome, exhausting, ineffective and especially way too time consuming for
graduating with a PhD in bioinformatics before my funding runs out despite
being severely limited by my visual disability.  I would also need help
with writing a good literature review and applying the described techniques
to my own yeast Affimetrix microarray dataset because I cannot see well
enough to find all relevant publications on my own.



Some examples for specific tasks I urgently need help with are:



1.    Analyzing and comparing the three publically available microarray
datasets that can be accessed at:

A.    http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE41860

B.    http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE38635

C.   http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE9217



2.    Learning how to use the Affymetrics microarray analysis software for
the Yeast 2 chip, which can be found at
http://www.affymetrix.com/support/technical/libraryfilesmain.affx



3.    For Cytoscape I need somebody, who can teach me how to execute the
tutorials at the following links because due to my very limited vision
field I cannot see tutorial and program interface simultaneously.

A.
http://opentutorials.cgl.ucsf.edu/index.php/Tutorial:Introduction_to_Cytoscape_3.1-part2#Importing_and_Exploring_Your_Data

B.
http://opentutorials.cgl.ucsf.edu/index.php/Tutorial:Filtering_and_Editing_in_Cytoscape_3

C.
http://cytoscape.org/manual/Cytoscape2_8Manual.html#Import%20Fixed-Format%20Network%20Files

D.   http://wiki.cytoscape.org/Cytoscape_User_Manual/Network_Formats



4.    Learning how to use the TopGo R package to perform statistical
analysis on GO enrichments.



Since I am legally blind the rehab agency is giving me money to pay tutors
for this purpose.  Could you please help me getting in touch regarding this
with anybody, who could potentially be interested in teaching me one on one
thus saving me time for acquiring new information and skills, which I need
to finish my thesis on time, so that I can remain eligible for funding to
continue in my bioinformatics PhD program despite being almost blind?  The
tutoring can be done remotely via TeamViewer 5 and Skype.  Hence, it does
not matter where my tutors are physically located.  Currently I have tutors
in Croatia and UK.  But since they both work full time jobs while working
on their PhD dissertation they only have very limited time to teach me
online.  Could you therefore please forward this request for help to
anybody, who could potentially be interested or, who could connect me to
somebody, who might be, because my graduation and career depend on it?  Who
else would you recommend me to contact regarding this?  Where else could I
post this because I am in urgent need for help?



Could you please contact me directly via email at Thomas.F.Hahn2 at gmail.com
and/or Skype at tfh002 because my text to speech software has problems to
read out this website aloud to me?

I thank you very much in advance for your thoughts, ideas, suggestions,
recommendations, time, help, efforts and support.

With very warm regards,



*Thomas Hahn*

1)    *Graduate student in the Joint Bioinformatics Program at the
University of Arkansas at Little Rock (UALR) and the University of Arkansas
Medical Sciences (UAMS) &*

2)    *Research & Industry Advocate, Founder and Board Member of RADISH
MEDICAL SOLUTIONS, INC. (**http://www.radishmedical.com/thomas-hahn/*
<http://www.radishmedical.com/thomas-hahn/>*) *



*Primary email: **Thomas.F.Hahn2 at gmail.com* <Thomas.F.Hahn2 at gmail.com>

*Cell phone: 318 243 3940*

*Office phone: 501 682 1440*

*Office location: EIT 535*

*Skype ID: tfh002*

*Virtual Google Voice phone to reach me while logged into my email (i.e. *
*Thomas.F.Hahn2 at gmail.com* <Thomas.F.Hahn2 at gmail.com>*), even when having
no cell phone reception, e.g. in big massive buildings:  *(501) 301-4890
<%28501%29%20301-4890>



*Web links: *



1)      https://ualr.academia.edu/ThomasHahn

2)      https://www.linkedin.com/pub/thomas-hahn/42/b29/42

3)      http://facebook.com/Thomas.F.Hahn
<https://www.facebook.com/Thomas.F.Hahn>

4)      https://twitter.com/Thomas_F_Hahn
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From rustompmody at gmail.com  Sat Jan  3 22:45:41 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Sat, 3 Jan 2015 19:45:41 -0800 (PST)
Subject: Help with finding tutors for Python, Linux, R, Perl, Octave,
 MATLAB and/or Cytoscape for yeast microarray analysis, next generation
 sequencing and constructing gene interaction networks
In-Reply-To: <mailman.17364.1420341295.18130.python-list@python.org>
References: <mailman.17364.1420341295.18130.python-list@python.org>
Message-ID: <00573ecf-0a7e-4493-9af8-a1edf8d69316@googlegroups.com>

On Sunday, January 4, 2015 8:45:08 AM UTC+5:30, thomas hahn wrote:
> 
> 
> 
> 
> Help with finding tutors
> for Python, Linux, R, Perl, Octave, MATLAB and/or Cytoscape for yeast microarray
> analysis, next generation sequencing and constructing gene interaction networks

Hi Thomas

This is a reasonably friendly and generally knowledgeable place for python related questions.
Feel free to ask your questions here.

If you need help starting programming and python is your chosen medium
there is also a tutors list
https://mail.python.org/mailman/listinfo/tutor.

As for the rest...

Have a vague idea what yeast is
None whatever of cytospace
And probably think a 'microarray' other than what you do

[That was a joke. More seriously...]
Specialized areas of application of python are less likely to find help out here

That being the case, starting out with python needs a focussed approach
- Spend a few days getting into python
- Then worry about applying it to your needs

In your case you are not just starting python
but python perl R octave mathlab linux
In this manner you are setting yourself up for failure unless you have enough money to
hire people for all your programming work.

I can tell you that python ecosystem can offer most of what perl, R, octave mathlab offer. But for that you have to go beyond core python to things like
scipy, pandas etc.

Fans of perl, R, octave, mathlab will tell you the same for these as well....

You may want to start by throwing a 5-sided coin.

Best wishes on your studies

Rusi


From tjreedy at udel.edu  Sun Jan  4 02:10:41 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Sun, 04 Jan 2015 02:10:41 -0500
Subject: list comparison vs integer comparison, which is more efficient?
In-Reply-To: <d27586b9-017a-4519-a6bb-e0a1fac005d0@googlegroups.com>
References: <d27586b9-017a-4519-a6bb-e0a1fac005d0@googlegroups.com>
Message-ID: <m8ap1s$cug$1@ger.gmane.org>

On 1/3/2015 6:19 PM, austin aigbe wrote:

> I am currently implementing the LTE physical layer in Python (ver 2.7.7).
> For the qpsk, 16qam and 64qam modulation I would like to know which is more efficient to use, between an integer comparison and a list comparison:
>
> Integer comparison: bit_pair as an integer value before comparison
>
>      # QPSK - TS 36.211 V12.2.0, section 7.1.2, Table 7.1.2-1
>      def mp_qpsk(self):
>          r = []
>          for i in range(self.nbits/2):
>              bit_pair = (self.sbits[i*2] << 1) | self.sbits[i*2+1]
>              if bit_pair == 0:
>                  r.append(complex(1/math.sqrt(2),1/math.sqrt(2)))
>              elif bit_pair == 1:
>                  r.append(complex(1/math.sqrt(2),-1/math.sqrt(2)))
>              elif bit_pair == 2:
>                  r.append(complex(-1/math.sqrt(2),1/math.sqrt(2)))
>              elif bit_pair == 3:
>                  r.append(complex(-1/math.sqrt(2),-1/math.sqrt(2)))
>          return r
>
> List comparison: bit_pair as a list before comparison
>
>      # QPSK - TS 36.211 V12.2.0, section 7.1.2, Table 7.1.2-1
>      def mp_qpsk(self):
>          r = []
>          for i in range(self.nbits/2):
>              bit_pair = self.sbits[i*2:i*2+2]
>              if bit_pair == [0,0]:
>                  r.append()
>              elif bit_pair == [0,1]:
>                  r.append(complex(1/math.sqrt(2),-1/math.sqrt(2)))
>              elif bit_pair == [1,0]:
>                  r.append(complex(-1/math.sqrt(2),1/math.sqrt(2)))
>              elif bit_pair == [1,1]:
>                  r.append(complex(-1/math.sqrt(2),-1/math.sqrt(2)))
>          return r

Wrong question.  If you are worried about efficiency, factor out all 
repeated calculation of constants and eliminate the multiple comparisons.

sbits = self.sbits
a = 1.0 / math.sqrt(2)
b = -a
points = (complex(a,a), complex(a,b), complex(b,a), complex(b,b))
     complex(math.sqrt(2),1/math.sqrt(2))
def mp_qpsk(self):
     r = [points[sbits[i]*2 + sbits[i+1]]
         for i in range(0, self.nbits, 2)]
     return r

-- 
Terry Jan Reedy



From wxjmfauth at gmail.com  Sun Jan  4 03:12:52 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Sun, 4 Jan 2015 00:12:52 -0800 (PST)
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <fda3c983-e336-4f81-870f-bd03c7ef15db@googlegroups.com>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
 <9d2a330f-eaf8-4943-a246-d143b1b773ca@googlegroups.com>
 <9ade6cb4-6a78-4ebb-8104-83dbf1916482@googlegroups.com>
 <b5c4b11c-068b-4d8f-9fe7-c5eda1b44034@googlegroups.com>
 <fda3c983-e336-4f81-870f-bd03c7ef15db@googlegroups.com>
Message-ID: <03f6f7b0-df2e-4291-adff-793e0be14a10@googlegroups.com>

Le samedi 3 janvier 2015 18:11:22 UTC+1, Andr? Roberge a ?crit?:
> On Saturday, 3 January 2015 04:52:21 UTC-4, wxjm... at gmail.com  wrote:
> > Le vendredi 2 janvier 2015 20:11:25 UTC+1, Andr? Roberge a ?crit?:
> > > On Friday, 2 January 2015 06:29:37 UTC-4, wxjm... at gmail.com  wrote:
> > > > Le mercredi 31 d?cembre 2014 23:24:50 UTC+1, Andr? Roberge a ?crit?:
> > > > > EasyGUI_Qt version 0.9 has been released.  This is the first announcement about EasyGUI_Qt on this list.
> > > snip
> > > > I toyed and I spent a couple of hours with it.
> > > > I do not know to much what to say.
> > > Well, this is more positive than your previous comment expressing doubt that it would work. ;-)   So, thank you!
> > 
> > Do not get me wrong, I do not wish to be rude.
> > You are building a tool upon a toolkit which
> > simply does not work properly.
> > 
> > If for some reason you are not aware of this,
> > you are not aware of this, it is unfortunately
> > a simple as this.
> > 
> > (Not only I know why, I'm able to explain the
> > cause).
> 
> Would you care to elaborate?  All the code I have written works correctly on all the tests I have done.  I do have reports from a user using a Mac with Python 2.7 for which some widgets did not quite work properly ... but that's all I have heard about problems with it. 
> 
> I would like to hear about the problems you know about either here, on by filing an issue at https://github.com/aroberge/easygui_qt/issues
> > 

The Qt wrappers (PySide, PyQt4, PyQt5) for Py32 works
very smoothly. With the newer versions problems are
expected (and appear).

In a similar way, LibreOffice is also not working.



From auriocus at gmx.de  Sun Jan  4 03:23:10 2015
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Sun, 04 Jan 2015 09:23:10 +0100
Subject: Python Tk Tix GUI documentation & builder overview and tips
In-Reply-To: <mailman.17360.1420322282.18130.python-list@python.org>
References: <e92d6639-28e4-4b58-83f3-fa1e88a186db@k2g2000yql.googlegroups.com>
 <5373bac1-9d1b-4468-adb8-361240afef92@googlegroups.com>
 <mailman.17360.1420322282.18130.python-list@python.org>
Message-ID: <m8at8k$g39$1@dont-email.me>

Am 03.01.15 um 22:57 schrieb Terry Reedy:
> On 1/3/2015 1:30 PM, abaskm at gmail.com wrote:
>> Hi,
>>
>> I have had issues running Tix on python 2.7.6 and 3.4.2:
>>
>> More details on the issue here.
>>
>> http://stackoverflow.com/questions/27751923/tix-widgets-installation-issue
>>
>> Has anyone had similar issues with Tix?
>
> The current doc is wrong in any case.  I opened
> http://bugs.python.org/issue23156
>

Tix is a compiled extension, so this tix8.4.3.dll is needed as well as a 
couple of .tcl file including pkgIndex.tcl, which makes the package 
available to the Tcl interpreter. tix*.dll was never part of tk*.dll.

Note that Tix is LEGACY. There are much better options for its widgets 
available that are based on ttk. Just to try, I compiled Tix under OSX 
for my Tk8.6.3 and ran the widget demos.

Instead of

* Hierarchical Listbox use ttk::treeview, tablelist_tile or tkTreeCtrl, 
with increasing order of capabilities and install complexity

* TList: I think tkTreeCtrl can do it, never have used this layout

* CheckList: tablelist can be used with an editable field

* Grid widget: use tkTable

* NoteBook, PanedWindow, ComboBox, LabelFrame -> ttk::notebook, 
ttk::panedwindow, ttk::combobox, ttk::labelframe

* Balloon: tcllib::tooltip

Not to mention that the Tix widgets are extremely ugly, while the 
widgets from ttk have a near-native look and feel.

Caveat emptor: I've never used Tix, so this is just my impression as an 
experienced Tk programmer from running the widget demo

	Christian



From wxjmfauth at gmail.com  Sun Jan  4 04:32:10 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Sun, 4 Jan 2015 01:32:10 -0800 (PST)
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <mailman.17353.1420306762.18130.python-list@python.org>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
 <9d2a330f-eaf8-4943-a246-d143b1b773ca@googlegroups.com>
 <9ade6cb4-6a78-4ebb-8104-83dbf1916482@googlegroups.com>
 <b5c4b11c-068b-4d8f-9fe7-c5eda1b44034@googlegroups.com>
 <fda3c983-e336-4f81-870f-bd03c7ef15db@googlegroups.com>
 <mailman.17353.1420306762.18130.python-list@python.org>
Message-ID: <1e9a000b-efe2-4d85-a895-93b8786fecec@googlegroups.com>

Le samedi 3 janvier 2015 18:39:32 UTC+1, Mark Lawrence a ?crit?:
> On 03/01/2015 17:11, Andr? Roberge wrote:
> > On Saturday, 3 January 2015 04:52:21 UTC-4, wxjm... at gmail.com  wrote:
> >> Le vendredi 2 janvier 2015 20:11:25 UTC+1, Andr? Roberge a ?crit :
> >>> On Friday, 2 January 2015 06:29:37 UTC-4, wxjm... at gmail.com  wrote:
> >>>> Le mercredi 31 d?cembre 2014 23:24:50 UTC+1, Andr? Roberge a ?crit :
> >>>>> EasyGUI_Qt version 0.9 has been released.  This is the first announcement about EasyGUI_Qt on this list.
> >>> snip
> >>>> I toyed and I spent a couple of hours with it.
> >>>> I do not know to much what to say.
> >>> Well, this is more positive than your previous comment expressing doubt that it would work. ;-)   So, thank you!
> >>
> >> Do not get me wrong, I do not wish to be rude.
> >> You are building a tool upon a toolkit which
> >> simply does not work properly.
> >>
> >> If for some reason you are not aware of this,
> >> you are not aware of this, it is unfortunately
> >> a simple as this.
> >>
> >> (Not only I know why, I'm able to explain the
> >> cause).
> >
> > Would you care to elaborate?  All the code I have written works correctly on all the tests I have done.  I do have reports from a user using a Mac with Python 2.7 for which some widgets did not quite work properly ... but that's all I have heard about problems with it.
> >
> > I would like to hear about the problems you know about either here, on by filing an issue at https://github.com/aroberge/easygui_qt/issues
> >>
> >> jmf
> 
> I hope you know that you're engaging with a person who makes statements 
> about the inadequacies of various tools, but when challenged to provide 
> evidence to support his claims he can never do so.  He is our "Resident 
> Unicode Expert", in other words when it comes to Unicode he hasn't got 
> the faintest idea what he's talking about, at least with respect to PEP 
> 393 and the Flexible String Representation.  Please ignore him as he's 
> just not worth the effort.
> 
> -- 
> My fellow Pythonistas, ask not what our language can do for you, ask
> what you can do for our language.

Related to the subject.
I suggest you recommend "Qt" to use it. I will
certainly not do it.
At least, try to put MvL and PT in touch.

jmf


From python-ro-bounces at python.org  Sun Jan  4 06:08:16 2015
From: python-ro-bounces at python.org (python-ro-bounces at python.org)
Date: Sun, 04 Jan 2015 12:08:16 +0100
Subject: Forward of moderated message
Message-ID: <mailman.0.1420369696.19149.python-ro@python.org>

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Subject: Help with finding tutors for Python, Linux, R, Perl, Octave, MATLAB and/or Cytoscape for yeast microarray analysis, next generation sequencing and constructing gene interaction networks
Date: Sat, 3 Jan 2015 21:17:35 -0600
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From eshikafe at gmail.com  Sun Jan  4 06:20:09 2015
From: eshikafe at gmail.com (austin aigbe)
Date: Sun, 4 Jan 2015 03:20:09 -0800 (PST)
Subject: list comparison vs integer comparison, which is more efficient?
In-Reply-To: <mailman.17365.1420355468.18130.python-list@python.org>
References: <d27586b9-017a-4519-a6bb-e0a1fac005d0@googlegroups.com>
 <mailman.17365.1420355468.18130.python-list@python.org>
Message-ID: <5499f48c-26e3-41c5-8735-2641fde5f35e@googlegroups.com>

On Sunday, January 4, 2015 8:12:10 AM UTC+1, Terry Reedy wrote:
> On 1/3/2015 6:19 PM, austin aigbe wrote:
> 
> > I am currently implementing the LTE physical layer in Python (ver 2.7.7).
> > For the qpsk, 16qam and 64qam modulation I would like to know which is more efficient to use, between an integer comparison and a list comparison:
> >
> > Integer comparison: bit_pair as an integer value before comparison
> >
> >      # QPSK - TS 36.211 V12.2.0, section 7.1.2, Table 7.1.2-1
> >      def mp_qpsk(self):
> >          r = []
> >          for i in range(self.nbits/2):
> >              bit_pair = (self.sbits[i*2] << 1) | self.sbits[i*2+1]
> >              if bit_pair == 0:
> >                  r.append(complex(1/math.sqrt(2),1/math.sqrt(2)))
> >              elif bit_pair == 1:
> >                  r.append(complex(1/math.sqrt(2),-1/math.sqrt(2)))
> >              elif bit_pair == 2:
> >                  r.append(complex(-1/math.sqrt(2),1/math.sqrt(2)))
> >              elif bit_pair == 3:
> >                  r.append(complex(-1/math.sqrt(2),-1/math.sqrt(2)))
> >          return r
> >
> > List comparison: bit_pair as a list before comparison
> >
> >      # QPSK - TS 36.211 V12.2.0, section 7.1.2, Table 7.1.2-1
> >      def mp_qpsk(self):
> >          r = []
> >          for i in range(self.nbits/2):
> >              bit_pair = self.sbits[i*2:i*2+2]
> >              if bit_pair == [0,0]:
> >                  r.append()
> >              elif bit_pair == [0,1]:
> >                  r.append(complex(1/math.sqrt(2),-1/math.sqrt(2)))
> >              elif bit_pair == [1,0]:
> >                  r.append(complex(-1/math.sqrt(2),1/math.sqrt(2)))
> >              elif bit_pair == [1,1]:
> >                  r.append(complex(-1/math.sqrt(2),-1/math.sqrt(2)))
> >          return r
> 
> Wrong question.  If you are worried about efficiency, factor out all 
> repeated calculation of constants and eliminate the multiple comparisons.
> 
> sbits = self.sbits
> a = 1.0 / math.sqrt(2)
> b = -a
> points = (complex(a,a), complex(a,b), complex(b,a), complex(b,b))
>      complex(math.sqrt(2),1/math.sqrt(2))
> def mp_qpsk(self):
>      r = [points[sbits[i]*2 + sbits[i+1]]
>          for i in range(0, self.nbits, 2)]
>      return r
> 
> -- 
> Terry Jan Reedy

Cool. Thanks a lot.


From flebber.crue at gmail.com  Sun Jan  4 06:34:21 2015
From: flebber.crue at gmail.com (flebber)
Date: Sun, 4 Jan 2015 03:34:21 -0800 (PST)
Subject: Help with map python 2
Message-ID: <60e62263-6cd1-48b9-acbc-f1a0b947b8c9@googlegroups.com>

In repsonse to this question: Write a program that prints the first 100 members of the sequence 2, -3, 4, -5, 6, -7, 8.

This is my solution it works but ugly.

series = range(2,100)
# answer = [(x,(y* -1)) for x, y in series[::2]]
# print(answer)
answer = []
for item in series:
    if item % 2 != 0:
        answer.append(item * -1)
    else:
        answer.append(item)

print(answer)

I know I should be better off doing this with map but cannot get it to work. I understand also that map returns a generator so this solution should only working in python2(correct me please if I am wrong).

In [6]: map?
Type:       builtin_function_or_method
String Form:<built-in function map>
Namespace:  Python builtin
Docstring:
map(function, sequence[, sequence, ...]) -> list

Just getting something wrong
list(map((lambda x: x * -1 if (x%2 != 0)), series))


From rosuav at gmail.com  Sun Jan  4 06:47:03 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 4 Jan 2015 22:47:03 +1100
Subject: Help with map python 2
In-Reply-To: <60e62263-6cd1-48b9-acbc-f1a0b947b8c9@googlegroups.com>
References: <60e62263-6cd1-48b9-acbc-f1a0b947b8c9@googlegroups.com>
Message-ID: <CAPTjJmqxVmc3fPkSx85fjC_nGUk2U26_VOycG_KhdfBtnBMp4A@mail.gmail.com>

On Sun, Jan 4, 2015 at 10:34 PM, flebber <flebber.crue at gmail.com> wrote:
> Just getting something wrong
> list(map((lambda x: x * -1 if (x%2 != 0)), series))

Okay, and what happens when you run this? Do you get an exception? If
so (and I fully expect you will), copy and paste the entire exception
traceback and message. That's the best way to show what's going wrong.
If you're not getting an exception, what do you get that's wrong?

ChrisA


From alec.taylor6 at gmail.com  Sun Jan  4 06:47:32 2015
From: alec.taylor6 at gmail.com (Alec Taylor)
Date: Sun, 4 Jan 2015 22:47:32 +1100
Subject: Help with map python 2
In-Reply-To: <60e62263-6cd1-48b9-acbc-f1a0b947b8c9@googlegroups.com>
References: <60e62263-6cd1-48b9-acbc-f1a0b947b8c9@googlegroups.com>
Message-ID: <CAO+9iGf=T6HoTb6+hh3r+uGAArs-E9R3eYX2VTRQdByhNnaJXQ@mail.gmail.com>

map(lambda i: -i if i&1==1 else i, xrange(2, 10))

On Sun, Jan 4, 2015 at 10:34 PM, flebber <flebber.crue at gmail.com> wrote:
> In repsonse to this question: Write a program that prints the first 100 members of the sequence 2, -3, 4, -5, 6, -7, 8.
>
> This is my solution it works but ugly.
>
> series = range(2,100)
> # answer = [(x,(y* -1)) for x, y in series[::2]]
> # print(answer)
> answer = []
> for item in series:
>     if item % 2 != 0:
>         answer.append(item * -1)
>     else:
>         answer.append(item)
>
> print(answer)
>
> I know I should be better off doing this with map but cannot get it to work. I understand also that map returns a generator so this solution should only working in python2(correct me please if I am wrong).
>
> In [6]: map?
> Type:       builtin_function_or_method
> String Form:<built-in function map>
> Namespace:  Python builtin
> Docstring:
> map(function, sequence[, sequence, ...]) -> list
>
> Just getting something wrong
> list(map((lambda x: x * -1 if (x%2 != 0)), series))
> --
> https://mail.python.org/mailman/listinfo/python-list


From alec.taylor6 at gmail.com  Sun Jan  4 06:48:53 2015
From: alec.taylor6 at gmail.com (Alec Taylor)
Date: Sun, 4 Jan 2015 22:48:53 +1100
Subject: Help with map python 2
In-Reply-To: <CAO+9iGf=T6HoTb6+hh3r+uGAArs-E9R3eYX2VTRQdByhNnaJXQ@mail.gmail.com>
References: <60e62263-6cd1-48b9-acbc-f1a0b947b8c9@googlegroups.com>
 <CAO+9iGf=T6HoTb6+hh3r+uGAArs-E9R3eYX2VTRQdByhNnaJXQ@mail.gmail.com>
Message-ID: <CAO+9iGeSDE9k-4Oxjo3PXKB71w1kFCO6NKVm_9xmSrBYMgYd0g@mail.gmail.com>

^To print the first 8. To print the first 100: map(lambda i: -i if
i&1==1 else i, xrange(2, 102))

On Sun, Jan 4, 2015 at 10:47 PM, Alec Taylor <alec.taylor6 at gmail.com> wrote:
> map(lambda i: -i if i&1==1 else i, xrange(2, 10))
>
> On Sun, Jan 4, 2015 at 10:34 PM, flebber <flebber.crue at gmail.com> wrote:
>> In repsonse to this question: Write a program that prints the first 100 members of the sequence 2, -3, 4, -5, 6, -7, 8.
>>
>> This is my solution it works but ugly.
>>
>> series = range(2,100)
>> # answer = [(x,(y* -1)) for x, y in series[::2]]
>> # print(answer)
>> answer = []
>> for item in series:
>>     if item % 2 != 0:
>>         answer.append(item * -1)
>>     else:
>>         answer.append(item)
>>
>> print(answer)
>>
>> I know I should be better off doing this with map but cannot get it to work. I understand also that map returns a generator so this solution should only working in python2(correct me please if I am wrong).
>>
>> In [6]: map?
>> Type:       builtin_function_or_method
>> String Form:<built-in function map>
>> Namespace:  Python builtin
>> Docstring:
>> map(function, sequence[, sequence, ...]) -> list
>>
>> Just getting something wrong
>> list(map((lambda x: x * -1 if (x%2 != 0)), series))
>> --
>> https://mail.python.org/mailman/listinfo/python-list


From jpiitula at ling.helsinki.fi  Sun Jan  4 07:08:58 2015
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 04 Jan 2015 14:08:58 +0200
Subject: Help with map python 2
References: <60e62263-6cd1-48b9-acbc-f1a0b947b8c9@googlegroups.com>
Message-ID: <qotoaqe7nol.fsf@ruuvi.it.helsinki.fi>

flebber writes:

> In repsonse to this question: Write a program that prints the first
> 100 members of the sequence 2, -3, 4, -5, 6, -7, 8.
> 
> This is my solution it works but ugly.

Seems respectable to me, except that you are taking fewer than 100
elements. But I'd prefer the expressions that you are looking for.

> series = range(2,100)
> # answer = [(x,(y* -1)) for x, y in series[::2]]

You could do what mathematicians do when they deal with alternating
signs: they raise -1 to the power of the index to get an appropriate
multiplier.

   >>> [ n * (-1) ** n for n in range(10) ]
   [0, -1, 2, -3, 4, -5, 6, -7, 8, -9]
   >>> 

Or you could do here what you attempt to do with map below. See below.

> # print(answer)
> answer = []
> for item in series:
>     if item % 2 != 0:
>         answer.append(item * -1)
>     else:
>         answer.append(item)
> 
> print(answer)
> 
> I know I should be better off doing this with map but cannot get it
> to work. I understand also that map returns a generator so this
> solution should only working in python2(correct me please if I am
> wrong).
> 
> In [6]: map?
> Type:       builtin_function_or_method
> String Form:<built-in function map>
> Namespace:  Python builtin
> Docstring:
> map(function, sequence[, sequence, ...]) -> list
> 
> Just getting something wrong
> list(map((lambda x: x * -1 if (x%2 != 0)), series))

You are trying to use a binary expression. There are no binary
expressions. Add an else branch to make it ternary:

   lambda x : x if x % 2 == 0 else -x

But never mind the number of branches, the serious point is that you
didn't specify a value for when the condition is not true. It doesn't
make sense without that.

There's nothing wrong with a list comprehension, or the corresponding
generator expression if you want a generator. It's fine. Map's fine.


From eshikafe at gmail.com  Sun Jan  4 07:17:05 2015
From: eshikafe at gmail.com (austin aigbe)
Date: Sun, 4 Jan 2015 04:17:05 -0800 (PST)
Subject: list comparison vs integer comparison, which is more efficient?
In-Reply-To: <5499f48c-26e3-41c5-8735-2641fde5f35e@googlegroups.com>
References: <d27586b9-017a-4519-a6bb-e0a1fac005d0@googlegroups.com>
 <mailman.17365.1420355468.18130.python-list@python.org>
 <5499f48c-26e3-41c5-8735-2641fde5f35e@googlegroups.com>
Message-ID: <7968fa1c-9b4c-4d17-9f71-1bbc55392921@googlegroups.com>

On Sunday, January 4, 2015 12:20:26 PM UTC+1, austin aigbe wrote:
> On Sunday, January 4, 2015 8:12:10 AM UTC+1, Terry Reedy wrote:
> > On 1/3/2015 6:19 PM, austin aigbe wrote:
> > 
> > > I am currently implementing the LTE physical layer in Python (ver 2.7.7).
> > > For the qpsk, 16qam and 64qam modulation I would like to know which is more efficient to use, between an integer comparison and a list comparison:
> > >
> > > Integer comparison: bit_pair as an integer value before comparison
> > >
> > >      # QPSK - TS 36.211 V12.2.0, section 7.1.2, Table 7.1.2-1
> > >      def mp_qpsk(self):
> > >          r = []
> > >          for i in range(self.nbits/2):
> > >              bit_pair = (self.sbits[i*2] << 1) | self.sbits[i*2+1]
> > >              if bit_pair == 0:
> > >                  r.append(complex(1/math.sqrt(2),1/math.sqrt(2)))
> > >              elif bit_pair == 1:
> > >                  r.append(complex(1/math.sqrt(2),-1/math.sqrt(2)))
> > >              elif bit_pair == 2:
> > >                  r.append(complex(-1/math.sqrt(2),1/math.sqrt(2)))
> > >              elif bit_pair == 3:
> > >                  r.append(complex(-1/math.sqrt(2),-1/math.sqrt(2)))
> > >          return r
> > >
> > > List comparison: bit_pair as a list before comparison
> > >
> > >      # QPSK - TS 36.211 V12.2.0, section 7.1.2, Table 7.1.2-1
> > >      def mp_qpsk(self):
> > >          r = []
> > >          for i in range(self.nbits/2):
> > >              bit_pair = self.sbits[i*2:i*2+2]
> > >              if bit_pair == [0,0]:
> > >                  r.append()
> > >              elif bit_pair == [0,1]:
> > >                  r.append(complex(1/math.sqrt(2),-1/math.sqrt(2)))
> > >              elif bit_pair == [1,0]:
> > >                  r.append(complex(-1/math.sqrt(2),1/math.sqrt(2)))
> > >              elif bit_pair == [1,1]:
> > >                  r.append(complex(-1/math.sqrt(2),-1/math.sqrt(2)))
> > >          return r
> > 
> > Wrong question.  If you are worried about efficiency, factor out all 
> > repeated calculation of constants and eliminate the multiple comparisons.
> > 
> > sbits = self.sbits
> > a = 1.0 / math.sqrt(2)
> > b = -a
> > points = (complex(a,a), complex(a,b), complex(b,a), complex(b,b))
> >      complex(math.sqrt(2),1/math.sqrt(2))
> > def mp_qpsk(self):
> >      r = [points[sbits[i]*2 + sbits[i+1]]
> >          for i in range(0, self.nbits, 2)]
> >      return r
> > 
> > -- 
> > Terry Jan Reedy
> 
> Cool. Thanks a lot.

Hi Terry,

No difference between the int and list comparison in terms of the number of calls(24) and time (0.004s). Main part is the repeated call to sqrt().

However, it took a shorter time (0.004s) with 24 function calls than your code (0.005s) which took just 13 function calls to execute.

Why is this?

Integer comparison profile result:
>>> p = pstats.Stats('lte_phy_mod.txt')
>>> p.strip_dirs().sort_stats(-1).print_stats()
Sun Jan 04 12:36:32 2015    lte_phy_mod.txt

         24 function calls in 0.004 seconds

   Ordered by: standard name

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.004    0.004    0.004    0.004 lte_phy_layer.py:16(<module>)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:20(Scrambling)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:276(LayerMapping)

        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:278(Precoding)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:280(ResourceElementMapping)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:282(OFDMSignalGenerator)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:65(Modulation)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:71(__init__)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:87(mp_qpsk)
        1    0.000    0.000    0.000    0.000 {len}
        8    0.000    0.000    0.000    0.000 {math.sqrt}
        4    0.000    0.000    0.000    0.000 {method 'append' of 'list' objects}
        1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}
        1    0.000    0.000    0.000    0.000 {range}


<pstats.Stats instance at 0x028F3F08>
>>>

List comparison:
>>> import pstats
>>> p = pstats.Stats('lte_phy_mod2.txt')
>>> p.strip_dirs().sort_stats(-1).print_stats()
Sun Jan 04 12:57:24 2015    lte_phy_mod2.txt

         24 function calls in 0.004 seconds

   Ordered by: standard name

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.004    0.004    0.004    0.004 lte_phy_layer.py:16(<module>)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:20(Scrambling)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:276(LayerMapping)

        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:278(Precoding)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:280(ResourceElementMapping)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:282(OFDMSignalGenerator)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:65(Modulation)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:71(__init__)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:87(mp_qpsk)
        1    0.000    0.000    0.000    0.000 {len}
        8    0.000    0.000    0.000    0.000 {math.sqrt}
        4    0.000    0.000    0.000    0.000 {method 'append' of 'list' objects}
        1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}
        1    0.000    0.000    0.000    0.000 {range}


<pstats.Stats instance at 0x025E3418>
>>>


Terry's code:

>>> import pstats
>>> p = pstats.Stats('lte_phy_mod3.txt')
>>> p.strip_dirs().sort_stats(-1).print_stats()
Sun Jan 04 13:04:51 2015    lte_phy_mod3.txt

         13 function calls in 0.005 seconds

   Ordered by: standard name

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.004    0.004    0.005    0.005 lte_phy_layer.py:16(<module>)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:20(Scrambling)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:285(LayerMapping)

        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:287(Precoding)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:289(ResourceElementMapping)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:291(OFDMSignalGenerator)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:65(Modulation)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:71(__init__)
        1    0.000    0.000    0.000    0.000 lte_phy_layer.py:87(mp_qpsk)
        1    0.000    0.000    0.000    0.000 {len}
        1    0.000    0.000    0.000    0.000 {math.sqrt}
        1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}
        1    0.000    0.000    0.000    0.000 {range}


<pstats.Stats instance at 0x02783418>
>>>


From auriocus at gmx.de  Sun Jan  4 07:22:18 2015
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Sun, 04 Jan 2015 13:22:18 +0100
Subject: list comparison vs integer comparison, which is more efficient?
In-Reply-To: <7968fa1c-9b4c-4d17-9f71-1bbc55392921@googlegroups.com>
References: <d27586b9-017a-4519-a6bb-e0a1fac005d0@googlegroups.com>
 <mailman.17365.1420355468.18130.python-list@python.org>
 <5499f48c-26e3-41c5-8735-2641fde5f35e@googlegroups.com>
 <7968fa1c-9b4c-4d17-9f71-1bbc55392921@googlegroups.com>
Message-ID: <m8bb91$2h7$1@dont-email.me>

Am 04.01.15 um 13:17 schrieb austin aigbe:
> However, it took a shorter time (0.004s) with 24 function calls than
your code (0.005s) which took just 13 function calls to execute.

> Why is this?

These times are way too short for conclusive results. Typically, the OS 
timer operates with a millisecond resolution. You need to run a 
benchmark at least for a second to get reliable information about 
timing. INstead of 24 times, call your function 20000 times in loop.

	Christian



From jonas at wielicki.name  Sun Jan  4 07:24:26 2015
From: jonas at wielicki.name (Jonas Wielicki)
Date: Sun, 04 Jan 2015 13:24:26 +0100
Subject: list comparison vs integer comparison, which is more efficient?
In-Reply-To: <7968fa1c-9b4c-4d17-9f71-1bbc55392921@googlegroups.com>
References: <d27586b9-017a-4519-a6bb-e0a1fac005d0@googlegroups.com>
 <mailman.17365.1420355468.18130.python-list@python.org>
 <5499f48c-26e3-41c5-8735-2641fde5f35e@googlegroups.com>
 <7968fa1c-9b4c-4d17-9f71-1bbc55392921@googlegroups.com>
Message-ID: <54A930FA.5060405@wielicki.name>

On 04.01.2015 13:17, austin aigbe wrote
> Hi Terry,
> 
> No difference between the int and list comparison in terms of the number of calls(24) and time (0.004s). Main part is the repeated call to sqrt().
> 
> However, it took a shorter time (0.004s) with 24 function calls than your code (0.005s) which took just 13 function calls to execute.

How often did you run your measurement? 4ms is not a whole lot and can
easily be skewed by sudden system load or other noise. You should call
the function more often and/or repeat the measurement several times
before coming to a judgement (except, possibly, that it doesn?t matter).

cheers,
jwi


From rosuav at gmail.com  Sun Jan  4 07:25:46 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 4 Jan 2015 23:25:46 +1100
Subject: list comparison vs integer comparison, which is more efficient?
In-Reply-To: <7968fa1c-9b4c-4d17-9f71-1bbc55392921@googlegroups.com>
References: <d27586b9-017a-4519-a6bb-e0a1fac005d0@googlegroups.com>
 <mailman.17365.1420355468.18130.python-list@python.org>
 <5499f48c-26e3-41c5-8735-2641fde5f35e@googlegroups.com>
 <7968fa1c-9b4c-4d17-9f71-1bbc55392921@googlegroups.com>
Message-ID: <CAPTjJmoV9RbHwwi=8GbDW==mhGN5-5n46jbj9PhCvU55Jh5L=Q@mail.gmail.com>

On Sun, Jan 4, 2015 at 11:17 PM, austin aigbe <eshikafe at gmail.com> wrote:
> However, it took a shorter time (0.004s) with 24 function calls than your code (0.005s) which took just 13 function calls to execute.
>
> Why is this?

That looks to me like noise in your stats. One ULP in timing stats?
Not something to base *anything* on.

ChrisA


From breamoreboy at yahoo.co.uk  Sun Jan  4 07:30:33 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 04 Jan 2015 12:30:33 +0000
Subject: list comparison vs integer comparison, which is more efficient?
In-Reply-To: <m8bb91$2h7$1@dont-email.me>
References: <d27586b9-017a-4519-a6bb-e0a1fac005d0@googlegroups.com>
 <mailman.17365.1420355468.18130.python-list@python.org>
 <5499f48c-26e3-41c5-8735-2641fde5f35e@googlegroups.com>
 <7968fa1c-9b4c-4d17-9f71-1bbc55392921@googlegroups.com>
 <m8bb91$2h7$1@dont-email.me>
Message-ID: <m8bbpd$53n$1@ger.gmane.org>

On 04/01/2015 12:22, Christian Gollwitzer wrote:
> Am 04.01.15 um 13:17 schrieb austin aigbe:
>> However, it took a shorter time (0.004s) with 24 function calls than
> your code (0.005s) which took just 13 function calls to execute.
>
>> Why is this?
>
> These times are way too short for conclusive results. Typically, the OS
> timer operates with a millisecond resolution. You need to run a
> benchmark at least for a second to get reliable information about
> timing. INstead of 24 times, call your function 20000 times in loop.
>
>      Christian
>

Maybe using a custom built tool such as 
https://docs.python.org/3/library/timeit.html#module-timeit ?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From musicalhacksaw at yahoo.co.uk  Sun Jan  4 07:49:09 2015
From: musicalhacksaw at yahoo.co.uk (Simon Evans)
Date: Sun, 4 Jan 2015 04:49:09 -0800 (PST)
Subject: Python console rejects an object reference, having made an object
 with that reference as its name in previous line
In-Reply-To: <01937423-e700-4825-a502-568dcb2d5324@googlegroups.com>
References: <01937423-e700-4825-a502-568dcb2d5324@googlegroups.com>
Message-ID: <c16ce690-c44d-4ace-b010-552794aa7461@googlegroups.com>

Dear Michael Torrie,
Thanks for pointing that out to me re: it not being a syntax problem.
The thing is there is a file called 'EcologicalPyramid.html'. I put it in a folder called 'Soup' as the text advised on page 28. For what its worth I also shifted the Windows Command Prompt to that folder (re: cd Soup)as instructed on page 30, and put a duplicate file of 'EcologicalPyramid.html' in the python 2.8 directory. 
I therefore am wondering where I ought put this html file where the Python console will recognize it ? 
Thank you for your attention,
Yours 
Simon  



From breamoreboy at yahoo.co.uk  Sun Jan  4 08:11:24 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 04 Jan 2015 13:11:24 +0000
Subject: Python console rejects an object reference, having made an object
 with that reference as its name in previous line
In-Reply-To: <c16ce690-c44d-4ace-b010-552794aa7461@googlegroups.com>
References: <01937423-e700-4825-a502-568dcb2d5324@googlegroups.com>
 <c16ce690-c44d-4ace-b010-552794aa7461@googlegroups.com>
Message-ID: <m8be60$bka$1@ger.gmane.org>

On 04/01/2015 12:49, Simon Evans wrote:
> Dear Michael Torrie,
> Thanks for pointing that out to me re: it not being a syntax problem.
> The thing is there is a file called 'EcologicalPyramid.html'. I put it in a folder called 'Soup' as the text advised on page 28. For what its worth I also shifted the Windows Command Prompt to that folder (re: cd Soup)as instructed on page 30, and put a duplicate file of 'EcologicalPyramid.html' in the python 2.8 directory.
> I therefore am wondering where I ought put this html file where the Python console will recognize it ?
> Thank you for your attention,
> Yours
> Simon
>

You could put your file on the moon provided you give the code a 
complete path to it, something like 
r'c:\the\path\to\your\file\called\EcologicalPyramid.html'

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From steve+comp.lang.python at pearwood.info  Sun Jan  4 08:19:09 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Mon, 05 Jan 2015 00:19:09 +1100
Subject: OT Vernacular and empire building [was Re: How do I remove/unlink
 wildcarded files]
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
 <20150102135132.GE24572@arxnet.hu>
 <mailman.17324.1420207299.18130.python-list@python.org>
 <2a5bfb42-c0b4-40dc-ba86-10bb67001350@googlegroups.com>
 <f7a40fa7-18da-40aa-8002-25f2ee7071e9@googlegroups.com>
 <mailman.17332.1420232918.18130.python-list@python.org>
 <54a7be06$0$12989$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmrTYSEemnpaHRJBLDYq-gp2-wVpht4E_y1SnJmC8X6UVA@mail.gmail.com>
 <mailman.17344.1420281519.18130.python-list@python.org>
 <f69874c8-48f6-4696-8678-c2a761f2f18d@googlegroups.com>
 <mailman.17354.1420310173.18130.python-list@python.org>
Message-ID: <54a93dcf$0$13010$c3e8da3$5496439d@news.astraweb.com>

Dear gods, I know I'm going to regret this... 


Mark Lawrence wrote:

> On 03/01/2015 17:53, Rick Johnson wrote:
>> On Saturday, January 3, 2015 4:39:25 AM UTC-6, Mark Lawrence wrote:
>>
>>> I used to get very confused watching the old westerns.  The child when
>>> talking about "more" and "paw" wasn't referring to possibly an
>>> adjective, noun or adverb and a part of an animal, but what we would
>>> refer to in the UK as "mum" and "dad" :)

Mark, that's not very different from the plethora of terms used for mother
across the British Isles, including "mam".

- "mum" is common in the south of England;
- "mom" is used in the west midlands;
- "mam" is used in the north and Ireland;

http://www.bl.uk/learning/langlit/sounds/text-only/england/danesford/

Mam is usually spelled "mam", but British "mom" is always spelled "mum"
unless the author is deliberately emphasising the pronunciation by using
phonetic spelling.


Rick then said:
>> Early Americans are easy to satirize since most were
>> schooled at home by illiterate parents. I believe the
>> "redneck vernacular" substituted "mother" and "father" for
>> "maw" and "paw" respectively. Which is not surprising since
>> most uneducated folks tend to favor single syllable
>> simplifications of words over their multi-syllable
>> counterparts.

I think that is rather silly. "Uneducated folks" often have very high
linguistic skills, except that they are verbal. Linguistically, the pattern
is that languages tend to become more simpler as literacy spreads, not the
other way around.

Mum/mom and Dad has become the most common terms of address for parents in
most English-speaking countries, except in the most formal situations. I
can't imagine calling my parents "mother and father" directly, although I
will refer to them in the third person as "my mother and father".

Oh, for interest, here's an fascinating discussion on why the baby words for
mother and father are so similar across all languages:

http://languagelog.ldc.upenn.edu/nll/?p=1847

Read the comments as well as the comic.


And Rick again:
>> Widespread centralized free schooling did not exists until
>> almost the 1900's. Heck, looking back at American history,
>> the world *SHOULD* be in awe. To go from a rag-tag
>> illiterate bunch of cowboys, to the worlds most powerful and
>> technically advanced society (in roughly one hundred years!)
>> has to be the most amazing transformation in the history of
>> the human society.

A ridiculous fantasy. The USA wasn't "a rag-tag illiterate bunch of
cowboys", you've been watching too many John Wayne westerns.

The United States as a world power wasn't created by cowboys from the
midwest or farmers from the heartland. It was created by the educated
elites on the east and west coasts, and immigrants from Europe, many of who
were already intelligent, educated and cultured. The rise of the USA as a
world power was World War One: the US started to industrialise to European
standards, while the European powers were slaughtering each other in the
trenches. Had the US only had the low-population midwest states to draw on,
they could never have become a world power. It was the industrialised
high-population states, with their millions of workers, who manned the
factories that allowed the US to become a world power.


Mark replied:
> I suspect that the engineers who pushed the railways across North
> America were hardly "a rag-tag illiterate bunch of cowboys".  I won't
> mention that the transformation involved wiping out 99% of the
> indigenous population.

In fairness, most of the genocide was over before the first English arrived
in North America. Disease inadvertently introduced by the Spanish travelled
north and wiped out probably 90% of the native American population. By the
time the English arrived, the continent was already depopulated, and
defeating and killing the survivors was relatively easy. Without the effect
of disease, I expect that the Americas would be more like the bulk of
Africa and Asia. Despite European technological superiority, apart from a
few special cases, mass European migration would simply never have been
practical.


>> Of course with all success stories, timing and luck had a
>> little to do with it, but it was undoubtedly the rebellious
>> and self reliant nature of Americans that made them so
>> successful. 

Rebellious and self-reliant, it is to laugh.


>> So before you go and spouting off about how dumb 
>> Americans are/were, ask yourself, what greatness has *MY*
>> country achieved in the span of a century?
> 
> I'm not entirely sure how a little bit of gentle teasing about accents
> in fictional films translates into "spouting off about how dumb
> Americans are/were" but there you go.  Hardly a century but I believe
> that the British Empire covered 25% of the land surface on the planet.
> Quite an achievement for a tiny patch of islands sitting off the coast
> of Europe.  However I suspect that a large number of people were glad to
> see the back of us, although I still think it audacious for those people
> to actually want to run their own countries.

Yeah, the cheek of those people, wanting a say in how they are governed.



-- 
Steven



From davea at davea.name  Sun Jan  4 09:14:52 2015
From: davea at davea.name (Dave Angel)
Date: Sun, 04 Jan 2015 09:14:52 -0500
Subject: Python console rejects an object reference, having made an object
 with that reference as its name in previous line
In-Reply-To: <c16ce690-c44d-4ace-b010-552794aa7461@googlegroups.com>
References: <01937423-e700-4825-a502-568dcb2d5324@googlegroups.com>
 <c16ce690-c44d-4ace-b010-552794aa7461@googlegroups.com>
Message-ID: <54A94ADC.1000203@davea.name>

On 01/04/2015 07:49 AM, Simon Evans wrote:
> Dear Michael Torrie,
> Thanks for pointing that out to me re: it not being a syntax problem.
> The thing is there is a file called 'EcologicalPyramid.html'. I put it in a folder called 'Soup' as the text advised on page 28.
> For what its worth I also shifted the Windows Command Prompt to that folder (re: cd Soup)as instructed on page 30,
> and put a duplicate file of 'EcologicalPyramid.html' in the python 2.8 directory.

Never put any user files in the "python 2.8" directory, whatever that is.

> I therefore am wondering where I ought put this html file where the Python console will recognize it ?

Since your code expects it in the current directory, either change the 
code, or make sure it IS in the current directory.

The only obvious thing I can see is that you didn't spell the name the 
same.  But since Windows makes the error of ignoring case, it ought to 
be close enough.  However, you're typing the name, not pasting it, so 
maybe there's some other subtle difference, like you have more than one 
Soup directory.

Try the following, from the cmd.exe prompt:

myprompt> cd Soup
myprompt> dir *.html
   (something shows here)
myprompt> python
   (something shows here)


 >>> from bs4 import BeautifulSoup
 >>> with open("ecologicalpyramid.html","r") as ecological_pyramid:
...      soup= next(ecological_pyramid,"lxml")
...      producer_entries = soup.find("ul")
...

and see what happens.  Paste the whole thing into a message if it 
doesn't make sense to you.  And of course don't forget to include the 
traceback.



-- 
DaveA


From __peter__ at web.de  Sun Jan  4 11:33:14 2015
From: __peter__ at web.de (Peter Otten)
Date: Sun, 04 Jan 2015 17:33:14 +0100
Subject: Help with map python 2
References: <60e62263-6cd1-48b9-acbc-f1a0b947b8c9@googlegroups.com>
Message-ID: <m8bq0b$jks$1@ger.gmane.org>

flebber wrote:

> In repsonse to this question: Write a program that prints the first 100
> members of the sequence 2, -3, 4, -5, 6, -7, 8.
> 
> This is my solution it works but ugly.
> 
> series = range(2,100)
> # answer = [(x,(y* -1)) for x, y in series[::2]]
> # print(answer)
> answer = []
> for item in series:
>     if item % 2 != 0:
>         answer.append(item * -1)
>     else:
>         answer.append(item)
> 
> print(answer)

Hm, that's the only first 98 members.

> 
> I know I should be better off doing this with map but cannot get it to
> work. I understand also that map returns a generator so this solution
> should only working in python2(correct me please if I am wrong).
> 
> In [6]: map?
> Type:       builtin_function_or_method
> String Form:<built-in function map>
> Namespace:  Python builtin
> Docstring:
> map(function, sequence[, sequence, ...]) -> list
> 
> Just getting something wrong
> list(map((lambda x: x * -1 if (x%2 != 0)), series))

Here's another way to look at the problem -- start with an infinite series 
and then slice it:

>>> from itertools import *
>>> list(islice(count(2), 10))
[2, 3, 4, 5, 6, 7, 8, 9, 10, 11]

Factor out the slicing to focus on the important stuff:

>>> def first_ten(items):
...     return list(islice(items, 10))
... 
>>> first_ten(count(2))

Now add the alternating sign:

>>> first_ten(cycle([1, -1]))
[1, -1, 1, -1, 1, -1, 1, -1, 1, -1]

Combine the two:

>>> from operator import mul
>>> first_ten(imap(mul, cycle([1, -1]), count(2)))
[2, -3, 4, -5, 6, -7, 8, -9, 10, -11]

It is important that you use itertools.imap() in Python 2 because the map() 
builtin would try to build the infinite list...

Finally put the slicing back into the expression if you like:

>>> list(islice(imap(mul, cycle([1, -1]), count(2)), 10))
[2, -3, 4, -5, 6, -7, 8, -9, 10, -11]





From dieffedue at gmx.com  Sun Jan  4 11:40:36 2015
From: dieffedue at gmx.com (ALFREDO PIACENTINI. EX SYZ GENEVE.)
Date: Sun, 4 Jan 2015 08:40:36 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
References: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
Message-ID: <59e6a11e-e1f8-47a3-abcf-964cee2ddab1@googlegroups.com>

-- redacted --


From ole.andreas.gloersen at gmail.com  Sun Jan  4 12:03:18 2015
From: ole.andreas.gloersen at gmail.com (=?ISO-8859-1?Q?Ole_Andreas_Gl=F8ersen?=)
Date: Sun, 4 Jan 2015 09:03:18 -0800 (PST)
Subject: Probem with fbconsole
Message-ID: <62fdbcf0-0c40-4fde-b018-4a0b55921fb6@googlegroups.com>

I want to enter text msg and upload picture (so all friends can see and some private pictures) to my Facebook acount.

I'm working with fbconsole (it's important that it is text based command line) for setting up cron job on a Raspberry Pi.

My code:

import fbconsole

redirect_uri =  "https://local.fbconsole.com:8080/"
fbconsole.SITE_URL=redirect_uri

fbconsole.APP_ID = 'my_SW_ID'

fbconsole.AUTH_SCOPE = ['read_stream']
fbconsole.automatically_authenticate('my_FB_ID','my_FB_PWD','Security_code',fbconsole.SITE_URL,True)



My result:

pi at raspberrypi ~/facebook $ python f.py 
send: 'GET /dialog/oauth?scope=read_stream&state=Deletet....Deletet....&redirect_uri=https%3A%2F%2Flocal.fbconsole.com%3A8080%2F&client_id=Deletet.... HTTP/1.1\r\nAccept-Encoding: identity\r\nHost: www.facebook.com\r\nConnection: close\r\nUser-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.1) Gecko/2008071615 Fedora/3.0.1-1.fc9 Firefox/3.0.1\r\n\r\n'
reply: 'HTTP/1.1 200 OK\r\n'
header: Pragma: no-cache
header: Facebook-API-Version: v2.2
header: X-Frame-Options: DENY
header: Cache-Control: private, no-cache, no-store, must-revalidate
header: Expires: Sat, 01 Jan 2000 00:00:00 GMT
header: X-XSS-Protection: 0
header: X-Content-Type-Options: nosniff
header: Content-Type: text/html; charset=utf-8
header: X-FB-Debug: Deletet.............Deletet....
header: Date: Sun, 04 Jan 2015 16:51:31 GMT
header: Connection: close
Traceback (most recent call last):
  File "f.py", line 13, in <module>
    fbconsole.automatically_authenticate('Deletet....','Deletet....','Deletet....',fbconsole.SITE_URL,True)
  File "/usr/local/lib/python2.7/dist-packages/fbconsole.py", line 413, in automatically_authenticate
    browser.select_form(nr=0)
  File "/usr/local/lib/python2.7/dist-packages/mechanize/_mechanize.py", line 524, in select_form
    raise FormNotFoundError("no form matching "+description)
mechanize._mechanize.FormNotFoundError: no form matching nr 0
pi at raspberrypi ~/facebook $ 


Can anyone help me futher on?




From breamoreboy at yahoo.co.uk  Sun Jan  4 12:13:44 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 04 Jan 2015 17:13:44 +0000
Subject: Probem with fbconsole
In-Reply-To: <62fdbcf0-0c40-4fde-b018-4a0b55921fb6@googlegroups.com>
References: <62fdbcf0-0c40-4fde-b018-4a0b55921fb6@googlegroups.com>
Message-ID: <m8bscc$mil$1@ger.gmane.org>

On 04/01/2015 17:03, Ole Andreas Gl?ersen wrote:
> I want to enter text msg and upload picture (so all friends can see and some private pictures) to my Facebook acount.
>
> I'm working with fbconsole (it's important that it is text based command line) for setting up cron job on a Raspberry Pi.
>
> My code:
>
> import fbconsole
>
> redirect_uri =  "https://local.fbconsole.com:8080/"
> fbconsole.SITE_URL=redirect_uri
>
> fbconsole.APP_ID = 'my_SW_ID'
>
> fbconsole.AUTH_SCOPE = ['read_stream']
> fbconsole.automatically_authenticate('my_FB_ID','my_FB_PWD','Security_code',fbconsole.SITE_URL,True)
>
>
>
> My result:
>
> pi at raspberrypi ~/facebook $ python f.py
> send: 'GET /dialog/oauth?scope=read_stream&state=Deletet....Deletet....&redirect_uri=https%3A%2F%2Flocal.fbconsole.com%3A8080%2F&client_id=Deletet.... HTTP/1.1\r\nAccept-Encoding: identity\r\nHost: www.facebook.com\r\nConnection: close\r\nUser-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.1) Gecko/2008071615 Fedora/3.0.1-1.fc9 Firefox/3.0.1\r\n\r\n'
> reply: 'HTTP/1.1 200 OK\r\n'
> header: Pragma: no-cache
> header: Facebook-API-Version: v2.2
> header: X-Frame-Options: DENY
> header: Cache-Control: private, no-cache, no-store, must-revalidate
> header: Expires: Sat, 01 Jan 2000 00:00:00 GMT
> header: X-XSS-Protection: 0
> header: X-Content-Type-Options: nosniff
> header: Content-Type: text/html; charset=utf-8
> header: X-FB-Debug: Deletet.............Deletet....
> header: Date: Sun, 04 Jan 2015 16:51:31 GMT
> header: Connection: close
> Traceback (most recent call last):
>    File "f.py", line 13, in <module>
>      fbconsole.automatically_authenticate('Deletet....','Deletet....','Deletet....',fbconsole.SITE_URL,True)
>    File "/usr/local/lib/python2.7/dist-packages/fbconsole.py", line 413, in automatically_authenticate
>      browser.select_form(nr=0)
>    File "/usr/local/lib/python2.7/dist-packages/mechanize/_mechanize.py", line 524, in select_form
>      raise FormNotFoundError("no form matching "+description)
> mechanize._mechanize.FormNotFoundError: no form matching nr 0
> pi at raspberrypi ~/facebook $
>
>
> Can anyone help me futher on?
>
>

Maybe 
http://stackoverflow.com/questions/10507169/using-python-requests-to-select-forms 
failing which work your way down the remaining 816 hits on google after 
searching for the entire FormNotFoundError line :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From jcasale at activenetwerx.com  Sun Jan  4 12:58:55 2015
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Sun, 4 Jan 2015 17:58:55 +0000
Subject: Argparse defaults
Message-ID: <9f93cb34bd12460ebd0dc60c45e53001@exch.activenetwerx.com>

Does a facility exist to add an argument with a default being a function
that leverages the final parsed Namespace?

For example:

    group  = parser.add_argument_group(' some_group ')
    group.add_argument(
        '--some_group',
        nargs='*',
        type=str
    )
    group.add_argument(
        '-- some_group_def',
        default=func
    )

    args = parser.parse_args()

where func returns a value 'a' if args.some_group or 'b' otherwise?

Obviously I can break that out after but I am curious if the facility exists?

Thanks,
jlc


From drsalists at gmail.com  Sun Jan  4 13:06:06 2015
From: drsalists at gmail.com (Dan Stromberg)
Date: Sun, 4 Jan 2015 10:06:06 -0800
Subject: Help with map python 2
In-Reply-To: <60e62263-6cd1-48b9-acbc-f1a0b947b8c9@googlegroups.com>
References: <60e62263-6cd1-48b9-acbc-f1a0b947b8c9@googlegroups.com>
Message-ID: <CAGGBd_pv-gkieus0ubX2gM5rE=QEyX_oAVRFoj8u5e7yFcQmGA@mail.gmail.com>

I'm partial to:

#!/usr/local/cpython-3.4/bin/python

def gen_series(top=None):
    '''
    Generate the numbers from 2 to top, with alternating signs.
    If top is None, generate forever.
    If top is an integer, generate from 2 to top.
    '''
    sign = 1
    if top is None:
        number = 2
        while True:
            yield number * sign
            number += 1
            sign = -sign
    else:
        for number in range(2, top):
            yield number * sign
            sign = -sign


def main():
    list_ = list(gen_series(100))
    print(list_)

main()


It's not the shortest, but it's pretty clear what's going on, and
gen_series() is reusable.


On Sun, Jan 4, 2015 at 3:34 AM, flebber <flebber.crue at gmail.com> wrote:
> In repsonse to this question: Write a program that prints the first 100 members of the sequence 2, -3, 4, -5, 6, -7, 8.
>
> This is my solution it works but ugly.
>
> series = range(2,100)
> # answer = [(x,(y* -1)) for x, y in series[::2]]
> # print(answer)
> answer = []
> for item in series:
>     if item % 2 != 0:
>         answer.append(item * -1)
>     else:
>         answer.append(item)
>
> print(answer)
>
> I know I should be better off doing this with map but cannot get it to work. I understand also that map returns a generator so this solution should only working in python2(correct me please if I am wrong).
>
> In [6]: map?
> Type:       builtin_function_or_method
> String Form:<built-in function map>
> Namespace:  Python builtin
> Docstring:
> map(function, sequence[, sequence, ...]) -> list
>
> Just getting something wrong
> list(map((lambda x: x * -1 if (x%2 != 0)), series))
> --
> https://mail.python.org/mailman/listinfo/python-list


From grahn+nntp at snipabacken.se  Sun Jan  4 13:12:44 2015
From: grahn+nntp at snipabacken.se (Jorgen Grahn)
Date: 4 Jan 2015 18:12:44 GMT
Subject: Socket programming
References: <f8631430-9364-42c8-8b12-daa3da4edf7c@googlegroups.com>
 <mailman.17352.1420305910.18130.python-list@python.org>
Message-ID: <slrnmaj0kq.4et.grahn+nntp@frailea.sa.invalid>

On Sat, 2015-01-03, Dan Stromberg wrote:
> On Sat, Jan 3, 2015 at 3:43 AM, pramod gowda <pramod.sp78 at gmail.com> wrote:
...

> data=client_socket.recv(1024)
> print(data)
> client_socket.close()
>
>
> But note that if you send 10 bytes into a socket, it could be received
> as two chunks of 5, or other strangeness. So you should frame your
> data somehow - adding crlf to the end of your send's is one simple
> way.

I like to think of it as "defining the protocol" rather than "framing
your data".  But it ends up as the same thing: making sure each end
knows when it should stop looking for more data and start /acting/ on
it.

And yes, you can't do much with a TCP soocket without setting up these
rules. It's important to see that noone does it /for/ you.

/Jorgen

-- 
  // Jorgen Grahn <grahn@  Oo  o.   .     .
\X/     snipabacken.se>   O  o   .


From tjreedy at udel.edu  Sun Jan  4 15:45:59 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Sun, 04 Jan 2015 15:45:59 -0500
Subject: Python Tk Tix GUI documentation & builder overview and tips
In-Reply-To: <m8at8k$g39$1@dont-email.me>
References: <e92d6639-28e4-4b58-83f3-fa1e88a186db@k2g2000yql.googlegroups.com>
 <5373bac1-9d1b-4468-adb8-361240afef92@googlegroups.com>
 <mailman.17360.1420322282.18130.python-list@python.org>
 <m8at8k$g39$1@dont-email.me>
Message-ID: <m8c8qi$b16$1@ger.gmane.org>

On 1/4/2015 3:23 AM, Christian Gollwitzer wrote:

> Am 03.01.15 um 22:57 schrieb Terry Reedy:
>> The current doc is wrong in any case.  I opened
>> http://bugs.python.org/issue23156

> Tix is a compiled extension, so this tix8.4.3.dll is needed as well as a
> couple of .tcl file including pkgIndex.tcl, which makes the package
> available to the Tcl interpreter. tix*.dll was never part of tk*.dll.
>
> Note that Tix is LEGACY. There are much better options for its widgets
> available that are based on ttk. Just to try, I compiled Tix under OSX
> for my Tk8.6.3 and ran the widget demos.
>
> Instead of
>
> * Hierarchical Listbox use ttk::treeview, tablelist_tile or tkTreeCtrl,
> with increasing order of capabilities and install complexity
>
> * TList: I think tkTreeCtrl can do it, never have used this layout
>
> * CheckList: tablelist can be used with an editable field
>
> * Grid widget: use tkTable
>
> * NoteBook, PanedWindow, ComboBox, LabelFrame -> ttk::notebook,
> ttk::panedwindow, ttk::combobox, ttk::labelframe
>
> * Balloon: tcllib::tooltip
>
> Not to mention that the Tix widgets are extremely ugly, while the
> widgets from ttk have a near-native look and feel.
>
> Caveat emptor: I've never used Tix, so this is just my impression as an
> experienced Tk programmer from running the widget demo

I copied parts of this response with additional comments in a new 
tracker post.

-- 
Terry Jan Reedy



From tjreedy at udel.edu  Sun Jan  4 16:13:31 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Sun, 04 Jan 2015 16:13:31 -0500
Subject: Help with map python 2
In-Reply-To: <60e62263-6cd1-48b9-acbc-f1a0b947b8c9@googlegroups.com>
References: <60e62263-6cd1-48b9-acbc-f1a0b947b8c9@googlegroups.com>
Message-ID: <m8cae6$1ol$1@ger.gmane.org>

On 1/4/2015 6:34 AM, flebber wrote:
> In repsonse to this question: Write a program that prints the first 100 members of the sequence 2, -3, 4, -5, 6, -7, 8.
>
> This is my solution it works but ugly.
>
> series = range(2,100)
> # answer = [(x,(y* -1)) for x, y in series[::2]]
> # print(answer)
> answer = []
> for item in series:
>      if item % 2 != 0:
>          answer.append(item * -1)
>      else:
>          answer.append(item)

for item in series:
     if item % 2:  # since result is a number, same as != 0
         item *= -1
     answer.append(item)

> print(answer)
>
> I know I should be better off doing this with map but cannot get it to work. I understand also that map returns a generator so this solution should only working in python2(correct me please if I am wrong).
>
> In [6]: map?
> Type:       builtin_function_or_method
> String Form:<built-in function map>
> Namespace:  Python builtin
> Docstring:
> map(function, sequence[, sequence, ...]) -> list
>
> Just getting something wrong
> list(map((lambda x: x * -1 if (x%2 != 0)), series))

In py2, map produces a list already.  In any case, above is syntax error 
without else clause.

map(lambda x: x * -1 if x%2 else x, series)

If you do not have a function already, a list comp is better.

[(-1*k if k%2 else k) for k in range(2, N)]

Change [] to () and you have a generator expression.

-- 
Terry Jan Reedy



From flebber.crue at gmail.com  Sun Jan  4 16:22:19 2015
From: flebber.crue at gmail.com (Sayth Renshaw)
Date: Sun, 04 Jan 2015 21:22:19 +0000
Subject: Help with map python 2
References: <60e62263-6cd1-48b9-acbc-f1a0b947b8c9@googlegroups.com>
 <CAGGBd_pv-gkieus0ubX2gM5rE=QEyX_oAVRFoj8u5e7yFcQmGA@mail.gmail.com>
Message-ID: <CAN2of02Vf1UgY7uXoYCF-+2N2U2bOYvJj8ZXQ=wg4RDw-0tvZw@mail.gmail.com>

Thank you for those solutions so varied. Am going to have a party with them
to see what works best for me.

Strange is there a way too use lousy comprehension without returning just
the matching odd values?

Sayth

On Mon, 5 Jan 2015 5:06 AM Dan Stromberg <drsalists at gmail.com> wrote:

> I'm partial to:
>
> #!/usr/local/cpython-3.4/bin/python
>
> def gen_series(top=None):
>     '''
>     Generate the numbers from 2 to top, with alternating signs.
>     If top is None, generate forever.
>     If top is an integer, generate from 2 to top.
>     '''
>     sign = 1
>     if top is None:
>         number = 2
>         while True:
>             yield number * sign
>             number += 1
>             sign = -sign
>     else:
>         for number in range(2, top):
>             yield number * sign
>             sign = -sign
>
>
> def main():
>     list_ = list(gen_series(100))
>     print(list_)
>
> main()
>
>
> It's not the shortest, but it's pretty clear what's going on, and
> gen_series() is reusable.
>
>
> On Sun, Jan 4, 2015 at 3:34 AM, flebber <flebber.crue at gmail.com> wrote:
> > In repsonse to this question: Write a program that prints the first 100
> members of the sequence 2, -3, 4, -5, 6, -7, 8.
> >
> > This is my solution it works but ugly.
> >
> > series = range(2,100)
> > # answer = [(x,(y* -1)) for x, y in series[::2]]
> > # print(answer)
> > answer = []
> > for item in series:
> >     if item % 2 != 0:
> >         answer.append(item * -1)
> >     else:
> >         answer.append(item)
> >
> > print(answer)
> >
> > I know I should be better off doing this with map but cannot get it to
> work. I understand also that map returns a generator so this solution
> should only working in python2(correct me please if I am wrong).
> >
> > In [6]: map?
> > Type:       builtin_function_or_method
> > String Form:<built-in function map>
> > Namespace:  Python builtin
> > Docstring:
> > map(function, sequence[, sequence, ...]) -> list
> >
> > Just getting something wrong
> > list(map((lambda x: x * -1 if (x%2 != 0)), series))
> > --
> > https://mail.python.org/mailman/listinfo/python-list
>
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From rantingrickjohnson at gmail.com  Sun Jan  4 18:22:29 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Sun, 4 Jan 2015 15:22:29 -0800 (PST)
Subject: OT Vernacular and empire building [was Re: How do I remove/unlink
 wildcarded files]
In-Reply-To: <54a93dcf$0$13010$c3e8da3$5496439d@news.astraweb.com>
References: <20150102090051.GC22372@arxnet.hu>
 <20150102102153.GA89926@cskk.homeip.net>
 <20150102053552.6ed449b8@bigbox.christie.dr>
 <20150102123604.GB24295@arxnet.hu>
 <CAPTjJmoHV5OxZYfnDaYjrq-SBDdkWPf1uAhtgd47aioK0FoWFQ@mail.gmail.com>
 <20150102135132.GE24572@arxnet.hu>
 <mailman.17324.1420207299.18130.python-list@python.org>
 <2a5bfb42-c0b4-40dc-ba86-10bb67001350@googlegroups.com>
 <f7a40fa7-18da-40aa-8002-25f2ee7071e9@googlegroups.com>
 <mailman.17332.1420232918.18130.python-list@python.org>
 <54a7be06$0$12989$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmrTYSEemnpaHRJBLDYq-gp2-wVpht4E_y1SnJmC8X6UVA@mail.gmail.com>
 <mailman.17344.1420281519.18130.python-list@python.org>
 <f69874c8-48f6-4696-8678-c2a761f2f18d@googlegroups.com>
 <mailman.17354.1420310173.18130.python-list@python.org>
 <54a93dcf$0$13010$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <49a871c4-913e-466f-a7e7-1838fbd7992f@googlegroups.com>

On Sunday, January 4, 2015 7:19:23 AM UTC-6, Steven D'Aprano wrote:
> Dear gods, I know I'm going to regret this... [...]

Yes, but *NOT* for the reason you think!

With all the intellectual and philosophical *GOLD* i have
dropped into this thread (and others), the only response you
can muster is to re-affirm your hatred for America's
Greatness and your disdain for the classical American
vernacular?

  "Is this it? Is this all you can conjure, Saruman?"
    
Hmm... yours and Marks responses are leading me to believe
that perpetual bike-shedding is not a unique phenomenon of
python-ideas after all!


From rantingrickjohnson at gmail.com  Sun Jan  4 19:33:35 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Sun, 4 Jan 2015 16:33:35 -0800 (PST)
Subject: apostrophe not considered with tkinter's wordstart and wordend
In-Reply-To: <e6143cd5-3475-431a-b2cf-17fd9659681c@googlegroups.com>
References: <e6143cd5-3475-431a-b2cf-17fd9659681c@googlegroups.com>
Message-ID: <655cce0d-2db3-4a0d-ab3d-64d5db5e1634@googlegroups.com>

On Saturday, January 3, 2015 2:28:18 PM UTC-6, ravas wrote:

> Is it possible that this could be added in an upcoming
> version of Python -- or is this a Tk issue?

A quick look at the Tkinter.Text.get source code will answer
that question for you:

py> import inspect
py> from Tkinter import Text
py> print inspect.getsource(Text.get)
    def get(self, index1, index2=None):
        """Return the text from INDEX1 to INDEX2 (not included)."""
        return self.tk.call(self._w, 'get', index1, index2)

As you can see, this method is just a dumb wrapper. There is
no "python-side" processing going on here. Which is true for
just about the entire Tkinter module.

I'm not sure if you can edit the pre-defined "word capture
patterns" that exist within TK (never had the need to find
out), but you could implement any pattern matching you want
by binding the correct events and then processing the
"target string" on the Python side. 

However, i would say that not allowing customization of
patterns is a major flaw of the API, and one more reason why
Tkinter is a rusty old "Clostridium tetani infected" anchor
around Python's neck!

   FOR GUIDO'S SAKE, BE SURE YOUR IMMUNIZATIONS ARE UP TO DATE!


From elearn2014 at gmail.com  Mon Jan  5 00:49:22 2015
From: elearn2014 at gmail.com (length power)
Date: Mon, 5 Jan 2015 13:49:22 +0800
Subject: how to select all the monday form "20150101" till "20150620"?
Message-ID: <CAOmh463bQr2zrcNneMS3xt6SLK4JV+1oYGQRv_DX_7h66GqvSw@mail.gmail.com>

import pandas as pd
rng = pd.date_range("20150101","20150620",freq="D")
for day in rng:
   x = pd.to_datetime(day)
   y = x.timetuple().tm_wday
   if(y == 0) :print(x.strftime("%Y%m%d"))


I have selected all  the monday form "20150101" till "20150620",how to make
it more simple?
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From chambers.yin at gmail.com  Mon Jan  5 02:34:30 2015
From: chambers.yin at gmail.com (Chambers yin)
Date: Mon, 5 Jan 2015 15:34:30 +0800
Subject: which specified python module can monitor text information in Windows
 GUI
Message-ID: <CAGi_xtAnLKWuuzT_4+TP1JywShXCdjuJyRukM=17hUCPsfoYaQ@mail.gmail.com>

Which kind of specified python module can monitor text in Windows GUI or
support the similar function?


Br,
-Chambers
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From esj at harvee.org  Mon Jan  5 02:43:11 2015
From: esj at harvee.org (Eric S. Johansson)
Date: Mon, 05 Jan 2015 02:43:11 -0500
Subject: need some guidance on Python syntax smart editor for use with speech
 recognition
Message-ID: <54AA408F.4080101@harvee.org>

Some of you will recognize me as someone who pops up occasionally asking 
questions as I grope my way to a usable speech driven programming 
environment. My last set of experiments with a technique called 
togglename and speech driven template notation hit a pretty nasty wall 
of usability because of a fundamental incompatibility between GUIs and 
speech recognition and the lack of support Nuance gives to disabled 
users in general.

Before anybody suggests it, yes I know about that guy who gave a talk at 
a python convention and uses what we call the burp, belch, and fart 
school of speech recognition engine abuse. yes that is actually an 
affectionate description. :-) what he did is impressive but it's not 
where I'm going

I think the techniques I was experimenting with are good ones because 
they do make it easier to speak code. the problem comes about because of 
the irreversibility of the transformation making editing code as 
difficult as it was before.

A little background. Today, Python is an amazingly speech recognition 
friendly programming language (especially if you ignore pep-8). Using 
simple macros, you can pretty much noodle along and write code 
relatively easily. A few more specialized pieces and it's almost easy to 
rip, shred, and tear code into new shapes as you realize you went down 
the wrong path but still have lots of good idioms.

However, as easy as it is to noodle along, creating code I find myself 
somewhere around 0.8 as effective as I was with my hands and in editing 
code, I'm around 0.5 or less. My goal is to make speech driven 
programming at least on a parity with someone who has useful hands and 
hopefully 3 to 5 times faster.

a few years ago, a disabled friend of mine pointed out that the hard 
problem was not the creation of code but the editing of code. I took his 
observations to heart and have been working on trying to create a speech 
friendly environment that that can transform from the speech notation to 
the code notation and back again and still remain functionally 
identical. I have some ideas but I need some outside perspective from 
people who know Python better than I do.

The core of the idea is an editor which can present code in two forms. 
The first form is what you guys all know in love but is horrible to 
speak. The second form is something that is easy to speak, and as I said 
above, functionally identical to the code form. An ideal solution would 
give me the ability to toggle back and forth between these two 
representations. An experiment would be to play with is displaying both 
representations at the same time so you can see what you speak in near 
real-time.

The speech environment lends itself to speaking the broad intent and 
then answering questions to fill in the detail to create something 
concrete. For example, in one of my prototypes (shown below), I state 
that I want a class. Then I fill a detail like an initialization 
function, inheriting from a parent, copying in all the arguments etc. 
and I end up with a full class definition much more quickly than I could 
even type it with good hands. This is what I meant above by 3 to 5 times 
faster than hand generated code.

But with every experimental success, there is usually more than one 
problem. In this case is that I lose all the meta-information when I 
create the instance of the intent plus detail. I can't go back to that 
abstract form.

The obvious answer is saving that meta-information in conjunction with 
the code but when working in a team environment, that information is 
going to drive you handies up the wall because it's going to visually 
overwhelm the actual code. Serving the meta-information separately will 
mean it's even harder to recover a speech friendly version of the code 
after it's been touched.

Another thought experiment has been with always generating syntactically 
correct code and basing various code generation and navigation 
constructs around that.

So the questions I have right now are, or

what's a good open editor ( preferably multiplatform) that actually 
decomposes Python code into fundamental components such as class, 
expression, etc. and, lets you operate on those components? this is in 
contrast to editors such as Emacs which give you some fundamental pieces 
you can operate on but it's really character oriented and all of the 
syntax smartness not really available for coupling to speech recognition 
environment. it would be great if it was in Python so I don't have to 
learn yet another fricking language.

What would be the best way to store meta-information necessary to 
re-create the speech friendly presentation of code? I don't know if this 
is possible but I would like to be able to let handy programmers make 
changes that will be propagated automatically into the speech friendly 
code presentation without forcing them to learn the new notation.

An example of this is the definition of the class. In my world, a class 
definition looks like this:

uses name:sta
uses init:yes
uses parent:dict
uses arg_list:magic dictonary, long sting, nuance sucks
uses super_arg_list:$arg_list
template class

Note: yes, I speak every single character or type it but with a smart 
editor, there's a bunch of optimizations one can use in data entry given 
the context. also, since I wrote this example, I realize that the uses 
statement is superfluous and I could just use template: <name> As the 
trigger for creating the instance of the template.

going from speech notation to code notation, I generate this:

class simple_class (super_nasty_class):
     def __init__(self, magic dictonary, long sting, nuance sucks):
         super(simple_class,self).__init__(magic dictonary, long sting, 
nuance sucks)

Note: there is a mix of, what I call, codenames and string names in 
these examples. The togglename process would transform all string names 
into codenames at some later point in the user experience.

To elaborate on an earlier question, if someone put a doc string into 
the class definition I would need to be able to recognize it and put it 
back into the speech friendly form. Something like this:

class simple_class (super_nasty_class):
     """this is a real simple class to identify problems in the
        speech user interface
    """
     def __init__(self, magic dictonary, long sting, nuance sucks):
         super(simple_class,self).__init__(magic dictonary, long sting, 
nuance sucks)

when transformed back into speech friendly form, it should look like:
uses name:sta
uses init:yes
uses parent:dict
uses arg_list:magic dictonary, long sting, nuance sucks
uses doc_string:
this is a real simple class to identify problems in the speech user 
interface
uses super_arg_list:$arg_list
template class

Speech driven programming is a hard problem. So thoughts, ideas would be 
welcome. Don't worry about giving me old ideas that have been looked at 
and rejected because you may have a take on it that I haven't seen 
considered and it's worth trying.

Thank you for reading this far. I know it's a long message and on an 
unfamiliar topic so I appreciate your attention.

--- eric





From ravas at outlook.com  Mon Jan  5 03:01:01 2015
From: ravas at outlook.com (ravas)
Date: Mon, 5 Jan 2015 00:01:01 -0800 (PST)
Subject: apostrophe not considered with tkinter's wordstart and wordend
In-Reply-To: <655cce0d-2db3-4a0d-ab3d-64d5db5e1634@googlegroups.com>
References: <e6143cd5-3475-431a-b2cf-17fd9659681c@googlegroups.com>
 <655cce0d-2db3-4a0d-ab3d-64d5db5e1634@googlegroups.com>
Message-ID: <714d9211-9b50-4e62-a7dd-25ff94a32d8a@googlegroups.com>

Thanks guys :-]

Rick Johnson:
> but you could implement any pattern matching you want
> by binding the correct events and then processing the
> "target string" on the Python side. 

I'm curious about what events you would use.
The only work around I thought of is to
create a word list and then apply tags & use tag_bind().



From rosuav at gmail.com  Mon Jan  5 03:12:08 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 5 Jan 2015 19:12:08 +1100
Subject: need some guidance on Python syntax smart editor for use with
 speech recognition
In-Reply-To: <54AA408F.4080101@harvee.org>
References: <54AA408F.4080101@harvee.org>
Message-ID: <CAPTjJmre67svt-zSFskxf42HCWx84p1K=S2S207YZFMF70iW-A@mail.gmail.com>

On Mon, Jan 5, 2015 at 6:43 PM, Eric S. Johansson <esj at harvee.org> wrote:
> The obvious answer is saving that meta-information in conjunction with the
> code but when working in a team environment, that information is going to
> drive you handies up the wall because it's going to visually overwhelm the
> actual code. Serving the meta-information separately will mean it's even
> harder to recover a speech friendly version of the code after it's been
> touched.
>

This, I think, is going to be your hardest problem to solve. Once
someone edits your code using a conventional set of tools, any saved
meta-information will be out of date, and that's a critical failure;
ergo you can't save anything, and have to deduce it all from the code.
So your only option, as I see it, is to devise some kind of 100%
reversible transliteration format.

Interestingly, this is sometimes needed between human languages.
Romanization of (say) Korean text involves representing the sounds of
the syllables in some kind of Latin script. If those transliterations
are perfectly reversible, you can manipulate the Korean text using a
US-English keyboard [1], while still producing correct Korean output.

It ought, in theory at least, to be possible to craft a reversible
transliteration between Python code and a more efficient speakable
form. You might have to place some restrictions on the Python code
(for instance, strict formatting rules, to avoid having spurious edits
when you use speech mode), and maybe you'd need a "fall-back" spoken
form that spells out the exact code, in case someone's done something
weird. But this would be something where you'd be better able to judge
than I am.

ChrisA

[1] I know this because I wrote myself a script to let me do exactly
that: https://github.com/Rosuav/shed/blob/master/translit.pike to make
https://github.com/Rosuav/LetItTrans/blob/master/Korean%20-%20%EB%8B%A4%20%EC%9E%8A%EC%96%B4.srt
(and other languages).


From skybuck2000 at hotmail.com  Mon Jan  5 03:53:50 2015
From: skybuck2000 at hotmail.com (Skybuck Flying)
Date: Mon, 5 Jan 2015 09:53:50 +0100
Subject: Direct3D/DirectX interception ?
Message-ID: <b63cc$54aa511b$5419aafe$9891@news.ziggo.nl>

Hello,

On the topic of Direct3D/DirectX interception ?

Is this possible with Python ?

If so how to do it ? Can you give example and/or links ?

Bye,
  Skybuck.




From jonas at wielicki.name  Mon Jan  5 04:34:52 2015
From: jonas at wielicki.name (Jonas Wielicki)
Date: Mon, 05 Jan 2015 10:34:52 +0100
Subject: need some guidance on Python syntax smart editor for use with
 speech recognition
In-Reply-To: <54AA408F.4080101@harvee.org>
References: <54AA408F.4080101@harvee.org>
Message-ID: <54AA5ABC.4020103@wielicki.name>

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

Dear Eric,

On 05.01.2015 08:43, Eric S. Johansson wrote:
> what's a good open editor ( preferably multiplatform) that
> actually decomposes Python code into fundamental components such as
> class, expression, etc. and, lets you operate on those components?
> this is in contrast to editors such as Emacs which give you some
> fundamental pieces you can operate on but it's really character
> oriented and all of the syntax smartness not really available for
> coupling to speech recognition environment. it would be great if it
> was in Python so I don't have to learn yet another fricking
> language.

As a first iteration, I would try with any editor written in Python.
Are you familiar with the ast[1] module? It could be worth trying to
use this module and perform some kind of pattern matching on the
results to recover the information.

In case you don?t know, the module produces a tree of objects
representing the syntactic representation of the Python code. The
example you gave should be easily recoverable from the AST
representation, assuming togglename has run through (appearantly, the
code is not valid python without the togglename transformation).

I would start small in that case. At some point, one would probably
need a XML Stylesheet-ish transformation language (not neccessarily in
XML; the main point is that you may need complex matching rules). For
the beginning, hardcoded rules might suffice, and for the cases where
it doesn?t work, you could persue Chris? approach of falling back to
spelled-out code.

Basically, you could formalize your template language to operate on
ASTs and write a pattern matcher recognizing ASTs which have been
generated from a given template.

Hope this helps. I find that topic pretty interesting. Is there
anything I can follow to see progress on this?

regards,
jwi

   [1]: https://docs.python.org/3/library/ast.html
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From flebber.crue at gmail.com  Mon Jan  5 06:33:46 2015
From: flebber.crue at gmail.com (flebber)
Date: Mon, 5 Jan 2015 03:33:46 -0800 (PST)
Subject: Help with map python 2
In-Reply-To: <qotoaqe7nol.fsf@ruuvi.it.helsinki.fi>
References: <60e62263-6cd1-48b9-acbc-f1a0b947b8c9@googlegroups.com>
 <qotoaqe7nol.fsf@ruuvi.it.helsinki.fi>
Message-ID: <597df0f8-234a-468c-bb48-1954db491b3c@googlegroups.com>


> You could do what mathematicians do when they deal with alternating
> signs: they raise -1 to the power of the index to get an appropriate
> multiplier.
> 
>    >>> [ n * (-1) ** n for n in range(10) ]
>    [0, -1, 2, -3, 4, -5, 6, -7, 8, -9]
>    >>> 
> 
> Or you could do here what you attempt to do with map below. See below.
> 

> 
> You are trying to use a binary expression. There are no binary
> expressions. Add an else branch to make it ternary:
> 
>    lambda x : x if x % 2 == 0 else -x
> 
> But never mind the number of branches, the serious point is that you
> didn't specify a value for when the condition is not true. It doesn't
> make sense without that.
> 
> There's nothing wrong with a list comprehension, or the corresponding
> generator expression if you want a generator. It's fine. Map's fine.

Thanks Jussi  I really like the multiplier solution.


From flebber.crue at gmail.com  Mon Jan  5 06:37:22 2015
From: flebber.crue at gmail.com (flebber)
Date: Mon, 5 Jan 2015 03:37:22 -0800 (PST)
Subject: Help with map python 2
In-Reply-To: <mailman.17382.1420406037.18130.python-list@python.org>
References: <60e62263-6cd1-48b9-acbc-f1a0b947b8c9@googlegroups.com>
 <mailman.17382.1420406037.18130.python-list@python.org>
Message-ID: <f6e70150-5e6a-4b41-be79-53e888eb4f0d@googlegroups.com>


> In py2, map produces a list already.  In any case, above is syntax error 
> without else clause.
> 
> map(lambda x: x * -1 if x%2 else x, series)
> 
> If you do not have a function already, a list comp is better.
> 
> [(-1*k if k%2 else k) for k in range(2, N)]
> 
> Change [] to () and you have a generator expression.

Thanks Terry
[(-1*k if k%2 else k) for k in range(2, N)] 

is really short and I think pythonic being a list comprehension and works in py2 and py3.

Sayth


From flebber.crue at gmail.com  Mon Jan  5 06:54:06 2015
From: flebber.crue at gmail.com (flebber)
Date: Mon, 5 Jan 2015 03:54:06 -0800 (PST)
Subject: If you were starting a project with  XML datasource using python
Message-ID: <55e354fd-a5bc-4f1f-a59a-55951fe81ca3@googlegroups.com>

Hi

I need some advice on managing data in the form of xml. I will have to repeatedly import a small xml file but with many complex attributes.

If I want to retain data integrity and keep the import process simple and querying from the stored source simple what are my best options?

There are several options for converting XML into objects such as:
http://lxml.de/objectify.html
https://pypi.python.org/pypi/pyxml2obj/
http://eulxml.readthedocs.org/en/latest/xmlmap.html

I could push this as an embedded object into mongo and search from there.

Could ignore XML by just converting to json with something like xml2json and pushing to many databases from there.

MySQL, Mongodb, couchdb and existdb are all viable options. Existdb is  directly an XML db so I could directly store from there and use the REST API to access http://exist-db.org/exist/apps/doc/devguide_rest.xml

somewhat bamboozled by the range of options and no clear obvious solution.

If you were starting a project, it relied on XML as its datasource what would you use and why? And have you used it or just speculating?

Thank you for your time

Sayth


From rosuav at gmail.com  Mon Jan  5 07:13:07 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 5 Jan 2015 23:13:07 +1100
Subject: how to select all the monday form "20150101" till "20150620"?
In-Reply-To: <CAOmh463bQr2zrcNneMS3xt6SLK4JV+1oYGQRv_DX_7h66GqvSw@mail.gmail.com>
References: <CAOmh463bQr2zrcNneMS3xt6SLK4JV+1oYGQRv_DX_7h66GqvSw@mail.gmail.com>
Message-ID: <CAPTjJmrPMJb4KHR56rETt28M2nxJX=nwYTgnz13uyBEv7ZV7nw@mail.gmail.com>

On Mon, Jan 5, 2015 at 4:49 PM, length power <elearn2014 at gmail.com> wrote:
> import pandas as pd
> rng = pd.date_range("20150101","20150620",freq="D")
> for day in rng:
>    x = pd.to_datetime(day)
>    y = x.timetuple().tm_wday
>    if(y == 0) :print(x.strftime("%Y%m%d"))
>
>
> I have selected all  the monday form "20150101" till "20150620",how to make
> it more simple?

I'm not sure, but I suspect your freq="D" parameter means that it
gives you sequential days. If you start at 20150105 (which is a
Monday), and change that to freq="W" or possibly freq="7D", it might
work just like that. Hint: Have you looked at the pandas
documentation?

ChrisA


From rosuav at gmail.com  Mon Jan  5 07:24:29 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 5 Jan 2015 23:24:29 +1100
Subject: need some guidance on Python syntax smart editor for use with
 speech recognition
In-Reply-To: <54AA5ABC.4020103@wielicki.name>
References: <54AA408F.4080101@harvee.org>
	<54AA5ABC.4020103@wielicki.name>
Message-ID: <CAPTjJmqa6HU-bk-33OHkORHky39zRkJ_ZGGYaR+tFzR5QvrCyg@mail.gmail.com>

On Mon, Jan 5, 2015 at 8:34 PM, Jonas Wielicki <jonas at wielicki.name> wrote:
> As a first iteration, I would try with any editor written in Python.
> Are you familiar with the ast[1] module? It could be worth trying to
> use this module and perform some kind of pattern matching on the
> results to recover the information.

An AST parse throws away a lot of information. You can't easily
reconstruct the original code from that; at best, you can decompile
the AST back into functionally-equivalent source code, but it's not
something you want to do as part of editing code. There's an
Unparser() in CPython/Tools/parser/unparse.py [1] which is great for
visualizing an AST structure, but if you take a .py file, compile it
to AST, and then unparse it, you'll end up with something quite
different.

However, back when I was doing my PEP 463 research, someone suggested
looking into the 2to3 parser. I regretfully admit that I have yet to
actually do so, but it ought in theory allow source-level
transformations with a measure of intelligence. It's not a ready-made
solution by any means, but it could be a useful tool. [2]

> Hope this helps. I find that topic pretty interesting. Is there
> anything I can follow to see progress on this?

Likewise!

ChrisA

[1] https://hg.python.org/cpython/file/tip/Tools/parser/unparse.py
[2] http://time-loop.tumblr.com/post/47664644/python-ast-preserving-whitespace-and-comments


From rantingrickjohnson at gmail.com  Mon Jan  5 08:20:32 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Mon, 5 Jan 2015 05:20:32 -0800 (PST)
Subject: apostrophe not considered with tkinter's wordstart and wordend
In-Reply-To: <714d9211-9b50-4e62-a7dd-25ff94a32d8a@googlegroups.com>
References: <e6143cd5-3475-431a-b2cf-17fd9659681c@googlegroups.com>
 <655cce0d-2db3-4a0d-ab3d-64d5db5e1634@googlegroups.com>
 <714d9211-9b50-4e62-a7dd-25ff94a32d8a@googlegroups.com>
Message-ID: <f1bcb866-b07f-478d-83a4-dcf4b2b096e5@googlegroups.com>

On Monday, January 5, 2015 2:01:22 AM UTC-6, ravas wrote:
> I'm curious about what events you would use. The only work
> around I thought of is to create a word list and then
> apply tags & use tag_bind().

Well i'm not sure what you are doing exactly, so i'll have
to take some liberties here, but i don't foresee "tag_bind"
as helping you. In order to use the binding applied to a
tag, you'll first have to apply the tag to the range of the
text containing the "target word"... (Ahhh, the old "quid
pro quo brings back a good memory!)

    https://www.youtube.com/watch?v=qr2bKXBV67o

then and only then could you expect an event to fire. I was
thinking more of binding on the "widget level". Here is what
you said earlier:

> When I place my mouse over a word (and I press something)
> I want the program to analyze the word. Tkinter almost
> provides the perfect option: but [...]

>From *that* description, a simple binding of "<Button-1>" to
a callback will give you the chance to process the "word" on
the Python side. Of course, that's easier said than done my
friend!

O:-)

Because (in your case) you cannot rely on the "TK wordstart
pattern" to define the edges correctly,  you'll have to
capture the entire line, THEN compute the location of the
cursor within the sub-string ("local offset in absolute
terms"), THEN back pedal until you find the first space (or
whatever defines the start of a word in your app), THEN use
the re module (or some other method) to find the end of the
word (if it exists at all), THEN if it does, do something.

*GASP*! Of course all this could be avoided if those short-
sighted TK folks would have allowed the programmer to define
the pattern! 

?_?

One thing to consider though: left-mouse-down is a common
event for most of us --except for those few immortals among
us who have sworn to a "mouse free life"[1] and have
officially completed space cadet training--  and you don't
want Python doing all that work for nothing! So unless you
can justify all that processing for every left-mouse-down
event, i would suggest using another event.

[1]: Of which the phrase would make for interesting
satirical replacement of the chorus in: little orphan
Annie's, "it's a hard knock life".

    It's a mouse free life, for us...
    It's a mouse free life, for us...
    Instead of clicks, WE get pecks...
    It's a mouse free life!



From mysior.darek at gmail.com  Mon Jan  5 09:27:46 2015
From: mysior.darek at gmail.com (Dariusz Mysior)
Date: Mon, 5 Jan 2015 06:27:46 -0800 (PST)
Subject: problem with for and if
Message-ID: <a71e126d-4b27-42a3-8103-3381b62794d2@googlegroups.com>

I want search count of szukana in zmienna but code below counting all 12 letters from "traktorzysta" word

szukana="t"
zmienna="traktorzysta"


def gen():
    count=int(0)
    for a in zmienna:
        if szukana in zmienna:
            count+=1
        else:
            continue
    return count


print("Literka '",szukana,"' w s?owie ",zmienna,
      "wyst?pi?a ",gen()," razy")


From i at introo.me  Mon Jan  5 09:38:02 2015
From: i at introo.me (Shiyao Ma)
Date: Mon, 5 Jan 2015 22:38:02 +0800
Subject: problem with for and if
In-Reply-To: <a71e126d-4b27-42a3-8103-3381b62794d2@googlegroups.com>
References: <a71e126d-4b27-42a3-8103-3381b62794d2@googlegroups.com>
Message-ID: <20150105143802.GB45241@FuzzyHorror>

On Jan 05 at 06:27 -0800, Dariusz Mysior wrote:
> I want search count of szukana in zmienna but code below counting all 12 letters from "traktorzysta" word
>
> szukana="t"
> zmienna="traktorzysta"
>
>
> def gen():
>     count=int(0)
>     for a in zmienna:
>         if szukana in zmienna:
>             count+=1
>         else:
>             continue
>     return count

def gen():
    count = 0
    for a in zmienna:
        # we assume szukana is a single letter
        if szukana == a:
            count+=1
        else:
            continue
    return count

More preferably, you should repetitively use "str.find"

Or just use `max(0,len(zmienna.split(szukana))-1)`

-- 
Shiyao Ma
http://introo.me


From ybmess at nooos.fr.invalid  Mon Jan  5 09:39:57 2015
From: ybmess at nooos.fr.invalid (YBM)
Date: Mon, 05 Jan 2015 15:39:57 +0100
Subject: problem with for and if
In-Reply-To: <a71e126d-4b27-42a3-8103-3381b62794d2@googlegroups.com>
References: <a71e126d-4b27-42a3-8103-3381b62794d2@googlegroups.com>
Message-ID: <54aaa23e$0$2112$426a74cc@news.free.fr>

Le 05/01/2015 15:27, Dariusz Mysior a ?crit :
> I want search count of szukana in zmienna but code below counting all 12 letters from "traktorzysta" word
>
> szukana="t"
> zmienna="traktorzysta"
>
>
> def gen():
>      count=int(0)
>      for a in zmienna:
>          if szukana in zmienna:
>              count+=1
>          else:
>              continue
>      return count
>
>
> print("Literka '",szukana,"' w s?owie ",zmienna,
>        "wyst?pi?a ",gen()," razy")

In the for loop a is iterating through "traktorzysta" ("t", then "r",
then "a", ...): 12 steps

moreover the expression szukana in zmienna is always true (as t is
a letter of "traktorzysta"), so count += 1 is executed twelve times.

def gen():
     count=int(0)
     for a in zmienna:
         if a == szukana:
             count+=1
         else:
             continue
     return count

will work (even if quite ugly, why int(0)? why defining a function
without parameters? etc.)



From kwpolska at gmail.com  Mon Jan  5 09:41:25 2015
From: kwpolska at gmail.com (Chris Warrick)
Date: Mon, 5 Jan 2015 15:41:25 +0100
Subject: problem with for and if
In-Reply-To: <a71e126d-4b27-42a3-8103-3381b62794d2@googlegroups.com>
References: <a71e126d-4b27-42a3-8103-3381b62794d2@googlegroups.com>
Message-ID: <CAMw+j7K-WY6OdWP+L=RqQ22Csn29drdzmMb7=_biha2CziJLdQ@mail.gmail.com>

On Mon, Jan 5, 2015 at 3:27 PM, Dariusz Mysior <mysior.darek at gmail.com> wrote:
> I want search count of szukana in zmienna but code below counting all 12 letters from "traktorzysta" word

First off, I recommend that you do not write code in Polish ? use
English so that everyone can understand your code.

Your error is here:
>     for a in zmienna:
>         if szukana in zmienna:

You shouldn?t be looking in `zmienna`, you should be checking `a` ?
the letter of the word used in the current iteration.  Moreover, you
should use == for the comparison ? compare the letter in the current
iteration to 't'.  The correct line WOULD be

    if a == szukana:

BUT there is actually a better solution.  You see, Python is a
language with ?batteries included? ? that is, many things are already
available for you to use without need to re-implement them.  Just use
str.count, which will do it for you:

zmienna = 'traktorzysta'
szukana = 't'
print("Literka '",szukana,"' w s?owie ",zmienna,
      "wyst?pi?a ",zmienna.count(szukana)," razy")

-- 
Chris Warrick <https://chriswarrick.com/>
PGP: 5EAAEA16


From mysior.darek at gmail.com  Mon Jan  5 09:47:52 2015
From: mysior.darek at gmail.com (Dariusz Mysior)
Date: Mon, 5 Jan 2015 06:47:52 -0800 (PST)
Subject: problem with for and if
In-Reply-To: <a71e126d-4b27-42a3-8103-3381b62794d2@googlegroups.com>
References: <a71e126d-4b27-42a3-8103-3381b62794d2@googlegroups.com>
Message-ID: <e647b330-be3e-4d8b-9e6e-32d17b1c3cf9@googlegroups.com>

W dniu poniedzia?ek, 5 stycznia 2015 15:28:07 UTC+1 u?ytkownik Dariusz Mysior napisa?:
> I want search count of szukana in zmienna but code below counting all 12 letters from "traktorzysta" word
> 
> szukana="t"
> zmienna="traktorzysta"
> 
> 
> def gen():
>     count=int(0)
>     for a in zmienna:
>         if szukana in zmienna:
>             count+=1
>         else:
>             continue
>     return count
> 
> 
> print("Literka '",szukana,"' w s?owie ",zmienna,
>       "wyst?pi?a ",gen()," razy")

Now I understand it!

Thank You!!!


From python at mrabarnett.plus.com  Mon Jan  5 09:48:53 2015
From: python at mrabarnett.plus.com (MRAB)
Date: Mon, 05 Jan 2015 14:48:53 +0000
Subject: problem with for and if
In-Reply-To: <a71e126d-4b27-42a3-8103-3381b62794d2@googlegroups.com>
References: <a71e126d-4b27-42a3-8103-3381b62794d2@googlegroups.com>
Message-ID: <54AAA455.1010406@mrabarnett.plus.com>

On 2015-01-05 14:27, Dariusz Mysior wrote:
> I want search count of szukana in zmienna but code below counting all 12 letters from "traktorzysta" word
>
> szukana="t"
> zmienna="traktorzysta"
>
>
> def gen():
>      count=int(0)
>      for a in zmienna:
>          if szukana in zmienna:
>              count+=1
>          else:
>              continue
>      return count
>
>
> print("Literka '",szukana,"' w s?owie ",zmienna,
>        "wyst?pi?a ",gen()," razy")
>
It's asking whether szukana is in zmienna for each character in zmienna.

There are 12 characters in zmienna, so it's asking 12 times.

Because szukana is in zmienna, it adds 1 to count each time, giving a
total of 12.

If szukana wasn't in zmienna, then nothing would be added to count,
giving a total of 0.

The body of the loop should be:

       for a in zmienna:
           if a == szukana:
               count += 1

Other notes:

0 is already an int, so int(0) is just 0!

There's no need for the 'else' part in the 'if' statement

Strings have a .count method, so you can, in fact, simplify it to just:

def gen():
     return zmienna.count(szukana)



From i at introo.me  Mon Jan  5 09:57:34 2015
From: i at introo.me (Shiyao Ma)
Date: Mon, 5 Jan 2015 22:57:34 +0800
Subject: problem with for and if
In-Reply-To: <20150105143802.GB45241@FuzzyHorror>
References: <a71e126d-4b27-42a3-8103-3381b62794d2@googlegroups.com>
 <20150105143802.GB45241@FuzzyHorror>
Message-ID: <20150105145734.GC45241@FuzzyHorror>

On Jan 05 at 22:38 +0800, Shiyao Ma wrote:

> More preferably, you should repetitively use "str.find"
>
> Or just use `max(0,len(zmienna.split(szukana))-1)`

Forgot there was a `str.count`, ;).

-- 
Shiyao Ma
http://introo.me


From esj at harvee.org  Mon Jan  5 13:02:22 2015
From: esj at harvee.org (Eric S. Johansson)
Date: Mon, 05 Jan 2015 13:02:22 -0500
Subject: need some guidance on Python syntax smart editor for use with
 speech recognition
In-Reply-To: <CAPTjJmre67svt-zSFskxf42HCWx84p1K=S2S207YZFMF70iW-A@mail.gmail.com>
References: <54AA408F.4080101@harvee.org>
 <CAPTjJmre67svt-zSFskxf42HCWx84p1K=S2S207YZFMF70iW-A@mail.gmail.com>
Message-ID: <54AAD1AE.4070801@harvee.org>


On 1/5/2015 3:12 AM, Chris Angelico wrote:
> On Mon, Jan 5, 2015 at 6:43 PM, Eric S. Johansson <esj at harvee.org> wrote:
>> The obvious answer is saving that meta-information in conjunction with the
>> code but when working in a team environment, that information is going to
>> drive you handies up the wall because it's going to visually overwhelm the
>> actual code. Serving the meta-information separately will mean it's even
>> harder to recover a speech friendly version of the code after it's been
>> touched.
>>
> This, I think, is going to be your hardest problem to solve. Once
> someone edits your code using a conventional set of tools, any saved
> meta-information will be out of date, and that's a critical failure;
> ergo you can't save anything, and have to deduce it all from the code.

Exactly. That's one of the reasons why I was heading down the path of 
embedded meta-metadata. It might be acceptable if I could devise rules 
for hiding the metadata but even with that, the reversal is still a bit 
of a challenge..
> So your only option, as I see it, is to devise some kind of 100%
> reversible transliteration format.
With the right metadata, you have that reversibility. I think what makes 
it easier and harder is that when you write code using speech, you tend 
to use idioms (a.k.a. templates). My gut sense tells me that I should be 
able to recognize the structure of an idiom for going back from the code 
form to the speakable form. the metadata should help this process.

In the example I gave of class, the actual template generating code has 
a bunch of conditionals to add or delete subcomponents of the template. 
the template tool I use is something I developed myself which is a 
speakable template form, can do recursive expansion but has no 
conditionals in it (doing so reduces speak ability).

I think a form of pattern matching or shape recognition would be core to 
creating the code to speakable form translation but I'm feeling a bit 
stumped because I don't know where to find how other people have solved 
this kind of problem.

I should clarify that by shape recognition, I don't mean a geometric or 
image-based shape. it's more of an abstraction I used in my own mental 
models of how code is constructed.  for what it's worth, what I just 
described is one of the things that makes programming by speech so 
difficult. We all have different mental models of how code works. I see 
code in three dimensions  varying in time. I know not everybody does. :-)

One of the side effects of this visualization of code is that it lets me 
identify potential idioms. Some idioms are task transient, others are 
more general. If there's some way to recognize the pattern of code that 
is in an idiom and be able to preserve the variations within the idiom 
then I think we are on the right path.

>
> Interestingly, this is sometimes needed between human languages.
> Romanization of (say) Korean text involves representing the sounds of
> the syllables in some kind of Latin script. If those transliterations
> are perfectly reversible, you can manipulate the Korean text using a
> US-English keyboard [1], while still producing correct Korean output.
>
> It ought, in theory at least, to be possible to craft a reversible
> transliteration between Python code and a more efficient speakable
> form. You might have to place some restrictions on the Python code
> (for instance, strict formatting rules, to avoid having spurious edits
> when you use speech mode), and maybe you'd need a "fall-back" spoken
> form that spells out the exact code, in case someone's done something
> weird. But this would be something where you'd be better able to judge
> than I am.

it'll never be 100% speech driven. There will always be a time when you 
have to use your hands. The goal is to minimize that time.

I should also point out that going from A -> B -> A' is not going to 
result in A = A' at least not at a character for character level.  
however, given a set of inputs, you will get identical results on 
outputs when using A and A'.  Yes, this will make differences in 
revision control hard to track unless the check in process performs a A 
-> B -> A' transformation and only checks in A'

So maybe now the question has changed to how does one specify an idiom 
such that one can extract the arguments defining that idiom instance 
from existing source code.

--- eric



From suhailmahmood.c070 at gmail.com  Mon Jan  5 13:04:54 2015
From: suhailmahmood.c070 at gmail.com (Suhail Mahmood)
Date: Mon, 5 Jan 2015 10:04:54 -0800 (PST)
Subject: toStringList in PyQt5
Message-ID: <fab6a2bc-051f-42fa-a0f0-4dd6d6d87752@googlegroups.com>

I was following the examples in 'Rapid GUI Development with Python and Qt' by Mark Summerfield. Sadly I am using PyQt5 and all the examples in this book are for PyQt4. But I have converted the codes to PyQt5 codes. But still I am having some problems. In chapter 6, there is something called QString, which I can't import(I guess this is more available in Pyqt5). Also, there is QSettings, returning something in by using 

            settings.value("Recent files").toStringList()

where settings is an instance of QSettings. Now as I can't import QString, this line is giving me an error like this:

           self.recentFiles = settings.value("RecentFiles").toStringList()
       AttributeError: 'NoneType' object has no attribute 'toStringList'

How can I get around with this problem?
Thanks.


From esj at harvee.org  Mon Jan  5 13:18:45 2015
From: esj at harvee.org (Eric S. Johansson)
Date: Mon, 05 Jan 2015 13:18:45 -0500
Subject: need some guidance on Python syntax smart editor for use with
 speech recognition
In-Reply-To: <CAPTjJmqa6HU-bk-33OHkORHky39zRkJ_ZGGYaR+tFzR5QvrCyg@mail.gmail.com>
References: <54AA408F.4080101@harvee.org>	<54AA5ABC.4020103@wielicki.name>
 <CAPTjJmqa6HU-bk-33OHkORHky39zRkJ_ZGGYaR+tFzR5QvrCyg@mail.gmail.com>
Message-ID: <54AAD585.1070407@harvee.org>


On 1/5/2015 7:24 AM, Chris Angelico wrote:
> On Mon, Jan 5, 2015 at 8:34 PM, Jonas Wielicki <jonas at wielicki.name> wrote:
>> As a first iteration, I would try with any editor written in Python.
>> Are you familiar with the ast[1] module? It could be worth trying to
>> use this module and perform some kind of pattern matching on the
>> results to recover the information.
> An AST parse throws away a lot of information. You can't easily
> reconstruct the original code from that; at best, you can decompile
> the AST back into functionally-equivalent source code, but it's not
> something you want to do as part of editing code.

Chris is right. I looked at this and came up with the same conclusion. 
Here's a use case that I haven't talked about yet but is part of the 
problem of speech driven programming. I have a chunk of code that I 
created that is exactly right but it's in the wrong place or wrong 
method or even just the wrong environment. I need to capture it and then 
move it to the right place.

At first glance, this would look like a simple cut-and-paste and, 
sometimes it is but more often it's not. Let's take the example of a 
simple file generator. Opening the file, iterating over the input until 
the input data transformation process runs out of data.

This is a real common pattern and what changes are certain elements of 
the code, variables, strings whatever but also the indentation. So 
putting the old chunk of code into the new place requires transformation 
that most of you guys do by hand without thinking twice. Me it's, 
#()@!&#$, and I use a whole bunch of kill words to strip out the old 
data and put in the new.

Imagine being able to rip out a piece of code, identify the substitution 
points and the indentation adjustment levels and then being able to put 
in that piece of code in other places and just fill in the blanks as a 
part of the insertion dialogue.  Now this gets us to the same point I 
was first talking about which is the ability to identify the idiom and 
code to operate on it as an idiom. some of the stuff I've seen with 
snippets is partly there, again it is a one-way transform.

It seems to me that those of us with hands and those of us with broken 
hands could use this same functionality given the right supportive user 
interface.

Now I've been living with this kind of idea for a while and I realize 
that may not make sense in this abstract written description. What do I 
need to fill in?

> However, back when I was doing my PEP 463 research, someone suggested
> looking into the 2to3 parser. I regretfully admit that I have yet to
> actually do so, but it ought in theory allow source-level
> transformations with a measure of intelligence. It's not a ready-made
> solution by any means, but it could be a useful tool. [2]

Good idea.
>> Hope this helps. I find that topic pretty interesting. Is there
>> anything I can follow to see progress on this?
> Likewise!
>
> ChrisA

Is there any problem with keeping the conversation going here or would 
you prefer some other way of talking about it? I've been hesitant to put 
my work up on github because it's flailing about with also the bloody 
loose ends because I'm trying to solve up number of problems all at the 
same time.   The problem first being a framework where I can add speech 
driven UI elements to an editor so I can start experimenting with a 
bunch of these pieces.

Another way you can help is be my hands. sometimes I just run out of 
hand time and it takes a while for me build up enough energy so I can 
spend the day working for money and a day working on this.

--- eric



From flebber.crue at gmail.com  Mon Jan  5 13:24:25 2015
From: flebber.crue at gmail.com (flebber)
Date: Mon, 5 Jan 2015 10:24:25 -0800 (PST)
Subject: If you were starting a project with  XML datasource using python
In-Reply-To: <mailman.17395.1420466196.18130.python-list@python.org>
References: <55e354fd-a5bc-4f1f-a59a-55951fe81ca3@googlegroups.com>
 <mailman.17395.1420466196.18130.python-list@python.org>
Message-ID: <792cb61b-d351-4b4b-aa7b-35e959111c0a@googlegroups.com>

> 
> >If you were starting a project, it relied on XML as its datasource what would you use and why? And have you used it or just speculating?
> >
> 	If I were starting a project, I'd argue furiously that XML is NOT
> something that should be used for dynamic data storage (the original GRAMPS
> not withstanding -- I see it now uses BSDdb). It may be a useful
> representation for transferring/transforming data, but not for
> persistance/updates.
> 
> 	If used for data transfer, the schema should be well thought out to
> facilitate updates to the long-term storage format.

So you would convert it to json so it can then be stored? 

Note I don't control the XML at all that is a separate organisation I just have to deal with it?

Sayth


From vern.muhr at gmail.com  Mon Jan  5 14:59:09 2015
From: vern.muhr at gmail.com (vern.muhr at gmail.com)
Date: Mon, 5 Jan 2015 11:59:09 -0800 (PST)
Subject: which specified python module can monitor text information in
 Windows GUI
In-Reply-To: <mailman.17387.1420459589.18130.python-list@python.org>
References: <mailman.17387.1420459589.18130.python-list@python.org>
Message-ID: <4b97b9b4-84ec-428c-848e-0ac64dc3684f@googlegroups.com>

On Monday, January 5, 2015 4:06:52 AM UTC-8, Chambers yin wrote:
> Which kind of specified python module can monitor text in Windows GUI or support the similar function?
> 
> 
> Br,
> -Chambers

Sikuli (http://www.sikuli.org/) might be helpful. It is scripted in Jython. Not quite a "standard" module, but Sikuli is very good at dealing with the windows GUI. Really an amazing program.


From jacob at blindza.co.za  Mon Jan  5 15:04:14 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Mon, 5 Jan 2015 22:04:14 +0200
Subject: need some guidance on Python syntax smart editor for use with
 speech recognition
In-Reply-To: <54AAD585.1070407@harvee.org>
References: <54AA408F.4080101@harvee.org>	<54AA5ABC.4020103@wielicki.name>
 <CAPTjJmqa6HU-bk-33OHkORHky39zRkJ_ZGGYaR+tFzR5QvrCyg@mail.gmail.com>
 <54AAD585.1070407@harvee.org>
Message-ID: <B116E5F9B32341BC9AA9E9355F6A96D6@JakesPC>

Eric, not really related, but, from the blind perspective, some of the 
end-users would also love to be able to define their own sets of voice 
commands, and have something like a personal assistant app handle that for 
them, instead of having to necessarily work with PC in normal ways all the 
time, and I played around with something relating to implementing the bare 
basics in a python command line app a little while ago, but, it only really 
used the windows voice recognition system/service, which meant it wasn't 
really useful from my side since the training interface for that is also 
pretty much useless to me, but anyway.

Stay well

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."

----- Original Message ----- 
From: "Eric S. Johansson" <esj at harvee.org>
To: <python-list at python.org>
Sent: Monday, January 05, 2015 8:18 PM
Subject: Re: need some guidance on Python syntax smart editor for use with 
speech recognition


>
> On 1/5/2015 7:24 AM, Chris Angelico wrote:
>> On Mon, Jan 5, 2015 at 8:34 PM, Jonas Wielicki <jonas at wielicki.name> 
>> wrote:
>>> As a first iteration, I would try with any editor written in Python.
>>> Are you familiar with the ast[1] module? It could be worth trying to
>>> use this module and perform some kind of pattern matching on the
>>> results to recover the information.
>> An AST parse throws away a lot of information. You can't easily
>> reconstruct the original code from that; at best, you can decompile
>> the AST back into functionally-equivalent source code, but it's not
>> something you want to do as part of editing code.
>
> Chris is right. I looked at this and came up with the same conclusion. 
> Here's a use case that I haven't talked about yet but is part of the 
> problem of speech driven programming. I have a chunk of code that I 
> created that is exactly right but it's in the wrong place or wrong method 
> or even just the wrong environment. I need to capture it and then move it 
> to the right place.
>
> At first glance, this would look like a simple cut-and-paste and, 
> sometimes it is but more often it's not. Let's take the example of a 
> simple file generator. Opening the file, iterating over the input until 
> the input data transformation process runs out of data.
>
> This is a real common pattern and what changes are certain elements of the 
> code, variables, strings whatever but also the indentation. So putting the 
> old chunk of code into the new place requires transformation that most of 
> you guys do by hand without thinking twice. Me it's, #()@!&#$, and I use a 
> whole bunch of kill words to strip out the old data and put in the new.
>
> Imagine being able to rip out a piece of code, identify the substitution 
> points and the indentation adjustment levels and then being able to put in 
> that piece of code in other places and just fill in the blanks as a part 
> of the insertion dialogue.  Now this gets us to the same point I was first 
> talking about which is the ability to identify the idiom and code to 
> operate on it as an idiom. some of the stuff I've seen with snippets is 
> partly there, again it is a one-way transform.
>
> It seems to me that those of us with hands and those of us with broken 
> hands could use this same functionality given the right supportive user 
> interface.
>
> Now I've been living with this kind of idea for a while and I realize that 
> may not make sense in this abstract written description. What do I need to 
> fill in?
>
>> However, back when I was doing my PEP 463 research, someone suggested
>> looking into the 2to3 parser. I regretfully admit that I have yet to
>> actually do so, but it ought in theory allow source-level
>> transformations with a measure of intelligence. It's not a ready-made
>> solution by any means, but it could be a useful tool. [2]
>
> Good idea.
>>> Hope this helps. I find that topic pretty interesting. Is there
>>> anything I can follow to see progress on this?
>> Likewise!
>>
>> ChrisA
>
> Is there any problem with keeping the conversation going here or would you 
> prefer some other way of talking about it? I've been hesitant to put my 
> work up on github because it's flailing about with also the bloody loose 
> ends because I'm trying to solve up number of problems all at the same 
> time.   The problem first being a framework where I can add speech driven 
> UI elements to an editor so I can start experimenting with a bunch of 
> these pieces.
>
> Another way you can help is be my hands. sometimes I just run out of hand 
> time and it takes a while for me build up enough energy so I can spend the 
> day working for money and a day working on this.
>
> --- eric
>
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 



From rosuav at gmail.com  Mon Jan  5 16:37:46 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 6 Jan 2015 08:37:46 +1100
Subject: need some guidance on Python syntax smart editor for use with
 speech recognition
In-Reply-To: <54AAD585.1070407@harvee.org>
References: <54AA408F.4080101@harvee.org> <54AA5ABC.4020103@wielicki.name>
 <CAPTjJmqa6HU-bk-33OHkORHky39zRkJ_ZGGYaR+tFzR5QvrCyg@mail.gmail.com>
 <54AAD585.1070407@harvee.org>
Message-ID: <CAPTjJmoGUg1mjuG7Ky1hk9wfm=XGRWSSgc=2vE3Skn6Sta=uoQ@mail.gmail.com>

On Tue, Jan 6, 2015 at 5:18 AM, Eric S. Johansson <esj at harvee.org> wrote:
> Is there any problem with keeping the conversation going here or would you
> prefer some other way of talking about it? I've been hesitant to put my work
> up on github because it's flailing about with also the bloody loose ends
> because I'm trying to solve up number of problems all at the same time.
> The problem first being a framework where I can add speech driven UI
> elements to an editor so I can start experimenting with a bunch of these
> pieces.

The conversation is perfectly on-topic here, so it's just the code.
Personally, I don't mind letting loose ends, even exsanguinated ones,
be visible on github; but you might prefer to hide all of that.

ChrisA


From rosuav at gmail.com  Mon Jan  5 16:40:32 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 6 Jan 2015 08:40:32 +1100
Subject: toStringList in PyQt5
In-Reply-To: <fab6a2bc-051f-42fa-a0f0-4dd6d6d87752@googlegroups.com>
References: <fab6a2bc-051f-42fa-a0f0-4dd6d6d87752@googlegroups.com>
Message-ID: <CAPTjJmowhX6NHLPr1-5qds2yOaP_C7MJEm8D_6+8CsStp0uUKA@mail.gmail.com>

On Tue, Jan 6, 2015 at 5:04 AM, Suhail Mahmood
<suhailmahmood.c070 at gmail.com> wrote:
>            self.recentFiles = settings.value("RecentFiles").toStringList()
>        AttributeError: 'NoneType' object has no attribute 'toStringList'

This sounds to me like your RecentFiles setting doesn't exist yet. You
could try a two-step approach:

files = settings.value("RecentFiles")
if files: self.recentFiles = files.toStringList()
# else self.recentFiles = ... something else? ...

or you could look at the docs for your QSettings object and see if you
can provide a default for it to return. That might save you some
trouble.

ChrisA


From drsalists at gmail.com  Mon Jan  5 17:45:57 2015
From: drsalists at gmail.com (Dan Stromberg)
Date: Mon, 5 Jan 2015 14:45:57 -0800
Subject: If you were starting a project with XML datasource using python
In-Reply-To: <55e354fd-a5bc-4f1f-a59a-55951fe81ca3@googlegroups.com>
References: <55e354fd-a5bc-4f1f-a59a-55951fe81ca3@googlegroups.com>
Message-ID: <CAGGBd_rWOq3ZUaDAqjgU8rpxwwfK5kzzc9Th9aD=i9aMQKBFqA@mail.gmail.com>

On Mon, Jan 5, 2015 at 3:54 AM, flebber <flebber.crue at gmail.com> wrote:
> Hi
>
> I need some advice on managing data in the form of xml. I will have to repeatedly import a small xml file but with many complex attributes.

If I have a choice, I choose JSON over XML.

If stuck with XML, I like xmltodict: https://pypi.python.org/pypi/xmltodict

I've used xmltodict in two projects - both worked well, except I
needed to define:

def dict_constructor(*args, **kwargs):
    '''
    With this higher order function passed to xmltodict.parse, we're
forcing singleton tags to be returned as lists.
    See also https://github.com/martinblech/xmltodict/issues/14 .
    '''
    return collections.defaultdict(list, *args, **kwargs)

...and use it like:
    xml_dict = xmltodict.parse(xml_string, dict_constructor=dict_constructor)

This was necessary to keep singletons from being returned as
singletons, instead returning them as single-element lists.  Sometimes
singletons are fine, but other times you need to be able to accept 1
or more of something  without a traceback.

HTH


From tjreedy at udel.edu  Mon Jan  5 18:28:40 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Mon, 05 Jan 2015 18:28:40 -0500
Subject: Help with map python 2
In-Reply-To: <597df0f8-234a-468c-bb48-1954db491b3c@googlegroups.com>
References: <60e62263-6cd1-48b9-acbc-f1a0b947b8c9@googlegroups.com>
 <qotoaqe7nol.fsf@ruuvi.it.helsinki.fi>
 <597df0f8-234a-468c-bb48-1954db491b3c@googlegroups.com>
Message-ID: <m8f6nj$mos$1@ger.gmane.org>

On 1/5/2015 6:33 AM, flebber wrote:
>
>> You could do what mathematicians do when they deal with alternating
>> signs: they raise -1 to the power of the index to get an appropriate
>> multiplier.
>>
>>     >>> [ n * (-1) ** n for n in range(10) ]
>>     [0, -1, 2, -3, 4, -5, 6, -7, 8, -9]

Mathematicians operating in the timeless Platonic universe of 
mathemtical forms are not concerned with such droll issues as 
computation time.  I think most regard '(-1)**n' as an abbreviation for 
'(-1 if odd(n) else 1)', where odd(n) is regarded as an O(1) operation, 
not as an indication to actually raise -1 to an arbitrarily large power. 
which could take an arbitrarily long time.


>> Or you could do here what you attempt to do with map below. See below.
>>
>
>>
>> You are trying to use a binary expression. There are no binary
>> expressions. Add an else branch to make it ternary:
>>
>>     lambda x : x if x % 2 == 0 else -x
>>
>> But never mind the number of branches, the serious point is that you
>> didn't specify a value for when the condition is not true. It doesn't
>> make sense without that.
>>
>> There's nothing wrong with a list comprehension, or the corresponding
>> generator expression if you want a generator. It's fine. Map's fine.
>
> Thanks Jussi  I really like the multiplier solution.
>


-- 
Terry Jan Reedy



From steve+comp.lang.python at pearwood.info  Mon Jan  5 20:12:20 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 06 Jan 2015 12:12:20 +1100
Subject: problem with for and if
References: <a71e126d-4b27-42a3-8103-3381b62794d2@googlegroups.com>
Message-ID: <54ab3675$0$12986$c3e8da3$5496439d@news.astraweb.com>

Dariusz Mysior wrote:

> I want search count of szukana in zmienna but code below counting all 12
> letters from "traktorzysta" word
> 
> szukana="t"
> zmienna="traktorzysta"
> 
> 
> def gen():
>     count=int(0)
>     for a in zmienna:
>         if szukana in zmienna:
>             count+=1
>         else:
>             continue
>     return count


I think what you want is:

zmienna.count(szukana)




-- 
Steven



From steve+comp.lang.python at pearwood.info  Mon Jan  5 20:30:01 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 06 Jan 2015 12:30:01 +1100
Subject: Help with map python 2
References: <60e62263-6cd1-48b9-acbc-f1a0b947b8c9@googlegroups.com>
 <qotoaqe7nol.fsf@ruuvi.it.helsinki.fi>
 <597df0f8-234a-468c-bb48-1954db491b3c@googlegroups.com>
 <mailman.17406.1420500655.18130.python-list@python.org>
Message-ID: <54ab3a9a$0$12980$c3e8da3$5496439d@news.astraweb.com>

Terry Reedy wrote:

> On 1/5/2015 6:33 AM, flebber wrote:
>>
>>> You could do what mathematicians do when they deal with alternating
>>> signs: they raise -1 to the power of the index to get an appropriate
>>> multiplier.
>>>
>>>     >>> [ n * (-1) ** n for n in range(10) ]
>>>     [0, -1, 2, -3, 4, -5, 6, -7, 8, -9]
> 
> Mathematicians operating in the timeless Platonic universe of
> mathemtical forms are not concerned with such droll issues as
> computation time.  I think most regard '(-1)**n' as an abbreviation for
> '(-1 if odd(n) else 1)', where odd(n) is regarded as an O(1) operation,
> not as an indication to actually raise -1 to an arbitrarily large power.
> which could take an arbitrarily long time.

Theoretically it could, but in practical terms no programming language would
use such a poor implementation.

At worst, you should expect n**m to take no more than O(log m)
multiplications, and in the specific case of n == 1 or -1, you might even
hope for constant time. How does CPython go?


[steve at ando ~]$ python2.7 -m timeit "(-1)**1000"
10000000 loops, best of 3: 0.0479 usec per loop
[steve at ando ~]$ python2.7 -m timeit "(-1)**1000000000"
10000000 loops, best of 3: 0.0477 usec per loop

But wait! Maybe I'm tripping over the keyhole optimizer. Let's try again:


[steve at ando ~]$ python2.7 -m timeit -s "n = -1; m = 1000" "n**m"
1000000 loops, best of 3: 0.195 usec per loop
[steve at ando ~]$ python2.7 -m timeit -s "n = -1; m = 1000000000" "n**m"
1000000 loops, best of 3: 0.447 usec per loop
[steve at ando ~]$ python2.7 -m timeit -s "n = -1; m = 1000000000000000" "n**m"
100000 loops, best of 3: 9.32 usec per loop


So it appears that CPython 2.7 eschews some possible ** optimizations, but
even so, it's pretty fast. Increasing the power by a factor of one million
only doubles the time, so long as the power is an int. Increasing it by
another factor of a million makes the power a long, and the time taken
increases by a factor of about 20. But in absolute terms, it's still very
fast: less than 10 microseconds.


How does Python 3.3 go? For small powers, it is slower than 2.7, but for
large powers, it is faster.

[steve at ando ~]$ python3.3 -m timeit -s "n = -1; m = 1000" "n**m"
1000000 loops, best of 3: 0.606 usec per loop
[steve at ando ~]$ python3.3 -m timeit -s "n = -1; m = 1000000000" "n**m"
1000000 loops, best of 3: 1.16 usec per loop
[steve at ando ~]$ python3.3 -m timeit -s "n = -1; m = 1000000000000000" "n**m"
1000000 loops, best of 3: 1.97 usec per loop

Let's keep going:

[steve at ando ~]$ python3.3 -m timeit -s "n = -1; m = 10**100 + 1" "n**m"
100000 loops, best of 3: 9.47 usec per loop
[steve at ando ~]$ python3.3 -m timeit -s "n = -1; m = 10**1000 + 1" "n**m"
10000 loops, best of 3: 83.9 usec per loop

I don't think that this will be a problem in practical terms.


-- 
Steven



From rosuav at gmail.com  Mon Jan  5 20:55:57 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 6 Jan 2015 12:55:57 +1100
Subject: If you were starting a project with XML datasource using python
In-Reply-To: <r3cmaap018mue2ujmdvfqi9ledj7jai2jo@4ax.com>
References: <55e354fd-a5bc-4f1f-a59a-55951fe81ca3@googlegroups.com>
 <mailman.17395.1420466196.18130.python-list@python.org>
 <792cb61b-d351-4b4b-aa7b-35e959111c0a@googlegroups.com>
 <r3cmaap018mue2ujmdvfqi9ledj7jai2jo@4ax.com>
Message-ID: <CAPTjJmoGTAaj7p7GGqjmeG-JzvwgJ=Pv0JfSYB9vqG0mX7qk3A@mail.gmail.com>

On Tue, Jan 6, 2015 at 11:49 AM, Dennis Lee Bieber
<wlfraed at ix.netcom.com> wrote:
>>So you would convert it to json so it can then be stored?
>>
>         NO!
>
>         JSON and XML, in my mind, are equivalents -- (human-readable) notations
> for transferring data between applications. JSON may just have fewer
> "options" for how to notate basic data.

JSON corresponds much more closely to Python data types, but
converting from one to the other can't improve matters any.

ChrisA


From georger.silva at gmail.com  Mon Jan  5 21:24:31 2015
From: georger.silva at gmail.com (George Silva)
Date: Tue, 6 Jan 2015 00:24:31 -0200
Subject: If you were starting a project with XML datasource using python
In-Reply-To: <CAPTjJmoGTAaj7p7GGqjmeG-JzvwgJ=Pv0JfSYB9vqG0mX7qk3A@mail.gmail.com>
References: <55e354fd-a5bc-4f1f-a59a-55951fe81ca3@googlegroups.com>
 <mailman.17395.1420466196.18130.python-list@python.org>
 <792cb61b-d351-4b4b-aa7b-35e959111c0a@googlegroups.com>
 <r3cmaap018mue2ujmdvfqi9ledj7jai2jo@4ax.com>
 <CAPTjJmoGTAaj7p7GGqjmeG-JzvwgJ=Pv0JfSYB9vqG0mX7qk3A@mail.gmail.com>
Message-ID: <CAGyPVTsueOu7hV-sdb=yNQN7QzMWidDwONwsD=mosd59EYfrJw@mail.gmail.com>

As people already said, don't use XML for persistence.

Read it, parse it, and persist it in another format. databases are quite
good for that. even sqlite3 will outperfom any few MB xml files.

On Mon, Jan 5, 2015 at 11:55 PM, Chris Angelico <rosuav at gmail.com> wrote:

> On Tue, Jan 6, 2015 at 11:49 AM, Dennis Lee Bieber
> <wlfraed at ix.netcom.com> wrote:
> >>So you would convert it to json so it can then be stored?
> >>
> >         NO!
> >
> >         JSON and XML, in my mind, are equivalents -- (human-readable)
> notations
> > for transferring data between applications. JSON may just have fewer
> > "options" for how to notate basic data.
>
> JSON corresponds much more closely to Python data types, but
> converting from one to the other can't improve matters any.
>
> ChrisA
> --
> https://mail.python.org/mailman/listinfo/python-list
>



-- 
George R. C. Silva
SIGMA Consultoria
----------------------------
http://www.consultoriasigma.com.br/
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From hayesstw at telkomsa.net  Mon Jan  5 22:59:06 2015
From: hayesstw at telkomsa.net (Steve Hayes)
Date: Tue, 06 Jan 2015 05:59:06 +0200
Subject: If you were starting a project with  XML datasource using python
References: <55e354fd-a5bc-4f1f-a59a-55951fe81ca3@googlegroups.com>
Message-ID: <2bnmaa5nu4dhv1qvhk40r7jdfghrua20oj@4ax.com>

On Mon, 5 Jan 2015 03:54:06 -0800 (PST), flebber <flebber.crue at gmail.com>
wrote:

Hi

I need some advice on managing data in the form of xml. I will have to
repeatedly import a small xml file but with many complex attributes.

If I want to retain data integrity and keep the import process simple and
querying from the stored source simple what are my best options?

There are several options for converting XML into objects such as:
http://lxml.de/objectify.html
https://pypi.python.org/pypi/pyxml2obj/
http://eulxml.readthedocs.org/en/latest/xmlmap.html

I could push this as an embedded object into mongo and search from there.

Could ignore XML by just converting to json with something like xml2json and
pushing to many databases from there.

(reposted to fix the long lines produced by the lame GoogleGroups editor)

-- 
Steve Hayes from Tshwane, South Africa
Web:  http://www.khanya.org.za/stevesig.htm
Blog: http://khanya.wordpress.com
E-mail - see web page, or parse: shayes at dunelm full stop org full stop uk


From andrew3 at r3dsolutions.com  Tue Jan  6 05:27:22 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Tue, 06 Jan 2015 02:27:22 -0800
Subject: Comparisons and sorting of a numeric class....
Message-ID: <54ABB88A.7070504@r3dsolutions.com>

Hi,
I'm building a custom numeric class that works with values that have 
uncertainty and am wanting to make it as compatible with floating point 
objects as possible -- so as to be usable in legacy code with minimal 
rewites; but but I am having trouble understanding how to handle 
magnitude comparison return values for __lt__ __gt__ etc.

The problem with magnitude comparisons in my class is that the 
comparison may fail to be True for various reasons, and in various ways, 
but it's important for programming to retain the general reason a 
comparison wasn't strictly 'True'.

For example, to 1 significant figure, I can write two values 
a=mynum(0.1) and b=mynum(0.01) ; as written both of them have an 
uncertainty of 1 least significant figure, so it is possible both values 
are really a 0.   But, there is a bias/mean/average which suggests that 
more often than not -- 0.1 will be bigger than 0.01. So, what is the 
proper response of a>b ?,  the answer is that a>b depends on the context 
of how the values were obtained and what is being done with them, 
although strictly speaking 'a' is not greater than 'b' in this case, 
although 'a' has a much better chance of being greater than 'b' on 
average which may be important for the user to know.

Where I'm getting stuck is how to encode the return values of the 
comparison operators to be compatible with python floating point object 
return values (and python's sort algorithms for lists of floats) but 
still give extra functionality that is needed for uncertainty ... and as 
I'm writing in python 2.xx but with an eye toward python 3 in the 
future, I've become concerned that __cmp__ has been discontinued so that 
I need to write this using only __gt__() and friends.  I don't know how 
to do it.

What I would like is for operators like '>' to return a boolean True or 
False equivalent, which also encodes the reason for failure in one of 
five ways:

True:          Sufficient information and confidence exists that the 
comparison is thoroughly True.
PartTrue:    The comparison is uncertain for any single sample, but True 
is at least minimally more probable.
Unbiased:  The comparison is uncertain for any single sample.
PartFalse:   The comparison is uncertain for any single sample, but 
False is at least minimally more probable.
False:         Sufficient information and confidence exists that the 
comparison is thoroughly False.

By default, only True would evaluate in conditional statement as a 
logical True.  All other values would be equivalent to False, but 
hopefully, a programmer could find out which 'False' was returned by 
some kind of object inspection or operator, like:

if (a>b) is PartTrue:     print "I don't really know if 'a' really is 
greater than 'b'. but it might be"
if (a>b) > Unbiased:   print "a sorts after b because it's at least more 
probable that a>b than not."
if (a>b):  print "this message will not print if the value 'b' might 
occasionally be less than or equal to 'a'."

For sorting, it would be ideal if the sorting algorithms min(), max(), 
etc. could automatically recognize that:
False < PartFalse < Unknown < PartTrue < True.

But, even if that can't be done -- if there were a way, or method I 
could add to my classes, which would intercept sort functions and 
replace an absolute certain compare function with a merely Unbiased 
detecting one; sort functions would all operate properly.

However, I'm not sure how to create these return values nor do I know 
how to get the sort() functions to use them.

I've tried subclassing float() to see if I could actually make a 
subclass that inherited all that float has, and be able to add extra 
methods for my own use -- but Python doesn't seem to allow subclassing 
float.  I either am not doing it right, or it can't be done.

So, I'm not sure I can subclass boolean either because that too is a 
built in class ...  but I'm not sure how else to make an object that 
acts as boolean False, but can be differentiated from false by the 'is' 
operator.  It's frustrating -- what good is subclassing, if one cant 
subclass all the base classes the language has?

What other approaches can I take?

'False' is a singleton, so I was pretty sure this wouldn't work -- but I 
tried it...
PartTrue = False
if (1>2) is PartTrue: print "This is an obvious failure...  False is not 
the object PartTrue."

And I am seriously stumped....


















From davea at davea.name  Tue Jan  6 06:21:14 2015
From: davea at davea.name (Dave Angel)
Date: Tue, 06 Jan 2015 06:21:14 -0500
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54ABB88A.7070504@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com>
Message-ID: <54ABC52A.1050507@davea.name>

On 01/06/2015 05:27 AM, Andrew Robinson wrote:
> Hi,
> I'm building a custom numeric class that works with values that have
> uncertainty and am wanting to make it as compatible with floating point
> objects as possible -- so as to be usable in legacy code with minimal
> rewites; but but I am having trouble understanding how to handle
> magnitude comparison return values for __lt__ __gt__ etc.
>
> The problem with magnitude comparisons in my class is that the
> comparison may fail to be True for various reasons, and in various ways,
> but it's important for programming to retain the general reason a
> comparison wasn't strictly 'True'.
>
> For example, to 1 significant figure, I can write two values
> a=mynum(0.1) and b=mynum(0.01) ; as written both of them have an
> uncertainty of 1 least significant figure, so it is possible both values
> are really a 0.   But, there is a bias/mean/average which suggests that
> more often than not -- 0.1 will be bigger than 0.01. So, what is the
> proper response of a>b ?,  the answer is that a>b depends on the context
> of how the values were obtained and what is being done with them,
> although strictly speaking 'a' is not greater than 'b' in this case,
> although 'a' has a much better chance of being greater than 'b' on
> average which may be important for the user to know.
>
> Where I'm getting stuck is how to encode the return values of the
> comparison operators to be compatible with python floating point object
> return values (and python's sort algorithms for lists of floats) but
> still give extra functionality that is needed for uncertainty ... and as
> I'm writing in python 2.xx but with an eye toward python 3 in the
> future, I've become concerned that __cmp__ has been discontinued so that
> I need to write this using only __gt__() and friends.  I don't know how
> to do it.
>
> What I would like is for operators like '>' to return a boolean True or
> False equivalent, which also encodes the reason for failure in one of
> five ways:
>
> True:          Sufficient information and confidence exists that the
> comparison is thoroughly True.
> PartTrue:    The comparison is uncertain for any single sample, but True
> is at least minimally more probable.
> Unbiased:  The comparison is uncertain for any single sample.
> PartFalse:   The comparison is uncertain for any single sample, but
> False is at least minimally more probable.
> False:         Sufficient information and confidence exists that the
> comparison is thoroughly False.
>

Just a few comments, not a thorough examination.  And I don't have time 
to actually try it today.

1) to subclass built-in types, you frequently have to implement your own 
constructor.  You probably tried it by only implementing the 
initializer.  The constructor has the name __new__

and you probably should read:
     http://rhettinger.wordpress.com/2011/05/26/super-considered-super/

2) to be sortable, your comparison mechanism needs to be stable.  (I 
think that's the word).  Anyway, if a < b  and b < c,  then a must be < 
c.  It's not clear that you can accomplish that with the approach you're 
describing.  But if you modify your definition for values near zero, it 
may be possible.

3) Your user will have to be aware that she's not using regular float 
values.  Sooner or later some functions will have to be used 
differently.  But you should still be able to mostly preserve the illusion.

4) When you convert to Python version 3.x, you'll have to re-study all 
these issues.  It may be to your advantage to do both versions at once, 
or to just support version 3.x


> By default, only True would evaluate in conditional statement as a
> logical True.  All other values would be equivalent to False, but
> hopefully, a programmer could find out which 'False' was returned by
> some kind of object inspection or operator, like:
>
> if (a>b) is PartTrue:     print "I don't really know if 'a' really is
> greater than 'b'. but it might be"
> if (a>b) > Unbiased:   print "a sorts after b because it's at least more
> probable that a>b than not."
> if (a>b):  print "this message will not print if the value 'b' might
> occasionally be less than or equal to 'a'."
>

Those should all be possible.

> For sorting, it would be ideal if the sorting algorithms min(), max(),
> etc. could automatically recognize that:
> False < PartFalse < Unknown < PartTrue < True.
>
> But, even if that can't be done -- if there were a way, or method I
> could add to my classes, which would intercept sort functions and
> replace an absolute certain compare function with a merely Unbiased
> detecting one; sort functions would all operate properly.
>
> However, I'm not sure how to create these return values nor do I know
> how to get the sort() functions to use them.
>
> I've tried subclassing float() to see if I could actually make a
> subclass that inherited all that float has, and be able to add extra
> methods for my own use -- but Python doesn't seem to allow subclassing
> float.  I either am not doing it right, or it can't be done.
>
> So, I'm not sure I can subclass boolean either because that too is a
> built in class ...  but I'm not sure how else to make an object that
> acts as boolean False, but can be differentiated from false by the 'is'
> operator.  It's frustrating -- what good is subclassing, if one cant
> subclass all the base classes the language has?

As I said above, make sure you have a constructor.  If you still get an 
error, post a message that shows exactly what you did, and what 
exception you saw.

>
> What other approaches can I take?
>
> 'False' is a singleton, so I was pretty sure this wouldn't work -- but I
> tried it...
> PartTrue = False
> if (1>2) is PartTrue: print "This is an obvious failure...  False is not
> the object PartTrue."

You misunderstand the term singleton in this context.  When you execute
    PartTrue = False

you are just rebinding PartTrue to the object called False.  There's 
still only one object.



-- 
DaveA


From andrew3 at r3dsolutions.com  Tue Jan  6 08:30:43 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Tue, 06 Jan 2015 05:30:43 -0800
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54ABC52A.1050507@davea.name>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
Message-ID: <54ABE383.3020801@r3dsolutions.com>


>> So, I'm not sure I can subclass boolean either because that too is a
>> built in class ...  but I'm not sure how else to make an object that
>> acts as boolean False, but can be differentiated from false by the 'is'
>> operator.  It's frustrating -- what good is subclassing, if one cant
>> subclass all the base classes the language has?
>
> As I said above, make sure you have a constructor.  If you still get 
> an error, post a message that shows exactly what you did, and what 
> exception you saw.
>

OK.
I tried to subclass bool, using __new__ just to see if it would even 
accept the definition... eg: python 2.7.5

 >>> class UBool( bool ):
...     def __new__( self, default ): return bool.__new__( self, default )
...
Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
TypeError: Error when calling the metaclass bases
     type 'bool' is not an acceptable base type

I also tried using return int.__new__( self, bool(default) ) but that 
too failed the exact same way.


I came across this in my searches, perhaps it has something to do with 
why I can't do this?
https://mail.python.org/pipermail/python-dev/2002-March/020822.html

I thought about this last night, and realized that you shouldn't be
allowed to subclass bool at all!  A subclass would only be useful when
it has instances, but the mere existance of an instance of a subclass
of bool would break the invariant that True and False are the only
instances of bool!  (An instance of a subclass of C is also an
instance of C.)  I think it's important not to provide a backdoor to
create additional bool instances, so I think bool should not be
subclassable.

...

--Guido van Rossum

So, I think Guido may have done something so that there are only two 
instances of bool, ever.
eg: False and True, which aren't truly singletons -- but follow the 
singleton restrictive idea of making a single instance of an object do 
the work for everyone; eg: of False being the only instance of bool 
returning False, and True being the only instance of bool returning True.

Why this is so important to Guido, I don't know ... but it's making it 
VERY difficult to add named aliases of False which will still be 
detected as False and type-checkable as a bool.  If my objects don't 
type check right -- they will likely break some people's legacy code...  
and I really don't even care to create a new instance of the bool object 
in memory which is what Guido seems worried about, rather I'm really 
only after the ability to detect the subclass wrapper name as distinct 
from bool False or bool True with the 'is' operator.  If there were a 
way to get the typecheck to match, I wouldn't mind making a totally 
separate class which returned the False instance; eg: something like an 
example I modified from searching on the web:

class UBool():
     def __nonzero__(self): return self.default
     def __init__( self, default=False ): self.default = bool(default)
     def default( self, default=False ): self.defualt = bool(default)

but, saying:
 >>> error=UBool(False)
 >>> if error is False: print "type and value match"
...
 >>>

Failed to have type and value match, and suggests that 'is' tests the 
type before expanding the value.
It's rather non intuitive, and will break code -- for clearly error 
expands to 'False' when evaluated without comparison functions like ==.

 >>> if not error: print "yes it is false"
...
yes it is false
 >>> print error.__nonzero__()
False
 >>> if error==False: print "It compares to False properly"
...
 >>>

So, both 'is' and == seems to compare the type before attempting to 
expand the value.
As a simple cross check, I tried to make a one valued tuple.

 >>> a=(False,None)
 >>> print a
(False, None)
 >>> a=(False,)
 >>> if a is False: print "yes!!!"
...
 >>>
 >>> if not a: print "a is False"
...
 >>> if a == False: print "a is False"

but that obviously failed, too; and if == fails to say False==False ... 
well, it's just to sensitive for wrapper classes to be involved unless 
they are a subclass of bool...

Any ideas ?













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From rosuav at gmail.com  Tue Jan  6 08:35:49 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 7 Jan 2015 00:35:49 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54ABE383.3020801@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
Message-ID: <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>

On Wed, Jan 7, 2015 at 12:30 AM, Andrew Robinson
<andrew3 at r3dsolutions.com> wrote:
> Why this is so important to Guido, I don't know ... but it's making it VERY
> difficult to add named aliases of False which will still be detected as
> False and type-checkable as a bool.  If my objects don't type check right --
> they will likely break some people's legacy code...  and I really don't even
> care to create a new instance of the bool object in memory which is what
> Guido seems worried about, rather I'm really only after the ability to
> detect the subclass wrapper name as distinct from bool False or bool True
> with the 'is' operator.  If there were a way to get the typecheck to match,
> I wouldn't mind making a totally separate class which returned the False
> instance; eg: something like an example I modified from searching on the
> web:

Okay, so why not just go with your own class, and deal with the
question of the type check? Simple solution: Instead of fiddling with
__gt__/__lt__, create your own method, and use your own comparison
function to sort these things.

ChrisA


From davea at davea.name  Tue Jan  6 09:02:01 2015
From: davea at davea.name (Dave Angel)
Date: Tue, 06 Jan 2015 09:02:01 -0500
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54ABE383.3020801@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
Message-ID: <54ABEAD9.8070000@davea.name>

On 01/06/2015 08:30 AM, Andrew Robinson wrote:
>
>>> So, I'm not sure I can subclass boolean either because that too is a
>>> built in class ...  but I'm not sure how else to make an object that
>>> acts as boolean False, but can be differentiated from false by the 'is'
>>> operator.  It's frustrating -- what good is subclassing, if one cant
>>> subclass all the base classes the language has?

I said earlier that I don't think it's possible to do what you're doing 
without your users code being somewhat aware of your changes.

But as long as the user doesn't check for the subclass-ness of your 
bool-like function, you should manage.  In Python, duck-typing is 
encouraged, unlike java or C++, where the only substitutable classes are 
subclasses.

>>
>> As I said above, make sure you have a constructor.  If you still get
>> an error, post a message that shows exactly what you did, and what
>> exception you saw.
>>
>
> OK.
> I tried to subclass bool, using __new__ just to see if it would even
> accept the definition... eg: python 2.7.5
>
>  >>> class UBool( bool ):
> ...     def __new__( self, default ): return bool.__new__( self, default )
> ...
> Traceback (most recent call last):
>    File "<stdin>", line 1, in <module>
> TypeError: Error when calling the metaclass bases
>      type 'bool' is not an acceptable base type
>
> I also tried using return int.__new__( self, bool(default) ) but that
> too failed the exact same way.
>
>
> I came across this in my searches, perhaps it has something to do with
> why I can't do this?
> https://mail.python.org/pipermail/python-dev/2002-March/020822.html
>
> I thought about this last night, and realized that you shouldn't be
> allowed to subclass bool at all!  A subclass would only be useful when
> it has instances, but the mere existance of an instance of a subclass
> of bool would break the invariant that True and False are the only
> instances of bool!  (An instance of a subclass of C is also an
> instance of C.)  I think it's important not to provide a backdoor to
> create additional bool instances, so I think bool should not be
> subclassable.
>
> ...
>
> --Guido van Rossum
>
> So, I think Guido may have done something so that there are only two
> instances of bool, ever.
> eg: False and True, which aren't truly singletons -- but follow the
> singleton restrictive idea of making a single instance of an object do
> the work for everyone; eg: of False being the only instance of bool
> returning False, and True being the only instance of bool returning True.
>
> Why this is so important to Guido, I don't know ... but it's making it
> VERY difficult to add named aliases of False which will still be
> detected as False and type-checkable as a bool.  If my objects don't
> type check right -- they will likely break some people's legacy code...
> and I really don't even care to create a new instance of the bool object
> in memory which is what Guido seems worried about, rather I'm really
> only after the ability to detect the subclass wrapper name as distinct
> from bool False or bool True with the 'is' operator.  If there were a

There's already a contradiction in what you want.  You say you don't 
want to create a new bool object (distinct from True and False), but you 
have to create an instance of your class.  If it WERE a subclass of 
bool, it'd be a bool, and break singleton.

If you ignore your subclass "requirement,"  'is' should do the right 
thing.  Whatever your class instance is, it won't be the same object as 
True or as False.

> way to get the typecheck to match,

That's a piece of legacy code which you won't be able to support, as far 
as I can see.

> I wouldn't mind making a totally
> separate class which returned the False instance; eg: something like an
> example I modified from searching on the web:
>
> class UBool():
>      def __nonzero__(self): return self.default
>      def __init__( self, default=False ): self.default = bool(default)
>      def default( self, default=False ): self.defualt = bool(default)
>
> but, saying:
>  >>> error=UBool(False)
>  >>> if error is False: print "type and value match"
> ...
>  >>>
>
> Failed to have type and value match, and suggests that 'is' tests the
> type before expanding the value.

Not at all.  It doesn't check the type or the value.  It checks whether 
it's the SAME object.

> It's rather non intuitive, and will break code -- for clearly error
> expands to 'False' when evaluated without comparison functions like ==.
>
>  >>> if not error: print "yes it is false"
> ...
> yes it is false

No, the object False is not referenced in the above expression. You're 
checking the "falseness" of the expression.  Same as if you say
       if not 0
       if not mylist

>  >>> print error.__nonzero__()
> False
>  >>> if error==False: print "It compares to False properly"
> ...

You control this one by your __eq__ method.

>  >>>
>
> So, both 'is' and == seems to compare the type before attempting to
> expand the value.
> As a simple cross check, I tried to make a one valued tuple.
>
>  >>> a=(False,None)
>  >>> print a
> (False, None)
>  >>> a=(False,)
>  >>> if a is False: print "yes!!!"
> ...
>  >>>
>  >>> if not a: print "a is False"
> ...
>  >>> if a == False: print "a is False"
>
> but that obviously failed, too; and if == fails to say False==False ...
> well, it's just to sensitive for wrapper classes to be involved unless
> they are a subclass of bool...
>

1)  read up more closely on special methods, and on the meanings of id() 
and 'is'

2) And don't expect that any change you make at this level could be 
transparent to all existing applications.  It's a contradiction in terms.


-- 
DaveA


From phd at phdru.name  Tue Jan  6 10:53:44 2015
From: phd at phdru.name (Oleg Broytman)
Date: Tue, 6 Jan 2015 16:53:44 +0100
Subject: SQLObject 2.1.0
Message-ID: <20150106155344.GB25782@phdru.name>

Hello!

I'm pleased to announce version 2.1.0, the first stable release of branch
2.1 of SQLObject.


What's new in SQLObject
=======================

Minor features
--------------

* In queries generated with SQLObject's tables columns are sorted in the
  order they are declared in the table.

* In queries generated with sqlbuilder's Insert/Update, if values are
  passed using dictionaries, columns are sorted alphabetically.

* Tables in SELECT...FROM clause are sorted alphabetically.

* MySQLConnection, PostgresConnection and SQLiteConnection have got
  a new method listDatabases() that lists databases in the connection
  and returns a list of names.

* MySQLConnection, PostgresConnection and SQLiteConnection have got
  a new method listTables() that returns a list of table names in the database.

Contributor for this release is Ian Cordasco.

For a more complete list, please see the news:
http://sqlobject.org/News.html


What is SQLObject
=================

SQLObject is an object-relational mapper.  Your database tables are described
as classes, and rows are instances of those classes.  SQLObject is meant to be
easy to use and quick to get started with.

SQLObject supports a number of backends: MySQL, PostgreSQL, SQLite,
Firebird, Sybase, MSSQL and MaxDB (also known as SAPDB).

Python 2.6 or 2.7 is required.


Where is SQLObject
==================

Site:
http://sqlobject.org

Development:
http://sqlobject.org/devel/

Mailing list:
https://lists.sourceforge.net/mailman/listinfo/sqlobject-discuss

Archives:
http://news.gmane.org/gmane.comp.python.sqlobject

Download:
https://pypi.python.org/pypi/SQLObject/2.1.0

News and changes:
http://sqlobject.org/News.html

Oleg.
-- 
     Oleg Broytman            http://phdru.name/            phd at phdru.name
           Programmers don't die, they just GOSUB without RETURN.


From g.rodola at gmail.com  Tue Jan  6 11:02:29 2015
From: g.rodola at gmail.com (Giampaolo Rodola')
Date: Tue, 6 Jan 2015 17:02:29 +0100
Subject: ANN: psutil 2.2.0 released
Message-ID: <CAFYqXL--L422s1zHCk=Tw7YVc-81CUcu3otM2pn9GB=4UdM4Cg@mail.gmail.com>

Hello all,
I'm glad to announce the release of psutil 2.2.0.
In this new release I decided to drop support for Python 2.4 and 2.5 for
good.
Whoever is still on Python 2.4 and 2.5 can use old 2.1.3 version:
https://pypi.python.org/pypi?name=psutil&version=2.1.3&:action=files

Main features and bugfixes
==========================

- FreeBSD has now support for process CPU affinity
- new pstree.py and pidof.py example scripts
- C extension version mismatch in case the user messed up with psutil
installation or with sys.path is now detected at import time
- [Linux] a lot of file descriptors were left open
- [Windows] use proper encoding for psutil.Process.username() and
psutil.users().
- [Solaris] fixed a high-priority bug which crashed psutil on import.

The list of all enhancements and bugfixes is here:
https://github.com/giampaolo/psutil/blob/master/HISTORY.rst#220---2015-01-06

Links
=====

* Home page: https://github.com/giampaolo/psutil
* Downloads:
https://pypi.python.org/pypi?:action=display&name=psutil#downloads
* Documentation: http://pythonhosted.org/psutil/

Please try out this new release and let me know if you experience any
problem by filing issues on the bug tracker.

All the best,

-- 
Giampaolo - http://grodola.blogspot.com
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From steve+comp.lang.python at pearwood.info  Tue Jan  6 11:25:38 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 07 Jan 2015 03:25:38 +1100
Subject: Comparisons and sorting of a numeric class....
References: <mailman.17411.1420540134.18130.python-list@python.org>
Message-ID: <54ac0c83$0$12992$c3e8da3$5496439d@news.astraweb.com>

Andrew Robinson wrote:

> Hi,
> I'm building a custom numeric class that works with values that have
> uncertainty and am wanting to make it as compatible with floating point
> objects as possible -- so as to be usable in legacy code with minimal
> rewites; but but I am having trouble understanding how to handle
> magnitude comparison return values for __lt__ __gt__ etc.
> 
> The problem with magnitude comparisons in my class is that the
> comparison may fail to be True for various reasons, and in various ways,
> but it's important for programming to retain the general reason a
> comparison wasn't strictly 'True'.

It sounds like you want some sort of multi-valued or fuzzy logic here.
Skipping ahead, you wrote:


> What I would like is for operators like '>' to return a boolean True or
> False equivalent, which also encodes the reason for failure in one of
> five ways:
> 
> True:          Sufficient information and confidence exists that the
> comparison is thoroughly True.
> PartTrue:    The comparison is uncertain for any single sample, but True
> is at least minimally more probable.
> Unbiased:  The comparison is uncertain for any single sample.
> PartFalse:   The comparison is uncertain for any single sample, but
> False is at least minimally more probable.
> False:         Sufficient information and confidence exists that the
> comparison is thoroughly False.
> 
> By default, only True would evaluate in conditional statement as a
> logical True.  All other values would be equivalent to False, 
[...] 


Before you spend too much time on this, I recommend that you research some
of the existing theory on multi-value logic. There are a number of standard
types that you may be able to use for your needs, or possibly even find an
existing library for. Or there is fuzzy logic, where truth values vary
continuously between 0.0 and 1.0, with 0.0 being "absolutely false" and 1.0
being "absolutely true".

Start here: http://en.wikipedia.org/wiki/Many-valued_logic

Assuming nothing standard suits, you can't actually subclass bool, as you
have discovered. But that doesn't mean that you can't still use bools! You
just need some other values to use as well.

For simplicity, let's just create three singleton values. We're going to
have to bootstrap the instances into existence, so this will be a bit
messy:


# untested
class MultiLogic(object):
    PartTrue = Unbiased = PartFalse = None    
    def __new__(cls):
        raise TypeError('cannot create more instances')
    def __repr__(self):
        if self is type(self).PartTrue:
            return "PartTrue"
        if self is type(self).PartFalse:
            return "PartFalse"
        if self is type(self).Unbiased:
            return "Unbiased"
    # Python 2
    def __nonzero__(self):
        return False
    # Python 3
    def __bool__(self):
        return False

# Bootstrap the instances into existence.
PartTrue = MultiLogic.PartTrue = object.__new__(MultiLogic)
PartFalse = MultiLogic.PartFalse = object.__new__(MultiLogic)
Unbiased = MultiLogic.Unbiased = object.__new__(MultiLogic)


There's other ways to handle this, of course, but what we have now is
three "singleton" (tripleton?) values, PartTrue, PartFalse and Unbiased.
You can access them either by the global name, or via the MultiLogic.*
class attribute.


Now, let's use these in your numeric class:


# I don't think we should inherit from float.
class MyNumber(object):
    # See the source code for decimal.Decimal or fractions.Fraction
    # for ways to program a numeric type.

    def __eq__(self, other):
        if not isinstance(other, MyNumber):
            # Signal that we don't know how to do this comparison.
            return NotImplemented
        if some_condition:
            # Certainly equal.
            return True
        elif another_condition:
            # Probably equal.
            return PartTrue
        elif a_third_condition:
            # Probably not equal.
            return PartFalse
        elif yet_another_condition:
            # Definitely not equal.
            return False
        else:
            # Unknown.
            return Unbiased

    # Now do the same for __ne__ __lt__ __gt__ __le__ __ge__
    # (not equal, less than, greater than, less than or equal, 
    # greater than or equal)


You probably will want a helper method to avoid too much duplicate code in
your comparison operators.

By the way, you seem to be working on a form of fuzzy number or interval
arithmetic:

http://en.wikipedia.org/wiki/Fuzzy_number
http://en.wikipedia.org/wiki/Interval_arithmetic


> For example, to 1 significant figure, I can write two values
> a=mynum(0.1) and b=mynum(0.01) ; as written both of them have an
> uncertainty of 1 least significant figure, so it is possible both values
> are really a 0.   But, there is a bias/mean/average which suggests that
> more often than not -- 0.1 will be bigger than 0.01. So, what is the
> proper response of a>b ?,  the answer is that a>b depends on the context
> of how the values were obtained and what is being done with them,
> although strictly speaking 'a' is not greater than 'b' in this case,
> although 'a' has a much better chance of being greater than 'b' on
> average which may be important for the user to know.
> 
> Where I'm getting stuck is how to encode the return values of the
> comparison operators to be compatible with python floating point object
> return values (and python's sort algorithms for lists of floats) 

With this design, you probably will be able to sort lists of MyNumbers. But
sorting probably won't be stable! I expect that it will depend on the order
that you give the numbers. That is:

sorted([a, b, c, d] != sorted([b, c, a, d]

in general. The reason is that your comparison operators may not be
transitive. For real numbers, we have the rule:

    if a > b and b > c
    then a > c

and similar for the other comparisons, but once you add uncertainties those
may no longer apply. If they don't, then sorting will be unpredictable. If
they remain transitive, then sorting will behave sensibly.

Note: the programming language APL uses intransitive comparisons, including
fuzzy equality. In APL, if you had a == b, and b == c, that did not
necessarily mean that a == c.


[...]
> but 
> still give extra functionality that is needed for uncertainty ... and as
> I'm writing in python 2.xx but with an eye toward python 3 in the
> future, I've become concerned that __cmp__ has been discontinued so that
> I need to write this using only __gt__() and friends.  I don't know how
> to do it.


I don't think you can solve this problem with __cmp__ since it can only
represent three values, "less", "equal" or "greater".

[...]
> For sorting, it would be ideal if the sorting algorithms min(), max(),
> etc. could automatically recognize that:
> False < PartFalse < Unknown < PartTrue < True.

I don't think that is possible with the standard Python sort, but you could
write your own sort routines. It may be possible to come up with a clever
key function or cmp routine for sort that will do that.


> But, even if that can't be done -- if there were a way, or method I
> could add to my classes, which would intercept sort functions and
> replace an absolute certain compare function with a merely Unbiased
> detecting one; sort functions would all operate properly.
> 
> However, I'm not sure how to create these return values nor do I know
> how to get the sort() functions to use them.
> 
> I've tried subclassing float() to see if I could actually make a
> subclass that inherited all that float has, and be able to add extra
> methods for my own use -- but Python doesn't seem to allow subclassing
> float.  I either am not doing it right, or it can't be done.

Unless you are using a truly ancient version of Python, you can subclass
float. This has been possible since version 2.2.

If you show us what you tried, we can tell you what you've done wrong.


> So, I'm not sure I can subclass boolean either because that too is a
> built in class ...  

You cannot subclass bool.


> but I'm not sure how else to make an object that 
> acts as boolean False, but can be differentiated from false by the 'is'
> operator.

That is easy. Here is a trivial example:


class X:
    # Like False, but different.
    def __nonzero__(self):  # for Python 2
        return False
    def __bool__(self):  # for Python 3
        return False

x = X()

x now acts like boolean False, but can be differentiated by the 'is'
operator.


> It's frustrating -- what good is subclassing, if one cant 
> subclass all the base classes the language has?

Just because you can't subclass bool doesn't mean that subclassing (say)
list, dict, float, str, Exception, set and others isn't useful.


> What other approaches can I take?
> 
> 'False' is a singleton, so I was pretty sure this wouldn't work -- but I
> tried it...
> PartTrue = False
> if (1>2) is PartTrue: print "This is an obvious failure...  False is not
> the object PartTrue."
> 
> And I am seriously stumped....

Hopefully I've given you some good pointers. Feel free to ask many more
questions, although it is late here now (technically, it is very early) so
I'll be going to bed soon and may not get to answer until some time
tomorrow. But others may chime in with their own suggestions.



-- 
Steven



From andrew3 at r3dsolutions.com  Tue Jan  6 21:01:48 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Tue, 06 Jan 2015 18:01:48 -0800
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54ABEAD9.8070000@davea.name>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
Message-ID: <54AC938C.7040206@r3dsolutions.com>


On 01/06/2015 06:02 AM, Dave Angel wrote:
> On 01/06/2015 08:30 AM, Andrew Robinson wrote:
>>
>>>> So, I'm not sure I can subclass boolean either because that too is a
>>>> built in class ...  but I'm not sure how else to make an object that
>>>> acts as boolean False, but can be differentiated from false by the 
>>>> 'is'
>>>> operator.  It's frustrating -- what good is subclassing, if one cant
>>>> subclass all the base classes the language has?
>
> I said earlier that I don't think it's possible to do what you're 
> doing without your users code being somewhat aware of your changes.
Aye. You did.  And I didn't disagree. :)
The goal is merely to trip up those who don't know what I'm doing as 
little as possible and only break their code where the very notion of 
uncertainty is incompatible with what they are doing, or where they did 
something very stupid anyway... eg: to break it where there is a good 
reason for it to be broken.
I may not achieve my goal, but I at least hope to come close...

>
> But as long as the user doesn't check for the subclass-ness of your 
> bool-like function, you should manage.  In Python, duck-typing is 
> encouraged, unlike java or C++, where the only substitutable classes 
> are subclasses.

but if you can't subclass a built in type -- you can't duck type it -- 
for I seem to recall that Python forbids duck typing any built in class 
nut not subclasses.  So your two solutions are mutually damaged by 
Guido's decision;  And there seem to be a lot of classes that python 
simply won't allow anyone to subclass.  ( I still need to retry 
subclassing float, that might still be possible. )

Removing both options in one blow is like hamstringing the object 
oriented re-useability principle completely.  You must always re-invent 
the wheel from near scratch in Python....
>>
>> --Guido van Rossum
>>
>> So, I think Guido may have done something so that there are only two
>> instances of bool, ever.
>> eg: False and True, which aren't truly singletons -- but follow the
>> singleton restrictive idea of making a single instance of an object do
>> the work for everyone; eg: of False being the only instance of bool
>> returning False, and True being the only instance of bool returning 
>> True.
>>
>> Why this is so important to Guido, I don't know ... but it's making it
>> VERY difficult to add named aliases of False which will still be
>> detected as False and type-checkable as a bool.  If my objects don't
>> type check right -- they will likely break some people's legacy code...
>> and I really don't even care to create a new instance of the bool object
>> in memory which is what Guido seems worried about, rather I'm really
>> only after the ability to detect the subclass wrapper name as distinct
>> from bool False or bool True with the 'is' operator.  If there were a
>
> There's already a contradiction in what you want.  You say you don't 
> want to create a new bool object (distinct from True and False), but 
> you have to create an instance of your class.  If it WERE a subclass 
> of bool, it'd be a bool, and break singleton.
Yes there seems to be a contradiction but I'm not sure there is ... and 
it stems in part from too little sleep and familiarity with other 
languages...

Guido mentioned subclassing in 'C' as part of his justification for not 
allowing subclassing bool in python.
That's what caused me to digress a bit...  consider:

In 'C++' I can define a subclass without ever instantiating it; and I 
can define static member functions of the subclass that operate even 
when there exists not a single instance of the class; and I can typecast 
an instance of the base class as being an instance of the subclass.  So 
-- (against what Guido seems to have considered) I can define a function 
anywhere which returns my new subclass object as it's return value 
without ever instantiating the subclass -- because my new function can 
simply return a typecasting of a base class instance;  The user of my 
function would never need to know that the subclass itself was never 
instantiated... for they would only be allowed to call static member 
functions on the subclass anyway, but all the usual methods found in the 
superclass(es) would still be available to them.  All the benefits of 
subclassing still exist, without ever needing to violate the singleton 
character of the base class instance.

So part of Guido's apparent reason for enforcing singleton ( dual 
singleton / dualton? ) nature of 'False' and 'True' isn't really 
justified by what 'C++' would allow because C++ could still be made to 
enforce singleton instances while allowing subclassing *both* at the 
same time.

There seems to be some philosophical reason for what Guido wants that he 
hasn't fully articulated...?
If I understood him better-- I wouldn't be making wild ass guesses and 
testing everything I can think of to work around what he chose...

>
>
> If you ignore your subclass "requirement,"  'is' should do the right 
> thing.  Whatever your class instance is, it won't be the same object 
> as True or as False.
It was never a requirement; It was an experiment to see how close I 
could get to identical behavior.
It didn't work... it will have to be discarded... Therefore, I know I 
will break some peoples code...

>
>> way to get the typecheck to match,
>
> That's a piece of legacy code which you won't be able to support, as 
> far as I can see.
>

Yep.  Python cuts off re-usability at the ankles...
I have NO way to signal to my users that my object is compatible with 
bool.  For that's what subclass typechecks are about...  If someone 
*needs* an object that does everything bool does (proto-type bool), the 
only portable test for compatibility is to check if the object is a bool...
That pretty much kills legacy support / compatability... no one can know 
my object is compatible with bool in a portable fashion...

>> I wouldn't mind making a totally
>> separate class which returned the False instance; eg: something like an
>> example I modified from searching on the web:
>>
>> class UBool():
>>      def __nonzero__(self): return self.default
>>      def __init__( self, default=False ): self.default = bool(default)
>>      def default( self, default=False ): self.defualt = bool(default)
>>
>> but, saying:
>>  >>> error=UBool(False)
>>  >>> if error is False: print "type and value match"
>> ...
>>  >>>
>>
>> Failed to have type and value match, and suggests that 'is' tests the
>> type before expanding the value.
>
> Not at all.  It doesn't check the type or the value.  It checks 
> whether it's the SAME object.
>

DOOOOOOH!!!!
I hate ever having learned PHP before I learned python.  I bet you can 
guess what version of 'is' I remembered the rule for when overtired...
>> It's rather non intuitive, and will break code -- for clearly error
>> expands to 'False' when evaluated without comparison functions like ==.
>>
>>  >>> if not error: print "yes it is false"
>> ...
>> yes it is false
>
> No, the object False is not referenced in the above expression. You're 
> checking the "falseness" of the expression.  Same as if you say
>       if not 0
>       if not mylist

Hmm... your a bit confusing / unclear ?
I think the object returned by 'not' is True or False.  So the 
expression as a whole does reference either False or True objects. I 
didn't think that 'error' was the False object itself, just that the 
evaluation of any expression containing 'error' eventually called 
__nonzero__() which I defined to return the False object.

What I was trying to figure out is order of precedence ; when does 
__nonzero__() get called, and is it called at all.  I think it was 
called, because the object reference itself is something that is a non 
null pointer... and I would expect 'not (...something nonzero.,.) ' to 
evaluate as false and the print statement NOT to be executed.

However, the print statement was executed -- so that possibility was 
eliminated.  So, I am pretty sure that at some point __nonzero__() was 
called, and error was replaced with whatever __nonzero__() returned;  In 
my test, that would be the 'False' object. Correct?

>
>>  >>> print error.__nonzero__()
>> False
>>  >>> if error==False: print "It compares to False properly"
>> ...
>
> You control this one by your __eq__ method.

Yes... now we're really getting somewhere.
That's something I overlooked.

Question:  If two different class's instances are being compared by 
'==', and both define an __eq__ method, which method gets called?  ( I 
don't know if that applied here... but I'm not familiar with order of 
operations )

> 1) read up more closely on special methods, and on the meanings of 
> id() and 'is'
>
> 2) And don't expect that any change you make at this level could be 
> transparent to all existing applications.  It's a contradiction in terms.
>
>
1) Yes -- I'll do that.  although -- my interpretation of 'is' was 
simply tiredness... I knew better and forgot.  You put my head back on 
right.  Thanks.

2) I never did have that expectation ; I just want to do the best I 
can... and not settle for third best...
Thanks. :)

To sum up:
It's fairly clear that whenever my library returns actual True and False 
objects from magnitude comparison operators, there will be full backward 
compatibility with float.  So -- for cases where the two numeric types 
don't have any difference in meaning, there will still be full 
compatibility.  (That, thankfully, is the most typical use case...)

For the remaining quasi 'False'  return values,  I know the 'is' 
operator must always fail.  So if anyone stupidly puts '(a>b) is False' 
in their legacy floating point code for no really good reason -- well, 
too bad; it breaks --  But that's the best I can do.

However; I think I can still hope to be compatible with '(a>b) == False' 
by defining my own '==' operator ; and still allow users an explicit 
'is' test for my singleton-like instances of PartTrue, Unknown, and 
PartFalse so that they can distinguish them from an actual 'False' object...

I think I can also define a relative certainty magnitude operator for 
falseness so users can test if  PartTrue is more true than False. ( 
PartTrue > False ) etc. and thereby allow them to make their own custom 
sorts based on relative true-ness when needed.

And, finally, on the sort operation consistency you mentioned in an 
earlier email -- your comments, and another posters, about that is well 
taken.  It's something I'll have to review again later... but in 
essence, I don't think it's a problem because whenever two variables are 
definitely '>' or '<' each other with an actual True or False object 
returned -- I already know the consistency with respect to a third 
variable will hold.  On the other hand, By definition, all quasi false 
values return false for both '>' and '<', so what ends up happening is 
that python treats any uncertainty as if the variables were equal, and 
so they are grouped together but left in the same order as they were 
originally sent to the search. (stable).

But I don't think that stops me from treating the sort order of all 
items which are quasi-equal, as a second search (hierarchical search). 
eg: Sort first by definite magnitude, then among those deemed 'equal', 
sort them by average expectation value...  That's going to be good 
enough for me and my users, for the sort order of truly quasi equal 
things is arbitrary anyway... as long as it's not 'defintely wrong' 
they'll have no reason to complain.











From andrew3 at r3dsolutions.com  Tue Jan  6 21:20:09 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Tue, 06 Jan 2015 18:20:09 -0800
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
Message-ID: <54AC97D9.4010504@r3dsolutions.com>


On 01/06/2015 05:35 AM, Chris Angelico wrote:
> On Wed, Jan 7, 2015 at 12:30 AM, Andrew Robinson
> <andrew3 at r3dsolutions.com> wrote:
>> Why this is so important to Guido, I don't know ... but it's making it VERY
>> difficult to add named aliases of False which will still be detected as
>> False and type-checkable as a bool.  If my objects don't type check right --
>> they will likely break some people's legacy code...  and I really don't even
>> care to create a new instance of the bool object in memory which is what
>> Guido seems worried about, rather I'm really only after the ability to
>> detect the subclass wrapper name as distinct from bool False or bool True
>> with the 'is' operator.  If there were a way to get the typecheck to match,
>> I wouldn't mind making a totally separate class which returned the False
>> instance; eg: something like an example I modified from searching on the
>> web:
> Okay, so why not just go with your own class, and deal with the
> question of the type check? Simple solution: Instead of fiddling with
> __gt__/__lt__, create your own method, and use your own comparison
> function to sort these things.
>
> ChrisA
Because defining a bunch of special methods defeats the very purpose of 
making my class compatible with float variables.
eg: No legacy code would work...

I know (belatedly) that am going to have to define my own class.
That's pretty much a given, but I want to do it in a way which requires 
my users to make very few changes to their traditional floating point 
algorithms and code.

The type check issue is mostly about compatability in the first place ; 
eg: users typecheck either unintentionally -- (novices syndrome) -- or 
because they need all the capabilities of a given type, and the only 
simple way to find out if they are all there are there is to typecheck.  
eg: That's the whole point of subclassing bool ... to let the user know 
they have at their disposal (in a portable, simple way) all the features 
of the base type.

Well, if I make a new object -- type checking is pointless.   No user 
thinking they were coding for floating point in the past would know that 
my new return type is totally compatible with bool.  They would have to 
have written individual tests for the existence of every method in bool, 
and why would they be crazy enough to do that? It's a lot of work for 
nothing...









From rosuav at gmail.com  Tue Jan  6 21:31:35 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 7 Jan 2015 13:31:35 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54AC97D9.4010504@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
Message-ID: <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>

On Wed, Jan 7, 2015 at 1:20 PM, Andrew Robinson
<andrew3 at r3dsolutions.com> wrote:
> Because defining a bunch of special methods defeats the very purpose of
> making my class compatible with float variables.
> eg: No legacy code would work...
>
> I know (belatedly) that am going to have to define my own class.
> That's pretty much a given, but I want to do it in a way which requires my
> users to make very few changes to their traditional floating point
> algorithms and code.

If you use a dedicated function instead of methods, that function can
be written to take any combination of float and pseudo-float.

> The type check issue is mostly about compatability in the first place ; eg:
> users typecheck either unintentionally -- (novices syndrome) -- or because
> they need all the capabilities of a given type, and the only simple way to
> find out if they are all there are there is to typecheck.  eg: That's the
> whole point of subclassing bool ... to let the user know they have at their
> disposal (in a portable, simple way) all the features of the base type.

Thing is, you're not fulfilling bool's contract, so it's better to not
subclass, and just make your new type always falsy. If your users are
type-checking bools, you might just have to let it break, and tell
them not to do that.

ChrisA


From tjreedy at udel.edu  Tue Jan  6 21:34:57 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Tue, 06 Jan 2015 21:34:57 -0500
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54AC938C.7040206@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
 <54AC938C.7040206@r3dsolutions.com>
Message-ID: <m8i60t$fp3$1@ger.gmane.org>

On 1/6/2015 9:01 PM, Andrew Robinson wrote:

[snip]

There are very few (about 4) builtin classes that cannot be subclassed. 
  bool is one of those few, float is not.  Go ahead and subclass it.

 >>> class F(float): pass

 >>> F
<class '__main__.F'>
 >>> F(2.3) + F(3.3)
5.6


-- 
Terry Jan Reedy



From andrew3 at r3dsolutions.com  Tue Jan  6 21:53:23 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Tue, 06 Jan 2015 18:53:23 -0800
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <m8i60t$fp3$1@ger.gmane.org>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
 <54AC938C.7040206@r3dsolutions.com> <m8i60t$fp3$1@ger.gmane.org>
Message-ID: <54AC9FA3.3050509@r3dsolutions.com>


On 01/06/2015 06:34 PM, Terry Reedy wrote:
> On 1/6/2015 9:01 PM, Andrew Robinson wrote:
>
> [snip]
>
> There are very few (about 4) builtin classes that cannot be 
> subclassed.  bool is one of those few, float is not.  Go ahead and 
> subclass it.
>
> >>> class F(float): pass
>
> >>> F
> <class '__main__.F'>
> >>> F(2.3) + F(3.3)
> 5.6
>
>
Thanks terry! That's a relief.  Ive just managed to find a few classes 
that won't subtype by trial and error in the last two months and was 
getting pessimistic.  ( eg: doing web pages I wanted to customize the 
error output traceback stack from a python script based on where the 
exception occurred..... UUUUGH!  I worked around the no sub-typing 
issue, but it took a lot of guessing to trick python into accepting a 
fake class to the print traceback functions the webserver used... )



From andrew3 at r3dsolutions.com  Tue Jan  6 22:37:40 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Tue, 06 Jan 2015 19:37:40 -0800
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
Message-ID: <54ACAA04.60801@r3dsolutions.com>


On 01/06/2015 06:31 PM, Chris Angelico wrote:
>
>> The type check issue is mostly about compatability in the first place ; eg:
>> users typecheck either unintentionally -- (novices syndrome) -- or because
>> they need all the capabilities of a given type, and the only simple way to
>> find out if they are all there are there is to typecheck.  eg: That's the
>> whole point of subclassing bool ... to let the user know they have at their
>> disposal (in a portable, simple way) all the features of the base type.
> Thing is, you're not fulfilling bool's contract, so it's better to not
> subclass, and just make your new type always falsy. If your users are
> type-checking bools, you might just have to let it break, and tell
> them not to do that.
>
> ChrisA

Explain; How does mere subclassing of bool break the contract that bool has?
eg: What method or data would the superclass have that my subclass would 
not?

Are you speaking about the quasi singleton nature of bool ?
If so, I spent a little time browsing my design patterns book by Gamma, 
Helm, Johnson, and Vlissides; and I'm looking at the singleton pattern 
on p.127.

The author writes, "Use the singleton pattern when:
-- There must be exactly one instance of a class, and it must be 
accessible to clients from a well-known access point.
-- When the _sole instance_ should be extensible by subclassing, and 
clients should be able to use an extended instance *without modifying 
their code*.
"

So, it's clear that in typical programming scenarios -- objects which 
are even more restrictive than bool by having only a single allowed 
instance rather than TWO -- are *Still* intentionally allowed to be 
subclassed for compatibility reasons.

And later in design patterns, the authors continue on:

"2. Subclassing the singleton class.
   The _main issue is not so much defining the subclass_ but installing 
its unique instance so that clients will be able to use it."

So, the general programming community is aware of the issue Rossum 
brings up about a singleton's subclass having an instance; it's just 
apparent that there are ways to work around the issue and preserve a 
singleton's character while still allowing a subclass.

So:  I'm really curious -- If subclassing is generally permitted for 
singletons as an industrial practice, why is it wrong to allow it in python?

I mean, If this is because Python doesn't support sub-classes for 
singletons, then it seems that Python is lacking something that should 
be added.

This isn't limited to bool, for as a library writer I might want to 
create a singleton class for my own purposes that has nothing to do with 
any of python's built in types.  And so, it would be appropriate to have 
a mechanism for subclassing user created singletons as well....

I already KNOW that 'C++' does have a workaround mechanism, as I've 
mentioned in a different e-mail, so that there's no reason to 
instantiate an instance of the subclass of a singleton if you don't want 
to.  That objection is really spurrious... so I really don't understand 
why Rossum cut off subclassability itself ... wasn't there any other way 
he could have prevented instantiation of subclasses without preventing 
the definition of a subclass itself?

I mean, even in python I can execute some methods of a class without 
actually INSTANTIATING that class.
eg:

import decimal
decimal.getcontext()

So, I don't understand your objection.
How does merely defining a subclass of bool violate the contract that 
bool puts out?

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From davea at davea.name  Tue Jan  6 22:39:49 2015
From: davea at davea.name (Dave Angel)
Date: Tue, 06 Jan 2015 22:39:49 -0500
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54AC938C.7040206@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
 <54AC938C.7040206@r3dsolutions.com>
Message-ID: <54ACAA85.3040806@davea.name>

On 01/06/2015 09:01 PM, Andrew Robinson wrote:
>
> On 01/06/2015 06:02 AM, Dave Angel wrote:
>> On 01/06/2015 08:30 AM, Andrew Robinson wrote:
>>>
>>>>> So, I'm not sure I can subclass boolean either because that too is a
>>>>> built in class ...  but I'm not sure how else to make an object that
>>>>> acts as boolean False, but can be differentiated from false by the
>>>>> 'is'
>>>>> operator.  It's frustrating -- what good is subclassing, if one cant
>>>>> subclass all the base classes the language has?
>>
>> I said earlier that I don't think it's possible to do what you're
>> doing without your users code being somewhat aware of your changes.
> Aye. You did.  And I didn't disagree. :)
> The goal is merely to trip up those who don't know what I'm doing as
> little as possible and only break their code where the very notion of
> uncertainty is incompatible with what they are doing, or where they did
> something very stupid anyway... eg: to break it where there is a good
> reason for it to be broken.
> I may not achieve my goal, but I at least hope to come close...
>
>>
>> But as long as the user doesn't check for the subclass-ness of your
>> bool-like function, you should manage.  In Python, duck-typing is
>> encouraged, unlike java or C++, where the only substitutable classes
>> are subclasses.
>
> but if you can't subclass a built in type -- you can't duck type it --
> for I seem to recall that Python forbids duck typing any built in class
> nut not subclasses.  So your two solutions are mutually damaged by
> Guido's decision;  And there seem to be a lot of classes that python
> simply won't allow anyone to subclass.  ( I still need to retry
> subclassing float, that might still be possible. )
>
> Removing both options in one blow is like hamstringing the object
> oriented re-useability principle completely.  You must always re-invent
> the wheel from near scratch in Python....
>>>
>>> --Guido van Rossum
>>>
>>> So, I think Guido may have done something so that there are only two
>>> instances of bool, ever.
>>> eg: False and True, which aren't truly singletons -- but follow the
>>> singleton restrictive idea of making a single instance of an object do
>>> the work for everyone; eg: of False being the only instance of bool
>>> returning False, and True being the only instance of bool returning
>>> True.
>>>
>>> Why this is so important to Guido, I don't know ... but it's making it
>>> VERY difficult to add named aliases of False which will still be
>>> detected as False and type-checkable as a bool.  If my objects don't
>>> type check right -- they will likely break some people's legacy code...
>>> and I really don't even care to create a new instance of the bool object
>>> in memory which is what Guido seems worried about, rather I'm really
>>> only after the ability to detect the subclass wrapper name as distinct
>>> from bool False or bool True with the 'is' operator.  If there were a
>>
>> There's already a contradiction in what you want.  You say you don't
>> want to create a new bool object (distinct from True and False), but
>> you have to create an instance of your class.  If it WERE a subclass
>> of bool, it'd be a bool, and break singleton.
> Yes there seems to be a contradiction but I'm not sure there is ... and
> it stems in part from too little sleep and familiarity with other
> languages...
>
> Guido mentioned subclassing in 'C' as part of his justification for not
> allowing subclassing bool in python.
> That's what caused me to digress a bit...  consider:
>
> In 'C++' I can define a subclass without ever instantiating it; and I
> can define static member functions of the subclass that operate even
> when there exists not a single instance of the class; and I can typecast
> an instance of the base class as being an instance of the subclass.  So
> -- (against what Guido seems to have considered) I can define a function
> anywhere which returns my new subclass object as it's return value
> without ever instantiating the subclass -- because my new function can
> simply return a typecasting of a base class instance;  The user of my
> function would never need to know that the subclass itself was never
> instantiated... for they would only be allowed to call static member
> functions on the subclass anyway, but all the usual methods found in the
> superclass(es) would still be available to them.  All the benefits of
> subclassing still exist, without ever needing to violate the singleton
> character of the base class instance.

PYTHON IS NOT C++.  There is no typecasting, because Python "variables" 
don't have types, only the object has a type, and you can't force it to 
be something different.  Unlike C++, Python has strict typing.  And 
unlike Python that typing is on the data, NOT on the "variable."  A 
Python variable is just a reference to the real data, and has no type of 
its own.

If you try to create a new instance of bool, it'd either be True or it'd 
be False (exactly two objects, singletons), and in no way would it 
belong to your hypothetical subclass.

As long as the user is not foolish enough to check the type, you can 
create a class that's equivalent to bool, and PRETEND it's a subclass. 
You really need to read up on duck-typing.

If you create an object that pretends to be bool, but isn't quite, then 
you have to decide just which characteristics of the original class 
you're going to violate, and convince your users not to use those 
characteristics.  That's true in any language, but Python makes it 
especially easy.




>   ...phical reason for what Guido wants that he
> hasn't fully articulated...?
> If I understood him better-- I wouldn't be making wild ass guesses and
> testing everything I can think of to work around what he chose...
>

Don't try to understand Guido, try to understand Python.  Names do not 
have types, objects do.

>
> Yep.  Python cuts off re-usability at the ankles...
> I have NO way to signal to my users that my object is compatible with
> bool.

Duck typing.

>  For that's what subclass typechecks are about...  If someone
> *needs* an object that does everything bool does (proto-type bool), the
> only portable test for compatibility is to check if the object is a bool...

Nonsense.  Duck typing.  If you're told it will behave in a certain way, 
you use it as though it is of that type.  If you check the type, you're 
probably thinking in some other language.

> That pretty much kills legacy support / compatability... no one can know
> my object is compatible with bool in a portable fashion...

Documentation.

>
>>> I wouldn't mind making a totally
>>> separate class which returned the False instance; eg: something like an
>>> example I modified from searching on the web:
>>>
>>> class UBool():
>>>      def __nonzero__(self): return self.default
>>>      def __init__( self, default=False ): self.default = bool(default)
>>>      def default( self, default=False ): self.defualt = bool(default)
>>>
>>> but, saying:
>>>  >>> error=UBool(False)
>>>  >>> if error is False: print "type and value match"

Wny use "is" here?  That's obviously contradicting the singleton nature 
of the False object.

>>>
>>>  >>> if not error: print "yes it is false"
>>> ...
>>> yes it is false
>>
>> No, the object False is not referenced in the above expression. You're
>> checking the "falseness" of the expression.  Same as if you say
>>       if not 0
>>       if not mylist
>
> Hmm... your a bit confusing / unclear ?
> I think the object returned by 'not' is True or False.

You can think it.  But you created that object with UBool().  So it 
clearly isn't the False object.

>  So the
> expression as a whole does reference either False or True objects.

When you applied "not" to the object, the result will be True.  But your 
object is not False.  It's false.

> I
> didn't think that 'error' was the False object itself, just that the
> evaluation of any expression containing 'error' eventually called
> __nonzero__() which I defined to return the False object.
>
> What I was trying to figure out is order of precedence ; when does
> __nonzero__() get called, and is it called at all.  I think it was
> called, because the object reference itself is something that is a non
> null pointer

No pointers in Python.  Just bindings.  And they're never null.  A name 
is either bound to an object or the name doesn't exist.

Here we need help from someone who knows more about this particular 
detail.  I don't know which special methods bool() or not will call, but 
I'd think it would be something with a better name than __nonzero__


> ... and I would expect 'not (...something nonzero.,.) ' to
> evaluate as false and the print statement NOT to be executed.
>
> However, the print statement was executed -- so that possibility was
> eliminated.  So, I am pretty sure that at some point __nonzero__() was
> called, and error was replaced with whatever __nonzero__() returned;  In
> my test, that would be the 'False' object. Correct?
>
Still somebody else needed.

>>
>>>  >>> print error.__nonzero__()
>>> False
>>>  >>> if error==False: print "It compares to False properly"
>>> ...
>>
>> You control this one by your __eq__ method.
>
> Yes... now we're really getting somewhere.
> That's something I overlooked.
>
> Question:  If two different class's instances are being compared by
> '==', and both define an __eq__ method, which method gets called?  ( I
> don't know if that applied here... but I'm not familiar with order of
> operations )

The left object's methods are generally examined first.  So if you said
     mylist * 5

you'd be using a __mul__ method of list class.

>
>> 1) read up more closely on special methods, and on the meanings of
>> id() and 'is'
>>
>> 2) And don't expect that any change you make at this level could be
>> transparent to all existing applications.  It's a contradiction in terms.
>>
>>
> 1) Yes -- I'll do that.  although -- my interpretation of 'is' was
> simply tiredness... I knew better and forgot.  You put my head back on
> right.  Thanks.
>
> 2) I never did have that expectation ; I just want to do the best I
> can... and not settle for third best...
> Thanks. :)
>
> To sum up:
> It's fairly clear that whenever my library returns actual True and False
> objects from magnitude comparison operators, there will be full backward
> compatibility with float.  So -- for cases where the two numeric types
> don't have any difference in meaning, there will still be full
> compatibility.  (That, thankfully, is the most typical use case...)
>
> For the remaining quasi 'False'  return values,  I know the 'is'
> operator must always fail.  So if anyone stupidly puts '(a>b) is False'
> in their legacy floating point code for no really good reason -- well,
> too bad; it breaks --  But that's the best I can do.
>
> However; I think I can still hope to be compatible with '(a>b) == False'

Just talk your users into saying:
       a <= b
   or  not (a > b)

instead of (a>b) == False
It's not clear what value you'd WANT that last comparison to give.

IE. what value should:
      PartTrue == False
produce, with no other context?

> by defining my own '==' operator ; and still allow users an explicit
> 'is' test for my singleton-like instances of PartTrue, Unknown, and
> PartFalse so that they can distinguish them from an actual 'False'
> object...
>
> I think I can also define a relative certainty magnitude operator for
> falseness so users can test if  PartTrue is more true than False. (
> PartTrue > False ) etc. and thereby allow them to make their own custom
> sorts based on relative true-ness when needed.
>
> And, finally, on the sort operation consistency you mentioned in an
> earlier email -- your comments, and another posters, about that is well
> taken.  It's something I'll have to review again later... but in
> essence, I don't think it's a problem because whenever two variables are
> definitely '>' or '<' each other with an actual True or False object
> returned -- I already know the consistency with respect to a third
> variable will hold.  On the other hand, By definition, all quasi false
> values return false for both '>' and '<', so what ends up happening is
> that python treats any uncertainty as if the variables were equal, and
> so they are grouped together but left in the same order as they were
> originally sent to the search. (stable).

Without more specifics, I kinda doubt it.  But without more specifics I 
can't refute it either.

> But I don't think that stops me from treating the sort order of all
> items which are quasi-equal, as a second search (hierarchical search).
> eg: Sort first by definite magnitude, then among those deemed 'equal',
> sort them by average expectation value...  That's going to be good
> enough for me and my users, for the sort order of truly quasi equal
> things is arbitrary anyway... as long as it's not 'defintely wrong'
> they'll have no reason to complain.

You could write a sort that works that way, but I don't think you can 
assume that the built-in sort will.  sort assumes that the comparison 
works in a certain way, and if it doesn't, the symptoms could range from 
random ordering (including items drastically out of order) to a possibly 
never terminating sort.

-- 
DaveA


From rosuav at gmail.com  Tue Jan  6 23:01:27 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 7 Jan 2015 15:01:27 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54ACAA85.3040806@davea.name>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
 <54AC938C.7040206@r3dsolutions.com> <54ACAA85.3040806@davea.name>
Message-ID: <CAPTjJmr0sw3D4_nJUoGzFo3E+sMYAwwBcRdx+5CwYaG0DJa1Vg@mail.gmail.com>

On Wed, Jan 7, 2015 at 2:39 PM, Dave Angel <davea at davea.name> wrote:
> Here we need help from someone who knows more about this particular detail.
> I don't know which special methods bool() or not will call, but I'd think it
> would be something with a better name than __nonzero__

In Python 2, it is indeed __nonzero__, but in Python 3, it's __bool__:

Python 2.7.3 (default, Mar 13 2014, 11:03:55)
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> class X:
...  def __nonzero__(self): print("called")
...
>>> bool(X())
called
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: __nonzero__ should return an int


Python 3.5.0a0 (default:1c51f1650c42+, Dec 29 2014, 02:29:06)
[GCC 4.7.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> class X:
...  def __bool__(self): print("called")
...
>>> bool(X())
called
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: __bool__ should return bool, returned NoneType


Also, as you can see, Py2's method allows any integer to be returned,
while Py3's expects a bool. The boolification of an object MUST result
in either True or False, nothing else.

>> Question:  If two different class's instances are being compared by
>> '==', and both define an __eq__ method, which method gets called?  ( I
>> don't know if that applied here... but I'm not familiar with order of
>> operations )
>
>
> The left object's methods are generally examined first.  So if you said
>     mylist * 5
>
> you'd be using a __mul__ method of list class.

Order of operations has nothing to do with this; that's to do with
operator precedence/associativity, which is what stipulates that all
of these parentheses are unnecessary:

a + (b * c)
(a + b) + c
a ** (b ** c)
a or (b and c)
(a + b) in c
a if (b + c) else d

The operator precedence tables neither know nor care what the objects
in question are. But once the interpreter gets to the next step, and
starts actually figuring out the value of the expression, then it
usually goes for the left object's methods first; if that object
returns NotImplemented, it'll try the right object (sometimes with a
reflected method):

>>> class X:
...  def __eq__(self, other): print("Am I equal to:",other)
...  def __add__(self, other): print("me +",other)
...  def __radd__(self, other): print(other,"+ me")
...
>>> X() == 1
Am I equal to: 1
>>> 2 == X()
Am I equal to: 2
>>> X() + 3
me + 3
>>> 4 + X()
4 + me

>> But I don't think that stops me from treating the sort order of all
>> items which are quasi-equal, as a second search (hierarchical search).
>> eg: Sort first by definite magnitude, then among those deemed 'equal',
>> sort them by average expectation value...  That's going to be good
>> enough for me and my users, for the sort order of truly quasi equal
>> things is arbitrary anyway... as long as it's not 'defintely wrong'
>> they'll have no reason to complain.
>
>
> You could write a sort that works that way, but I don't think you can assume
> that the built-in sort will.  sort assumes that the comparison works in a
> certain way, and if it doesn't, the symptoms could range from random
> ordering (including items drastically out of order) to a possibly never
> terminating sort.

If you can separate the value into two parts, magnitude and
expectation, you could have a key function that makes them sortable:

def mag_exp(val):
    if not isinstance(val, MagicFloat): return (val, None)
    return int(val), val-int(val) # example

srtlst = sorted(lst, key=mag_exp)

That'll sort all elements by the first value in the tuple, and if
they're identical on that, by the second value. That's the easiest way
to do a multi-part sort.

ChrisA


From davea at davea.name  Wed Jan  7 02:16:24 2015
From: davea at davea.name (Dave Angel)
Date: Wed, 07 Jan 2015 02:16:24 -0500
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54ACAA04.60801@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com>
Message-ID: <54ACDD48.2030501@davea.name>

On 01/06/2015 10:37 PM, Andrew Robinson wrote:
>
> On 01/06/2015 06:31 PM, Chris Angelico wrote:
>>
>
> I already KNOW that 'C++' does have a workaround mechanism, as I've
> mentioned in a different e-mail, so that there's no reason to
> instantiate an instance of the subclass of a singleton if you don't want
> to.  That objection is really spurrious... so I really don't understand
> why Rossum cut off subclassability itself ... wasn't there any other way
> he could have prevented instantiation of subclasses without preventing
> the definition of a subclass itself?
>
> I mean, even in python I can execute some methods of a class without
> actually INSTANTIATING that class.
> eg:
>
> import decimal
> decimal.getcontext()

Interesting that you pick as your example an ordinary function, not in a 
class at all.  In this example, decimal is a module;  you're calling a 
module level function.  Perfectly normal.

But you're right, you can call staticmethods of a class without 
instantiating it, and you can also call classmethods.  But in both 
cases, the caller knows exactly what class he's referring to.  Doesn't 
help your argument any.

If you're not going to instantiate the class, then the fact that such a 
class is, or is not, a subclass of another is invisible, in any context 
I can think of (other than debuggers and such that do inspection by 
reflection).

-- 
DaveA


From steve at pearwood.info  Wed Jan  7 03:10:25 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 07 Jan 2015 08:10:25 GMT
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com>
 <54ABC52A.1050507@davea.name> <54ABE383.3020801@r3dsolutions.com>
 <54ABEAD9.8070000@davea.name>
 <mailman.17424.1420596200.18130.python-list@python.org>
Message-ID: <54ace9f0$0$2738$c3e8da3$76491128@news.astraweb.com>

On Tue, 06 Jan 2015 18:01:48 -0800, Andrew Robinson wrote:

> but if you can't subclass a built in type -- you can't duck type it --
> for I seem to recall that Python forbids duck typing any built in class
> nut not subclasses.

I fear that you have completely misunderstood the nature of duck-typing.

The name comes from the phrase "if it walks like a duck and swims like a 
duck and quacks like a duck, it might as well be a duck". The idea with 
duck-typing is that you don't care whether an object *actually is* a bool 
(list, float, dict, etc.) but only whether it offers the same interface 
as a bool. Not necessarily the entire interface, but just the parts you 
need: if you need something that quacks, you shouldn't care whether or 
not it has a swim() method.

In the case of bool, literally every object in Python can "quack like a 
bool", so to speak, unless you deliberately go out of your way to prevent 
it. Here is an example of duck-typing non-bools in a boolean context:


py> values = [0, None, "hello", 23.0, TypeError, {'a': 42}, {}, len]
py> for obj in values:
...     typename = type(obj).__name__
...     if obj:
...             print "%s %r is a truthy object" % (typename, obj)
...     else:
...             print "%s %r is a falsey object" % (typename, obj)
... 
int 0 is a falsey object
NoneType None is a falsey object
str 'hello' is a truthy object
float 23.0 is a truthy object
type <type 'exceptions.TypeError'> is a truthy object
dict {'a': 42} is a truthy object
dict {} is a falsey object
builtin_function_or_method <built-in function len> is a truthy object


You can see I didn't convert obj to a bool, I just used obj in an if-
statement as if it were a bool. That's duck-typing.


[...]
>>> Why this is so important to Guido, I don't know ... but it's making it
>>> VERY difficult to add named aliases of False which will still be
>>> detected as False and type-checkable as a bool.

That part is absolutely wrong. Given these three named aliases of False, 
I challenge you to find any way to distinguish them from the actual False:

NOT_TRUE = False
NICHTS = False
WRONG = False


That's a safe bet, of course, because those three aliases are just names 
bound to the False object. You can't distinguish the WRONG object from 
the False object because they are the same object.

(You can, however, re-bind the WRONG *name* to a different object:

WRONG = "something else"

But that is another story.)

>>> If my objects don't
>>> type check right -- they will likely break some people's legacy
>>> code... 

There's nothing you can do about that. You can't control what stupid 
things people might choose to do:

if str(flag).lower() == 'false':
    print "flag is false"


All you can do is offer to support some set of operations. It's up to 
your users whether or not they will limit themselves to the operations 
you promise to support. You can make an object which quacks like a bool 
(or list, tuple, dict, bool, str...), swims like a bool and walks like a 
bool, but ultimately Python's introspection powers are too strong for you 
to fool everybody that it *actually is* a bool.

And you know, that's actually a good thing.


[...]
> In 'C++' I can define a subclass without ever instantiating it; and I
> can define static member functions of the subclass that operate even
> when there exists not a single instance of the class; and I can typecast
> an instance of the base class as being an instance of the subclass.

And in Python, we can do all those things too, except that what you call 
"static member function" we call "class method". But we hardly ever 
bother, because it's simply not needed or is an unnatural way to do 
things in Python. But to prove it can be done:


from abc import ABCMeta

class MyFloat(float):
    __metaclass__ = ABCMeta
    @classmethod
    def __subclasshook__(cls, C):
        if cls is MyFloat:
            if C is float: return True
        return NotImplemented
    @classmethod
    def spam(cls, n):
        return ' '.join(["spam"]*n)

MyFloat.register(float)


And in use:

py> MyFloat.spam(5)
'spam spam spam spam spam'
py> isinstance(23.0, MyFloat)
True


Should you do this? Almost certainly not.


> So
> -- (against what Guido seems to have considered) I can define a function
> anywhere which returns my new subclass object as it's return value
> without ever instantiating the subclass -- because my new function can
> simply return a typecasting of a base class instance;  The user of my
> function would never need to know that the subclass itself was never
> instantiated... for they would only be allowed to call static member
> functions on the subclass anyway, but all the usual methods found in the
> superclass(es) would still be available to them.  All the benefits of
> subclassing still exist, without ever needing to violate the singleton
> character of the base class instance.

This is all very well and good, but what exactly is the point of it all? 
What is the *actual problem* this convoluted mess is supposed to solve?

An awful lot of programming idioms, including some language features, in 
Java and C++ exist only to allow the programmer to escape from the 
straight-jacket of other language features. When programming in Python, 
we simply don't need to use them, because the problem they solve doesn't 
come up. Now I don't know for sure that this is one of those cases, but 
so far it is looking like it: it appears to me that you're trying to 
solve a problem which occurs in C++ but not in Python, by using C++ 
idioms in Python.

 
[...]
> Yep.  Python cuts off re-usability at the ankles... I have NO way to
> signal to my users that my object is compatible with bool.

In Python terms, the way to check whether something is compatible with a 
bool is to try it and catch the exception if it fails. Or don't bother 
catching the exception, and allow some higher piece of code to deal with 
the problem.

py> CouldBeTrue = 0.75
py> if CouldBeTrue:
...     print "seems likely to be true"
... 
seems likely to be true


As for the rest of your post, I have run out of time so I'll have to come 
back to it later.



-- 
Steven


From rosuav at gmail.com  Wed Jan  7 03:21:28 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 7 Jan 2015 19:21:28 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54ace9f0$0$2738$c3e8da3$76491128@news.astraweb.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
 <mailman.17424.1420596200.18130.python-list@python.org>
 <54ace9f0$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <CAPTjJmrDn3=4LaHStnDP_-u+730t_zpbbkN9ABAVYkpuW=BfgA@mail.gmail.com>

On Wed, Jan 7, 2015 at 7:10 PM, Steven D'Aprano <steve at pearwood.info> wrote:
> ou can make an object which quacks like a bool
> (or list, tuple, dict, bool, str...), swims like a bool...

Huh. You mean like an Olympic swimming bool?

ChrisA


From marko at pacujo.net  Wed Jan  7 05:01:34 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Wed, 07 Jan 2015 12:01:34 +0200
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
 <mailman.17424.1420596200.18130.python-list@python.org>
 <54ace9f0$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <87tx02gb9d.fsf@elektro.pacujo.net>

Steven D'Aprano <steve at pearwood.info>:

> int 0 is a falsey object
> NoneType None is a falsey object
> str 'hello' is a truthy object
> float 23.0 is a truthy object

I prefer the Scheme way:

   #f is a falsey object

   everything else is a truthy object


Marko


From jacob at blindza.co.za  Wed Jan  7 06:04:16 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Wed, 7 Jan 2015 13:04:16 +0200
Subject: String character encoding when converting data from one type/format
 to another
Message-ID: <9A569F491BCD444E9512731789AC7853@JakesPC>

I'm busy using something like pyodbc to pull data out of MS access .mdb files, and then generate .sql script files to execute against MySQL databases using MySQLdb module, but, issue is forms of characters in string values that don't fit inside the 0-127 range - current one seems to be something like \xa3, and if I pass it through ord() function, it comes out as character number 163.

Now issue is, yes, could just run through the hundreds of thousands of characters in these resulting strings, and strip out any that are not within the basic 0-127 range, but, that could result in corrupting data - think so anyway.

Anyway, issue is, for example, if I try something like str('\xa3').encode('utf-8') or str('\xa3').encode('ascii'), or str('\xa3').encode('latin7') - that last one is actually our preferred encoding for the MySQL database - they all just tell me they can't work with a character out of range.

Any thoughts on a sort of generic method/means to handle any/all characters that might be out of range when having pulled them out of something like these MS access databases?

Another side note is for binary values that might store binary values, I use something like the following to generate hex-based strings that work alright when then inserting said same binary values into longblob fields, but, don't think this would really help for what are really just most likely badly chosen copy/pasted strings from documents, with strange encoding, or something:
#sample code line for binary encoding into string output
s_values += "0x" + str(l_data[J][I]).encode("hex").replace("\\", "\\\\") + ", "

TIA

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."
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From ned at nedbatchelder.com  Wed Jan  7 07:02:34 2015
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Wed, 07 Jan 2015 07:02:34 -0500
Subject: String character encoding when converting data from one
 type/format to another
In-Reply-To: <9A569F491BCD444E9512731789AC7853@JakesPC>
References: <9A569F491BCD444E9512731789AC7853@JakesPC>
Message-ID: <m8j78q$680$1@ger.gmane.org>

On 1/7/15 6:04 AM, Jacob Kruger wrote:
> I'm busy using something like pyodbc to pull data out of MS access .mdb
> files, and then generate .sql script files to execute against MySQL
> databases using MySQLdb module, but, issue is forms of characters in
> string values that don't fit inside the 0-127 range - current one seems
> to be something like \xa3, and if I pass it through ord() function, it
> comes out as character number 163.
> Now issue is, yes, could just run through the hundreds of thousands of
> characters in these resulting strings, and strip out any that are not
> within the basic 0-127 range, but, that could result in corrupting data
> - think so anyway.

That will definitely corrupt your data, since you will be discarding data.

> Anyway, issue is, for example, if I try something like
> str('\xa3').encode('utf-8') or str('\xa3').encode('ascii'), or
> str('\xa3').encode('latin7') - that last one is actually our preferred
> encoding for the MySQL database - they all just tell me they can't work
> with a character out of range.

Are you using Python 2 or Python 3? This is one area where the two are 
very different.  I suspect you are on Python 2, in which case these all 
fail the same way because you are calling encode on a bytestring.  You 
can't encode a bytestring, you can only encode a Unicode string, so 
encode is helpfully trying to decode your bytestring first, using the 
default encoding (ascii), and '\xa3' is not an ascii character.

If that was confusing, this talk covers these fundamentals: 
http://bit.ly/unipain .

> Any thoughts on a sort of generic method/means to handle any/all
> characters that might be out of range when having pulled them out of
> something like these MS access databases?

The best thing is to know what encoding was used to produce these byte 
values.  Then you can manipulate them as Unicode if you need to.  The 
second best thing is to simply pass them through as bytes.

> Another side note is for binary values that might store binary values, I
> use something like the following to generate hex-based strings that work
> alright when then inserting said same binary values into longblob
> fields, but, don't think this would really help for what are really just
> most likely badly chosen copy/pasted strings from documents, with
> strange encoding, or something:
> #sample code line for binary encoding into string output
> s_values += "0x" + str(l_data[J][I]).encode("hex").replace("\\", "\\\\")
> + ", "
> TIA
>
> Jacob Kruger
> Blind Biker
> Skype: BlindZA
> "Roger Wilco wants to welcome you...to the space janitor's closet..."
>
>


-- 
Ned Batchelder, http://nedbatchelder.com



From __peter__ at web.de  Wed Jan  7 07:11:48 2015
From: __peter__ at web.de (Peter Otten)
Date: Wed, 07 Jan 2015 13:11:48 +0100
Subject: String character encoding when converting data from one
 type/format to another
References: <9A569F491BCD444E9512731789AC7853@JakesPC>
Message-ID: <m8j7q4$c3r$1@ger.gmane.org>

Jacob Kruger wrote:

> I'm busy using something like pyodbc to pull data out of MS access .mdb
> files, and then generate .sql script files to execute against MySQL
> databases using MySQLdb module, but, issue is forms of characters in
> string values that don't fit inside the 0-127 range - current one seems to
> be something like \xa3, and if I pass it through ord() function, it comes
> out as character number 163.
> 
> Now issue is, yes, could just run through the hundreds of thousands of
> characters in these resulting strings, and strip out any that are not
> within the basic 0-127 range, but, that could result in corrupting data -
> think so anyway.
> 
> Anyway, issue is, for example, if I try something like
> str('\xa3').encode('utf-8') or str('\xa3').encode('ascii'), or

"\xa3" already is a str; str("\xa3") is as redundant as 
str(str(str("\xa3"))) ;)

> str('\xa3').encode('latin7') - that last one is actually our preferred
> encoding for the MySQL database - they all just tell me they can't work
> with a character out of range.

encode() goes from unicode to byte; you want to convert bytes to unicode and 
thus need decode().

In this context it is important that you tell us the Python version. In 
Python 2 str.encode(encoding) is basically 

str.decode("ascii").encode(encoding)

which is why you probably got a UnicodeDecodeError in the traceback:

>>> "\xa3".encode("latin7")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.7/encodings/iso8859_13.py", line 12, in encode
    return codecs.charmap_encode(input,errors,encoding_table)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xa3 in position 0: 
ordinal not in range(128)

>>> "\xa3".decode("latin7")
u'\xa3'
>>> print "\xa3".decode("latin7")
?

Aside: always include the traceback in your posts -- and always read it 
carefully. The fact that "latin7" is not mentioned might have given you a 
hint that the problem was not what you thought it was.

> Any thoughts on a sort of generic method/means to handle any/all
> characters that might be out of range when having pulled them out of
> something like these MS access databases?

Assuming the data in Access is not broken and that you know the encoding
decode() will work.

> Another side note is for binary values that might store binary values, I
> use something like the following to generate hex-based strings that work
> alright when then inserting said same binary values into longblob fields,
> but, don't think this would really help for what are really just most
> likely badly chosen copy/pasted strings from documents, with strange
> encoding, or something:
> #sample code line for binary encoding into string output
> s_values += "0x" + str(l_data[J][I]).encode("hex").replace("\\", "\\\\") +
> ", "

I would expect that you can feed bytestrings directly into blobs, without 
any preparatory step. Try it, and if you get failures show us the failing 
code and the corresponding traceback.



From rosuav at gmail.com  Wed Jan  7 07:20:16 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 7 Jan 2015 23:20:16 +1100
Subject: String character encoding when converting data from one
 type/format to another
In-Reply-To: <m8j78q$680$1@ger.gmane.org>
References: <9A569F491BCD444E9512731789AC7853@JakesPC>
 <m8j78q$680$1@ger.gmane.org>
Message-ID: <CAPTjJmo5vHNSm0c9ryTgLYEF-bxmHSd_G9OUWs5C2XttmdNB8A@mail.gmail.com>

On Wed, Jan 7, 2015 at 11:02 PM, Ned Batchelder <ned at nedbatchelder.com> wrote:
>> Any thoughts on a sort of generic method/means to handle any/all
>> characters that might be out of range when having pulled them out of
>> something like these MS access databases?
>
>
> The best thing is to know what encoding was used to produce these byte
> values.  Then you can manipulate them as Unicode if you need to.  The second
> best thing is to simply pass them through as bytes.

If you can't know for sure, you could hazard a guess. There's a good
chance that an eight-bit encoding from a Microsoft product is CP-1252.
In fact, when I interoperate with Unicode-unaware Windows programs, I
usually attempt a UTF-8 decode, and if that fails, I simply assume
CP-1252; this generally gives correct results for data coming from
US-English Windows users.

Jacob, have a look at your data. Contextually, would the '\xa3' be
likely to be a pound sign, ?? Would '\x85' make sense as an ellipsis?
Would \x90, \x91, \x92, and \x93 seem to be used for quote marks? If
so, CP-1252 would be the encoding to use.

ChrisA


From road01 at yahoo.fr  Wed Jan  7 07:20:43 2015
From: road01 at yahoo.fr (brice DORA)
Date: Wed, 7 Jan 2015 04:20:43 -0800 (PST)
Subject: how to create a soap enveloppe with python suds for consume a bssv
 web service
Message-ID: <5975f1a8-dc9a-4ab3-b4f4-6e3695f4485a@googlegroups.com>

Hi all I am working on a app in python and I have to call a web service deployed on JDE (bssv). I use it for the suds lib which seems pretty friendly. but the problem is the JDE web service that uses bssv technology necessarily requires sending a soap envelope. as far as I spend my fesais parameters required in my suds client. My concern then is how to work around this problem, or is this possible to create a soap envelope with suds? thank you in advance


From davea at davea.name  Wed Jan  7 07:22:03 2015
From: davea at davea.name (Dave Angel)
Date: Wed, 07 Jan 2015 07:22:03 -0500
Subject: String character encoding when converting data from one
 type/format to another
In-Reply-To: <9A569F491BCD444E9512731789AC7853@JakesPC>
References: <9A569F491BCD444E9512731789AC7853@JakesPC>
Message-ID: <54AD24EB.4080208@davea.name>

On 01/07/2015 06:04 AM, Jacob Kruger wrote:
> I'm busy using something like pyodbc to pull data out of MS access .mdb files, and then generate .sql script files to execute

  against MySQL databases using MySQLdb module, but, issue is forms of 
characters in string values that don't fit inside

  the 0-127 range - current one seems to be something like \xa3, and if 
I pass it through ord() function,

  it comes out as character number 163.

First question, of course is what version of Python.  Clearly, you're 
not using Python 3.x, so I'll assume 2.7.  But you really should specify 
it in your query.

Next question is what OS you're using.  You're reading .mdb files, which 
are most likely created in Windows, but that doesn't guarantee you're 
actually using Windows to do this conversion.


>
> Now issue is, yes, could just run through the hundreds of thousands of characters in these resulting strings, and strip out any that are not within the basic 0-127 range, but, that could result in corrupting data - think so anyway.
>
> Anyway, issue is, for example, if I try something like str('\xa3').encode('utf-8') or str('\xa3').encode('ascii'), or str('\xa3').encode('latin7') - that last one is actually our preferred encoding for the MySQL database - they all just tell me they can't work with a character out of range.
>

That's because your input data isn't ASCII.  So before you encode it, 
you have to decode it.  Any idea what encoding it's already in?  Maybe 
it's in latin1, which permits all 256 values.  Or utf-8, which permits a 
few hundred thousand values, but uses multiple bytes for any of those 
over 127.  Or any of hundreds of other encodings.

Does an .mdb file have a field specifying what encoding was used?  Or do 
you have some other external knowledge?

If you don't know what encoding it's currently in, you'll have to guess, 
and the guess you're using so far is ASCII, which you know is false.

As for the encoding you should actually use in the database, that almost 
certainly ought to be utf-8, which supports far more international 
characters than latin1.  And make sure the database has a way to tell 
the future user what encoding you picked.

> Any thoughts on a sort of generic method/means to handle any/all characters that might be out of range when having pulled them out of something like these MS access databases?

The only invalid characters are those which aren't valid in the encoding 
used.  Those can probably be safely converted to "?" or something similar.

>
> Another side note is for binary values that might store binary values, I use something like the following to generate hex-based strings that work alright when then inserting said same binary values into longblob fields, but, don't think this would really help for what are really just most likely badly chosen copy/pasted strings from documents, with strange encoding, or something:
> #sample code line for binary encoding into string output
> s_values += "0x" + str(l_data[J][I]).encode("hex").replace("\\", "\\\\") + ", "
>

Best to not pretend they're text at all.  But if your db doesn't support 
binary blobs, then use an encoding which supports all 256 values 
unambiguously, while producing printable characters.  Like uuencod, 
using module uu

You might also look into mime, where you store the encoding of the data 
with the data.  See for example mimetypes.



-- 
DaveA


From tim_grove at sil.org  Wed Jan  7 08:09:38 2015
From: tim_grove at sil.org (Timothy W. Grove)
Date: Wed, 07 Jan 2015 13:09:38 +0000
Subject: include "icudt53.dll, icuin53.dll, icuuc53.dll" ?
Message-ID: <54AD3012.7000305@sil.org>

Does anyone have an idea of what the following .dll's are for? Cx_freeze 
includes them in a Python3.4-PyQt5 deployment adding about 23 Mb to my 
application. Removing them doesn't appear to make any difference on my 
computer, but I hesitate to distribute the application to others without 
them. Thanks for any response.

Best regards,
Tim Grove

icudt53.dll
icuin53.dll
icuuc53.dll


From tim_grove at sil.org  Wed Jan  7 08:23:22 2015
From: tim_grove at sil.org (Timothy W. Grove)
Date: Wed, 07 Jan 2015 13:23:22 +0000
Subject: include "icudt53.dll, icuin53.dll, icuuc53.dll" ?
In-Reply-To: <54AD3012.7000305@sil.org>
References: <54AD3012.7000305@sil.org>
Message-ID: <54AD334A.8070001@sil.org>

I think my answer is probably "Yes!" Anyone else interested, see 
http://qt-project.org/wiki/Deploying-Windows-Applications.

Tim

On 07/01/2015 13:09, Timothy W. Grove wrote:
> Does anyone have an idea of what the following .dll's are for? 
> Cx_freeze includes them in a Python3.4-PyQt5 deployment adding about 
> 23 Mb to my application. Removing them doesn't appear to make any 
> difference on my computer, but I hesitate to distribute the 
> application to others without them. Thanks for any response.
>
> Best regards,
> Tim Grove
>
> icudt53.dll
> icuin53.dll
> icuuc53.dll



From rosuav at gmail.com  Wed Jan  7 08:30:55 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 8 Jan 2015 00:30:55 +1100
Subject: include "icudt53.dll, icuin53.dll, icuuc53.dll" ?
In-Reply-To: <54AD334A.8070001@sil.org>
References: <54AD3012.7000305@sil.org>
	<54AD334A.8070001@sil.org>
Message-ID: <CAPTjJmpzJ5AOA9+-zWiQih42Om-qoXuW6TqKC9RQ80nu-BTJMA@mail.gmail.com>

On Thu, Jan 8, 2015 at 12:23 AM, Timothy W. Grove <tim_grove at sil.org> wrote:
> I think my answer is probably "Yes!" Anyone else interested, see
> http://qt-project.org/wiki/Deploying-Windows-Applications.

This is one of the disadvantages to packaging Python code up into a
monolithic executable. You end up needing quite a bit of ancillary
'stuff' to make it all work. Personally, I'd rather just distribute
the .py files, and let people download Python separately; much less
load on my servers, and they don't have to download Python twice for
two programs.

ChrisA


From jacob at blindza.co.za  Wed Jan  7 08:32:00 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Wed, 7 Jan 2015 15:32:00 +0200
Subject: String character encoding when converting data from one
 type/format to another
In-Reply-To: <m8j78q$680$1@ger.gmane.org>
References: <9A569F491BCD444E9512731789AC7853@JakesPC>
 <m8j78q$680$1@ger.gmane.org>
Message-ID: <6EE7BA91A39240A99E16099BF6078F0A@JakesPC>

Thanks.

Yes, using python 2.7, and all you said makes sense, so will check out the 
talk, and the byte'ing, etc. (yes, bad joke, I know)

Issue with knowing encoding could just be that am pretty sure at least some 
of the data capture is done via copy/paste from one MS app to another, which 
could possibly result in a whole bunch of different character sets, etc. 
being copied across, so it comes down to that while can't control sources of 
data, need to manipulate/work with it to make it useful on our side now.

Thanks again

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."

----- Original Message ----- 
From: "Ned Batchelder" <ned at nedbatchelder.com>
To: <python-list at python.org>
Sent: Wednesday, January 07, 2015 2:02 PM
Subject: Re: String character encoding when converting data from one 
type/format to another


> On 1/7/15 6:04 AM, Jacob Kruger wrote:
>> I'm busy using something like pyodbc to pull data out of MS access .mdb
>> files, and then generate .sql script files to execute against MySQL
>> databases using MySQLdb module, but, issue is forms of characters in
>> string values that don't fit inside the 0-127 range - current one seems
>> to be something like \xa3, and if I pass it through ord() function, it
>> comes out as character number 163.
>> Now issue is, yes, could just run through the hundreds of thousands of
>> characters in these resulting strings, and strip out any that are not
>> within the basic 0-127 range, but, that could result in corrupting data
>> - think so anyway.
>
> That will definitely corrupt your data, since you will be discarding data.
>
>> Anyway, issue is, for example, if I try something like
>> str('\xa3').encode('utf-8') or str('\xa3').encode('ascii'), or
>> str('\xa3').encode('latin7') - that last one is actually our preferred
>> encoding for the MySQL database - they all just tell me they can't work
>> with a character out of range.
>
> Are you using Python 2 or Python 3? This is one area where the two are 
> very different.  I suspect you are on Python 2, in which case these all 
> fail the same way because you are calling encode on a bytestring.  You 
> can't encode a bytestring, you can only encode a Unicode string, so encode 
> is helpfully trying to decode your bytestring first, using the default 
> encoding (ascii), and '\xa3' is not an ascii character.
>
> If that was confusing, this talk covers these fundamentals: 
> http://bit.ly/unipain .
>
>> Any thoughts on a sort of generic method/means to handle any/all
>> characters that might be out of range when having pulled them out of
>> something like these MS access databases?
>
> The best thing is to know what encoding was used to produce these byte 
> values.  Then you can manipulate them as Unicode if you need to.  The 
> second best thing is to simply pass them through as bytes.
>
>> Another side note is for binary values that might store binary values, I
>> use something like the following to generate hex-based strings that work
>> alright when then inserting said same binary values into longblob
>> fields, but, don't think this would really help for what are really just
>> most likely badly chosen copy/pasted strings from documents, with
>> strange encoding, or something:
>> #sample code line for binary encoding into string output
>> s_values += "0x" + str(l_data[J][I]).encode("hex").replace("\\", "\\\\")
>> + ", "
>> TIA
>>
>> Jacob Kruger
>> Blind Biker
>> Skype: BlindZA
>> "Roger Wilco wants to welcome you...to the space janitor's closet..."
>>
>>
>
>
> -- 
> Ned Batchelder, http://nedbatchelder.com
>
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 



From jacob at blindza.co.za  Wed Jan  7 08:38:03 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Wed, 7 Jan 2015 15:38:03 +0200
Subject: String character encoding when converting data from one
 type/format to another
In-Reply-To: <m8j7q4$c3r$1@ger.gmane.org>
References: <9A569F491BCD444E9512731789AC7853@JakesPC>
 <m8j7q4$c3r$1@ger.gmane.org>
Message-ID: <55DF4024DEB04E468BA7C2C493967DB8@JakesPC>

Thanks.

Makes more sense now, and yes, using 2.7 here.

Unfortunately, while could pass the binary values into blob fields well 
enough, using forms of parameterised statements, the actual generation of 
sql script text files is a step they want to work with at times, if someone 
is handling this on site, so had to work first with generating string 
values, and then handle executing those statements against a MySQL server 
later on using MySQLdb.

Stay well

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."

----- Original Message ----- 
From: "Peter Otten" <__peter__ at web.de>
To: <python-list at python.org>
Sent: Wednesday, January 07, 2015 2:11 PM
Subject: Re: String character encoding when converting data from one 
type/format to another


> Jacob Kruger wrote:
>
>> I'm busy using something like pyodbc to pull data out of MS access .mdb
>> files, and then generate .sql script files to execute against MySQL
>> databases using MySQLdb module, but, issue is forms of characters in
>> string values that don't fit inside the 0-127 range - current one seems 
>> to
>> be something like \xa3, and if I pass it through ord() function, it comes
>> out as character number 163.
>>
>> Now issue is, yes, could just run through the hundreds of thousands of
>> characters in these resulting strings, and strip out any that are not
>> within the basic 0-127 range, but, that could result in corrupting data -
>> think so anyway.
>>
>> Anyway, issue is, for example, if I try something like
>> str('\xa3').encode('utf-8') or str('\xa3').encode('ascii'), or
>
> "\xa3" already is a str; str("\xa3") is as redundant as
> str(str(str("\xa3"))) ;)
>
>> str('\xa3').encode('latin7') - that last one is actually our preferred
>> encoding for the MySQL database - they all just tell me they can't work
>> with a character out of range.
>
> encode() goes from unicode to byte; you want to convert bytes to unicode 
> and
> thus need decode().
>
> In this context it is important that you tell us the Python version. In
> Python 2 str.encode(encoding) is basically
>
> str.decode("ascii").encode(encoding)
>
> which is why you probably got a UnicodeDecodeError in the traceback:
>
>>>> "\xa3".encode("latin7")
> Traceback (most recent call last):
>  File "<stdin>", line 1, in <module>
>  File "/usr/lib/python2.7/encodings/iso8859_13.py", line 12, in encode
>    return codecs.charmap_encode(input,errors,encoding_table)
> UnicodeDecodeError: 'ascii' codec can't decode byte 0xa3 in position 0:
> ordinal not in range(128)
>
>>>> "\xa3".decode("latin7")
> u'\xa3'
>>>> print "\xa3".decode("latin7")
> ?
>
> Aside: always include the traceback in your posts -- and always read it
> carefully. The fact that "latin7" is not mentioned might have given you a
> hint that the problem was not what you thought it was.
>
>> Any thoughts on a sort of generic method/means to handle any/all
>> characters that might be out of range when having pulled them out of
>> something like these MS access databases?
>
> Assuming the data in Access is not broken and that you know the encoding
> decode() will work.
>
>> Another side note is for binary values that might store binary values, I
>> use something like the following to generate hex-based strings that work
>> alright when then inserting said same binary values into longblob fields,
>> but, don't think this would really help for what are really just most
>> likely badly chosen copy/pasted strings from documents, with strange
>> encoding, or something:
>> #sample code line for binary encoding into string output
>> s_values += "0x" + str(l_data[J][I]).encode("hex").replace("\\", "\\\\") 
>> +
>> ", "
>
> I would expect that you can feed bytestrings directly into blobs, without
> any preparatory step. Try it, and if you get failures show us the failing
> code and the corresponding traceback.
>
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 



From jacob at blindza.co.za  Wed Jan  7 08:41:10 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Wed, 7 Jan 2015 15:41:10 +0200
Subject: String character encoding when converting data from one
 type/format to another
In-Reply-To: <54AD24EB.4080208@davea.name>
References: <9A569F491BCD444E9512731789AC7853@JakesPC>
 <54AD24EB.4080208@davea.name>
Message-ID: <7AAF296AECCA436BBCE74374B6D02092@JakesPC>

Thanks.

Yes, sorry didn't mention 2.7, and, unfortunately in this sense, all of this 
will be running on windows machines.

Stay well

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."

----- Original Message ----- 
From: "Dave Angel" <davea at davea.name>
To: <python-list at python.org>
Sent: Wednesday, January 07, 2015 2:22 PM
Subject: Re: String character encoding when converting data from one 
type/format to another


> On 01/07/2015 06:04 AM, Jacob Kruger wrote:
>> I'm busy using something like pyodbc to pull data out of MS access .mdb 
>> files, and then generate .sql script files to execute
>
>  against MySQL databases using MySQLdb module, but, issue is forms of 
> characters in string values that don't fit inside
>
>  the 0-127 range - current one seems to be something like \xa3, and if I 
> pass it through ord() function,
>
>  it comes out as character number 163.
>
> First question, of course is what version of Python.  Clearly, you're not 
> using Python 3.x, so I'll assume 2.7.  But you really should specify it in 
> your query.
>
> Next question is what OS you're using.  You're reading .mdb files, which 
> are most likely created in Windows, but that doesn't guarantee you're 
> actually using Windows to do this conversion.
>
>
>>
>> Now issue is, yes, could just run through the hundreds of thousands of 
>> characters in these resulting strings, and strip out any that are not 
>> within the basic 0-127 range, but, that could result in corrupting data - 
>> think so anyway.
>>
>> Anyway, issue is, for example, if I try something like 
>> str('\xa3').encode('utf-8') or str('\xa3').encode('ascii'), or 
>> str('\xa3').encode('latin7') - that last one is actually our preferred 
>> encoding for the MySQL database - they all just tell me they can't work 
>> with a character out of range.
>>
>
> That's because your input data isn't ASCII.  So before you encode it, you 
> have to decode it.  Any idea what encoding it's already in?  Maybe it's in 
> latin1, which permits all 256 values.  Or utf-8, which permits a few 
> hundred thousand values, but uses multiple bytes for any of those over 
> 127.  Or any of hundreds of other encodings.
>
> Does an .mdb file have a field specifying what encoding was used?  Or do 
> you have some other external knowledge?
>
> If you don't know what encoding it's currently in, you'll have to guess, 
> and the guess you're using so far is ASCII, which you know is false.
>
> As for the encoding you should actually use in the database, that almost 
> certainly ought to be utf-8, which supports far more international 
> characters than latin1.  And make sure the database has a way to tell the 
> future user what encoding you picked.
>
>> Any thoughts on a sort of generic method/means to handle any/all 
>> characters that might be out of range when having pulled them out of 
>> something like these MS access databases?
>
> The only invalid characters are those which aren't valid in the encoding 
> used.  Those can probably be safely converted to "?" or something similar.
>
>>
>> Another side note is for binary values that might store binary values, I 
>> use something like the following to generate hex-based strings that work 
>> alright when then inserting said same binary values into longblob fields, 
>> but, don't think this would really help for what are really just most 
>> likely badly chosen copy/pasted strings from documents, with strange 
>> encoding, or something:
>> #sample code line for binary encoding into string output
>> s_values += "0x" + str(l_data[J][I]).encode("hex").replace("\\", "\\\\") 
>> + ", "
>>
>
> Best to not pretend they're text at all.  But if your db doesn't support 
> binary blobs, then use an encoding which supports all 256 values 
> unambiguously, while producing printable characters.  Like uuencod, using 
> module uu
>
> You might also look into mime, where you store the encoding of the data 
> with the data.  See for example mimetypes.
>
>
>
> -- 
> DaveA
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 



From davea at davea.name  Wed Jan  7 08:52:42 2015
From: davea at davea.name (Dave Angel)
Date: Wed, 07 Jan 2015 08:52:42 -0500
Subject: String character encoding when converting data from one
 type/format to another
In-Reply-To: <6EE7BA91A39240A99E16099BF6078F0A@JakesPC>
References: <9A569F491BCD444E9512731789AC7853@JakesPC>
 <m8j78q$680$1@ger.gmane.org> <6EE7BA91A39240A99E16099BF6078F0A@JakesPC>
Message-ID: <54AD3A2A.6010906@davea.name>

On 01/07/2015 08:32 AM, Jacob Kruger wrote:
> Thanks.
>
Please don't top-post.  Put your responses after each quoted part you're 
responding to.  And if there are parts you're not responding to, please 
delete them.
>
> Issue with knowing encoding could just be that am pretty sure at least
> some of the data capture is done via copy/paste from one MS app to
> another, which could possibly result in a whole bunch of different
> character sets, etc. being copied across, so it comes down to that while
> can't control sources of data, need to manipulate/work with it to make
> it useful on our side now.
>

Copy/paste to/from properly written Windows programs is done in Unicode, 
so the problem should only be one of how the data was saved.  There, 
Windows is much more sloppy.

Chances are that a given machine will use a consistent encoding, so a 
given file should be consistent, unless it was used over a network.  And 
if all the machines that generate this data are in the same company, 
they might all use the same one as well.


-- 
DaveA


From davea at davea.name  Wed Jan  7 08:56:56 2015
From: davea at davea.name (Dave Angel)
Date: Wed, 07 Jan 2015 08:56:56 -0500
Subject: String character encoding when converting data from one
 type/format to another
In-Reply-To: <55DF4024DEB04E468BA7C2C493967DB8@JakesPC>
References: <9A569F491BCD444E9512731789AC7853@JakesPC>
 <m8j7q4$c3r$1@ger.gmane.org> <55DF4024DEB04E468BA7C2C493967DB8@JakesPC>
Message-ID: <54AD3B28.7080503@davea.name>

On 01/07/2015 08:38 AM, Jacob Kruger wrote:
> Thanks.
>
> Makes more sense now, and yes, using 2.7 here.
>
> Unfortunately, while could pass the binary values into blob fields well
> enough, using forms of parameterised statements, the actual generation
> of sql script text files is a step they want to work with at times, if
> someone is handling this on site, so had to work first with generating
> string values, and then handle executing those statements against a
> MySQL server later on using MySQLdb.
>

There must be an encoding method used for describing blobs in an sql 
statement.  Use exactly that method;  don't try to get creative.

For example in sqlite, use  sqlite.encode()

-- 
DaveA


From fomcl at yahoo.com  Wed Jan  7 13:38:25 2015
From: fomcl at yahoo.com (Albert-Jan Roskam)
Date: Wed, 7 Jan 2015 10:38:25 -0800
Subject: include "icudt53.dll, icuin53.dll, icuuc53.dll" ?
Message-ID: <1420655905.68800.BPMail_high_carrier@web163802.mail.gq1.yahoo.com>


----------------------------
On Wed, Jan 7, 2015 2:09 PM CET Timothy W. Grove wrote:

>Does anyone have an idea of what the following .dll's are for? Cx_freeze includes them in a Python3.4-PyQt5 deployment adding about 23 Mb to my application. Removing them doesn't appear to make any difference on my computer, but I hesitate to distribute the application to others without them. Thanks for any response.
>
>Best regards,
>Tim Grove
>
>icudt53.dll
>icuin53.dll
>icuuc53.dll
>-- 

It is unicode related, see 
http://stackoverflow.com/questions/16736579/deploying-a-qt-project-without-icu-dependencies

https://mail.python.org/mailman/listinfo/python-list



From john_ladasky at sbcglobal.net  Wed Jan  7 15:12:25 2015
From: john_ladasky at sbcglobal.net (John Ladasky)
Date: Wed, 7 Jan 2015 12:12:25 -0800 (PST)
Subject: pickle, modules, and ImportErrors
Message-ID: <eb5918fb-41ea-4199-b2f2-ae28b454c983@googlegroups.com>

I am progressing towards organizing a recent project of mine as a proper Python package.  It is not a huge package, about 700 lines of code so far.  But it breaks into logical pieces, and I don't feel like scrolling back and forth through a 700-line file.

I am running Python 3.4.0 on Ubuntu 14.04, if it matters.  

I want a package which I can use in an iPython session, as well as in programs which share the package directory.  Compatibility within the package directory appears to be easy.  From outside the package, I am getting ImportErrors that I have not been able to fix.

Although I have used pickle often, this is the first time that I have written a package with an __init__.py.  It reads thus:


# __init__.py for my_svr module

from .database import MasterDatabase
from .sampling import Input
from .sampling import MultiSample
from .sampling import Sample
from .sampling import Target
from .sampling import DataPoint
from .model import Prediction
from .model import SVRModel
from .model import comparison
from .training import TrainingSession

__all__ = ("MasterDatabase", "Input", "MultiSample", "Sample", "Target",
           "DataPoint", "Prediction", "SVRModel", "comparison",
           "TrainingSession")


If I execute "import my_svr" in an iPython interpreter, everything works as I think that I should expect:


In [8]: dir(my_svr)
Out[8]: 
['Input',
 'MasterDatabase',
 'MultiSample',
 'Prediction',
 'SVRModel',
 'Sample',
 'Target',
 'DataPoint',
 'TrainingSession',
 '__all__',
 '__builtins__',
 '__cached__',
 '__doc__',
 '__file__',
 '__loader__',
 '__name__',
 '__package__',
 '__path__',
 '__spec__',
 'comparison',
 'database',
 'model',
 'sampling',
 'training']



My training.py program produces an SVRModel object, and pickles it to a binary file.  The following simple program will unpickle the file saved by training.py, provided that the program resides in the module's own folder:


# reload_test.py

from pickle import load

with open("../models/sample model.pkl", "rb") as f:
    model = load(f)
print(model)


And, I get the str representation of my SVRModel instance.

However, a nearly-identical program in the parent folder fails (note that all I change is the relative path to the file):


# parent_folder_reload_test.py

from pickle import load

with open("models/sample model.pkl", "rb") as f:
    model = load(f)
print(model)


Traceback (most recent call last):
  File "reload test different directory.py", line 6, in <module>
    model = load(f)
ImportError: No module named 'model'


Do I need to "import my_svr.model as model" then?  Adding that line changes nothing. I get the exact same "ImportError: No module named 'model'".  

Likewise for "import my_svr", "from my_svr import *", or even "from my_svr.model import SVRModel".

It is clear that I'm failing to understand something important.

I do not have any circular import dependencies; however, some of the files in my package do need to import definitions from files earlier in my data pipeline.  In order to make everything work inside the module, as well as making a parent-folder "import my_svr" work from a iPython,  I find myself needing to use statements like these inside my training.py program:


try:
    from model import *
    from sampling import *
except ImportError:
    from .model import *
    from .sampling import *


This bothers me.  I don't know whether it is correct usage.  I don't know whether it is causing my remaining ImportError problem.

Any advice is appreciated.  Thanks!


From jeanpierreda at gmail.com  Wed Jan  7 15:55:32 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Wed, 7 Jan 2015 14:55:32 -0600
Subject: pickle, modules, and ImportErrors
In-Reply-To: <eb5918fb-41ea-4199-b2f2-ae28b454c983@googlegroups.com>
References: <eb5918fb-41ea-4199-b2f2-ae28b454c983@googlegroups.com>
Message-ID: <CABicbJKELoA+TXRecC96kGgY+e_WwCff_hALYZ_acMNCnFcVAA@mail.gmail.com>

On Wed, Jan 7, 2015 at 2:12 PM, John Ladasky <john_ladasky at sbcglobal.net> wrote:
> If I execute "import my_svr" in an iPython interpreter, everything works as I think that I should expect:
-snip-
> However, a nearly-identical program in the parent folder fails (note that all I change is the relative path to the file):
> Traceback (most recent call last):
>   File "reload test different directory.py", line 6, in <module>
>     model = load(f)
> ImportError: No module named 'model'
>
>
> Do I need to "import my_svr.model as model" then?  Adding that line changes nothing. I get the exact same "ImportError: No module named 'model'".
>
> Likewise for "import my_svr", "from my_svr import *", or even "from my_svr.model import SVRModel".
>
> It is clear that I'm failing to understand something important.

in the first case, the model module was available as a top-level
module, "model". Pickles referenced that module when serialized. In
the second case, the model module was available as a submodule of the
top level my_svr package. So any pickles serialized from there would
use my_svr.model to refer to the model module. There *is* no model
module in this second case, so deserializing fails.

If you never run model directly, and only ever import it or run it as
my_svr.model, then you will be fine, and pickles will all serialize
and deserialize the same way.

For example, instead of python -i my_svr/model.py, you can use python
-im my_svr.model . (or ipython -im my_svr.model).

P.S. don't use pickle, it is a security vulnerability equivalent in
severity to using exec in your code, and an unversioned opaque
schemaless blob that is very difficult to work with when circumstances
change.

> I do not have any circular import dependencies; however, some of the files in my package do need to import definitions from files earlier in my data pipeline.  In order to make everything work inside the module, as well as making a parent-folder "import my_svr" work from a iPython,  I find myself needing to use statements like these inside my training.py program:
>
>
> try:
>     from model import *
>     from sampling import *
> except ImportError:
>     from .model import *
>     from .sampling import *
>
>
> This bothers me.  I don't know whether it is correct usage.  I don't know whether it is causing my remaining ImportError problem.

This is a symptom of the differing ways you are importing these
modules, as above. If you only ever run them and import them as
my_svr.blahblah, then only the second set of imports are necessary.

P.S. don't use import *, and if you do use import *, don't use more
than one per file -- it makes it really hard to figure out where a
given global came from (was it defined here? was it defined in model?
was it defined in sampling?)

I hope that resolves all your questions!

-- Devin


From ian.g.kelly at gmail.com  Wed Jan  7 16:01:16 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 7 Jan 2015 14:01:16 -0700
Subject: pickle, modules, and ImportErrors
In-Reply-To: <eb5918fb-41ea-4199-b2f2-ae28b454c983@googlegroups.com>
References: <eb5918fb-41ea-4199-b2f2-ae28b454c983@googlegroups.com>
Message-ID: <CALwzidkxwoi0Jz1GtUqMDQKkfY=vKo89sE9uHvY=KK0aZwYQPA@mail.gmail.com>

On Wed, Jan 7, 2015 at 1:12 PM, John Ladasky <john_ladasky at sbcglobal.net> wrote:
> Do I need to "import my_svr.model as model" then?  Adding that line changes nothing. I get the exact same "ImportError: No module named 'model'".
>
> Likewise for "import my_svr", "from my_svr import *", or even "from my_svr.model import SVRModel".
>
> It is clear that I'm failing to understand something important.
>
> I do not have any circular import dependencies; however, some of the files in my package do need to import definitions from files earlier in my data pipeline.  In order to make everything work inside the module, as well as making a parent-folder "import my_svr" work from a iPython,  I find myself needing to use statements like these inside my training.py program:
>
>
> try:
>     from model import *
>     from sampling import *
> except ImportError:
>     from .model import *
>     from .sampling import *
>
>
> This bothers me.  I don't know whether it is correct usage.  I don't know whether it is causing my remaining ImportError problem.

It sounds like you have import path confusion. The first imports there
are absolute imports. If the absolute paths of the named modules are
just "model" and "sampling", then that would be correct. However, it
sounds like these modules are part of a "my_svr" package, so the
absolute paths of these modules are actually "my_svr.model" and
"my_svr.sampling". In that case, the the absolute path that you're
trying to use for the import is wrong. Either fully specify the module
path, or use the relative import you have below.

Now, why might those absolute imports appear to work even though the
paths are incorrect? Well, it sounds like you may be running a file
inside the package as your main script. This causes some problems.

1) Python doesn't realize that the script it's running is part of a
package. It just calls that module '__main__', and if something else
happens to import the module later by its real name, then you'll end
up loading a second copy of the module by that name, which can lead to
confusing behavior.

2) Python implicitly adds the directory containing the script to the
front of the sys.path list. Since the directory containing the package
is presumably already on the sys.path, this means that the internal
modules now appear in sys.path *twice*, with two different names:
"my_svr.model" and "model" refer to the same source file. Python
doesn't realize this however, and so they don't refer to the same
module. As a result, importing both "my_svr.model" and "model" will
again result in two separate copies of the module being loaded, with
two different names.

It sounds like your pickle file was created from an object from the
"model" module. This works fine when the sys.path is set such that
"model" is the absolute path of a module, i.e. when you run your main
script within the package. When running an external main script,
sys.path doesn't get set that way, and so it can't find the "model"
module.

The solution to this is to avoid executing a module within a package
as your main script. Run a script outside the package and have it
import and call into the package instead. An alternative is to run the
module using the -m flag of the Python executable; this fixes problem
2 above but not problem 1.


From adam at poczta.emiter-uslugi.pl  Wed Jan  7 16:17:09 2015
From: adam at poczta.emiter-uslugi.pl (adam)
Date: Wed, 07 Jan 2015 22:17:09 +0100
Subject: application console with window
Message-ID: <m8k10h$cpe$1@news.icm.edu.pl>

Is in here maybe someone who speak Polish?

I would like to write application witch looks like this 
http://linuxiarze.pl/obrazy/internet1/ceni1.png

I'm looking for some libs, tutorials, or other informations.
I'm searching this informations for python3.

adam


From am1r.ar3alan at gmail.com  Wed Jan  7 16:24:00 2015
From: am1r.ar3alan at gmail.com (Amir Arsalan)
Date: Thu, 8 Jan 2015 00:54:00 +0330
Subject: application console with window
In-Reply-To: <m8k10h$cpe$1@news.icm.edu.pl>
References: <m8k10h$cpe$1@news.icm.edu.pl>
Message-ID: <CANNmrNawkjFdGTtyi1yUj3D=wG5oA+TMU3nO5N_jxBJxqD0r_Q@mail.gmail.com>

Hi adam,

U can use from npyscreen.

Npyscreen.readthedocs.org
On Jan 8, 2015 12:50 AM, "adam" <adam at poczta.emiter-uslugi.pl> wrote:

> Is in here maybe someone who speak Polish?
>
> I would like to write application witch looks like this
> http://linuxiarze.pl/obrazy/internet1/ceni1.png
>
> I'm looking for some libs, tutorials, or other informations.
> I'm searching this informations for python3.
>
> adam
> --
> https://mail.python.org/mailman/listinfo/python-list
>
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From am1r.ar3alan at gmail.com  Wed Jan  7 16:32:56 2015
From: am1r.ar3alan at gmail.com (Amir Arsalan)
Date: Thu, 8 Jan 2015 01:02:56 +0330
Subject: application console with window
In-Reply-To: <CANNmrNawkjFdGTtyi1yUj3D=wG5oA+TMU3nO5N_jxBJxqD0r_Q@mail.gmail.com>
References: <m8k10h$cpe$1@news.icm.edu.pl>
 <CANNmrNawkjFdGTtyi1yUj3D=wG5oA+TMU3nO5N_jxBJxqD0r_Q@mail.gmail.com>
Message-ID: <CANNmrNbyJDBzYzeppA=ZndE8hE-nSZMMH1WepF-ZppbLp4K98Q@mail.gmail.com>

and u have another below choice

http://docs.python.org/howto/curses.html
http://urwid.org/



On Thu, Jan 8, 2015 at 12:54 AM, Amir Arsalan <am1r.ar3alan at gmail.com>
wrote:

> Hi adam,
>
> U can use from npyscreen.
>
> Npyscreen.readthedocs.org
> On Jan 8, 2015 12:50 AM, "adam" <adam at poczta.emiter-uslugi.pl> wrote:
>
>> Is in here maybe someone who speak Polish?
>>
>> I would like to write application witch looks like this
>> http://linuxiarze.pl/obrazy/internet1/ceni1.png
>>
>> I'm looking for some libs, tutorials, or other informations.
>> I'm searching this informations for python3.
>>
>> adam
>> --
>> https://mail.python.org/mailman/listinfo/python-list
>>
>
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From jacek.pozniak at flowservice.pl  Wed Jan  7 16:51:08 2015
From: jacek.pozniak at flowservice.pl (jacek pozniak)
Date: Wed, 07 Jan 2015 22:51:08 +0100
Subject: application console with window
References: <m8k10h$cpe$1@news.icm.edu.pl>
Message-ID: <54adaa47$0$2652$65785112@news.neostrada.pl>

adam wrote:

> Is in here maybe someone who speak Polish?
> 
> I would like to write application witch looks like this
> http://linuxiarze.pl/obrazy/internet1/ceni1.png
Je?li chodzi Ci o przeniesienie na wersj? okienkow? to na przyk?ad: tkinter.

jp

> 
> I'm looking for some libs, tutorials, or other informations.
> I'm searching this informations for python3.
> 
> adam



From steve+comp.lang.python at pearwood.info  Wed Jan  7 18:46:03 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 08 Jan 2015 10:46:03 +1100
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
 <mailman.17424.1420596200.18130.python-list@python.org>
 <54ace9f0$0$2738$c3e8da3$76491128@news.astraweb.com>
 <87tx02gb9d.fsf@elektro.pacujo.net>
Message-ID: <54adc53c$0$12999$c3e8da3$5496439d@news.astraweb.com>

Marko Rauhamaa wrote:

> Steven D'Aprano <steve at pearwood.info>:
> 
>> int 0 is a falsey object
>> NoneType None is a falsey object
>> str 'hello' is a truthy object
>> float 23.0 is a truthy object
> 
> I prefer the Scheme way:
> 
>    #f is a falsey object
> 
>    everything else is a truthy object


The Scheme way has no underlying model of what truthiness represents, just
an arbitrary choice to make a single value have one truthiness, and
everything else the other. It's just as meaningless and just as arbitrary
as the opposite would be:

    #t is True
    everything else is falsey


In both cases, you have the vast infinity of values apart from #f (or #t, as
the case may be) which are indistinguishable from each other under the
operation of "use in a boolean context". In other words, apart from #f or
#t, bool(x) maps everything to a single value. That makes it useless for
anything except distinguishing #f (or #t) from "everything else".

(I'm mixing scheme and python here, but I trust my meaning is clear.)

Given x of some type other than the Boolean type, bool(x) always gives the
same result. Since all non-Booleans are indistinguishable under that
operation, it is pointless to apply that operation to them.

I'd rather the Pascal way:

    #t is True
    #f is False
    everything else is an error


That at least gives you the benefits (if any) of strongly-typed bools.

Python has a (mostly) consistent model for truthiness: truthy values
represent "something", falsey values represent "nothing" or emptiness:

Falsey values:
  None
  Numeric zeroes: 0, 0.0, 0j, Decimal(0), Fraction(0)
  Empty strings '', u''
  Empty containers [], (), {}, set(), frozenset()

Truthy values:
  Numeric non-zeroes
  Non-empty strings
  Non-empty containers
  Any other arbitrary object


The model isn't quite perfect (I don't believe any model using truthiness
can be) but the number of gotchas in the built-ins and standard library are
very small. I can only think of two:

- datetime.time(0) is falsey. Why midnight should be falsey is an 
  accident of implementation: datetime.time objects inherit from 
  int, and midnight happens to be represented by zero seconds.

- Empty iterators are truthy. Since in general you can't tell in 
  advance whether an iterator will be empty or not until you try 
  it, this makes sense.




-- 
Steven



From ethan at stoneleaf.us  Wed Jan  7 19:04:47 2015
From: ethan at stoneleaf.us (Ethan Furman)
Date: Wed, 07 Jan 2015 16:04:47 -0800
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54ACAA04.60801@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com>
Message-ID: <54ADC99F.3020405@stoneleaf.us>

On 01/06/2015 07:37 PM, Andrew Robinson wrote:

> Explain; How does mere subclassing of bool break the contract that bool has?
> eg: What method or data would the superclass have that my subclass would not?

bool's contract is that there are only two values (True and False) and only one instance each of those two values (True
and False).  If bool were subclassable, new values could be added with either completely different values (PartTrue) or
with more of the same value (True, ReallyTrue, AbsolutelyTrue) -- hence, broken contract.

--
~Ethan~

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From garyfallidis at gmail.com  Wed Jan  7 19:22:18 2015
From: garyfallidis at gmail.com (Eleftherios Garyfallidis)
Date: Thu, 8 Jan 2015 02:22:18 +0200
Subject: Happy new year with Dipy 0.8!
Message-ID: <CAN6JmWOa-djvbYYpNZ5G6OJRBCXv7F-mgD__WZbdY3R2xJjbUg@mail.gmail.com>

Dear all,


We are very happy to announce a new release of Diffusion Imaging in Python
(Dipy).


Here is a summary of the most important new features and developments.


DIPY 0.8.0 (Released on Tuesday, 6 Jan 2015)


Nonlinear Image-based Registration (SyN)


An implementation of the Symmetric Normalization method for nonlinear
diffeomorphic registration. This implementation is lightweight, and does
not depend on ITK or ANTS. It is written entirely in Python and Cython.


Streamline-based Linear Registration (SLR)


A new method that allows direct registration of bundles of streamlines.
Especially useful for creating atlases of specific types of bundles.


Linear Fascicle Evaluation (LiFE)


This is a Python implementation of a new method for evaluation of
tractrography solutions.


Sparse Fascicle Model (SFM)


A new signal reconstruction method , added to the large stack of
reconstruction models already available in Dipy, including implementations
of CSD and SHORE.


Non-local means denoising (NLMEANS)


Denoising is a technique that can boost most of your analysis techniques as
it can increase the signal to noise ratio of your data. We started this new
module by implementing a very generic denoising technique that can be used
also for fMRI and T1 images.


New modular tracking machinery


This is a collection of new objects which allows rapid development of new
fiber tracking algorithms.


In summary, since January 2014 (version 0.7.1), we closed 388 issues and
merged 155 pull requests. The project now has a total of more than 4000
commits and 29 contributors.


We would appreciate if you could forward this information to any interested
individuals or labs.


Yours sincerely,


On behalf of the Dipy developers,

Eleftherios Garyfallidis

http://dipy.org
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From john_ladasky at sbcglobal.net  Wed Jan  7 19:23:43 2015
From: john_ladasky at sbcglobal.net (John Ladasky)
Date: Wed, 7 Jan 2015 16:23:43 -0800 (PST)
Subject: pickle, modules, and ImportErrors
In-Reply-To: <mailman.17453.1420664176.18130.python-list@python.org>
References: <eb5918fb-41ea-4199-b2f2-ae28b454c983@googlegroups.com>
 <mailman.17453.1420664176.18130.python-list@python.org>
Message-ID: <d8565079-64ae-432f-bff5-18c67891ed40@googlegroups.com>

On Wednesday, January 7, 2015 12:56:29 PM UTC-8, Devin Jeanpierre wrote:

[snip]

> If you never run model directly, and only ever import it or run it as
> my_svr.model, then you will be fine, and pickles will all serialize
> and deserialize the same way.

Thank you Devin... I re-ran TrainingSession from within ipython, and everything worked the way I hoped.  I obtained an SVRModel object which I could pickle to disk, and unpickle in a subsequent session.  I don't actually need to run the test code that I appended to training.py any more, so I won't.

[snip]

> P.S. don't use pickle, it is a security vulnerability equivalent in
> severity to using exec in your code, and an unversioned opaque
> schemaless blob that is very difficult to work with when circumstances
> change.

For all of its shortcomings, I can't live without pickle.  In this case, I am doing data mining.  My TrainingSession class commandeers seven CPU cores via Multiprocessing.Pool.  Still, even my "toy" TrainingSessions take several minutes to run.  I can't afford to re-run TrainingSession every time I need my models.  I need a persistent object.

Besides, the opportunity for mischief is low.  My code is for my own personal use.  And I trust the third-party libraries that I am using.  My SVRModel object wraps the NuSVR object from scikit-learn, which in turn wraps the libsvm binary.

> > try:
> >     from model import *
> >     from sampling import *
> > except ImportError:
> >     from .model import *
> >     from .sampling import *
> >
> >
> > This bothers me.  I don't know whether it is correct usage.  I don't know whether it is causing my remaining ImportError problem.
> 
> This is a symptom of the differing ways you are importing these
> modules, as above. If you only ever run them and import them as
> my_svr.blahblah, then only the second set of imports are necessary.

OK, I will try refactoring the import code at some point.
 
> I hope that resolves all your questions!

I think so, thanks.


From rosuav at gmail.com  Wed Jan  7 20:06:27 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 8 Jan 2015 12:06:27 +1100
Subject: pickle, modules, and ImportErrors
In-Reply-To: <d8565079-64ae-432f-bff5-18c67891ed40@googlegroups.com>
References: <eb5918fb-41ea-4199-b2f2-ae28b454c983@googlegroups.com>
 <mailman.17453.1420664176.18130.python-list@python.org>
 <d8565079-64ae-432f-bff5-18c67891ed40@googlegroups.com>
Message-ID: <CAPTjJmoQtCiLAKC+2-0PVJS68Qtvw3-8rYtsFb8h+-zbpmuVLA@mail.gmail.com>

On Thu, Jan 8, 2015 at 11:23 AM, John Ladasky
<john_ladasky at sbcglobal.net> wrote:
>> P.S. don't use pickle, it is a security vulnerability equivalent in
>> severity to using exec in your code, and an unversioned opaque
>> schemaless blob that is very difficult to work with when circumstances
>> change.
>
> For all of its shortcomings, I can't live without pickle.  In this case, I am doing data mining.  My TrainingSession class commandeers seven CPU cores via Multiprocessing.Pool.  Still, even my "toy" TrainingSessions take several minutes to run.  I can't afford to re-run TrainingSession every time I need my models.  I need a persistent object.
>
> Besides, the opportunity for mischief is low.  My code is for my own personal use.  And I trust the third-party libraries that I am using.  My SVRModel object wraps the NuSVR object from scikit-learn, which in turn wraps the libsvm binary.

There are several issues, not all of which are easily dodged. Devin cited two:

* Security: it's fundamentally equivalent to using 'exec'
* Unversioned: it's hard to make updates to your code and then load old data

"For your own personal use" dodges the first one, but makes the second
one even more of a concern. You can get much better persistence using
a textual format like JSON, and adding in a simple 'version' member
can make it even easier. Then, when you make changes, you can cope
with old data fairly readily.

Pickle is still there if you want it, but you do have to be aware of
its limitations. If you edit the TrainingSession class, you may well
have to rerun the training... but maybe that's not a bad thing.

ChrisA


From ganesh1pal at gmail.com  Wed Jan  7 21:00:41 2015
From: ganesh1pal at gmail.com (Ganesh Pal)
Date: Thu, 8 Jan 2015 07:30:41 +0530
Subject: Playing with threads
In-Reply-To: <CACT3xuUzuMH1CF3AsakdGMwa3U3BX3N+nA1ZVy4NhVmnA9-6gw@mail.gmail.com>
References: <CACT3xuUzuMH1CF3AsakdGMwa3U3BX3N+nA1ZVy4NhVmnA9-6gw@mail.gmail.com>
Message-ID: <CACT3xuWmGF7OpoTKmEHEwzzsZNPXECn-rDKVnDtUo8-p1B1fww@mail.gmail.com>

Hi friends,

I'm trying to use threads  to achieve the below work flow

1. Start a process , while its running grep for a string 1
2. Apply the string 1 to the command in step 1 and exit step 2
3. Monitor the stdout of step1 and print success if the is pattern  found

Questions:

1. Can the above be achieved without threads ? I prefer keep ing code
simple  .threads can become confusion when this workflow grows larger

Regards,
Ganesh
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From jeanpierreda at gmail.com  Wed Jan  7 21:09:24 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Wed, 7 Jan 2015 20:09:24 -0600
Subject: Playing with threads
In-Reply-To: <CACT3xuWmGF7OpoTKmEHEwzzsZNPXECn-rDKVnDtUo8-p1B1fww@mail.gmail.com>
References: <CACT3xuUzuMH1CF3AsakdGMwa3U3BX3N+nA1ZVy4NhVmnA9-6gw@mail.gmail.com>
 <CACT3xuWmGF7OpoTKmEHEwzzsZNPXECn-rDKVnDtUo8-p1B1fww@mail.gmail.com>
Message-ID: <CABicbJKYu=k4QAdHsxWy9fUeQBSezRcJ4-Kg=j4+j+-YHnmfXw@mail.gmail.com>

I can't tell what you mean, but you can start a process via
subprocess.Popen, do some work, and wait for it to finish.
https://docs.python.org/2/library/subprocess.html

Note that you don't need the stdout (or likely the stdin) of the
process, you just need the return code -- whether or not grep
succeeded -- so you can redirect stdout and stderr to os.devnull and
avoid using .communicate().  Also, if you can't use .communicate(),
but need to access stdout, this is the most common reason to need
threads with subprocess.

-- Devin

On Wed, Jan 7, 2015 at 8:00 PM, Ganesh Pal <ganesh1pal at gmail.com> wrote:
> Hi friends,
>
> I'm trying to use threads  to achieve the below work flow
>
> 1. Start a process , while its running grep for a string 1
> 2. Apply the string 1 to the command in step 1 and exit step 2
> 3. Monitor the stdout of step1 and print success if the is pattern  found
>
> Questions:
>
> 1. Can the above be achieved without threads ? I prefer keep ing code simple
> .threads can become confusion when this workflow grows larger
>
> Regards,
> Ganesh
>
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>


From davea at davea.name  Wed Jan  7 21:18:06 2015
From: davea at davea.name (Dave Angel)
Date: Wed, 07 Jan 2015 21:18:06 -0500
Subject: Playing with threads
In-Reply-To: <CACT3xuWmGF7OpoTKmEHEwzzsZNPXECn-rDKVnDtUo8-p1B1fww@mail.gmail.com>
References: <CACT3xuUzuMH1CF3AsakdGMwa3U3BX3N+nA1ZVy4NhVmnA9-6gw@mail.gmail.com>
 <CACT3xuWmGF7OpoTKmEHEwzzsZNPXECn-rDKVnDtUo8-p1B1fww@mail.gmail.com>
Message-ID: <54ADE8DE.5000803@davea.name>

On 01/07/2015 09:00 PM, Ganesh Pal wrote:
> Hi friends,
>
> I'm trying to use threads  to achieve the below work flow
>
> 1. Start a process , while its running grep for a string 1
> 2. Apply the string 1 to the command in step 1 and exit step 2
> 3. Monitor the stdout of step1 and print success if the is pattern  found
>

None of those three "statements" make sense to me.  Could you translate, 
or elaborate?  And fix typos?

What OS is this running on?

Is the process a program called grep.exe?  Or a second Python program? 
Who's doing the grep, that separate program or your original one?

Define Apply.  What's it mean to apply a string to a command?

What's an "is pattern" ?  And who's looking for it?

What's the real goal?  Or is this just a paraphrasing of an arbitrary 
school assignment (which don't always make sense).

> Questions:
>
> 1. Can the above be achieved without threads ? I prefer keep ing code
> simple  .threads can become confusion when this workflow grows larger

Sure, nothing in that description implies threads, just a separate 
process.  No idea why that's simpler, though.



-- 
DaveA


From rosuav at gmail.com  Wed Jan  7 21:24:52 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 8 Jan 2015 13:24:52 +1100
Subject: Playing with threads
In-Reply-To: <CACT3xuWmGF7OpoTKmEHEwzzsZNPXECn-rDKVnDtUo8-p1B1fww@mail.gmail.com>
References: <CACT3xuUzuMH1CF3AsakdGMwa3U3BX3N+nA1ZVy4NhVmnA9-6gw@mail.gmail.com>
 <CACT3xuWmGF7OpoTKmEHEwzzsZNPXECn-rDKVnDtUo8-p1B1fww@mail.gmail.com>
Message-ID: <CAPTjJmqOa-3cpxpOxw2aWaYR+6P2dcFUhC9RqKBBspV3oK_AuA@mail.gmail.com>

On Thu, Jan 8, 2015 at 1:00 PM, Ganesh Pal <ganesh1pal at gmail.com> wrote:
> I'm trying to use threads  to achieve the below work flow
>
> 1. Start a process , while its running grep for a string 1
> 2. Apply the string 1 to the command in step 1 and exit step 2
> 3. Monitor the stdout of step1 and print success if the is pattern  found

If by "grep" you mean "search", then this would be best done by
spawning a subprocess and monitoring its output.

https://docs.python.org/3/library/subprocess.html

Set stdout=PIPE, then read from the stdout member, and you'll be
reading the program's output. Something like this:

with subprocess.Popen(["find","/","-name","*.py"],stdout=subprocess.PIPE)
as findpy:
    for line in findpy.stdout:
        # do something with line

You'll get lines as they're produced, and can use standard string
manipulation on them. I don't know what your step 2 is, but you can
set stdin to be a pipe as well, and then you just write to your end
and the process will receive that on its standard input.

No threads needed; just your Python process and the subprocess.

ChrisA


From emil at fuse.pl  Wed Jan  7 22:16:32 2015
From: emil at fuse.pl (Emil Oppeln-Bronikowski)
Date: Thu, 8 Jan 2015 04:16:32 +0100
Subject: application console with window
In-Reply-To: <m8k10h$cpe$1@news.icm.edu.pl>
References: <m8k10h$cpe$1@news.icm.edu.pl>
Message-ID: <20150108031632.GA2141@mikrus>

On Wed, Jan 07, 2015 at 10:17:09PM +0100, adam wrote:
> Is in here maybe someone who speak Polish?

M?wi?, a raczej pisz?.

> I'm looking for some libs, tutorials, or other informations.

This is terminal application using (n)curses or smilar library that helps you draw & interact with windows, forms and other widgets.

You can use curses library, but it's a little big hairy. There are a few extra libraries that make writing "full-screen" terminal application a breeze.

The most popular one (?and complete?) is urwid, and there are pages of tutorial once you google for it. 

PS. if you need some help feel free to e-mail me off-list.

-- 
vag?a?bond adjective \?va-g?-?b?nd\
 a :? of, relating to, or characteristic of a wanderer 
 b :? leading an unsettled, irresponsible, or disreputable life



From tjreedy at udel.edu  Wed Jan  7 23:16:47 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Wed, 07 Jan 2015 23:16:47 -0500
Subject: Playing with threads
In-Reply-To: <CACT3xuWmGF7OpoTKmEHEwzzsZNPXECn-rDKVnDtUo8-p1B1fww@mail.gmail.com>
References: <CACT3xuUzuMH1CF3AsakdGMwa3U3BX3N+nA1ZVy4NhVmnA9-6gw@mail.gmail.com>
 <CACT3xuWmGF7OpoTKmEHEwzzsZNPXECn-rDKVnDtUo8-p1B1fww@mail.gmail.com>
Message-ID: <m8l0br$nj0$1@ger.gmane.org>

On 1/7/2015 9:00 PM, Ganesh Pal wrote:
> Hi friends,
>
> I'm trying to use threads  to achieve the below work flow
>
> 1. Start a process , while its running grep for a string 1
> 2. Apply the string 1 to the command in step 1 and exit step 2
> 3. Monitor the stdout of step1 and print success if the is pattern  found
>
> Questions:
>
> 1. Can the above be achieved without threads ? I prefer keep ing code
> simple  .threads can become confusion when this workflow grows larger

I do not understand the work flow either.  What I do know is that Idle 
Edit -> Find in Files is implemented in idlelib/grep.py and that the 
non-gui code could be copied and adapted to other purposes.

-- 
Terry Jan Reedy



From steve at pearwood.info  Wed Jan  7 23:35:35 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 08 Jan 2015 04:35:35 GMT
Subject: Announce: PyPrimes 0.2.1a
Message-ID: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>

At long last, I am pleased to announce the latest version of PyPrimes, a 
pure Python package for working with prime numbers.

PyPrimes is compatible with Python 2 and 3, and includes multiple 
algorithms for the generating and testing of prime numbers, including the 
Sieve of Eratosthenes, Croft Spiral, Miller-Rabin and Fermat 
probabilistic tests.

https://pypi.python.org/pypi/pyprimes/


Examples
========


Generate prime numbers on demand:

py> it = pyprimes.primes()
py> next(it)
2
py> next(it)
3


Test whether numbers are prime:

py> pyprimes.is_prime(23)
True


Generate primes between an upper and lower limit:

py> import pyprimes
py> list(pyprimes.primes(11000000, 11000500))
[11000027, 11000053, 11000057, 11000081, 11000083, 11000089, 11000111,
 11000113, 11000149, 11000159, 11000179, 11000189, 11000273, 11000281,
 11000287, 11000291, 11000293, 11000299, 11000347, 11000351, 11000369,
 11000383, 11000387, 11000393, 11000399, 11000401, 11000419, 11000441,
 11000461, 11000467]


Find the previous and next primes from a given value:

py> pyprimes.prev_prime(10**9)
999999937
py> pyprimes.next_prime(999999937)
1000000007


Find the prime factorisation of small numbers:

py> import pyprimes.factors
py> pyprimes.factors.factorise(999999997)
[71, 2251, 6257]


Pyprimes also includes examples of naive and poor-quality, but popular, 
algorithms which should be avoided:

py> from pyprimes.awful import turner
py> it = turner()
py> [next(it) for i in range(20)]
[2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59,
61, 67, 71]

Study the source code of the "awful" module to see what not to do!


Performance
===========

As PyPrimes is written entirely in Python, it is not suitable for 
demanding high-performance applications, but performance can be quite 
reasonable for less-demanding applications. On a laptop with a AMD Turion
(tm) II P520 Dual-Core Processor, it takes 0.005 second to generate the 
first prime larger than 2**63, and about 10 seconds to generate the first 
one million primes. Testing whether 2**63+7 is prime takes under 0.1 
millisecond.


Installing PyPrimes
===================

You can download PyPrimes from here:

    https://pypi.python.org/pypi/pyprimes/

For Windows users, run the installer. For Linux, Mac and Unix users, 
unpack the source tar ball and follow the instructions.

You can also install using pip:

    pip install pyprimes==0.2.1a


(Note: pip may have problems downloading the right version if you don't 
specify a version number.)

Or you can access the latest development version:

    hg clone https://code.google.com/p/pyprimes/




-- 
Steve


From marko at pacujo.net  Thu Jan  8 01:21:36 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 08 Jan 2015 08:21:36 +0200
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
 <mailman.17424.1420596200.18130.python-list@python.org>
 <54ace9f0$0$2738$c3e8da3$76491128@news.astraweb.com>
 <87tx02gb9d.fsf@elektro.pacujo.net>
 <54adc53c$0$12999$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <877fwx3i8f.fsf@elektro.pacujo.net>

Steven D'Aprano <steve+comp.lang.python at pearwood.info>:

> Marko Rauhamaa wrote:
>> I prefer the Scheme way:
>>    #f is a falsey object
>>    everything else is a truthy object
>
> The Scheme way has no underlying model of what truthiness represents, just
> an arbitrary choice to make a single value have one truthiness, and
> everything else the other. It's just as meaningless and just as arbitrary
> as the opposite would be:
>
>     #t is True
>     everything else is falsey
> [...]
> I'd rather the Pascal way:
>
>     #t is True
>     #f is False
>     everything else is an error

An advantage of the Scheme way is the chaining of "and" and "or". For
example, this breaks in Python:

   def dir_contents(path):
       if os.path.isdir(path):
           return os.listdir(path)
       return None

   def get_choices():
       return dir_contents(PRIMARY) or \
           dir_contents(SECONDARY) or \
           [ BUILTIN_PATH ]


Marko


From ben+python at benfinney.id.au  Thu Jan  8 02:12:07 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Thu, 08 Jan 2015 18:12:07 +1100
Subject: Announce: PyPrimes 0.2.1a
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <85siflwxtk.fsf@benfinney.id.au>

Steven D'Aprano <steve at pearwood.info> writes:

> (Note: pip may have problems downloading the right version if you
> don't specify a version number.)
>
> Or you can access the latest development version:
>
>     hg clone https://code.google.com/p/pyprimes/

The source has a ?CHANGES.txt? file which has no entry later than
version 0.2a. Why was the later version made, and when will the change
log be updated for that?

-- 
 \              ?Ignorance more frequently begets confidence than does |
  `\           knowledge.? ?Charles Darwin, _The Descent of Man_, 1871 |
_o__)                                                                  |
Ben Finney



From dieter at handshake.de  Thu Jan  8 02:22:32 2015
From: dieter at handshake.de (dieter)
Date: Thu, 08 Jan 2015 08:22:32 +0100
Subject: PyGILState API and Py_Main
References: <54928B82.1080309@cea.fr>
Message-ID: <8761chrb2f.fsf@handshake.de>

Adrien Bruneton <adrien.bruneton at cea.fr> writes:

> I am having a hard time understanding what is the proper use of
> PyGILState_Ensure/Release.
> My understanding is that one should always be matched with the other,
> and that this high level API auto-magically deals with the ThreadState
> creation.
>
> However the following piece of code (executed with a simple "print
> 'hello world' " script as argv) triggers the message:
>
>     Fatal Python error: auto-releasing thread-state, but no
> thread-state for this thread

Each function at the Python C interface has (with high probability)
a notion whether it is called from Python (GIL acquired) or from pure C code
(GIL not acquired). When you call the function yourself, you must match
this expectation. "Py_Main" likely expects to be called without
acquired GIL. Thus, likely, you should not call "PyGILState_Ensure"
before "Py_Main".

> Minimal code:
>
> void initPython(int initsigs)
> {
>   if (Py_IsInitialized() == 0)
>     {
>       Py_InitializeEx(initsigs);
>       // Put default SIGINT handler back after
> Py_Initialize/Py_InitializeEx.
>       signal(SIGINT, SIG_DFL);
>     }
>
>   int threadInit = PyEval_ThreadsInitialized();
>   PyEval_InitThreads(); // safe to call this multiple time
>
>   if(!threadInit)
>     PyEval_SaveThread(); // release GIL
> }
>
> int main(int argc, char ** argv)
> {
>   initPython(1);
>   PyGILState_STATE _gstate_avoid_clash = PyGILState_Ensure();
>   int ret = Py_Main(argc, argv);
>   PyGILState_Release(_gstate_avoid_clash);  // this one triggers the
> Fatal error
>   Py_Finalize();
>   return ret;
> }
>
>
> Removing the last PyGILState_Release works, but I have a bad feeling
> about it :-)
> Any help would be welcome! Thanks in advance.

Likely, "Py_Main" has already released the GIL and cleaned up
the thread state.



From auriocus at gmx.de  Thu Jan  8 02:27:53 2015
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Thu, 08 Jan 2015 08:27:53 +0100
Subject: Announce: PyPrimes 0.2.1a
In-Reply-To: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <m8lbgt$sgd$1@dont-email.me>

Hi Steve,

Am 08.01.15 um 05:35 schrieb Steven D'Aprano:
> At long last, I am pleased to announce the latest version of PyPrimes, a
> pure Python package for working with prime numbers.

Nice.

> PyPrimes is compatible with Python 2 and 3, and includes multiple
> algorithms for the generating and testing of prime numbers, including the
> Sieve of Eratosthenes, Croft Spiral, Miller-Rabin and Fermat
> probabilistic tests.
>
> https://pypi.python.org/pypi/pyprimes/

I don't want to badmouth your effort, but it seems to me that this is 
still a collectino of rather simple algorithms. What about the AKS test, 
which is O(P) and deterministic for all primes, what about elliptic 
curve factorization or a quadratic sieve?

I'm sure that other people with better knowledge of number theory could 
propose some more generally useful algorithms.

	Christian



From dieter at handshake.de  Thu Jan  8 02:51:49 2015
From: dieter at handshake.de (dieter)
Date: Thu, 08 Jan 2015 08:51:49 +0100
Subject: how to create a soap enveloppe with python suds for consume a
 bssv web service
References: <5975f1a8-dc9a-4ab3-b4f4-6e3695f4485a@googlegroups.com>
Message-ID: <871tn5r9pm.fsf@handshake.de>

brice DORA <road01 at yahoo.fr> writes:

> Hi all I am working on a app in python and I have to call a web service deployed on JDE (bssv). I use it for the suds lib which seems pretty friendly. but the problem is the JDE web service that uses bssv technology necessarily requires sending a soap envelope. as far as I spend my fesais parameters required in my suds client. My concern then is how to work around this problem, or is this possible to create a soap envelope with suds? thank you in advance

"suds" should generate those required "SOAP envelope".

"suds" can be set up to log the precise messages sent and received
(consult the "suds" documentation about logging and the Python
documentation about its "logging" module). With these messages
(and a precise description of the encountered problem), you can
contact someone responsible for the web service to resolve your problems.



From road01 at yahoo.fr  Thu Jan  8 03:41:53 2015
From: road01 at yahoo.fr (brice DORA)
Date: Thu, 8 Jan 2015 00:41:53 -0800 (PST)
Subject: how to create a soap enveloppe with python suds for consume a
 bssv web service
In-Reply-To: <mailman.17467.1420703579.18130.python-list@python.org>
References: <5975f1a8-dc9a-4ab3-b4f4-6e3695f4485a@googlegroups.com>
 <mailman.17467.1420703579.18130.python-list@python.org>
Message-ID: <06c7101c-a7dc-489e-9cba-935e7e65fc3b@googlegroups.com>

Le jeudi 8 janvier 2015 07:53:12 UTC, dieter a ?crit?:
> brice DORA <road01 at yahoo.fr> writes:
> 
> > Hi all I am working on a app in python and I have to call a web service deployed on JDE (bssv). I use it for the suds lib which seems pretty friendly. but the problem is the JDE web service that uses bssv technology necessarily requires sending a soap envelope. as far as I spend my fesais parameters required in my suds client. My concern then is how to work around this problem, or is this possible to create a soap envelope with suds? thank you in advance
> 
> "suds" should generate those required "SOAP envelope".
> 
> "suds" can be set up to log the precise messages sent and received
> (consult the "suds" documentation about logging and the Python
> documentation about its "logging" module). With these messages
> (and a precise description of the encountered problem), you can
> contact someone responsible for the web service to resolve your problems.

okey thanks for your help but can you tell me if it's possible to see the content of this soap envelope that's sent by suds? if yes then please how can i do it?thanks you in advance


From steve+comp.lang.python at pearwood.info  Thu Jan  8 06:16:37 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 08 Jan 2015 22:16:37 +1100
Subject: Announce: PyPrimes 0.2.1a
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
Message-ID: <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>

Ben Finney wrote:

> Steven D'Aprano <steve at pearwood.info> writes:
> 
>> (Note: pip may have problems downloading the right version if you
>> don't specify a version number.)
>>
>> Or you can access the latest development version:
>>
>>     hg clone https://code.google.com/p/pyprimes/
> 
> The source has a ?CHANGES.txt? file which has no entry later than
> version 0.2a. Why was the later version made, and when will the change
> log be updated for that?
> 

Ah, I knew I forgot something!

0.2.1a was a version bump to try to work around an issue with PyPI. There
are no functional differences.

I screwed up the upload to PyPI, and it won't allow you to upload the same
version twice. (At least, I don't know of any way to do so.) So I had to
bump the version number to re-upload.



-- 
Steven



From steve+comp.lang.python at pearwood.info  Thu Jan  8 06:20:52 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 08 Jan 2015 22:20:52 +1100
Subject: Announce: PyPrimes 0.2.1a
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <m8lbgt$sgd$1@dont-email.me>
Message-ID: <54ae6815$0$13010$c3e8da3$5496439d@news.astraweb.com>

Christian Gollwitzer wrote:

> Hi Steve,
> 
> Am 08.01.15 um 05:35 schrieb Steven D'Aprano:
>> At long last, I am pleased to announce the latest version of PyPrimes, a
>> pure Python package for working with prime numbers.
> 
> Nice.
> 
>> PyPrimes is compatible with Python 2 and 3, and includes multiple
>> algorithms for the generating and testing of prime numbers, including the
>> Sieve of Eratosthenes, Croft Spiral, Miller-Rabin and Fermat
>> probabilistic tests.
>>
>> https://pypi.python.org/pypi/pyprimes/
> 
> I don't want to badmouth your effort, but it seems to me that this is
> still a collectino of rather simple algorithms. What about the AKS test,
> which is O(P) and deterministic for all primes, what about elliptic
> curve factorization or a quadratic sieve?

It's a 0.2 version number, what do you expect? :-)

AKS may be O(P), but the constant factor is quite large. In practice I
expect that it will probably be slower than Miller-Rabin. Nevertheless,
I'll eventually include that.



-- 
Steven



From rosuav at gmail.com  Thu Jan  8 07:11:11 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 8 Jan 2015 23:11:11 +1100
Subject: Oddity with lambda and yield
Message-ID: <CAPTjJmrVpBReySTvnxLgKnS519EoPDR5Y1W4gD851E4j-a4kvQ@mail.gmail.com>

As yield is an expression, it's legal in a lambda function, which then
means you have a generator function. But it's not quite the same as
the equivalent function made with def:

$ python3
Python 3.5.0a0 (default:1c51f1650c42+, Dec 29 2014, 02:29:06)
[GCC 4.7.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> f=lambda: (yield 5)
>>> x=f()
>>> next(x)
5
>>> x.send(123)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
StopIteration
>>> def f(): return (yield 5)
...
>>> x=f()
>>> next(x)
5
>>> x.send(123)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
StopIteration: 123


Is this a bug? I very much doubt any sane code will ever run into
this; I discovered this purely by chance, after noting that
Python/compile.c had code to create a generator. The same thing
happens with Python 3.4.2 on Debian Jessie, so this isn't a bug I've
introduced in my local fiddling around.

If nothing else, it's an amusing proof that you shouldn't just stuff
every cool thing you can think of into a single line of code :)

ChrisA


From albert at spenarnc.xs4all.nl  Thu Jan  8 07:43:33 2015
From: albert at spenarnc.xs4all.nl (Albert van der Horst)
Date: 08 Jan 2015 12:43:33 GMT
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmpVK4L-1kBVywd4o=mXFN=iWhjJzWZbxZDgw3nfK8WbSQ@mail.gmail.com>
 <m75pfm$2ah$1@ger.gmane.org>
 <mailman.17077.1419144290.18130.python-list@python.org>
Message-ID: <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>

In article <mailman.17077.1419144290.18130.python-list at python.org>,
Chris Angelico  <rosuav at gmail.com> wrote:
>On Sun, Dec 21, 2014 at 5:31 PM, Terry Reedy <tjreedy at udel.edu> wrote:
>> Just to be clear, writing to sys.stdout works fine in Idle.
>>>>> import sys; sys.stdout.write('hello ')
>> hello  #2.7
>>
>> In 3.4, the number of chars? bytes? is returned and written also.
>>
>> Whether you mean something different by 'stdout' or not, I am not sure.  The
>> error is from writing to a non-existent file descriptor.
>
>That's because sys.stdout is replaced. But stdout itself, file
>descriptor 1, is not available:
>
>>>> os.fdopen(1,"w").write("Hello, world\n")
>Traceback (most recent call last):
>  File "<pyshell#4>", line 1, in <module>
>    os.fdopen(1,"w").write("Hello, world\n")
>OSError: [Errno 9] Bad file descriptor

I don't trust sudo because it is too complicated.
(To the point that I removed it from my machine.)
I do
su
..
#
su nobody

Who needs sudo?

It's like instead of telling a 4-year old to stay on the
side walk, learning him to read and then give him a 8-page
brochure about "safety in traffic".


>
>This works fine in command-line Python, just not in IDLE. It's not
>Windows vs Unix, it's Idle vs terminal.
>
>ChrisA

Groetjes Albert
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert at spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst



From rosuav at gmail.com  Thu Jan  8 07:53:38 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 8 Jan 2015 23:53:38 +1100
Subject: Hello World
In-Reply-To: <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmpVK4L-1kBVywd4o=mXFN=iWhjJzWZbxZDgw3nfK8WbSQ@mail.gmail.com>
 <m75pfm$2ah$1@ger.gmane.org>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
Message-ID: <CAPTjJmoCAXem6dMXZyGMoSGN80hBgPiNiDw-SgVLXp0Do2dELg@mail.gmail.com>

On Thu, Jan 8, 2015 at 11:43 PM, Albert van der Horst
<albert at spenarnc.xs4all.nl> wrote:
> I don't trust sudo because it is too complicated.
> (To the point that I removed it from my machine.)
> I do
> su
> ..
> #
> su nobody
>
> Who needs sudo?

With sudo, you get MUCH finer control. I can grant some user the power
to run "sudo eject sr0", but no other commands. I can permit someone
to execute any of a large number of commands, all individually logged.
I can allow sudo to other users than root, without having to reveal
those accounts' passwords (chances are they don't even have
passwords).

But sure. If you want to cut out complication, dispense with user
accounts altogether and run everything as root. That's WAY simpler!

ChrisA


From albert at spenarnc.xs4all.nl  Thu Jan  8 08:10:58 2015
From: albert at spenarnc.xs4all.nl (Albert van der Horst)
Date: 08 Jan 2015 13:10:58 GMT
Subject: How do I remove/unlink wildcarded files
References: <20150102090051.GC22372@arxnet.hu>
 <CAPTjJmrTYSEemnpaHRJBLDYq-gp2-wVpht4E_y1SnJmC8X6UVA@mail.gmail.com>
 <mailman.17344.1420281519.18130.python-list@python.org>
 <f69874c8-48f6-4696-8678-c2a761f2f18d@googlegroups.com>
Message-ID: <54ae81e2$0$15882$e4fe514c@dreader35.news.xs4all.nl>

In article <f69874c8-48f6-4696-8678-c2a761f2f18d at googlegroups.com>,
Rick Johnson  <rantingrickjohnson at gmail.com> wrote:
>On Saturday, January 3, 2015 4:39:25 AM UTC-6, Mark Lawrence wrote:
>
>> I used to get very confused watching the old westerns.  The child when
>> talking about "more" and "paw" wasn't referring to possibly an
>> adjective, noun or adverb and a part of an animal, but what we would
>> refer to in the UK as "mum" and "dad" :)
>
>Early Americans are easy to satirize since most were
>schooled at home by illiterate parents. I believe the
>"redneck vernacular" substituted "mother" and "father" for
>"maw" and "paw" respectively. Which is not surprising since
>most uneducated folks tend to favor single syllable
>simplifications of words over their multi-syllable
>counterparts.
>
>Widespread centralized free schooling did not exists until
>almost the 1900's. Heck, looking back at American history,
>the world *SHOULD* be in awe. To go from a rag-tag
>illiterate bunch of cowboys, to the worlds most powerful and
>technically advanced society (in roughly one hundred years!)
>has to be the most amazing transformation in the history of
>the human society.

It isn't. The Russian transformation under Stalin from a feodalist
society with wooden plows to atomic bombs and space travel is. Most
capitalist politicians are reluctant to admit this, but e.g. Churchill
recognized this. A comboy on horse back who has ever seen a revolver
is a far cry in backwardness from a feodalist peasant who *expects* to
be flogged by a knut. Feodalism goes to the brain, like slavery does.
(It took generations for the US negroes to shed of their slavery
inheritance. )

Groetjes Albert
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert at spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst



From albert at spenarnc.xs4all.nl  Thu Jan  8 08:37:16 2015
From: albert at spenarnc.xs4all.nl (Albert van der Horst)
Date: 08 Jan 2015 13:37:16 GMT
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
Message-ID: <54ae880c$0$15929$e4fe514c@dreader35.news.xs4all.nl>

In article <mailman.17471.1420721626.18130.python-list at python.org>,
Chris Angelico  <rosuav at gmail.com> wrote:
>On Thu, Jan 8, 2015 at 11:43 PM, Albert van der Horst
><albert at spenarnc.xs4all.nl> wrote:
>> I don't trust sudo because it is too complicated.
>> (To the point that I removed it from my machine.)
>> I do
>> su
>> ..
>> #
>> su nobody
>>
>> Who needs sudo?
>
>With sudo, you get MUCH finer control. I can grant some user the power
>to run "sudo eject sr0", but no other commands. I can permit someone
>to execute any of a large number of commands, all individually logged.
>I can allow sudo to other users than root, without having to reveal
>those accounts' passwords (chances are they don't even have
>passwords).

You've answered   it. sudo works for a system with a very
knowledgeable system administrator and at least one other user.
Not for an electronic engineer who uses Python on his Raspberry Pi.

>
>But sure. If you want to cut out complication, dispense with user
>accounts altogether and run everything as root. That's WAY simpler!

I've no problem explaining to an electronic engineer not to do this,
while not offering him to do the system administration for him.
Having a separate account for system things is a useful distinction
that he can grasp and handle easily. Beyond that he is indeed inclined
to do everything as root, because what he wants is to make a turnkey to
feed his gold fish.

So a separate root account is the best protection for a single user
system. For quite a considerable part of the systems around,
sudo is over the top and stimulates no protection at all, i.e.
what I'd call counter productive.

I can save a 4-years olds life by imprinting on him to
stay on the side walk.

>
>ChrisA

Groetjes Albert
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert at spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst



From marko at pacujo.net  Thu Jan  8 09:06:16 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 08 Jan 2015 16:06:16 +0200
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmpVK4L-1kBVywd4o=mXFN=iWhjJzWZbxZDgw3nfK8WbSQ@mail.gmail.com>
 <m75pfm$2ah$1@ger.gmane.org>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
Message-ID: <87bnm9fjtz.fsf@elektro.pacujo.net>

Chris Angelico <rosuav at gmail.com>:

> With sudo, you get MUCH finer control. I can grant some user the power
> to run "sudo eject sr0", but no other commands. I can permit someone
> to execute any of a large number of commands, all individually logged.

I can't remember ever having a need for that. I sometimes use sudo but
most times su is the way.

> I can allow sudo to other users than root, without having to reveal
> those accounts' passwords (chances are they don't even have
> passwords).

An administrator doesn't need the users' passwords for anything but
should be assumed to know them.

> But sure. If you want to cut out complication, dispense with user
> accounts altogether and run everything as root. That's WAY simpler!

In the era of personal computers, the main advantage of the root account
is that you can breathe more easily as an ordinary user, as the
potential for accidental damage is lower.


Marko


From michael at stroeder.com  Thu Jan  8 09:11:37 2015
From: michael at stroeder.com (=?UTF-8?B?TWljaGFlbCBTdHLDtmRlcg==?=)
Date: Thu, 08 Jan 2015 15:11:37 +0100
Subject: Hello World
In-Reply-To: <mailman.17471.1420721626.18130.python-list@python.org>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmpVK4L-1kBVywd4o=mXFN=iWhjJzWZbxZDgw3nfK8WbSQ@mail.gmail.com>
 <m75pfm$2ah$1@ger.gmane.org>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
Message-ID: <m8m35v$r74$1@dont-email.me>

Chris Angelico wrote:
> With sudo, you get MUCH finer control.

But it's very hard, almost impossible, to really implement fine-grained
control with sudo. Too many programs provide shell exits.

Well, it's off-topic here.
How about taking this to news:comp.security.unix ?

Ciao, Michael.



From qualsivoglia at dovetipare.nz  Thu Jan  8 09:15:57 2015
From: qualsivoglia at dovetipare.nz (maurog)
Date: Thu, 8 Jan 2015 14:15:57 +0000 (UTC)
Subject: where in Nan defined
Message-ID: <m8m3et$1gu$2@speranza.aioe.org>

I'm running some pandas examples and I canno find in what module NaN is 
defined. Does anyone know what module I have to import in order to have 
it defined?


From alister.nospam.ware at ntlworld.com  Thu Jan  8 09:21:46 2015
From: alister.nospam.ware at ntlworld.com (alister)
Date: Thu, 08 Jan 2015 14:21:46 GMT
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmpVK4L-1kBVywd4o=mXFN=iWhjJzWZbxZDgw3nfK8WbSQ@mail.gmail.com>
 <m75pfm$2ah$1@ger.gmane.org>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <87bnm9fjtz.fsf@elektro.pacujo.net>
Message-ID: <_nwrw.363401$AC.149510@fx29.am4>

On Thu, 08 Jan 2015 16:06:16 +0200, Marko Rauhamaa wrote:

> Chris Angelico <rosuav at gmail.com>:
> 
>> With sudo, you get MUCH finer control. I can grant some user the power
>> to run "sudo eject sr0", but no other commands. I can permit someone to
>> execute any of a large number of commands, all individually logged.
> 
> I can't remember ever having a need for that. I sometimes use sudo but
> most times su is the way.
> 
>> I can allow sudo to other users than root, without having to reveal
>> those accounts' passwords (chances are they don't even have passwords).
> 
> An administrator doesn't need the users' passwords for anything but
> should be assumed to know them.

The administrator may be able to change them but he should NEVER know 
them (or need to)!
> 
>> But sure. If you want to cut out complication, dispense with user
>> accounts altogether and run everything as root. That's WAY simpler!
> 
> In the era of personal computers, the main advantage of the root account
> is that you can breathe more easily as an ordinary user, as the
> potential for accidental damage is lower.
> 
> 
> Marko





-- 
Davis' Law of Traffic Density:
	The density of rush-hour traffic is directly proportional to
	1.5 times the amount of extra time you allow to arrive on time.


From ian.g.kelly at gmail.com  Thu Jan  8 09:24:12 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 8 Jan 2015 07:24:12 -0700
Subject: where in Nan defined
In-Reply-To: <m8m3et$1gu$2@speranza.aioe.org>
References: <m8m3et$1gu$2@speranza.aioe.org>
Message-ID: <CALwzidnbUuM+DbTy_TNR-wGqACR8KQ0qwy+mCC6gbd8i+g+ffA@mail.gmail.com>

On Thu, Jan 8, 2015 at 7:15 AM, maurog <qualsivoglia at dovetipare.nz> wrote:
> I'm running some pandas examples and I canno find in what module NaN is
> defined. Does anyone know what module I have to import in order to have
> it defined?

It's not defined anywhere. To get nan as a literal just do:

    nan = float("nan")


From rosuav at gmail.com  Thu Jan  8 09:28:16 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 9 Jan 2015 01:28:16 +1100
Subject: where in Nan defined
In-Reply-To: <m8m3et$1gu$2@speranza.aioe.org>
References: <m8m3et$1gu$2@speranza.aioe.org>
Message-ID: <CAPTjJmrLy_CdujXf+F75nQBtF3L06LRLLKkfUnd0V=ttFkLHiA@mail.gmail.com>

On Fri, Jan 9, 2015 at 1:15 AM, maurog <qualsivoglia at dovetipare.nz> wrote:
> I'm running some pandas examples and I canno find in what module NaN is
> defined. Does anyone know what module I have to import in order to have
> it defined?

It's simply float("nan"). If you want a name, you can give it one:

NaN = float("nan")
# or
nan = float("nan")

ChrisA


From ian.g.kelly at gmail.com  Thu Jan  8 09:30:11 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 8 Jan 2015 07:30:11 -0700
Subject: Oddity with lambda and yield
In-Reply-To: <CAPTjJmrVpBReySTvnxLgKnS519EoPDR5Y1W4gD851E4j-a4kvQ@mail.gmail.com>
References: <CAPTjJmrVpBReySTvnxLgKnS519EoPDR5Y1W4gD851E4j-a4kvQ@mail.gmail.com>
Message-ID: <CALwzid=1snkUP5E_PN_Eyci=i4yG60ZejGhEJSOB3D+StF3vfQ@mail.gmail.com>

On Thu, Jan 8, 2015 at 5:11 AM, Chris Angelico <rosuav at gmail.com> wrote:
> As yield is an expression, it's legal in a lambda function, which then
> means you have a generator function. But it's not quite the same as
> the equivalent function made with def:
>
> $ python3
> Python 3.5.0a0 (default:1c51f1650c42+, Dec 29 2014, 02:29:06)
> [GCC 4.7.2] on linux
> Type "help", "copyright", "credits" or "license" for more information.
>>>> f=lambda: (yield 5)
>>>> x=f()
>>>> next(x)
> 5
>>>> x.send(123)
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> StopIteration
>>>> def f(): return (yield 5)
> ...
>>>> x=f()
>>>> next(x)
> 5
>>>> x.send(123)
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> StopIteration: 123
>
>
> Is this a bug? I very much doubt any sane code will ever run into
> this; I discovered this purely by chance, after noting that
> Python/compile.c had code to create a generator. The same thing
> happens with Python 3.4.2 on Debian Jessie, so this isn't a bug I've
> introduced in my local fiddling around.

I don't see anything in PEP 380 suggesting that it shouldn't apply to
lambda functions.

>>> def f(g):
...     v = (yield from g)
...     yield v
...
>>> g = lambda: (yield 42) or (yield 43) or (yield 44) or "hello world"
>>> list(f(g()))
[42, 43, 44, None]

Seems like a bug to me.


From marko at pacujo.net  Thu Jan  8 09:31:22 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 08 Jan 2015 16:31:22 +0200
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmpVK4L-1kBVywd4o=mXFN=iWhjJzWZbxZDgw3nfK8WbSQ@mail.gmail.com>
 <m75pfm$2ah$1@ger.gmane.org>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <87bnm9fjtz.fsf@elektro.pacujo.net> <_nwrw.363401$AC.149510@fx29.am4>
Message-ID: <874ms1fio5.fsf@elektro.pacujo.net>

alister <alister.nospam.ware at ntlworld.com>:

> On Thu, 08 Jan 2015 16:06:16 +0200, Marko Rauhamaa wrote:
>> An administrator doesn't need the users' passwords for anything but
>> should be assumed to know them.
>
> The administrator may be able to change them but he should NEVER know 
> them (or need to)!

When you are under an administrator's dominion, *you* must assume the
they know your password.

(Somewhat in the same vein, if you are running a virtual machine, *you*
must assume the owner of the host computer has root access to your
virtual machine. By extension, *you* must assume the government
officials of the physical jurisdiction of the host computer have root
access to your virtual machine.)


Marko


From marko at pacujo.net  Thu Jan  8 09:37:12 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 08 Jan 2015 16:37:12 +0200
Subject: where in Nan defined
References: <m8m3et$1gu$2@speranza.aioe.org>
 <mailman.17472.1420727095.18130.python-list@python.org>
Message-ID: <87zj9te3tz.fsf@elektro.pacujo.net>

Ian Kelly <ian.g.kelly at gmail.com>:

> To get nan as a literal just do:
>
>     nan = float("nan")

True, but that got me thinking: what standard Python math operation
evaluates to NaN?


Marko


From rosuav at gmail.com  Thu Jan  8 09:42:52 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 9 Jan 2015 01:42:52 +1100
Subject: Oddity with lambda and yield
In-Reply-To: <CALwzid=1snkUP5E_PN_Eyci=i4yG60ZejGhEJSOB3D+StF3vfQ@mail.gmail.com>
References: <CAPTjJmrVpBReySTvnxLgKnS519EoPDR5Y1W4gD851E4j-a4kvQ@mail.gmail.com>
 <CALwzid=1snkUP5E_PN_Eyci=i4yG60ZejGhEJSOB3D+StF3vfQ@mail.gmail.com>
Message-ID: <CAPTjJmo_SLB-=6xJvexNpOy4Odip6bbBPqfZN01SbgGY++UXmQ@mail.gmail.com>

On Fri, Jan 9, 2015 at 1:30 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
>
> Seems like a bug to me.

http://bugs.python.org/issue23192 created with a bit more info,
including disassembly.

ChrisA


From rosuav at gmail.com  Thu Jan  8 09:45:07 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 9 Jan 2015 01:45:07 +1100
Subject: where in Nan defined
In-Reply-To: <87zj9te3tz.fsf@elektro.pacujo.net>
References: <m8m3et$1gu$2@speranza.aioe.org>
 <mailman.17472.1420727095.18130.python-list@python.org>
 <87zj9te3tz.fsf@elektro.pacujo.net>
Message-ID: <CAPTjJmoxYxEOHyNeTKkkqRbH-ydJKuP80qf7da0Ug51dVqpBag@mail.gmail.com>

On Fri, Jan 9, 2015 at 1:37 AM, Marko Rauhamaa <marko at pacujo.net> wrote:
> Ian Kelly <ian.g.kelly at gmail.com>:
>
>> To get nan as a literal just do:
>>
>>     nan = float("nan")
>
> True, but that got me thinking: what standard Python math operation
> evaluates to NaN?

Subtracting infinity from infinity is one easy way.

>>> 1e309
inf
>>> 1e309-1e309
nan

ChrisA


From jpiitula at ling.helsinki.fi  Thu Jan  8 09:50:04 2015
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 08 Jan 2015 16:50:04 +0200
Subject: where in Nan defined
References: <m8m3et$1gu$2@speranza.aioe.org>
 <mailman.17472.1420727095.18130.python-list@python.org>
 <87zj9te3tz.fsf@elektro.pacujo.net>
Message-ID: <qotk30xjpib.fsf@ruuvi.it.helsinki.fi>

Marko Rauhamaa writes:
> Ian Kelly:
> 
> > To get nan as a literal just do:
> >
> >     nan = float("nan")
> 
> True, but that got me thinking: what standard Python math operation
> evaluates to NaN?

All manner of arithmetics gives overflow errors ("Numerical result out
of range") but a literal with a large exponent gives an inf, so:

   >>> 0*1e400
   nan

(That's on a Python 3.2.3 ... on linux2.)


From jpiitula at ling.helsinki.fi  Thu Jan  8 09:55:45 2015
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 08 Jan 2015 16:55:45 +0200
Subject: where in Nan defined
References: <m8m3et$1gu$2@speranza.aioe.org>
 <mailman.17472.1420727095.18130.python-list@python.org>
 <87zj9te3tz.fsf@elektro.pacujo.net>
 <mailman.17476.1420728314.18130.python-list@python.org>
Message-ID: <qotfvbljp8u.fsf@ruuvi.it.helsinki.fi>

Chris Angelico writes:
> On Fri, Jan 9, 2015 at 1:37 AM, Marko Rauhamaa wrote:
> >
> > True, but that got me thinking: what standard Python math
> > operation evaluates to NaN?
> 
> Subtracting infinity from infinity is one easy way.
> 
> >>> 1e309
> inf
> >>> 1e309-1e309
> nan

I managed to get inf by arithmetic on finite numbers:

  >>> 1e300/1e-300
  inf

  >>> o = 1e300/1e-300 ; o-o
  nan


From ian.g.kelly at gmail.com  Thu Jan  8 09:57:23 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 8 Jan 2015 07:57:23 -0700
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <877fwx3i8f.fsf@elektro.pacujo.net>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
 <mailman.17424.1420596200.18130.python-list@python.org>
 <54ace9f0$0$2738$c3e8da3$76491128@news.astraweb.com>
 <87tx02gb9d.fsf@elektro.pacujo.net>
 <54adc53c$0$12999$c3e8da3$5496439d@news.astraweb.com>
 <877fwx3i8f.fsf@elektro.pacujo.net>
Message-ID: <CALwzidkn5E3uxQ3Et9r-0_WUTjPLfHtY7mqwnhNVe2MGCi528Q@mail.gmail.com>

On Wed, Jan 7, 2015 at 11:21 PM, Marko Rauhamaa <marko at pacujo.net> wrote:
> Steven D'Aprano <steve+comp.lang.python at pearwood.info>:
>
>> Marko Rauhamaa wrote:
>>> I prefer the Scheme way:
>>>    #f is a falsey object
>>>    everything else is a truthy object
>>
>> The Scheme way has no underlying model of what truthiness represents, just
>> an arbitrary choice to make a single value have one truthiness, and
>> everything else the other. It's just as meaningless and just as arbitrary
>> as the opposite would be:
>>
>>     #t is True
>>     everything else is falsey
>> [...]
>> I'd rather the Pascal way:
>>
>>     #t is True
>>     #f is False
>>     everything else is an error
>
> An advantage of the Scheme way is the chaining of "and" and "or". For
> example, this breaks in Python:
>
>    def dir_contents(path):
>        if os.path.isdir(path):
>            return os.listdir(path)
>        return None
>
>    def get_choices():
>        return dir_contents(PRIMARY) or \
>            dir_contents(SECONDARY) or \
>            [ BUILTIN_PATH ]

That depends on what the function is intended to do in the first
place. Why would you want to return the contents of an empty directory
rather than the default?

Anyway, to make that work as you want it in Scheme, dir_contents would
have to return #f, not None. Does it really make sense for a
non-predicate function to be returning the value "false"?


From rosuav at gmail.com  Thu Jan  8 09:58:32 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 9 Jan 2015 01:58:32 +1100
Subject: where in Nan defined
In-Reply-To: <qotk30xjpib.fsf@ruuvi.it.helsinki.fi>
References: <m8m3et$1gu$2@speranza.aioe.org>
 <mailman.17472.1420727095.18130.python-list@python.org>
 <87zj9te3tz.fsf@elektro.pacujo.net>
 <qotk30xjpib.fsf@ruuvi.it.helsinki.fi>
Message-ID: <CAPTjJmr1xC7=h_H3TxaY-80Bxwd6Xv+PFGooEYsU4UdjWc+bTQ@mail.gmail.com>

On Fri, Jan 9, 2015 at 1:50 AM, Jussi Piitulainen
<jpiitula at ling.helsinki.fi> wrote:
>    >>> 0*1e400
>    nan

Nice, that's shorter than mine.

ChrisA


From alister.nospam.ware at ntlworld.com  Thu Jan  8 10:14:30 2015
From: alister.nospam.ware at ntlworld.com (alister)
Date: Thu, 08 Jan 2015 15:14:30 GMT
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmpVK4L-1kBVywd4o=mXFN=iWhjJzWZbxZDgw3nfK8WbSQ@mail.gmail.com>
 <m75pfm$2ah$1@ger.gmane.org>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <87bnm9fjtz.fsf@elektro.pacujo.net> <_nwrw.363401$AC.149510@fx29.am4>
 <874ms1fio5.fsf@elektro.pacujo.net>
Message-ID: <q9xrw.363402$AC.102150@fx29.am4>

On Thu, 08 Jan 2015 16:31:22 +0200, Marko Rauhamaa wrote:

> alister <alister.nospam.ware at ntlworld.com>:
> 
>> On Thu, 08 Jan 2015 16:06:16 +0200, Marko Rauhamaa wrote:
>>> An administrator doesn't need the users' passwords for anything but
>>> should be assumed to know them.
>>
>> The administrator may be able to change them but he should NEVER know
>> them (or need to)!
> 
> When you are under an administrator's dominion, *you* must assume the
> they know your password.
> 
> (Somewhat in the same vein, if you are running a virtual machine, *you*
> must assume the owner of the host computer has root access to your
> virtual machine. By extension, *you* must assume the government
> officials of the physical jurisdiction of the host computer have root
> access to your virtual machine.)
> 
> 
> Marko
I will agree with you there. The administrator 'should' never know your 
password but as a user you should never believe that password security 
has been correctly implemented (just ask Sony :-) )



-- 
"The subspace _W inherits the other 8 properties of _V. And there 
aren't
even any property taxes."
		-- J. MacKay, Mathematics 134b


From rantingrickjohnson at gmail.com  Thu Jan  8 10:33:33 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 8 Jan 2015 07:33:33 -0800 (PST)
Subject: How do I remove/unlink wildcarded files
In-Reply-To: <54ae81e2$0$15882$e4fe514c@dreader35.news.xs4all.nl>
References: <20150102090051.GC22372@arxnet.hu>
 <CAPTjJmrTYSEemnpaHRJBLDYq-gp2-wVpht4E_y1SnJmC8X6UVA@mail.gmail.com>
 <mailman.17344.1420281519.18130.python-list@python.org>
 <f69874c8-48f6-4696-8678-c2a761f2f18d@googlegroups.com>
 <54ae81e2$0$15882$e4fe514c@dreader35.news.xs4all.nl>
Message-ID: <fc2d2c81-02d8-45ad-82c9-3ce2861dddf1@googlegroups.com>

On Thursday, January 8, 2015 7:11:45 AM UTC-6, Albert van der Horst wrote:
> Rick Johnson wrote:
> >Widespread centralized free schooling did not exists until
> >almost the 1900's. Heck, looking back at American history,
> >the world *SHOULD* be in awe. To go from a rag-tag
> >illiterate bunch of cowboys, to the worlds most powerful and
> >technically advanced society (in roughly one hundred years!)
> >has to be the most amazing transformation in the history of
> >the human society.
> 
> It isn't. The Russian transformation under Stalin from a
> feodalist society with wooden plows to atomic bombs and
> space travel is.

Hmm, and i wonder where they got the technology from? Does
it count if the technology was stolen? For instance, if i
steal the source of Python and then proclaim to be the
*true* BDFL of Python, then do i get all the credit for
Python's existence?

    I DON'T THINK SO!

You're also ignoring a tiny thing called: "upward mobility".
In the 20th century, the whole of the American people gained
upward mobility. Anyone who dares to claim that a major
transformation of American society has not occurred, must be
blind to history!

Attaining advanced weaponry and scientific achievements is
nothing unless your people are benefiting *POSITIVELY* from
those advancements -- my statement was about transforming
*societies*, not about who popped the most Viagra pills and
achieved the largest erection in finite time!

---> [THUMP CHEST HERE]!

Farms did not vanish after the atomic/space ages, no,
societies still require food. But for the vast majority of
Russians, not a whole lot has changed. Sure, they have the
technology to fight wars on a global stage, but what good is
a strong arm without the guidance of a strong and *FREE*
mind? What good is ultimate power if you cannot improve you
own well being? -- just ask any genie trapped in a bottle!

    https://www.youtube.com/watch?v=v57sUtvNa5o

If history has taught us anything, it is that, intelligence
will *ALWAYS* defeat brute strength, and that the *MOST*
intelligent societies are consequently those who possess
both a humbled respect for freedom, and a vile rejection of
oppression.



From adam at poczta.emiter-uslugi.pl  Thu Jan  8 11:07:46 2015
From: adam at poczta.emiter-uslugi.pl (adam)
Date: Thu, 08 Jan 2015 17:07:46 +0100
Subject: application console with window
References: <m8k10h$cpe$1@news.icm.edu.pl>
 <54adaa47$0$2652$65785112@news.neostrada.pl>
Message-ID: <m8m38d$6ng$1@news.icm.edu.pl>

Hej, no w?a?nie niechodzi o przeniesienie do okienek tylko je?li znasz taki 
program jak np fk dla dos-a to chodzi mi o taki efekt. Czyli aplikacja 
konsolowa z pseudo okienkami.

Adam

jacek pozniak wrote:

> adam wrote:
> 
>> Is in here maybe someone who speak Polish?
>> 
>> I would like to write application witch looks like this
>> http://linuxiarze.pl/obrazy/internet1/ceni1.png
> Je?li chodzi Ci o przeniesienie na wersj? okienkow? to na przyk?ad:
> tkinter.
> 
> jp
> 
>> 
>> I'm looking for some libs, tutorials, or other informations.
>> I'm searching this informations for python3.
>> 
>> adam



From adam at poczta.emiter-uslugi.pl  Thu Jan  8 11:11:22 2015
From: adam at poczta.emiter-uslugi.pl (adam)
Date: Thu, 08 Jan 2015 17:11:22 +0100
Subject: application console with window
References: <m8k10h$cpe$1@news.icm.edu.pl>
 <mailman.17457.1420680810.18130.python-list@python.org>
Message-ID: <m8m3f5$6ng$2@news.icm.edu.pl>

Dennis Lee Bieber wrote:

> On Wed, 07 Jan 2015 22:17:09 +0100, adam <adam at poczta.emiter-uslugi.pl>
> declaimed the following:
> 
>>Is in here maybe someone who speak Polish?
>>
>>I would like to write application witch looks like this
>>http://linuxiarze.pl/obrazy/internet1/ceni1.png
>>
> Based upon the image, that is mainly an addressable console application
> with a line-draw character set. Something maybe possible using MS-DOS 3.x
> 
> What OS are you using?
Linux, fedora, debian, centOS, maybe windows 7 or 8.1
> 
>>I'm looking for some libs, tutorials, or other informations.
> 
> Check the documentation for the Python curses library.
> 
Thank you



From teeks99 at gmail.com  Thu Jan  8 11:11:43 2015
From: teeks99 at gmail.com (Tom Kent)
Date: Thu, 8 Jan 2015 08:11:43 -0800 (PST)
Subject: AssertionError (3.X only) when calling Py_Finalize with threads
Message-ID: <0d97bf89-9cc3-4253-885b-54c0bfd2cd37@googlegroups.com>

I'm getting an error output when I call the C-API's Py_Finalize() from a different C-thread than I made a python call on.

The error I'm seeing is:
Exception ignored in: <module 'threading' from 'C:\\Python34-32\\Lib\\threading.py'>
Traceback (most recent call last):
  File "C:\Python34-32\Lib\threading.py", line 1289, in _shutdown
    assert tlock.locked()
AssertionError:


Here's a minimal example that shows it happening when a C-thread is used, but not when everything happens on a single c-thread:

----------main.cpp--------------
#include <iostream>
#include <fstream>
#include <thread>
#include <cassert>

#include <Python.h>

void make_file()
{
   std::fstream file("my_test.py", std::ios::out);
   file << 
      "import threading\n"   << 
      "def my_function():\n" << 
      "    pass\n"             ;
   file.close();
}

void exec()
{
   PyGILState_STATE gstate = PyGILState_Ensure();
   PyObject* pdict = PyDict_New();
   PyDict_SetItemString(pdict, "__builtins__", PyEval_GetBuiltins());

   PyRun_String("import my_test", Py_file_input, pdict, pdict);
   PyRun_String("my_test.my_function()", Py_file_input, pdict, pdict);
   assert(!PyErr_Occurred());
   PyGILState_Release(gstate);
}

void basic()
{
   std::cout << "--Starting Basic--" << std::endl;

   Py_Initialize();
   PyEval_InitThreads();
   PyThreadState* threadState = PyEval_SaveThread();

   exec();

   PyEval_RestoreThread(threadState);
   Py_Finalize();

   std::cout << "--Basic Complete--" << std::endl;
}

void with_thread()
{
   std::cout << "--Starting With Thread--" << std::endl;

   Py_Initialize();
   PyEval_InitThreads();
   PyThreadState* threadState = PyEval_SaveThread();

   std::thread t(exec);
   t.join();

   PyEval_RestoreThread(threadState);
   Py_Finalize();

   std::cout << "--With Thread Complete--" << std::endl;
}

int main(int argc, char* argv[])
{
   make_file();
   basic();
   with_thread();

   return 0;
}
----------main.cpp--------------

----------output----------
--Starting Basic--
--Basic Complete--
--Starting With Thread--
Exception ignored in: <module 'threading' from 'C:\\Python34-32\\Lib\\threading.py'>
Traceback (most recent call last):
  File "C:\Python34-32\Lib\threading.py", line 1289, in _shutdown
    assert tlock.locked()
AssertionError:
--With Thread Complete--
----------output----------

The order of the basic()/with_thread() calls in main does not matter, I can even include those lines multiple times with no affect, each with_thread() call results in the error output.

Thanks,
Tom Kent


From adam at poczta.emiter-uslugi.pl  Thu Jan  8 11:18:07 2015
From: adam at poczta.emiter-uslugi.pl (adam)
Date: Thu, 08 Jan 2015 17:18:07 +0100
Subject: application console with window
References: <m8k10h$cpe$1@news.icm.edu.pl>
 <mailman.17463.1420686742.18130.python-list@python.org>
Message-ID: <m8m3rr$9k0$1@news.icm.edu.pl>

Emil Oppeln-Bronikowski wrote:

> On Wed, Jan 07, 2015 at 10:17:09PM +0100, adam wrote:
>> Is in here maybe someone who speak Polish?
> 
> M?wi?, a raczej pisz?.
> 
>> I'm looking for some libs, tutorials, or other informations.
> 
> This is terminal application using (n)curses or smilar library that helps
> you draw & interact with windows, forms and other widgets.
> 
> You can use curses library, but it's a little big hairy. There are a few
> extra libraries that make writing "full-screen" terminal application a
> breeze.
> 
> The most popular one (?and complete?) is urwid, and there are pages of
> tutorial once you google for it.
> 
> PS. if you need some help feel free to e-mail me off-list.
> 
thank you,

I just learn python. If you write in Polish it will be easier for me to 
explain any problem, because my English is very thin.

adam


From emil at fuse.pl  Thu Jan  8 11:32:52 2015
From: emil at fuse.pl (Emil Oppeln-Bronikowski)
Date: Thu, 8 Jan 2015 17:32:52 +0100
Subject: application console with window
In-Reply-To: <m8m3rr$9k0$1@news.icm.edu.pl>
References: <m8k10h$cpe$1@news.icm.edu.pl>
 <mailman.17463.1420686742.18130.python-list@python.org>
 <m8m3rr$9k0$1@news.icm.edu.pl>
Message-ID: <20150108163252.GA7798@mikrus>

On Thu, Jan 08, 2015 at 05:18:07PM +0100, adam wrote:

> I just learn python.

We all do. It's a constant process.

> If you write in Polish it will be easier for me to 
> explain any problem, because my English is very thin.

I don't really want to force others to read Polish, hit me private if you have any questions.

-- 
vag?a?bond adjective \?va-g?-?b?nd\
 a :? of, relating to, or characteristic of a wanderer 
 b :? leading an unsettled, irresponsible, or disreputable life



From adam at poczta.emiter-uslugi.pl  Thu Jan  8 11:42:23 2015
From: adam at poczta.emiter-uslugi.pl (adam)
Date: Thu, 08 Jan 2015 17:42:23 +0100
Subject: application console with window
References: <m8k10h$cpe$1@news.icm.edu.pl>
 <mailman.17463.1420686742.18130.python-list@python.org>
 <m8m3rr$9k0$1@news.icm.edu.pl>
 <mailman.17479.1420734504.18130.python-list@python.org>
Message-ID: <m8m59a$3v4$1@news.icm.edu.pl>

Emil Oppeln-Bronikowski wrote:

> On Thu, Jan 08, 2015 at 05:18:07PM +0100, adam wrote:
> 
>> I just learn python.
> 
> We all do. It's a constant process.
> 
>> If you write in Polish it will be easier for me to
>> explain any problem, because my English is very thin.
> 
> I don't really want to force others to read Polish, hit me private if you
> have any questions.
> 

Ok no problem


From kwpolska at gmail.com  Thu Jan  8 11:53:59 2015
From: kwpolska at gmail.com (Chris Warrick)
Date: Thu, 8 Jan 2015 17:53:59 +0100
Subject: application console with window
In-Reply-To: <m8m3rr$9k0$1@news.icm.edu.pl>
References: <m8k10h$cpe$1@news.icm.edu.pl>
 <mailman.17463.1420686742.18130.python-list@python.org>
 <m8m3rr$9k0$1@news.icm.edu.pl>
Message-ID: <CAMw+j7L+BN9EZkBD6FXvhwxkVcjcFb5_7bkzpCHap_eb4rJvYQ@mail.gmail.com>

On Thu, Jan 8, 2015 at 5:18 PM, adam <adam at poczta.emiter-uslugi.pl> wrote:
> I just learn python. If you write in Polish it will be easier for me to
> explain any problem, because my English is very thin.

You cannot really learn to program without speaking English well.  If
you can?t speak English, you will have lots of issues: it will be
harder to memorize things, you will be writing function/? names
brainlessly and, most importantly, you won?t be able to communicate
with other programmers (as demonstrated here).  English IS the
official language of technology, period. You should improve your
English first if you want to succeed in the industry (or create
anything advanced).

This Usenet newsgroup/mailing list is for English-language discussion
only.  Polish-language communities exist, you can search around if you
want.

As Emil said, urwid is the package to use to create a CLI
(command-line interface).  However, the list of OSes you provided
includes Windows, which makes it very problematic (you would have to
install Cygwin).  You could also switch to a GUI (graphical user
interface) with eg. Tkinter or something else that looks much better
than ugly old Tkinter (eg. PyQT).

---

Nie mo?esz si? nauczy? programowa? bez dobrej znajomo?ci angielskiego.
Je?li nie umiesz m?wi? po angielsku, b?dziesz mia? wiele problem?w:
trudniej b?dzie Ci zapami?ta? wszystko, b?dziesz zapisywa? nazwy
funkcji/? bezmy?lnie i, co najwa?niejsze, nie b?dziesz m?g? si?
komunikowa? z innymi programistami (co zosta?o tu zademonstrowane).
Angielski JEST j?zykiem oficjalnym technologii.  Powiniene?
podszlifowa? sw?j angielski je?li chcesz odnie?? sukces w bran?y (lub
nawet napisa? co? bardziej zaawansowanego)

Ta grupa Usenetowa/lista dyskusyjna jest przeznaczona tylko do
dyskusji w j?zyku angielskim.  Grupy w j?zyku polskim na pewno
istniej?, mo?esz poszuka?.

Jak powiedzia? Emil, powinienie? u?y? pakietu urwid je?li chcesz
utworzy? CLI (interfejs wiersza polece?).  Na li?cie system?w
operacyjnych jest Windows, co bardzo utrudnia spraw? (musia?by?
zainstalowa? Cygwina).  Mo?esz te? przej?? na GUI (graficzny interfejs
u?ytkownika), np. przy u?yciu biblioteki Tkinter lub czego? innego co
wygl?da lepiej ni? stary brzydki Tkinter (np. PyQT)

-- 
Chris Warrick <https://chriswarrick.com/>
PGP: 5EAAEA16


From hayesstw at telkomsa.net  Thu Jan  8 12:02:39 2015
From: hayesstw at telkomsa.net (Steve Hayes)
Date: Thu, 08 Jan 2015 19:02:39 +0200
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmpVK4L-1kBVywd4o=mXFN=iWhjJzWZbxZDgw3nfK8WbSQ@mail.gmail.com>
 <m75pfm$2ah$1@ger.gmane.org>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
Message-ID: <mtdtaalemtguc30127u5ifnbblrgndnrd3@4ax.com>

On 08 Jan 2015 12:43:33 GMT, albert at spenarnc.xs4all.nl (Albert van der Horst)
wrote:

>I don't trust sudo because it is too complicated.
>(To the point that I removed it from my machine.)
>I do

How do you do that?

I avoided Ubuntu because it had sudo, and then discovered that Fedora had it
as well. 


-- 
Steve Hayes from Tshwane, South Africa
Web:  http://www.khanya.org.za/stevesig.htm
Blog: http://khanya.wordpress.com
E-mail - see web page, or parse: shayes at dunelm full stop org full stop uk


From semeon.risom at gmail.com  Thu Jan  8 12:09:18 2015
From: semeon.risom at gmail.com (semeon.risom at gmail.com)
Date: Thu, 8 Jan 2015 09:09:18 -0800 (PST)
Subject: Generate jpg files using line length (pixels) and orientation
 (degrees)
Message-ID: <0f51bd21-7b0a-4ea0-8b13-27b1967d3b41@googlegroups.com>

Hello - 

Simple question. I hope.

I have 600 images (jpg) I am trying to generate. Each image will be made up of a line, with specific orientation (degrees) and length values (pixel). The background will be white (rgb: 255,255,255). I'm hoping each will have a name that corresponds to these values (i.e. 500px_600.jpg).

I was wondering if anyone had a piece of code, or at least point me to an example that might help.

Thanks,

Semeon


From rosuav at gmail.com  Thu Jan  8 12:11:33 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 9 Jan 2015 04:11:33 +1100
Subject: Hello World
In-Reply-To: <mtdtaalemtguc30127u5ifnbblrgndnrd3@4ax.com>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmpVK4L-1kBVywd4o=mXFN=iWhjJzWZbxZDgw3nfK8WbSQ@mail.gmail.com>
 <m75pfm$2ah$1@ger.gmane.org>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mtdtaalemtguc30127u5ifnbblrgndnrd3@4ax.com>
Message-ID: <CAPTjJmon63nE7j_KpR6Pfj69OQWmfFBXDeZKRQy6YNXyDtXf4g@mail.gmail.com>

On Fri, Jan 9, 2015 at 4:02 AM, Steve Hayes <hayesstw at telkomsa.net> wrote:
> On 08 Jan 2015 12:43:33 GMT, albert at spenarnc.xs4all.nl (Albert van der Horst)
> wrote:
>
>>I don't trust sudo because it is too complicated.
>>(To the point that I removed it from my machine.)
>>I do
>
> How do you do that?
>
> I avoided Ubuntu because it had sudo, and then discovered that Fedora had it
> as well.

Uhh, 'apt-get remove sudo'? That ought to work on any Debian-based
system. With Debian itself, you get the option during installation of
setting a root password, in which case it won't install sudo by
default.

ChrisA


From torriem at gmail.com  Thu Jan  8 12:53:50 2015
From: torriem at gmail.com (Michael Torrie)
Date: Thu, 08 Jan 2015 10:53:50 -0700
Subject: Hello World
In-Reply-To: <mtdtaalemtguc30127u5ifnbblrgndnrd3@4ax.com>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmpVK4L-1kBVywd4o=mXFN=iWhjJzWZbxZDgw3nfK8WbSQ@mail.gmail.com>
 <m75pfm$2ah$1@ger.gmane.org>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mtdtaalemtguc30127u5ifnbblrgndnrd3@4ax.com>
Message-ID: <54AEC42E.6050907@gmail.com>

On 01/08/2015 10:02 AM, Steve Hayes wrote:
> On 08 Jan 2015 12:43:33 GMT, albert at spenarnc.xs4all.nl (Albert van der Horst)
> wrote:
> 
>> I don't trust sudo because it is too complicated.
>> (To the point that I removed it from my machine.)
>> I do
> 
> How do you do that?
> 
> I avoided Ubuntu because it had sudo, and then discovered that Fedora had it
> as well. 

Of all the distro choosing criteria, this has to be one of the more
bizarre ones I've heard.  You could at least choose something
fashionable to avoid, like systemd.



From rustompmody at gmail.com  Thu Jan  8 12:56:50 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Thu, 8 Jan 2015 09:56:50 -0800 (PST)
Subject: Can numpy do better than this?
Message-ID: <71ecb9ec-5d8c-4503-a75b-1d4aeca79b08@googlegroups.com>

Given a matrix I want to shift the 1st column 0 (ie leave as is)
2nd by one place, 3rd by 2 places etc.

This code works.
But I wonder if numpy can do it shorter and simpler.

---------------------
def transpose(mat):
     return([[l[i] for l in mat]for i in range(0,len(mat[0]))])
def rotate(mat):
     return([mat[i][i:]+mat[i][:i] for i in range(0, len(mat))])
def shiftcols(mat):
    return ( transpose(rotate(transpose(mat))))

>>> mat = [[1,2,3,4,5,6],
        [7,8,9,10,11,12],
        [13,14,15,16,17,18],
        [19,20,21,22,23,24],
        [25,26,27,28,29,30],
        [31,32,33,34,35,36],
        [37,38,39,40,41,42]]

>>> shiftcols(mat)

[[1, 8, 15, 22, 29, 36],
[7, 14, 21, 28, 35, 42], 
[13, 20, 27, 34, 41, 6], 
[19, 26, 33, 40, 5, 12], 
[25, 32, 39, 4, 11, 18], 
[31, 38, 3, 10, 17, 24], 
[37, 2, 9, 16, 23, 30]]


I was hoping for something like the following APL operator

>>>   mat
 1  2  3  4  5  6
 7  8  9 10 11 12
13 14 15 16 17 18
19 20 21 22 23 24
25 26 27 28 29 30
31 32 33 34 35 36
>>>   0 1 2 3 4 5 ? mat
 1  8 15 22 29 36
 7 14 21 28 35  6
13 20 27 34  5 12
19 26 33  4 11 18
25 32  3 10 17 24
31  2  9 16 23 30


From marko at pacujo.net  Thu Jan  8 12:58:59 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 08 Jan 2015 19:58:59 +0200
Subject: How do I remove/unlink wildcarded files
References: <20150102090051.GC22372@arxnet.hu>
 <CAPTjJmrTYSEemnpaHRJBLDYq-gp2-wVpht4E_y1SnJmC8X6UVA@mail.gmail.com>
 <mailman.17344.1420281519.18130.python-list@python.org>
 <f69874c8-48f6-4696-8678-c2a761f2f18d@googlegroups.com>
 <54ae81e2$0$15882$e4fe514c@dreader35.news.xs4all.nl>
 <fc2d2c81-02d8-45ad-82c9-3ce2861dddf1@googlegroups.com>
Message-ID: <87y4pd17do.fsf@elektro.pacujo.net>

Rick Johnson <rantingrickjohnson at gmail.com>:

> If history has taught us anything, it is that, intelligence will
> *ALWAYS* defeat brute strength, and that the *MOST* intelligent
> societies are consequently those who possess both a humbled respect
> for freedom, and a vile rejection of oppression.

Impressive. With such a high percentage of the regular participants
falling for you, I think you have passed the Turing test.

Were you programmed in Python?


Marko


From ckaynor at zindagigames.com  Thu Jan  8 13:44:39 2015
From: ckaynor at zindagigames.com (Chris Kaynor)
Date: Thu, 8 Jan 2015 10:44:39 -0800
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <CALwzidkn5E3uxQ3Et9r-0_WUTjPLfHtY7mqwnhNVe2MGCi528Q@mail.gmail.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
 <mailman.17424.1420596200.18130.python-list@python.org>
 <54ace9f0$0$2738$c3e8da3$76491128@news.astraweb.com>
 <87tx02gb9d.fsf@elektro.pacujo.net>
 <54adc53c$0$12999$c3e8da3$5496439d@news.astraweb.com>
 <877fwx3i8f.fsf@elektro.pacujo.net>
 <CALwzidkn5E3uxQ3Et9r-0_WUTjPLfHtY7mqwnhNVe2MGCi528Q@mail.gmail.com>
Message-ID: <CALvWhxtbCrhpraYtQ8WpGiQfSULADbkBd9CEQ=EMiOW-LM168A@mail.gmail.com>

On Thu, Jan 8, 2015 at 6:57 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:

> On Wed, Jan 7, 2015 at 11:21 PM, Marko Rauhamaa <marko at pacujo.net> wrote:
> > Steven D'Aprano <steve+comp.lang.python at pearwood.info>:
> >
> >> Marko Rauhamaa wrote:
> >>> I prefer the Scheme way:
> >>>    #f is a falsey object
> >>>    everything else is a truthy object
> >>
> >> The Scheme way has no underlying model of what truthiness represents,
> just
> >> an arbitrary choice to make a single value have one truthiness, and
> >> everything else the other. It's just as meaningless and just as
> arbitrary
> >> as the opposite would be:
> >>
> >>     #t is True
> >>     everything else is falsey
> >> [...]
> >> I'd rather the Pascal way:
> >>
> >>     #t is True
> >>     #f is False
> >>     everything else is an error
> >
> > An advantage of the Scheme way is the chaining of "and" and "or". For
> > example, this breaks in Python:
> >
> >    def dir_contents(path):
> >        if os.path.isdir(path):
> >            return os.listdir(path)
> >        return None
> >
> >    def get_choices():
> >        return dir_contents(PRIMARY) or \
> >            dir_contents(SECONDARY) or \
> >            [ BUILTIN_PATH ]
>
> That depends on what the function is intended to do in the first
> place. Why would you want to return the contents of an empty directory
> rather than the default?
>
> Anyway, to make that work as you want it in Scheme, dir_contents would
> have to return #f, not None. Does it really make sense for a
> non-predicate function to be returning the value "false"?


I'd like to second this. I don't believe either way is inherently superior
to the other.

Lately, I've been doing quite a bit of work in lua, and many times have
wished that empty strings, tables, and 0 acted "falsey", but at the same
time, previously working in Python, there were plenty of times I wished
they acted "truthy". It merely depends on what algorithm I am using at the
time...
-------------- next part --------------
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From invalid at invalid.invalid  Thu Jan  8 13:57:19 2015
From: invalid at invalid.invalid (Grant Edwards)
Date: Thu, 8 Jan 2015 18:57:19 +0000 (UTC)
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmpVK4L-1kBVywd4o=mXFN=iWhjJzWZbxZDgw3nfK8WbSQ@mail.gmail.com>
 <m75pfm$2ah$1@ger.gmane.org>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mtdtaalemtguc30127u5ifnbblrgndnrd3@4ax.com>
 <mailman.17482.1420739647.18130.python-list@python.org>
Message-ID: <m8mjuf$g1r$1@reader2.panix.com>

On 2015-01-08, Michael Torrie <torriem at gmail.com> wrote:
> On 01/08/2015 10:02 AM, Steve Hayes wrote:
>> On 08 Jan 2015 12:43:33 GMT, albert at spenarnc.xs4all.nl (Albert van der Horst)
>> wrote:
>> 
>>> I don't trust sudo because it is too complicated. (To the point that
>>> I removed it from my machine.) I do
>> 
>> How do you do that?
>> 
>> I avoided Ubuntu because it had sudo, and then discovered that Fedora
>> had it as well. 
>
> Of all the distro choosing criteria, this has to be one of the more
> bizarre ones I've heard.

That's what I thought.  Especially since it's trivial to remove sudo.

Some system admin stuff on *buntu may require some extra thought since
the standard pointy-clicky recipes might not work exactly as described
in various fora, but anybody worried about security to the extent that
they refuse to use sudo probably shouldn't be using pointy-clicky
admin tools to start with.

> You could at least choose something fashionable to avoid, like
> systemd.

Or whatever the "desktop du jour" is for <distro-to-be-avoided>.

-- 
Grant Edwards               grant.b.edwards        Yow! Didn't I buy a 1951
                                  at               Packard from you last March
                              gmail.com            in Cairo?


From ian.g.kelly at gmail.com  Thu Jan  8 14:27:46 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 8 Jan 2015 12:27:46 -0700
Subject: Can numpy do better than this?
In-Reply-To: <71ecb9ec-5d8c-4503-a75b-1d4aeca79b08@googlegroups.com>
References: <71ecb9ec-5d8c-4503-a75b-1d4aeca79b08@googlegroups.com>
Message-ID: <CALwzidnreYc01Sv1z0=+juTuy9zpCBQyHUhWXBUUTd03yFX-EA@mail.gmail.com>

On Thu, Jan 8, 2015 at 10:56 AM, Rustom Mody <rustompmody at gmail.com> wrote:
> Given a matrix I want to shift the 1st column 0 (ie leave as is)
> 2nd by one place, 3rd by 2 places etc.
>
> This code works.
> But I wonder if numpy can do it shorter and simpler.
>
> ---------------------
> def transpose(mat):
>      return([[l[i] for l in mat]for i in range(0,len(mat[0]))])
> def rotate(mat):
>      return([mat[i][i:]+mat[i][:i] for i in range(0, len(mat))])
> def shiftcols(mat):
>     return ( transpose(rotate(transpose(mat))))

Without using numpy, your transpose function could be:

def transpose(mat):
    return list(zip(*mat))

numpy provides the roll function, but it doesn't allow for a varying
shift per index. I don't see a way to do it other than to roll each
column separately:

>>> mat = np.array([[1,2,3,4,5,6],
...         [7,8,9,10,11,12],
...         [13,14,15,16,17,18],
...         [19,20,21,22,23,24],
...         [25,26,27,28,29,30],
...         [31,32,33,34,35,36],
...         [37,38,39,40,41,42]])
>>> res = np.empty_like(mat)
>>> for i in range(mat.shape[1]):
...     res[:,i] = np.roll(mat[:,i], -i, 0)
...
>>> res
array([[ 1,  8, 15, 22, 29, 36],
       [ 7, 14, 21, 28, 35, 42],
       [13, 20, 27, 34, 41,  6],
       [19, 26, 33, 40,  5, 12],
       [25, 32, 39,  4, 11, 18],
       [31, 38,  3, 10, 17, 24],
       [37,  2,  9, 16, 23, 30]])


From marko at pacujo.net  Thu Jan  8 14:41:34 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 08 Jan 2015 21:41:34 +0200
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
 <mailman.17424.1420596200.18130.python-list@python.org>
 <54ace9f0$0$2738$c3e8da3$76491128@news.astraweb.com>
 <87tx02gb9d.fsf@elektro.pacujo.net>
 <54adc53c$0$12999$c3e8da3$5496439d@news.astraweb.com>
 <877fwx3i8f.fsf@elektro.pacujo.net>
 <mailman.17478.1420729591.18130.python-list@python.org>
Message-ID: <87sifl12mp.fsf@elektro.pacujo.net>

Ian Kelly <ian.g.kelly at gmail.com>:

>> An advantage of the Scheme way is the chaining of "and" and "or". For
>> example, this breaks in Python:
>>
>>    def dir_contents(path):
>>        if os.path.isdir(path):
>>            return os.listdir(path)
>>        return None
>>
>>    def get_choices():
>>        return dir_contents(PRIMARY) or \
>>            dir_contents(SECONDARY) or \
>>            [ BUILTIN_PATH ]
>
> That depends on what the function is intended to do in the first
> place. Why would you want to return the contents of an empty directory
> rather than the default?

To demonstrate the principle. Such short-circuited expressions have
spread to numerous high-level programming languages. Python has them,
too, but you have to be extra careful not to be hit by the surprising
false interpretations.

> Anyway, to make that work as you want it in Scheme, dir_contents would
> have to return #f, not None. Does it really make sense for a
> non-predicate function to be returning the value "false"?

By custom, #f acts as the de-facto None of Scheme for that very reason.
In classic Lisp, nil takes the roles of None, False and [], leading to
the confusion I mentioned.

Of course, Scheme now has to deal with distinguishing None (#f) and
False (#f as well). Luckily, that confusion rarely comes to play.


Marko


From kenakahn at gmail.com  Thu Jan  8 16:03:19 2015
From: kenakahn at gmail.com (kenakahn at gmail.com)
Date: Thu, 8 Jan 2015 13:03:19 -0800 (PST)
Subject: exporting c_variable to embedded python module
Message-ID: <ec235ae5-d926-4747-9a8f-2952956a2494@googlegroups.com>

I'm running a python script loaded via PyImport_Import in my C++ program on Linux.  Is there any way I can pass a value from the c-code to the loaded python module?


From denismfmcmahon at gmail.com  Thu Jan  8 17:07:03 2015
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Thu, 8 Jan 2015 22:07:03 +0000 (UTC)
Subject: Generate jpg files using line length (pixels) and orientation
 (degrees)
References: <0f51bd21-7b0a-4ea0-8b13-27b1967d3b41@googlegroups.com>
Message-ID: <m8mv27$k6e$2@dont-email.me>

On Thu, 08 Jan 2015 09:09:18 -0800, semeon.risom wrote:

> Simple question. I hope. .....

We just covered this in the PHP newsgroup where you were trying to use a 
PHP library to generate these images.

As your library code is written in PHP, I suggest you return to the 
discussion there unless you plan to rewrite your library in Python, and 
I'd point out now that the level of programming ability you've 
demonstrated so far in the PHP group does not bode well for you 
attempting to rewrite the PHP library code as Python!

You were given a complete PHP solution to your problem, showing different 
ways to loop through your variables.

-- 
Denis McMahon, denismfmcmahon at gmail.com


From irmen.NOSPAM at xs4all.nl  Thu Jan  8 17:32:06 2015
From: irmen.NOSPAM at xs4all.nl (Irmen de Jong)
Date: Thu, 08 Jan 2015 23:32:06 +0100
Subject: Announce: PyPrimes 0.2.1a
In-Reply-To: <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <54af0564$0$2919$e4fe514c@news.xs4all.nl>

On 8-1-2015 12:16, Steven D'Aprano wrote:

> I screwed up the upload to PyPI, and it won't allow you to upload the same
> version twice. (At least, I don't know of any way to do so.) So I had to
> bump the version number to re-upload.

You can manually log into PyPI and fix the uploaded files using the web interface.

There also seems to be an issue with the version number, if I pip install pyprimes, I
get the 0.1 version. I have to tell pip to allow prerelease versions to get your new
version. I think it is because of the 'a' after the version number.


Irmen



From jacek.pozniak at flowservice.pl  Thu Jan  8 17:32:11 2015
From: jacek.pozniak at flowservice.pl (jacek pozniak)
Date: Thu, 08 Jan 2015 23:32:11 +0100
Subject: application console with window
References: <m8k10h$cpe$1@news.icm.edu.pl>
 <54adaa47$0$2652$65785112@news.neostrada.pl> <m8m38d$6ng$1@news.icm.edu.pl>
Message-ID: <54af0567$0$2658$65785112@news.neostrada.pl>

adam wrote:

> Hej, no w?a?nie niechodzi o przeniesienie do okienek tylko je?li znasz
> taki program jak np fk dla dos-a to chodzi mi o taki efekt. Czyli
> aplikacja konsolowa z pseudo okienkami.
Napisz sobie w bashu z wykorzystaniem programu dialog (man dialog) i 
ewntualnym wo?aniem skrypt?w pythona o ile zajdzie taka potrzeba.


jp

> 
> Adam
> 
> jacek pozniak wrote:
> 
>> adam wrote:
>> 
>>> Is in here maybe someone who speak Polish?
>>> 
>>> I would like to write application witch looks like this
>>> http://linuxiarze.pl/obrazy/internet1/ceni1.png
>> Je?li chodzi Ci o przeniesienie na wersj? okienkow? to na przyk?ad:
>> tkinter.
>> 
>> jp
>> 
>>> 
>>> I'm looking for some libs, tutorials, or other informations.
>>> I'm searching this informations for python3.
>>> 
>>> adam



From fabiofz at gmail.com  Thu Jan  8 18:09:27 2015
From: fabiofz at gmail.com (Fabio Zadrozny)
Date: Thu, 8 Jan 2015 21:09:27 -0200
Subject: PyDev 3.9.1 Released
Message-ID: <CANXBEFp7GCFKPK_yuwb79uUo1xkXpmG251V86ecqFEDckuWtfA@mail.gmail.com>

What is PyDev?
---------------------------

PyDev is an open-source Python IDE on top of Eclipse for Python, Jython and
IronPython development.

It comes with goodies such as code completion, syntax highlighting, syntax
analysis, code analysis, refactor, debug, interactive console, etc.

Details on PyDev: http://pydev.org
Details on its development: http://pydev.blogspot.com


What is LiClipse?
---------------------------

LiClipse is a PyDev standalone with goodies such as support for Multiple
cursors, theming and a number of other languages such as Django Templates,
Kivy Language, Mako Templates, Html, Javascript, etc.

It's also a commercial counterpart which helps supporting the development
of PyDev.

Details on LiClipse: http://www.liclipse.com/


Release Highlights:
-------------------------------

* **Important**: PyDev requires Eclipse 3.8 or 4.3 onwards and Java 7! For
older versions, keep using PyDev 2.x (use LiClipse: http://www.liclipse.com
for a PyDev standalone with all requirements bundled).

* **Preferences**

  * PyDev preferences may now be saved and persisted for each project or in
the user settings (not just in the workspace).
  * Currently Save actions, Code Formatter, Typing and Imports are
supported (more to come in upcoming releases).
  * The same pages in the preferences are used to save settings to
(multiple) projects or user settings.
  * Configuration files are saved in Yaml format and are meant to be saved
in version control.

* **Editor**

  * The option to apply auto-formating was changed to apply any save
actions in non-workspace files.
  * Editor icon improved for dark theme (patch by Fathony Luthfillah).
  * When running the pep8 code analysis, the markers shown are no longer 1
character off.

* **Django**

  * Improved Django 1.7 support (patch by David Lehrian).

* **Profiling**

  * Integration with PyVmMonitor: http://pyvmmonitor.github.io/ (currently
only available for backers of the effort).

    * A profiling view was created where the location of PyVmMonitor should
be specified.
    * Just turning the option on will make all runs from that point on run
with the selected profile backend enabled.

* **Debugger**

  * Connecting to subprocesses working in Python 3.4.
  * Attach to running process is now supported on Mac OS.

* **Others**

  * Unset VIRTUAL_ENV before running external Python to protect the
sys.path (patch by James Blackburn).
  * pytest: Expected failure is no longer marked as a failure.
  * pytest: The working dir is changed so that conftests are loaded
properly (to workaround issue in pytest:
https://bitbucket.org/hpk42/pytest/issue/639/conftest-being-loaded-twice-giving
).
  * Fixed issue where an unused import would not be properly removed if it
was not a from import.
  * Fixed exception when drawing minimap overview ruler.


Cheers,

--
Fabio Zadrozny
------------------------------------------------------
Software Developer

LiClipse
http://www.liclipse.com

PyDev - Python Development Environment for Eclipse
http://pydev.org
http://pydev.blogspot.com

PyVmMonitor - Python Profiler
http://pyvmmonitor.github.io/
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From rosuav at gmail.com  Thu Jan  8 18:47:26 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 9 Jan 2015 10:47:26 +1100
Subject: exporting c_variable to embedded python module
In-Reply-To: <ec235ae5-d926-4747-9a8f-2952956a2494@googlegroups.com>
References: <ec235ae5-d926-4747-9a8f-2952956a2494@googlegroups.com>
Message-ID: <CAPTjJmpOmu9EWZ6vHmpQ_STf3uJnCFj70ZaqvVQdC4dpF3tbaw@mail.gmail.com>

On Fri, Jan 9, 2015 at 8:03 AM,  <kenakahn at gmail.com> wrote:
> I'm running a python script loaded via PyImport_Import in my C++ program on Linux.  Is there any way I can pass a value from the c-code to the loaded python module?

To answer this question, first think about how you would like to see
that value on the Python side. Does your C code call a function in
that module? If so, it can pass it a parameter. Or do you want the
top-level import to be aware of something? It might be best to put
something into another module, maybe even builtins. What makes sense
from the Python end? Pretty much anything can be done.

ChrisA


From ben+python at benfinney.id.au  Thu Jan  8 18:55:37 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Fri, 09 Jan 2015 10:55:37 +1100
Subject: PyPI files should not change their payload (was: Announce: PyPrimes
 0.2.1a)
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <85k30wx1xi.fsf_-_@benfinney.id.au>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:

> I screwed up the upload to PyPI, and it won't allow you to upload the
> same version twice. (At least, I don't know of any way to do so.) So I
> had to bump the version number to re-upload.

There is currently a hack that can be done (I won't say what it is) to
upload a different payload with the same filename. Please don't do it.

This is widely regarded, and I agree, as a bug: once PyPI has a file of
a particular name (including the package version), that filename should
only ever refer to that same content and never anything else.

Over at ?distutils-sig?, way back in 2014-09, a discussion reached the
consensus that the current undocumented ability to change the payload of
an existing file from PyPI is an oversight that needs to be closed
<URL:https://mail.python.org/pipermail/distutils-sig/2014-September/024890.html>,
with the Python Packaging Authority making its position known at
<URL:https://mail.python.org/pipermail/distutils-sig/2014-September/024921.html>:

    Silently changing released artefacts is actively user hostile. It
    breaks mirroring, it breaks redistribution, it breaks security
    audits, and it can even break installation for security conscious
    users that are using peep rather than pip.
    [?]

    I am thoroughly *against* retaining a general capability to silently
    substitute the contents of previously released files with a
    different payload solely to handle the case of packaging errors that
    aren't otherwise severe enough to warrant bumping the version number
    [?].
    
So, it seems you did the right thing in uploading different package
source content with a later version string.

The issue of remembering to update the Changelog document is another
matter, which I'll address in a different message.

-- 
 \     ?Capitalism has destroyed our belief in any effective power but |
  `\      that of self interest backed by force.? ?George Bernard Shaw |
_o__)                                                                  |
Ben Finney



From ben+python at benfinney.id.au  Thu Jan  8 19:06:31 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Fri, 09 Jan 2015 11:06:31 +1100
Subject: Using a ChangeLog as a canonical source of package metadata (was:
 Announce: PyPrimes 0.2.1a)
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <85fvbkx1fc.fsf_-_@benfinney.id.au>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:

> Ben Finney wrote:
> > The source has a ?CHANGES.txt? file which has no entry later than
> > version 0.2a. Why was the later version made, and when will the
> > change log be updated for that?
>
> Ah, I knew I forgot something!

The perils of duplicate sources of information: a Changelog makes claims
about which version is latest, but the packaging metadata comes from
somewhere else.

This problem is addressed quite well, in my opinion, by the Debian
packaging tools. The tools by default read the following information:

* release version string
* maintainer name
* maintainer email address
* target suite (a conceptual ?which Debian version should this go into?)

from the Changelog document, automatically. This means that the
Changelog document, as well as being directly useful to the recipient as
a text document, becomes the canonical place to record all those fields
for the packaging tools to read. No need to maintain duplicate records.


I would like Python's packaging tools to have the same capability.

This requires recording the Changelog document in a machine-parseable
format, with specified locations for each of the fields to be read for
each version.

I have recently gone through a process of converting the Changelog for a
package I maintain (?python-daemon?) to reStructuredText [0]. This has
all the above features: machine-parseable, a well-defined way to attach
fields to a section, etc.

[0] reStructuredText: <URL:http://docutils.sourceforge.net/rst.html>

I've now produced a small Python library which knows how to transform a
reST Changelog to package metadata; and how to get that package metadata
into and out of a Python distribution with Distutils.

The result is that I will never again upload the package with a mismatch
between what the Changelog claims is the latest version, and what the
package metadata says.


This may be generally useful to others. I'm interested to know how
people would expect to use this. As an extension to Distutils? As a
third-party library? Something else?

-- 
 \      ?Nullius in verba? (?Take no-one's word for it?) ?motto of the |
  `\                                   Royal Society, since 1663-06-30 |
_o__)                                                                  |
Ben Finney



From rosuav at gmail.com  Thu Jan  8 19:16:28 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 9 Jan 2015 11:16:28 +1100
Subject: Using a ChangeLog as a canonical source of package metadata (was:
 Announce: PyPrimes 0.2.1a)
In-Reply-To: <85fvbkx1fc.fsf_-_@benfinney.id.au>
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <85fvbkx1fc.fsf_-_@benfinney.id.au>
Message-ID: <CAPTjJmo8mLdRe_FesGbRyfBV2_ryx2Y+tDgAkEuUO2DWSqTC0Q@mail.gmail.com>

On Fri, Jan 9, 2015 at 11:06 AM, Ben Finney <ben+python at benfinney.id.au> wrote:
> I've now produced a small Python library which knows how to transform a
> reST Changelog to package metadata; and how to get that package metadata
> into and out of a Python distribution with Distutils.
>
> The result is that I will never again upload the package with a mismatch
> between what the Changelog claims is the latest version, and what the
> package metadata says.
>
>
> This may be generally useful to others. I'm interested to know how
> people would expect to use this. As an extension to Distutils? As a
> third-party library? Something else?

I can't speak as a package maintainer (because I'm not one), but
speaking as an end user, I'm in favour of anything that guarantees
consistency like that. It's only occasionally an issue, but for
instance, if I clone someone's source code repository and then install
a package from there, it's not necessarily obvious from 'pip freeze'
that I have something that can't so easily be downloaded. If the
Changelog were guaranteed to show that, then I could easily see what's
going on (eg if a new entry is created, immediately after the version
release, adding an alpha version tag).

ChrisA


From steve+comp.lang.python at pearwood.info  Thu Jan  8 19:38:00 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 09 Jan 2015 11:38:00 +1100
Subject: PyPI files should not change their payload (was: Announce:
 PyPrimes 0.2.1a)
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17487.1420761412.18130.python-list@python.org>
Message-ID: <54af22e9$0$12995$c3e8da3$5496439d@news.astraweb.com>

Ben Finney wrote:

> Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:
> 
>> I screwed up the upload to PyPI, and it won't allow you to upload the
>> same version twice. (At least, I don't know of any way to do so.) So I
>> had to bump the version number to re-upload.
> 
> There is currently a hack that can be done (I won't say what it is) to
> upload a different payload with the same filename. Please don't do it.

I had thought that I screwed up the metadata, but it turns out I didn't.
When I discovered pip was picking the wrong version number, selecting a
four year old 0.1 version instead of the newly uploaded 0.2 version,
googling suggested that the problem might have been that I had not run

    python setup.py register

before the upload:

    python setup.py sdist bdist_wininst upload

and that re-uploading would fix the problem. So I ended up bumping the
version number so I could re-register and re-upload, but that didn't fix
the problem with pip. (Oh Google, why hast thou failed me???)

 
> This is widely regarded, and I agree, as a bug: once PyPI has a file of
> a particular name (including the package version), that filename should
> only ever refer to that same content and never anything else.

If "content" means source code and related program data, I agree, but we
should be able to adjust incorrect metadata without a version bump.

[...]
> The issue of remembering to update the Changelog document is another
> matter, which I'll address in a different message.

Yes please.



-- 
Steven



From steve+comp.lang.python at pearwood.info  Thu Jan  8 19:41:32 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 09 Jan 2015 11:41:32 +1100
Subject: Announce: PyPrimes 0.2.1a
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <54af0564$0$2919$e4fe514c@news.xs4all.nl>
Message-ID: <54af23bc$0$12995$c3e8da3$5496439d@news.astraweb.com>

Irmen de Jong wrote:

> On 8-1-2015 12:16, Steven D'Aprano wrote:
> 
>> I screwed up the upload to PyPI, and it won't allow you to upload the
>> same version twice. (At least, I don't know of any way to do so.) So I
>> had to bump the version number to re-upload.
> 
> You can manually log into PyPI and fix the uploaded files using the web
> interface.

Thanks.

 
> There also seems to be an issue with the version number, if I pip install
> pyprimes, I get the 0.1 version. I have to tell pip to allow prerelease
> versions to get your new version. I think it is because of the 'a' after
> the version number.

Yes, I mentioned this in my announcement here.

Is there a good tutorial to learn about pip? Everything I've seen so far
seems to be of one of two extremes, either:

"pip is awesome, just run 'pip install packagename' and it cannot fail!!!1!"

or 

"oh, pip did the wrong thing again? you can fix that by standing on one leg,
sacrificing a goat to the Great Old Dark Ones, deleting these files, or
possibly some other ones, and if the phase of the moon is exactly right it
will behave as you want..."

I know that pip is Officially The Best Thing Evar, but my experience so far
has been less than satisfactory.



-- 
Steven



From rosuav at gmail.com  Thu Jan  8 19:50:26 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 9 Jan 2015 11:50:26 +1100
Subject: Announce: PyPrimes 0.2.1a
In-Reply-To: <54af23bc$0$12995$c3e8da3$5496439d@news.astraweb.com>
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <54af0564$0$2919$e4fe514c@news.xs4all.nl>
 <54af23bc$0$12995$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmpkUshWFo_BTh7iuTP465TzCUbuaAW-txF6FstTVZeGyQ@mail.gmail.com>

On Fri, Jan 9, 2015 at 11:41 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> "oh, pip did the wrong thing again? you can fix that by standing on one leg,
> sacrificing a goat to the Great Old Dark Ones, deleting these files, or
> possibly some other ones, and if the phase of the moon is exactly right it
> will behave as you want..."

Replacing an existing package, without changing the version number,
*is* messy. It's not pip's fault that it's hard. That's like saying
"Oops, I committed this to source control and pushed it out to all
users, but there's a big file in it and I want to delete it so they
don't have to download it". Sure, that's possible, but it's not a
normal action, so you'll have to jump through some hoops to make it
all work properly.

Or have you been having this whole sacrificing a goat thing with a
normal workflow?

ChrisA


From ben+python at benfinney.id.au  Thu Jan  8 20:11:13 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Fri, 09 Jan 2015 12:11:13 +1100
Subject: Where to learn current best Python packaging practices (was:
 Announce: PyPrimes 0.2.1a)
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <54af0564$0$2919$e4fe514c@news.xs4all.nl>
 <54af23bc$0$12995$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <85bnm8wyfi.fsf_-_@benfinney.id.au>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:

> Is there a good tutorial to learn about pip?

I'll answer what I think is the correct question: where to learn about
the current best Python packaging practices.

We have recently gained an official body whose explicit job is to
direct, and be opinionated about, packaging Python software: the Python
Packaging Authority <URL:https://www.pypa.io/>.

One of their many beneficial outputs is the Python Packaging User Guide
<URL:https://python-packaging-user-guide.readthedocs.org/>.

> I know that pip is Officially The Best Thing Evar, but my experience
> so far has been less than satisfactory.

For a very long time, Python packaging was in a truly awful state, and
seemed to get even worse with time. That is now reversed though (IMO),
and ?pip? does indeed represent the Best Thing So Far? for Python
package installation.

That does not contradict the position that it's an ornery beast full of
hidden traps and compromises though; it just means that everything that
came before it (in Python) is worse :-)

Seriously, even those who believe they know a lot about Python packaging
will benefit greatly from learning about the sweeping improvements that
have been made in the past handful of years. Get thee to the Python
Packaging Authority resources and learn where we're at, and how far we
have to go.

-- 
 \       ?You can stand tall without standing on someone. You can be a |
  `\         victor without having victims.? ?Harriet Woods, 1927?2007 |
_o__)                                                                  |
Ben Finney



From rustompmody at gmail.com  Thu Jan  8 20:13:34 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Thu, 8 Jan 2015 17:13:34 -0800 (PST)
Subject: Can numpy do better than this?
In-Reply-To: <mailman.17484.1420745315.18130.python-list@python.org>
References: <71ecb9ec-5d8c-4503-a75b-1d4aeca79b08@googlegroups.com>
 <mailman.17484.1420745315.18130.python-list@python.org>
Message-ID: <719d2a22-6c41-467c-a046-0a53704953c6@googlegroups.com>

On Friday, January 9, 2015 at 12:58:52 AM UTC+5:30, Ian wrote:
> On Thu, Jan 8, 2015 at 10:56 AM, Rustom Mody wrote:
> > Given a matrix I want to shift the 1st column 0 (ie leave as is)
> > 2nd by one place, 3rd by 2 places etc.
> >
> > This code works.
> > But I wonder if numpy can do it shorter and simpler.
> >
> > ---------------------
> > def transpose(mat):
> >      return([[l[i] for l in mat]for i in range(0,len(mat[0]))])
> > def rotate(mat):
> >      return([mat[i][i:]+mat[i][:i] for i in range(0, len(mat))])
> > def shiftcols(mat):
> >     return ( transpose(rotate(transpose(mat))))
> 
> Without using numpy, your transpose function could be:
> 
> def transpose(mat):
>     return list(zip(*mat))
> 
> numpy provides the roll function, but it doesn't allow for a varying
> shift per index. I don't see a way to do it other than to roll each
> column separately:
> 
> >>> mat = np.array([[1,2,3,4,5,6],
> ...         [7,8,9,10,11,12],
> ...         [13,14,15,16,17,18],
> ...         [19,20,21,22,23,24],
> ...         [25,26,27,28,29,30],
> ...         [31,32,33,34,35,36],
> ...         [37,38,39,40,41,42]])
> >>> res = np.empty_like(mat)
> >>> for i in range(mat.shape[1]):
> ...     res[:,i] = np.roll(mat[:,i], -i, 0)
> ...
> >>> res
> array([[ 1,  8, 15, 22, 29, 36],
>        [ 7, 14, 21, 28, 35, 42],
>        [13, 20, 27, 34, 41,  6],
>        [19, 26, 33, 40,  5, 12],
>        [25, 32, 39,  4, 11, 18],
>        [31, 38,  3, 10, 17, 24],
>        [37,  2,  9, 16, 23, 30]])

Thanks Ian!
With that I came up with the expression

transpose(array([list(roll(mat[:,i],i,0)) for i in range(mat.shape[1])]))

Not exactly pretty.
My hunch is it can be improved??...


From rustompmody at gmail.com  Thu Jan  8 20:19:52 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Thu, 8 Jan 2015 17:19:52 -0800 (PST)
Subject: Can numpy do better than this?
In-Reply-To: <719d2a22-6c41-467c-a046-0a53704953c6@googlegroups.com>
References: <71ecb9ec-5d8c-4503-a75b-1d4aeca79b08@googlegroups.com>
 <mailman.17484.1420745315.18130.python-list@python.org>
 <719d2a22-6c41-467c-a046-0a53704953c6@googlegroups.com>
Message-ID: <2dc64d02-e25b-444e-9406-732884f4d93d@googlegroups.com>

On Friday, January 9, 2015 at 6:43:45 AM UTC+5:30, Rustom Mody wrote:
> On Friday, January 9, 2015 at 12:58:52 AM UTC+5:30, Ian wrote:
> > On Thu, Jan 8, 2015 at 10:56 AM, Rustom Mody wrote:
> > > Given a matrix I want to shift the 1st column 0 (ie leave as is)
> > > 2nd by one place, 3rd by 2 places etc.
> > >
> > > This code works.
> > > But I wonder if numpy can do it shorter and simpler.
> > >
> > > ---------------------
> > > def transpose(mat):
> > >      return([[l[i] for l in mat]for i in range(0,len(mat[0]))])
> > > def rotate(mat):
> > >      return([mat[i][i:]+mat[i][:i] for i in range(0, len(mat))])
> > > def shiftcols(mat):
> > >     return ( transpose(rotate(transpose(mat))))
> > 
> > Without using numpy, your transpose function could be:
> > 
> > def transpose(mat):
> >     return list(zip(*mat))
> > 
> > numpy provides the roll function, but it doesn't allow for a varying
> > shift per index. I don't see a way to do it other than to roll each
> > column separately:
> > 
> > >>> mat = np.array([[1,2,3,4,5,6],
> > ...         [7,8,9,10,11,12],
> > ...         [13,14,15,16,17,18],
> > ...         [19,20,21,22,23,24],
> > ...         [25,26,27,28,29,30],
> > ...         [31,32,33,34,35,36],
> > ...         [37,38,39,40,41,42]])
> > >>> res = np.empty_like(mat)
> > >>> for i in range(mat.shape[1]):
> > ...     res[:,i] = np.roll(mat[:,i], -i, 0)
> > ...
> > >>> res
> > array([[ 1,  8, 15, 22, 29, 36],
> >        [ 7, 14, 21, 28, 35, 42],
> >        [13, 20, 27, 34, 41,  6],
> >        [19, 26, 33, 40,  5, 12],
> >        [25, 32, 39,  4, 11, 18],
> >        [31, 38,  3, 10, 17, 24],
> >        [37,  2,  9, 16, 23, 30]])
> 
> Thanks Ian!
> With that I came up with the expression
> 
> transpose(array([list(roll(mat[:,i],i,0)) for i in range(mat.shape[1])]))

That is numpy transpose of course (following a 'from numpy import *')
Not a vanilla (list) transpose


From ian.g.kelly at gmail.com  Thu Jan  8 20:36:23 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 8 Jan 2015 18:36:23 -0700
Subject: Can numpy do better than this?
In-Reply-To: <719d2a22-6c41-467c-a046-0a53704953c6@googlegroups.com>
References: <71ecb9ec-5d8c-4503-a75b-1d4aeca79b08@googlegroups.com>
 <mailman.17484.1420745315.18130.python-list@python.org>
 <719d2a22-6c41-467c-a046-0a53704953c6@googlegroups.com>
Message-ID: <CALwzidmHQO+9maMfoT2H-PAgw7h1bteYywx=wbO+8Nck9Z0DDg@mail.gmail.com>

On Thu, Jan 8, 2015 at 6:13 PM, Rustom Mody <rustompmody at gmail.com> wrote:
> With that I came up with the expression
>
> transpose(array([list(roll(mat[:,i],i,0)) for i in range(mat.shape[1])]))
>
> Not exactly pretty.
> My hunch is it can be improved??...

Hmm, you could use the column_stack constructor to avoid having to
transpose the array.

>>> np.column_stack(np.roll(mat[:,i],i,0) for i in range(mat.shape[1]))
array([[ 1, 38, 33, 28, 23, 18],
       [ 7,  2, 39, 34, 29, 24],
       [13,  8,  3, 40, 35, 30],
       [19, 14,  9,  4, 41, 36],
       [25, 20, 15, 10,  5, 42],
       [31, 26, 21, 16, 11,  6],
       [37, 32, 27, 22, 17, 12]])


From rustompmody at gmail.com  Thu Jan  8 20:39:49 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Thu, 8 Jan 2015 17:39:49 -0800 (PST)
Subject: Where to learn current best Python packaging practices (was:
 Announce: PyPrimes 0.2.1a)
In-Reply-To: <mailman.17491.1420765926.18130.python-list@python.org>
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <54af0564$0$2919$e4fe514c@news.xs4all.nl>
 <54af23bc$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17491.1420765926.18130.python-list@python.org>
Message-ID: <4bc786c8-1ad2-4c8c-9788-4c5a760927ef@googlegroups.com>

On Friday, January 9, 2015 at 6:42:18 AM UTC+5:30, Ben Finney wrote:
> Steven D'Aprano writes:
> 
> > Is there a good tutorial to learn about pip?
> 
> I'll answer what I think is the correct question: where to learn about
> the current best Python packaging practices.

In order to attain to full ISO 9000 buzzword compliance, how about calling it 
python-devops?
> 
> We have recently gained an official body whose explicit job is to
> direct, and be opinionated about, packaging Python software: the Python
> Packaging Authority <URL:https://www.pypa.io/>.
> 
> One of their many beneficial outputs is the Python Packaging User Guide
> <URL:https://python-packaging-user-guide.readthedocs.org/>.

Thanks
I need to look at that

Maybe good to also have something linking 'pure' python packaging with
debian python packaging


From rantingrickjohnson at gmail.com  Thu Jan  8 20:42:42 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 8 Jan 2015 17:42:42 -0800 (PST)
Subject: Where to learn current best Python packaging practices (was:
 Announce: PyPrimes 0.2.1a)
In-Reply-To: <mailman.17491.1420765926.18130.python-list@python.org>
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <54af0564$0$2919$e4fe514c@news.xs4all.nl>
 <54af23bc$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17491.1420765926.18130.python-list@python.org>
Message-ID: <b52c9bb6-fab5-467b-87ea-221cac95670e@googlegroups.com>

On Thursday, January 8, 2015 at 7:12:18 PM UTC-6, Ben Finney wrote:

> That does not contradict the position that [python
> packaging] is an ornery beast full of hidden traps and
> compromises though; it just means that everything that
> came before it (in Python) is worse

Ben, you've just proven the old truism of: 

    "When you're at the bottom, the only way you can go is up!"
    



From rustompmody at gmail.com  Thu Jan  8 20:45:34 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Thu, 8 Jan 2015 17:45:34 -0800 (PST)
Subject: Can numpy do better than this?
In-Reply-To: <mailman.17492.1420767434.18130.python-list@python.org>
References: <71ecb9ec-5d8c-4503-a75b-1d4aeca79b08@googlegroups.com>
 <mailman.17484.1420745315.18130.python-list@python.org>
 <719d2a22-6c41-467c-a046-0a53704953c6@googlegroups.com>
 <mailman.17492.1420767434.18130.python-list@python.org>
Message-ID: <852098c1-bba2-41a0-9585-323bf203aba7@googlegroups.com>

On Friday, January 9, 2015 at 7:07:26 AM UTC+5:30, Ian wrote:
> On Thu, Jan 8, 2015 at 6:13 PM, Rustom Mody wrote:
> > With that I came up with the expression
> >
> > transpose(array([list(roll(mat[:,i],i,0)) for i in range(mat.shape[1])]))
> >
> > Not exactly pretty.
> > My hunch is it can be improved??...
> 
> Hmm, you could use the column_stack constructor to avoid having to
> transpose the array.
> 
> >>> np.column_stack(np.roll(mat[:,i],i,0) for i in range(mat.shape[1]))
> array([[ 1, 38, 33, 28, 23, 18],
>        [ 7,  2, 39, 34, 29, 24],
>        [13,  8,  3, 40, 35, 30],
>        [19, 14,  9,  4, 41, 36],
>        [25, 20, 15, 10,  5, 42],
>        [31, 26, 21, 16, 11,  6],
>        [37, 32, 27, 22, 17, 12]])

You are my sweetheart!

Removing Javaish-dot-noise:

column_stack(roll(mat[:,i],i,0) for i in range(mat.shape[1]))


From steve+comp.lang.python at pearwood.info  Thu Jan  8 20:46:27 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 09 Jan 2015 12:46:27 +1100
Subject: where in Nan defined
References: <m8m3et$1gu$2@speranza.aioe.org>
 <mailman.17472.1420727095.18130.python-list@python.org>
 <87zj9te3tz.fsf@elektro.pacujo.net> <qotk30xjpib.fsf@ruuvi.it.helsinki.fi>
 <mailman.17477.1420729115.18130.python-list@python.org>
Message-ID: <54af32f4$0$12990$c3e8da3$5496439d@news.astraweb.com>

Chris Angelico wrote:

> On Fri, Jan 9, 2015 at 1:50 AM, Jussi Piitulainen
> <jpiitula at ling.helsinki.fi> wrote:
>>    >>> 0*1e400
>>    nan
> 
> Nice, that's shorter than mine.

o_O

Is that really the sort of thing you should be revealing here?

Oh wait, you're talking about code...

I'm not entirely sure, but I suspect that 0*1e400 may not be quite as
portable as your inf-inf. By the rules of IEEE-754 arithmetic, inf-inf has
to return a NAN, but if your floats have sufficient precision available to
represent 1e400, 0*1e400 might return 0.

The fallback rule I use when float('nan') fails is

    INF = 1e3000  # Hopefully, this should overflow to INF.
    NAN = INF-INF  # And this hopefully will give a NaN.



-- 
Steven



From rosuav at gmail.com  Thu Jan  8 21:07:01 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 9 Jan 2015 13:07:01 +1100
Subject: where in Nan defined
In-Reply-To: <54af32f4$0$12990$c3e8da3$5496439d@news.astraweb.com>
References: <m8m3et$1gu$2@speranza.aioe.org>
 <mailman.17472.1420727095.18130.python-list@python.org>
 <87zj9te3tz.fsf@elektro.pacujo.net>
 <qotk30xjpib.fsf@ruuvi.it.helsinki.fi>
 <mailman.17477.1420729115.18130.python-list@python.org>
 <54af32f4$0$12990$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmoN+PWTTYkc_DaADgwAeVc9QVSK8S1sJn9O28ugrDYExA@mail.gmail.com>

On Fri, Jan 9, 2015 at 12:46 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Chris Angelico wrote:
>
>> On Fri, Jan 9, 2015 at 1:50 AM, Jussi Piitulainen
>> <jpiitula at ling.helsinki.fi> wrote:
>>>    >>> 0*1e400
>>>    nan
>>
>> Nice, that's shorter than mine.
>
> I'm not entirely sure, but I suspect that 0*1e400 may not be quite as
> portable as your inf-inf. By the rules of IEEE-754 arithmetic, inf-inf has
> to return a NAN, but if your floats have sufficient precision available to
> represent 1e400, 0*1e400 might return 0.
>
> The fallback rule I use when float('nan') fails is
>
>     INF = 1e3000  # Hopefully, this should overflow to INF.
>     NAN = INF-INF  # And this hopefully will give a NaN.

The first question is "will 1eN overflow to inf?". I'm fairly sure
Python guarantees that an unrepresentable float constant will be
treated as infinity, so all you have to do is crank up the exponent
any time you suspect it'll be representable. The second is "will 0*inf
result in nan?", and I would expect that to be as reliable as INF-INF.

ChrisA


From rantingrickjohnson at gmail.com  Thu Jan  8 21:09:32 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 8 Jan 2015 18:09:32 -0800 (PST)
Subject: application console with window
In-Reply-To: <mailman.17480.1420736048.18130.python-list@python.org>
References: <m8k10h$cpe$1@news.icm.edu.pl>
 <mailman.17463.1420686742.18130.python-list@python.org>
 <m8m3rr$9k0$1@news.icm.edu.pl>
 <mailman.17480.1420736048.18130.python-list@python.org>
Message-ID: <2aa9be1c-dd66-459f-968f-444976f4f58e@googlegroups.com>

On Thursday, January 8, 2015 at 10:54:22 AM UTC-6, Chris Warrick wrote:
> On Thu, Jan 8, 2015 at 5:18 PM, adam wrote:
> > I just learn python. If you write in Polish it will be easier for me to
> > explain any problem, because my English is very thin.
> 
> You cannot really learn to program without speaking English well.  If
> you can't speak English, you will have lots of issues: it will be
> harder to memorize things, you will be writing function/... names
> brainlessly and, most importantly, you won't be able to communicate
> with other programmers (as demonstrated here).  English IS the
> official language of technology, period. You should improve your
> English first if you want to succeed in the industry (or create
> anything advanced).

Although your response will most likely illicit rebukes from
the bleeding-heart emotional little whine bags, i must say i
agree 100%, and i'm overjoyed to witness someone besides
myself who has the testicular fortitude to speak the truth!

    YOU SIR, ARE MY "HERO OF THE YEAR"!

Listen folks, we are not trying to be imperialist here, we
did not "personally" choose for English to be the "lingua
franca" of the world, but that *IS* the reality in which we
live.

If the Chinese or Russians had set up colonies around the
would, instead of the western Europeans, we'd all be
speaking Chinese or Russian today. The whining about who won
is just a waste of time. Instead of being sore losers, we
need to intelligently play the hand we were dealt. Besides,
there is an old Chinese proverb that goes something like:

    "If you wait long enough on the river bank, 
    the bodies of your enemies will float by"
    
What does that mean? It means that those who win today will
eventually lose -- this is the way of the universe. The
universe is using all of us as pawns, we are all in this
*together*, and all we can do is do our best with what we
are given. So stop whining and start communicating! All we
need to do is keep talking...

    https://www.youtube.com/watch?v=tS-qsh6eTik 

Anytime we can break down barriers to communication, we will
*ALL* benefit from the synergy of ideas.


From ian.g.kelly at gmail.com  Thu Jan  8 21:12:45 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 8 Jan 2015 19:12:45 -0700
Subject: where in Nan defined
In-Reply-To: <CAPTjJmoN+PWTTYkc_DaADgwAeVc9QVSK8S1sJn9O28ugrDYExA@mail.gmail.com>
References: <m8m3et$1gu$2@speranza.aioe.org>
 <mailman.17472.1420727095.18130.python-list@python.org>
 <87zj9te3tz.fsf@elektro.pacujo.net> <qotk30xjpib.fsf@ruuvi.it.helsinki.fi>
 <mailman.17477.1420729115.18130.python-list@python.org>
 <54af32f4$0$12990$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmoN+PWTTYkc_DaADgwAeVc9QVSK8S1sJn9O28ugrDYExA@mail.gmail.com>
Message-ID: <CALwzidm1kp6yXi_p_4r1WemhxR+=j5gLEHPt07B6M55qcEL4KA@mail.gmail.com>

On Thu, Jan 8, 2015 at 7:07 PM, Chris Angelico <rosuav at gmail.com> wrote:
> On Fri, Jan 9, 2015 at 12:46 PM, Steven D'Aprano
>> The fallback rule I use when float('nan') fails is
>>
>>     INF = 1e3000  # Hopefully, this should overflow to INF.
>>     NAN = INF-INF  # And this hopefully will give a NaN.
>
> The first question is "will 1eN overflow to inf?". I'm fairly sure
> Python guarantees that an unrepresentable float constant will be
> treated as infinity, so all you have to do is crank up the exponent
> any time you suspect it'll be representable.

Or to never have to worry about it:

INF = 1e400
while not math.isinf(INF):
    INF *= INF


From kenakahn at gmail.com  Thu Jan  8 21:16:46 2015
From: kenakahn at gmail.com (kenakahn at gmail.com)
Date: Thu, 8 Jan 2015 18:16:46 -0800 (PST)
Subject: exporting c_variable to embedded python module
In-Reply-To: <ec235ae5-d926-4747-9a8f-2952956a2494@googlegroups.com>
References: <ec235ae5-d926-4747-9a8f-2952956a2494@googlegroups.com>
Message-ID: <6f5ab1ed-e51a-4487-baa7-2296a00edfac@googlegroups.com>

I want to access c-side global variables from the python side.


From rosuav at gmail.com  Thu Jan  8 21:25:42 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 9 Jan 2015 13:25:42 +1100
Subject: where in Nan defined
In-Reply-To: <CALwzidm1kp6yXi_p_4r1WemhxR+=j5gLEHPt07B6M55qcEL4KA@mail.gmail.com>
References: <m8m3et$1gu$2@speranza.aioe.org>
 <mailman.17472.1420727095.18130.python-list@python.org>
 <87zj9te3tz.fsf@elektro.pacujo.net>
 <qotk30xjpib.fsf@ruuvi.it.helsinki.fi>
 <mailman.17477.1420729115.18130.python-list@python.org>
 <54af32f4$0$12990$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmoN+PWTTYkc_DaADgwAeVc9QVSK8S1sJn9O28ugrDYExA@mail.gmail.com>
 <CALwzidm1kp6yXi_p_4r1WemhxR+=j5gLEHPt07B6M55qcEL4KA@mail.gmail.com>
Message-ID: <CAPTjJmqQGYCDAhDkEjScvC=LL_1B7vvJQz-sG4-mhOVLoPyc1Q@mail.gmail.com>

On Fri, Jan 9, 2015 at 1:12 PM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> Or to never have to worry about it:
>
> INF = 1e400
> while not math.isinf(INF):
>     INF *= INF

With no imports whatsoever:

inf = 1e400
nan = inf-inf
while nan == nan:
    inf *= inf
    nan = inf-inf

But now we're getting stupid :)

ChrisA


From jeanpierreda at gmail.com  Thu Jan  8 21:33:21 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Thu, 8 Jan 2015 18:33:21 -0800
Subject: Decimals and other numbers
Message-ID: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>

I noticed some very PHP-ish behavior today:

>>> import decimal
>>> x = 0
>>> y = float(x)
>>> z = decimal.Decimal(x)
>>> x == y == z == x
True
>>> x ** x
1
>>> y**y
1.0
>>> z**z
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.7/decimal.py", line 2216, in __pow__
    return context._raise_error(InvalidOperation, '0 ** 0')
  File "/usr/lib/python2.7/decimal.py", line 3872, in _raise_error
    raise error(explanation)
decimal.InvalidOperation: 0 ** 0


I'd file a bug report but I'm anticipating some rational (heh)
explanation. Any ideas?

Python 3.4 also raises this exception, but the error message is less
informative. ("decimal.InvalidOperation: [<class
'decimal.InvalidOperation'>]").

-- Devin


From ben+python at benfinney.id.au  Thu Jan  8 21:37:04 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Fri, 09 Jan 2015 13:37:04 +1100
Subject: Where to learn current best Python packaging practices
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <54af0564$0$2919$e4fe514c@news.xs4all.nl>
 <54af23bc$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17491.1420765926.18130.python-list@python.org>
 <b52c9bb6-fab5-467b-87ea-221cac95670e@googlegroups.com>
Message-ID: <857fwwwugf.fsf@benfinney.id.au>

Rick Johnson <rantingrickjohnson at gmail.com> writes:

> On Thursday, January 8, 2015 at 7:12:18 PM UTC-6, Ben Finney wrote:
>
> > That does not contradict the position that [python packaging] is an
> > ornery beast full of hidden traps and compromises though; it just
> > means that everything that came before it (in Python) is worse

That's a mis-quoting of what I said. I was referring specifically to
?pip? there (i.e. that ?pip? is both an ornery beast, and that
everything which came before it in Python is worse). I did not say, and
do not claim, that for Python's packaging.

> Ben, you've just proven the old truism of: 
>     "When you're at the bottom, the only way you can go is up!"

And you've just proven the truism that it is easy to interpret someone
as supporting a position if you're willing to change what they actually
wrote.

-- 
 \         ?I call him Governor Bush because that's the only political |
  `\              office he's ever held legally.? ?George Carlin, 2008 |
_o__)                                                                  |
Ben Finney



From ben+python at benfinney.id.au  Thu Jan  8 21:43:04 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Fri, 09 Jan 2015 13:43:04 +1100
Subject: Decimals and other numbers
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
Message-ID: <85387kwu6f.fsf@benfinney.id.au>

Devin Jeanpierre <jeanpierreda at gmail.com> writes:

> decimal.InvalidOperation: 0 ** 0
>
> I'd file a bug report but I'm anticipating some rational (heh)
> explanation. Any ideas?

First note that it's explicitly documented as an invalid operation
<URL:file:///usr/share/doc/python3-doc/html/library/decimal.html#decimal.InvalidOperation>.
So someone has at least thought about it and deliberately decided it
should be so.

Why that should be, I don't know; I think the correct behaviour is for
?0 ** 0 == 1?. But perhaps someone else has a better explanation for why
Decimal should behave differently from ?int? and ?float? here.

-- 
 \      ?I bought a self learning record to learn Spanish. I turned it |
  `\        on and went to sleep; the record got stuck. The next day I |
_o__)                   could only stutter in Spanish.? ?Steven Wright |
Ben Finney



From davea at davea.name  Thu Jan  8 21:43:40 2015
From: davea at davea.name (Dave Angel)
Date: Thu, 08 Jan 2015 21:43:40 -0500
Subject: Decimals and other numbers
In-Reply-To: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
Message-ID: <54AF405C.6020609@davea.name>

On 01/08/2015 09:33 PM, Devin Jeanpierre wrote:
> I noticed some very PHP-ish behavior today:
>
>>>> import decimal
>>>> x = 0
>>>> y = float(x)
>>>> z = decimal.Decimal(x)
>>>> x == y == z == x
> True
>>>> x ** x
> 1
>>>> y**y
> 1.0
>>>> z**z
> Traceback (most recent call last):
>    File "<stdin>", line 1, in <module>
>    File "/usr/lib/python2.7/decimal.py", line 2216, in __pow__
>      return context._raise_error(InvalidOperation, '0 ** 0')
>    File "/usr/lib/python2.7/decimal.py", line 3872, in _raise_error
>      raise error(explanation)
> decimal.InvalidOperation: 0 ** 0
>
>
> I'd file a bug report but I'm anticipating some rational (heh)
> explanation. Any ideas?
>
> Python 3.4 also raises this exception, but the error message is less
> informative. ("decimal.InvalidOperation: [<class
> 'decimal.InvalidOperation'>]").


What you don't say is which behavior you actually expected.  Since 0**0 
is undefined mathematically, I'd expect either an exception or a NAN result.


-- 
DaveA


From clp2 at rebertia.com  Thu Jan  8 21:53:36 2015
From: clp2 at rebertia.com (Chris Rebert)
Date: Thu, 8 Jan 2015 18:53:36 -0800
Subject: Decimals and other numbers
In-Reply-To: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
Message-ID: <CAMZYqRS53YCF03aoGARdDo0K62tMhGxhthmKk94xL0prThpJ-g@mail.gmail.com>

On Thu, Jan 8, 2015 at 6:33 PM, Devin Jeanpierre <jeanpierreda at gmail.com> wrote:
> I noticed some very PHP-ish behavior today:
>
>>>> import decimal
>>>> x = 0
>>>> y = float(x)
>>>> z = decimal.Decimal(x)
>>>> x == y == z == x
> True
>>>> x ** x
> 1
>>>> y**y
> 1.0
>>>> z**z
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
>   File "/usr/lib/python2.7/decimal.py", line 2216, in __pow__
>     return context._raise_error(InvalidOperation, '0 ** 0')
>   File "/usr/lib/python2.7/decimal.py", line 3872, in _raise_error
>     raise error(explanation)
> decimal.InvalidOperation: 0 ** 0
>
> I'd file a bug report but I'm anticipating some rational (heh)
> explanation. Any ideas?

The `decimal` std lib module implements the General Decimal Arithmetic
Specification (http://speleotrove.com/decimal/decarith.html ).
In the "Exceptional conditions" section
(http://speleotrove.com/decimal/daexcep.html ), it specifies the
following:
    Invalid operation
        This occurs and signals invalid-operation if:
        [...]
        * both operands of the power operation are zero

No idea why it chose to differ from IEEE-754.

Cheers,
Chris


From denismfmcmahon at gmail.com  Thu Jan  8 21:54:00 2015
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Fri, 9 Jan 2015 02:54:00 +0000 (UTC)
Subject: Generate jpg files using line length (pixels) and orientation
 (degrees)
References: <0f51bd21-7b0a-4ea0-8b13-27b1967d3b41@googlegroups.com>
 <m8mv27$k6e$2@dont-email.me>
Message-ID: <m8nfs8$k6e$3@dont-email.me>

On Thu, 08 Jan 2015 22:07:03 +0000, Denis McMahon wrote:

> On Thu, 08 Jan 2015 09:09:18 -0800, semeon.risom wrote:
> 
>> Simple question. I hope. .....

To follow up, below is a solution to the problem you stated.

#!/usr/bin/python

import Image, ImageDraw, math

def makeimg(length, orientation):
    """
    Make an image file of a black 4 pixel wide line of defined length 
    crossing and centered on a white background of 800 px square, save
    as a png file identifying line length and orientation in the file 
    name.
    param length - pixels, length of the line
    param orientation - degrees, orientation ccw of the line from +ve x 
    axis
    Files are saved in imgs subdir, this must already exist.
    File name is image_lll_ooo.jpg
    lll = length, ooo = orientation, both 0 padded to 3 digits
    """

    # check length is +ve and not greater than 800
    if length < 0:
        length = length * -1
    if length > 800:
        length = 800

    # check orientation is positive in range 0 .. 179
    while orientation < 0:
        orientation = orientation + 360
    if orientation > 179:
        orientation = orientation % 180

    # calculate radius in pixels and orientation in radians
    radius = length / 2
    orient = math.radians(orientation)

    # calculate xy coords in image space of line end points
    x1 = int(400 + (radius * math.cos(orient)))
    y1 = int(400 - (radius * math.sin(orient)))
    x2 = int(400 + (-radius * math.cos(orient)))
    y2 = int(400 - (-radius * math.sin(orient)))

    # create an image
    img = Image.new('RGB', (800,800), 'rgb(255, 255, 255)')
    # create a draw interface
    draw = ImageDraw.Draw(img)

    # draw the line on the image
    draw.line([(x1, y1), (x2, y2)], fill='rgb(0, 0, 0)', width=4)

    # determine file name, save image file
    fn = 'imgs/image_{:03d}_{:03d}.jpg'.format(length,orientation)
    img.save(fn)

# stepping through ranges of values
for length in range(100, 601, 100):
    for orientation in range(0, 171, 10):
        makeimg(length, orientation)

# using lists of values
for length in [50, 150, 250, 350, 450, 550, 650]:
    for orientation in [0, 15, 40, 45, 60, 75, 90, 105, 120, 135, 150, 
165]:
        makeimg(length, orientation)




-- 
Denis McMahon, denismfmcmahon at gmail.com


From jeanpierreda at gmail.com  Thu Jan  8 22:02:31 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Thu, 8 Jan 2015 19:02:31 -0800
Subject: Decimals and other numbers
In-Reply-To: <54AF405C.6020609@davea.name>
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
Message-ID: <CABicbJK+zMLs=GV+0rsBw59NfU1rtEQLaT8Z8nXhgwYKKF=jgw@mail.gmail.com>

On Thu, Jan 8, 2015 at 6:43 PM, Dave Angel <davea at davea.name> wrote:
> What you don't say is which behavior you actually expected.  Since 0**0 is
> undefined mathematically, I'd expect either an exception or a NAN result.

It can be undefined, if you choose for it to be. You can also choose
to not define 0**1, of course. If 0**0 is defined, it must be 1. I
Googled around to find a mathematician to back me up, here:
http://arxiv.org/abs/math/9205211 (page 6, "ripples").

I expected 1, nan, or an exception, but more importantly, I expected
it to be the same for floats and decimals.

BTW, Ben, you linked to a file on your hard drive. You meant
https://docs.python.org/2/library/decimal.html#decimal.InvalidOperation

-- Devin


From ben+python at benfinney.id.au  Thu Jan  8 22:03:50 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Fri, 09 Jan 2015 14:03:50 +1100
Subject: Decimals and other numbers
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
Message-ID: <85tx00vend.fsf@benfinney.id.au>

Dave Angel <davea at davea.name> writes:

> What you don't say is which behavior you actually expected.  Since
> 0**0 is undefined mathematically, I'd expect either an exception or a
> NAN result.

Do you think that the ?int? and ?float? types, which do produce a number
result for ?0 ** 0?, are buggy and should be fixed?

I think the inconsistency is unnecessarily confusing. Perhaps the
consistency is in standards outside Python, but I think there is cause
here either for a change of behaviour or, if ther eis a good rationale
for the incompatible behaviours, to document the rationale. In either
case, a bug report is warranted IMO.

-- 
 \     ?We are all agreed that your theory is crazy. The question that |
  `\      divides us is whether it is crazy enough to have a chance of |
_o__)            being correct.? ?Niels Bohr (to Wolfgang Pauli), 1958 |
Ben Finney



From jeanpierreda at gmail.com  Thu Jan  8 22:13:32 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Thu, 8 Jan 2015 19:13:32 -0800
Subject: Decimals and other numbers
In-Reply-To: <85tx00vend.fsf@benfinney.id.au>
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name> <85tx00vend.fsf@benfinney.id.au>
Message-ID: <CABicbJJhFjQ9sd4LudVEFtaFsXDa5VzQipHaMKYAPtZ9rRZo2Q@mail.gmail.com>

Thanks Ben, with your encouragement I have filed
http://bugs.python.org/issue23201

-- Devin

On Thu, Jan 8, 2015 at 7:03 PM, Ben Finney <ben+python at benfinney.id.au> wrote:
> Dave Angel <davea at davea.name> writes:
>
>> What you don't say is which behavior you actually expected.  Since
>> 0**0 is undefined mathematically, I'd expect either an exception or a
>> NAN result.
>
> Do you think that the ?int? and ?float? types, which do produce a number
> result for ?0 ** 0?, are buggy and should be fixed?
>
> I think the inconsistency is unnecessarily confusing. Perhaps the
> consistency is in standards outside Python, but I think there is cause
> here either for a change of behaviour or, if ther eis a good rationale
> for the incompatible behaviours, to document the rationale. In either
> case, a bug report is warranted IMO.
>
> --
>  \     ?We are all agreed that your theory is crazy. The question that |
>   `\      divides us is whether it is crazy enough to have a chance of |
> _o__)            being correct.? ?Niels Bohr (to Wolfgang Pauli), 1958 |
> Ben Finney
>
> --
> https://mail.python.org/mailman/listinfo/python-list


From bclark at es.co.nz  Thu Jan  8 23:10:48 2015
From: bclark at es.co.nz (Brian)
Date: Fri, 09 Jan 2015 04:10:48 GMT
Subject: what is Jython?
Message-ID: <509995943442469175.487823bclark-es.co.nz@free.teranews.com>

I tried to find out more on the internet but didn't have much success. All
I know is that its a combination of Python and Java.
Is it more Java than Python or the other way around?
Is Jython free like Python?
Is the programming language for Jython similar to Python or similar to
Java?
Are there pros and cons then switching from Python to Jython?


-- 
Regards Brian


From rosuav at gmail.com  Thu Jan  8 23:50:20 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 9 Jan 2015 15:50:20 +1100
Subject: what is Jython?
In-Reply-To: <509995943442469175.487823bclark-es.co.nz@free.teranews.com>
References: <509995943442469175.487823bclark-es.co.nz@free.teranews.com>
Message-ID: <CAPTjJmqRkDVd2CFYiT0+BP=M4_h4NF_daJ0fOrButzCx4rM7Ew@mail.gmail.com>

On Fri, Jan 9, 2015 at 3:10 PM, Brian <bclark at es.co.nz> wrote:
> I tried to find out more on the internet but didn't have much success. All
> I know is that its a combination of Python and Java.
> Is it more Java than Python or the other way around?
> Is Jython free like Python?
> Is the programming language for Jython similar to Python or similar to
> Java?
> Are there pros and cons then switching from Python to Jython?

The most common Python interpreter is "CPython", which is the one you
get when you go to the main downloads page on python.org. But Python,
the language, is quite separate from CPython, the implementation, and
there are a number of other implementations of the same language. In
theory, a Python script should run on any Python interpreter. Jython
is a Python interpreter written in Java; IronPython is a Python
interpreter written in C# (I think; uses .NET or Mono, anyway). PyPy
is a Python interpreter written in Python. MicroPython or uPy is a
cut-down Python interpreter designed for embedded systems. Brython is
a Python interpreter designed to go in a web browser.

Jython is free software, just as CPython is. I don't know the details
of the licenses, and IANAL, but I know the intention is that it's free
software. The code you run in Jython will be broadly the same as the
code you'd run in CPython, but some of the modules available in
CPython aren't available in Jython, and vice versa. The main reason
for choosing Jython is that you can load up a Java class and call on
its methods; you can either use an existing Java module and write your
application in Jython, or you can write a module in Jython, compile it
to a .class file, and then load that up from a Java program. With
CPython, on the other hand, it's really easy to interface with C code
(or other languages that compile to machine code), so it's easy to
make use of a typical Unix library.

Jython isn't a combination of Python and Java; it's Python,
implemented in Java. Does that answer your question?

ChrisA


From marko at pacujo.net  Fri Jan  9 01:45:04 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Fri, 09 Jan 2015 08:45:04 +0200
Subject: Decimals and other numbers
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <mailman.17499.1420771441.18130.python-list@python.org>
Message-ID: <87egr41mhb.fsf@elektro.pacujo.net>

Dave Angel <davea at davea.name>:

> What you don't say is which behavior you actually expected. Since 0**0
> is undefined mathematically, I'd expect either an exception or a NAN
> result.

IEEE 754 mandates that 0**0 should evaluate to 1:

   <URL: http://en.wikipedia.org/wiki/NaN#Operations_generating_NaN>

    The standard pow function and the integer exponent pown function
    define 0**0, 1**?, and ?**0 as 1.

    The powr function defines all three indeterminate forms as invalid
    operations and so returns NaN.

Should IEEE 754's anomalies spill over to decimal, is a different
question.


Marko


From dieter at handshake.de  Fri Jan  9 02:01:55 2015
From: dieter at handshake.de (dieter)
Date: Fri, 09 Jan 2015 08:01:55 +0100
Subject: how to create a soap enveloppe with python suds for consume a
 bssv web service
References: <5975f1a8-dc9a-4ab3-b4f4-6e3695f4485a@googlegroups.com>
 <mailman.17467.1420703579.18130.python-list@python.org>
 <06c7101c-a7dc-489e-9cba-935e7e65fc3b@googlegroups.com>
Message-ID: <87oaq8bfoc.fsf@handshake.de>

brice DORA <road01 at yahoo.fr> writes:
> ...
>> "suds" should generate those required "SOAP envelope".
>> 
>> "suds" can be set up to log the precise messages sent and received
>> (consult the "suds" documentation about logging and the Python
>> documentation about its "logging" module). With these messages
>> (and a precise description of the encountered problem), you can
>> contact someone responsible for the web service to resolve your problems.
>
> okey thanks for your help but can you tell me if it's possible to see the content of this soap envelope that's sent by suds?

It is (as I wrote)

>if yes then please how can i do it?thanks you in advance

Read the "suds" documentation
("https://fedorahosted.org/suds/wiki/Documentation"), the
section about logging! It is on the first page, immediately following
the "OVERVIEW" section!



From jyoti690saini at gmail.com  Fri Jan  9 02:17:07 2015
From: jyoti690saini at gmail.com (jyoti690saini at gmail.com)
Date: Thu, 8 Jan 2015 23:17:07 -0800 (PST)
Subject: Array of hash table
Message-ID: <05c22fd5-bfae-4e09-9894-341f468e08dc@googlegroups.com>

Hello,

   Can any one tell me how to create 
   graph={
  "nodes": [
    {
      "id": "n0",
      "label": "A node",
      "x": 0,
      "y": 0,
      "size": 3
    },
    {
      "id": "n1",
      "label": "Another node",
      "x": 3,
      "y": 1,
      "size": 2
    },
    {
      "id": "n2",
      "label": "And a last one",
      "x": 1,
      "y": 3,
      "size": 1
    }
  ],
  "edges": [
    {
      "id": "e0",
      "source": "n0",
      "target": "n1",
      "label" : "dfghujikoi"
    },
    {
      "id": "e1",
      "label" : "dfghujikoi",
      "source": "n1",
      "target": "n2"
      
    },
    {
      "id": "e2",
      "source": "n2",
      "target": "n0",
      "label" : "dfghujikoi"
    }
  ]
}

using python?

its like a hash table and value is an array of hash table ?
I tried but it was giving error of "List out of index" .


From marko at pacujo.net  Fri Jan  9 02:28:23 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Fri, 09 Jan 2015 09:28:23 +0200
Subject: Decimals and other numbers
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
Message-ID: <87a91s1kh4.fsf@elektro.pacujo.net>

Devin Jeanpierre <jeanpierreda at gmail.com>:

> If 0**0 is defined, it must be 1.

You can "justify" any value a within [0, 1]. For example, choose

   y(a, x) = log(a, x)

Then,

    lim    y(a, x) = 0
   x -> 0+

and:

   lim[x -> 0+] x**y(a, x) = a

For example,

   >>> a = 0.5
   >>> x = 1e-100
   >>> y = math.log(a, x)
   >>> y
   0.0030102999566398118
   >>> x**y
   0.5


Marko


From davea at davea.name  Fri Jan  9 02:30:53 2015
From: davea at davea.name (Dave Angel)
Date: Fri, 09 Jan 2015 02:30:53 -0500
Subject: Array of hash table
In-Reply-To: <05c22fd5-bfae-4e09-9894-341f468e08dc@googlegroups.com>
References: <05c22fd5-bfae-4e09-9894-341f468e08dc@googlegroups.com>
Message-ID: <54AF83AD.3080201@davea.name>

On 01/09/2015 02:17 AM, jyoti690saini at gmail.com wrote:
> Hello,
>
>     Can any one tell me how to create
>     graph={
>    "nodes": [
>      {
>        "id": "n0",
>        "label": "A node",
>        "x": 0,
>        "y": 0,
>        "size": 3
>      },
>      {
>        "id": "n1",
>        "label": "Another node",
>        "x": 3,
>        "y": 1,
>        "size": 2
>      },
>      {
>        "id": "n2",
>        "label": "And a last one",
>        "x": 1,
>        "y": 3,
>        "size": 1
>      }
>    ],
>    "edges": [
>      {
>        "id": "e0",
>        "source": "n0",
>        "target": "n1",
>        "label" : "dfghujikoi"
>      },
>      {
>        "id": "e1",
>        "label" : "dfghujikoi",
>        "source": "n1",
>        "target": "n2"
>
>      },
>      {
>        "id": "e2",
>        "source": "n2",
>        "target": "n0",
>        "label" : "dfghujikoi"
>      }
>    ]
> }
>
> using python?
>
> its like a hash table and value is an array of hash table ?
> I tried but it was giving error of "List out of index" .
>

You just did.  If you'd like to see it, add a print(graph) .  What's 
your real question?

BTW, in Python, it's called a dict, not a hash table.  But you did it 
correctly.

And if you want to fetch a particular element, use:

print(graph["edges"][1]["id"])

-- 
DaveA


From rosuav at gmail.com  Fri Jan  9 02:37:45 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 9 Jan 2015 18:37:45 +1100
Subject: Decimals and other numbers
In-Reply-To: <87a91s1kh4.fsf@elektro.pacujo.net>
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <87a91s1kh4.fsf@elektro.pacujo.net>
Message-ID: <CAPTjJmrhZYw9vBhN6TUMuqFCL48SMNgSAYhAi5u27R4HWaDmUg@mail.gmail.com>

On Fri, Jan 9, 2015 at 6:28 PM, Marko Rauhamaa <marko at pacujo.net> wrote:
> Devin Jeanpierre <jeanpierreda at gmail.com>:
>
>> If 0**0 is defined, it must be 1.
>
> You can "justify" any value a within [0, 1]. For example, choose
>
>    y(a, x) = log(a, x)
>
> Then,
>
>     lim    y(a, x) = 0
>    x -> 0+
>
> and:
>
>    lim[x -> 0+] x**y(a, x) = a
>
> For example,
>
>    >>> a = 0.5
>    >>> x = 1e-100
>    >>> y = math.log(a, x)
>    >>> y
>    0.0030102999566398118
>    >>> x**y
>    0.5

I'm not a mathematical expert, so I don't quite 'get' this. How does
this justify 0**0 being equal to 0.5?

I know how to justify 0 and 1, and NaN (on the basis that both 0 and 1
can be justified). I don't follow how other values can be used.

ChrisA


From davea at davea.name  Fri Jan  9 02:49:27 2015
From: davea at davea.name (Dave Angel)
Date: Fri, 09 Jan 2015 02:49:27 -0500
Subject: Decimals and other numbers
In-Reply-To: <CAPTjJmrhZYw9vBhN6TUMuqFCL48SMNgSAYhAi5u27R4HWaDmUg@mail.gmail.com>
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <87a91s1kh4.fsf@elektro.pacujo.net>
 <CAPTjJmrhZYw9vBhN6TUMuqFCL48SMNgSAYhAi5u27R4HWaDmUg@mail.gmail.com>
Message-ID: <54AF8807.3080804@davea.name>

On 01/09/2015 02:37 AM, Chris Angelico wrote:
> On Fri, Jan 9, 2015 at 6:28 PM, Marko Rauhamaa <marko at pacujo.net> wrote:
>> Devin Jeanpierre <jeanpierreda at gmail.com>:
>>
>>> If 0**0 is defined, it must be 1.
>>
>> You can "justify" any value a within [0, 1]. For example, choose
>>
>>     y(a, x) = log(a, x)
>>
>> Then,
>>
>>      lim    y(a, x) = 0
>>     x -> 0+
>>
>> and:
>>
>>     lim[x -> 0+] x**y(a, x) = a
>>
>> For example,
>>
>>     >>> a = 0.5
>>     >>> x = 1e-100
>>     >>> y = math.log(a, x)
>>     >>> y
>>     0.0030102999566398118
>>     >>> x**y
>>     0.5
>
> I'm not a mathematical expert, so I don't quite 'get' this. How does
> this justify 0**0 being equal to 0.5?
>
> I know how to justify 0 and 1, and NaN (on the basis that both 0 and 1
> can be justified). I don't follow how other values can be used.

Roughly speaking, the idea is to have a relationship between x and y, 
such that even though they each get arbitrarily close to zero, the 
formula x**y is a constant 5.

So he plugged in 1e-100.  But if you plugged in 1e-500000000  and could 
handle the precision, the result x**y  would still be 0.5




-- 
DaveA


From __peter__ at web.de  Fri Jan  9 02:55:37 2015
From: __peter__ at web.de (Peter Otten)
Date: Fri, 09 Jan 2015 08:55:37 +0100
Subject: Array of hash table
References: <05c22fd5-bfae-4e09-9894-341f468e08dc@googlegroups.com>
Message-ID: <m8o1hq$bu1$1@ger.gmane.org>

jyoti690saini at gmail.com wrote:

> Hello,
> 
>    Can any one tell me how to create
>    graph={
>   "nodes": [
>     {
>       "id": "n0",
>       "label": "A node",
>       "x": 0,
>       "y": 0,
>       "size": 3
>     },
>     {
>       "id": "n1",
>       "label": "Another node",
>       "x": 3,
>       "y": 1,
>       "size": 2
>     },
>     {
>       "id": "n2",
>       "label": "And a last one",
>       "x": 1,
>       "y": 3,
>       "size": 1
>     }
>   ],
>   "edges": [
>     {
>       "id": "e0",
>       "source": "n0",
>       "target": "n1",
>       "label" : "dfghujikoi"
>     },
>     {
>       "id": "e1",
>       "label" : "dfghujikoi",
>       "source": "n1",
>       "target": "n2"
>       
>     },
>     {
>       "id": "e2",
>       "source": "n2",
>       "target": "n0",
>       "label" : "dfghujikoi"
>     }
>   ]
> }
> 
> using python?
> 
> its like a hash table and value is an array of hash table ?
> I tried but it was giving error of "List out of index" .

(1) Was that something like

>>> [][1]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
IndexError: list index out of range

? Please always copy and paste the traceback, don't rephrase.

(2) Show us the code that caused the error. If you provide some context it 
is easier for us to identify your problem. But if I were to guess: are you 
coming from a language where lists grow automatically? In Python they don't.

Instead of

mylist = []
for i in range(3):
   mylist[i] = 42 # WRONG, raises IndexError

you usually write

mylist = []
for i in range(3):
   mylist.append(42)

though in this particular case

mylist = [42] * 3

would work, too.



From steve+comp.lang.python at pearwood.info  Fri Jan  9 03:49:21 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 09 Jan 2015 19:49:21 +1100
Subject: Decimals and other numbers
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
Message-ID: <54af9612$0$12995$c3e8da3$5496439d@news.astraweb.com>

Devin Jeanpierre wrote:

> On Thu, Jan 8, 2015 at 6:43 PM, Dave Angel <davea at davea.name> wrote:
>> What you don't say is which behavior you actually expected.  Since 0**0
>> is undefined mathematically, I'd expect either an exception or a NAN
>> result.
> 
> It can be undefined, if you choose for it to be. You can also choose
> to not define 0**1, of course. 

No you can't -- that would make arithmetic inconsistent. 0**1 is perfectly
well defined as 0 however you look at it:

lim of x -> 0 of x**1 = 0
lim of y -> 1 of 0**y = 0


> If 0**0 is defined, it must be 1. I 
> Googled around to find a mathematician to back me up, here:
> http://arxiv.org/abs/math/9205211 (page 6, "ripples").

Not quite. I agree that, *generally speaking* having 0**0 equal 1 is the
right answer, or at least *a* right answer, but not always. It depends on
how you get to 0**0...

Since you can get difference results depending on the method you use to
calculate it, the "technically correct" result is that 0**0 is
indeterminate. But that's not terribly useful, and mathematicians with a
pragmatic bent (i.e. most of them) define 0**0 == 1 on the basis that it is
justifiable and useful, while 0**0 = 0 is justifiable but not useful and
leaving it as indeterminate is just a pain.

One argument comes from taking limits of x**y. If you set x to zero, and
take the limit as y approaches 1, you get:

lim of y -> 0 of 0**y = 0

But if you set y to 0, and take the limit as x approaches 0, you get:

lim of x -> 0 of x**0 = 1

There is a discontinuity in the graph of x**y, and no matter what value you
define 0**0 as, you cannot get rid of that discontinuity. Hence
indeterminate.

Here's another argument for keeping it indeterminate. Suppose we let 0**0 =
some value Q. Let's take the logarithm of Q.

log(Q) = log (0**0)

But log (a**b) = b*log(a), so:

log(Q) = 0*log(0)

What's log(0)? If we take the limit from above, we get log(x) -> -infinity.
If we take the limit from below, we get a complex infinity, so let's ignore
the limit from below and informally write:

log(Q) = 0*-inf

What is zero times infinity? In the real number system, that is
indeterminate, again because it depends on how you calculate it: naively it
sounds like it should be 0, but infinity is pretty big and if you add up
enough zeroes in the right way you can actually get something non-zero.
There's no one right answer. So if the log of Q is indeterminate, then so
must be Q.

But there are a host of good reasons for preferring 0**0 = 1. Donald Knuth
writes (using ^ for power):

    Some textbooks leave the quantity 0^0 undefined, because the 
    functions 0^x and x^0 have different limiting values when x 
    decreases to 0. But this is a mistake. We must define x^0=1 
    for all x , if the binomial theorem is to be valid when x=0, 
    y=0, and/or x=-y. The theorem is too important to be arbitrarily
    restricted! By contrast, the function 0^x is quite unimportant.

More discussion here:

http://mathforum.org/dr.math/faq/faq.0.to.0.power.html


> I expected 1, nan, or an exception, but more importantly, I expected
> it to be the same for floats and decimals.

Arguably, *integer* 0**0 could be zero, on the basis that you can't take
limits of integer-valued quantities, and zero times itself zero times
surely has to be zero.

But in practice, I agree that 0**0 should give the same result regardless of
the type of zeroes used, and if the result is a number rather than a NAN or
an exception, it should be 1.




-- 
Steven



From jeanpierreda at gmail.com  Fri Jan  9 03:51:51 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Fri, 9 Jan 2015 00:51:51 -0800
Subject: Decimals and other numbers
In-Reply-To: <87a91s1kh4.fsf@elektro.pacujo.net>
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <87a91s1kh4.fsf@elektro.pacujo.net>
Message-ID: <CABicbJKTQKni-9seVDNE6kUVbk5XtFuKjye28y4gKWQkJLB01Q@mail.gmail.com>

Marko, your argument is "this function x**y(a, x) must be continuous
on [0, inf), and to be continuous at 0, 0**0 must be a". Since there
are many possible values of a, this is not a "justification", this is
a proof by contradiction that the premise was faulty: x**y(a, x)
doesn't have to be continuous after all.

0**0 is 1, which makes some functions continuous and some functions
not, and who cares? It's 1 because that's what is demanded by
combinatorial definitions of exponentiation, and its origins in the
domain of the natural numbers.  Knuth says that thought of
combinatorially on the naturals, x**y counts the number of mappings
from a set of x values to a set of y values. Clearly there's only one
mapping from the empty set to itself: the empty mapping. Number theory
demands that performing multiplication among an empty bag of numbers
gives you the result of 1 -- even if the empty bag is an empty bag of
zeroes instead of an empty bag of fives. The result does not change.

Either of those ideas about exponentiation can be thought of as
descriptions of its behavior, or as definitions. They completely
describe its behavior on the naturals, from which we derive its
behavior on the reals.

-- Devin

On Thu, Jan 8, 2015 at 11:28 PM, Marko Rauhamaa <marko at pacujo.net> wrote:
> Devin Jeanpierre <jeanpierreda at gmail.com>:
>
>> If 0**0 is defined, it must be 1.
>
> You can "justify" any value a within [0, 1]. For example, choose
>
>    y(a, x) = log(a, x)
>
> Then,
>
>     lim    y(a, x) = 0
>    x -> 0+
>
> and:
>
>    lim[x -> 0+] x**y(a, x) = a
>
> For example,
>
>    >>> a = 0.5
>    >>> x = 1e-100
>    >>> y = math.log(a, x)
>    >>> y
>    0.0030102999566398118
>    >>> x**y
>    0.5
>
>
> Marko
> --
> https://mail.python.org/mailman/listinfo/python-list


From jeanpierreda at gmail.com  Fri Jan  9 03:58:47 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Fri, 9 Jan 2015 00:58:47 -0800
Subject: Decimals and other numbers
In-Reply-To: <54af9612$0$12995$c3e8da3$5496439d@news.astraweb.com>
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <54af9612$0$12995$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CABicbJLjogfGFgz5zn1v-y-nQ0QJzpfrRR_ScEm7jEtiNdrMXg@mail.gmail.com>

On Fri, Jan 9, 2015 at 12:49 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Devin Jeanpierre wrote:
>
>> On Thu, Jan 8, 2015 at 6:43 PM, Dave Angel <davea at davea.name> wrote:
>>> What you don't say is which behavior you actually expected.  Since 0**0
>>> is undefined mathematically, I'd expect either an exception or a NAN
>>> result.
>>
>> It can be undefined, if you choose for it to be. You can also choose
>> to not define 0**1, of course.
>
> No you can't -- that would make arithmetic inconsistent. 0**1 is perfectly
> well defined as 0 however you look at it:
>
> lim of x -> 0 of x**1 = 0
> lim of y -> 1 of 0**y = 0

This is a misunderstanding of limits. Limits are allowed to differ
from the actual evaluated result when you substitute the limit point:
that's what it means to be discontinuous.

What you call making  arithmetic "inconsistent", I call making the
function inside the limit discontinuous at 0.

>
>> If 0**0 is defined, it must be 1. I
>> Googled around to find a mathematician to back me up, here:
>> http://arxiv.org/abs/math/9205211 (page 6, "ripples").
>
> Not quite. I agree that, *generally speaking* having 0**0 equal 1 is the
> right answer, or at least *a* right answer, but not always. It depends on
> how you get to 0**0...

You don't "get to" a number. Those are limits. Limits and arithmetic
are different.

(Well, sort of. :)

> Since you can get difference results depending on the method you use to
> calculate it, the "technically correct" result is that 0**0 is
> indeterminate.

No, only limits are indeterminate. Calculations not involving limits
cannot be indeterminate.

-snip-
> log(Q) = 0*-inf
>
> What is zero times infinity? In the real number system, that is
> indeterminate, again because it depends on how you calculate it

In the real number system, infinity does not exist. It only exists in
limits or extended number systems.

> : naively it
> sounds like it should be 0, but infinity is pretty big and if you add up
> enough zeroes in the right way you can actually get something non-zero.
> There's no one right answer. So if the log of Q is indeterminate, then so
> must be Q.
>
> But there are a host of good reasons for preferring 0**0 = 1. Donald Knuth
> writes (using ^ for power):
>
>     Some textbooks leave the quantity 0^0 undefined, because the
>     functions 0^x and x^0 have different limiting values when x
>     decreases to 0. But this is a mistake. We must define x^0=1
>     for all x , if the binomial theorem is to be valid when x=0,
>     y=0, and/or x=-y. The theorem is too important to be arbitrarily
>     restricted! By contrast, the function 0^x is quite unimportant.
>
> More discussion here:
>
> http://mathforum.org/dr.math/faq/faq.0.to.0.power.html

I've already been citing Knuth. :P

>> I expected 1, nan, or an exception, but more importantly, I expected
>> it to be the same for floats and decimals.
>
> Arguably, *integer* 0**0 could be zero, on the basis that you can't take
> limits of integer-valued quantities, and zero times itself zero times
> surely has to be zero.

No. No no no. On natural numbers no other thing makes sense than 1.
All of the definitions of exponentiation for natural numbers require
it, except for those derived from analytical notions of
exponentiation. (Integers just give you ratios of natural
exponentials, so again no.)

-- Devin


From alister.nospam.ware at ntlworld.com  Fri Jan  9 04:05:53 2015
From: alister.nospam.ware at ntlworld.com (alister)
Date: Fri, 09 Jan 2015 09:05:53 GMT
Subject: Announce: PyPrimes 0.2.1a
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <54af0564$0$2919$e4fe514c@news.xs4all.nl>
 <54af23bc$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17490.1420764635.18130.python-list@python.org>
Message-ID: <RRMrw.501973$p95.379573@fx38.am4>

On Fri, 09 Jan 2015 11:50:26 +1100, Chris Angelico wrote:

> On Fri, Jan 9, 2015 at 11:41 AM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> "oh, pip did the wrong thing again? you can fix that by standing on one
>> leg,
>> sacrificing a goat to the Great Old Dark Ones, deleting these files, or
>> possibly some other ones, and if the phase of the moon is exactly right
>> it will behave as you want..."
> 
> Replacing an existing package, without changing the version number,
> *is* messy. It's not pip's fault that it's hard. That's like saying
> "Oops, I committed this to source control and pushed it out to all
> users, but there's a big file in it and I want to delete it so they
> don't have to download it". Sure, that's possible, but it's not a normal
> action, so you'll have to jump through some hoops to make it all work
> properly.
> 
> Or have you been having this whole sacrificing a goat thing with a
> normal workflow?
> 
> ChrisA

why not simply cheat & call it V 0.2.3 :-) it is not as if there is any 
regulation concerning what can & cannot constitute a minor release it is 
all at your own discretion.




-- 
Stamp out philately.


From jpiitula at ling.helsinki.fi  Fri Jan  9 04:07:51 2015
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 09 Jan 2015 11:07:51 +0200
Subject: Decimals and other numbers
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <87a91s1kh4.fsf@elektro.pacujo.net>
 <mailman.17512.1420793559.18130.python-list@python.org>
Message-ID: <qotr3v49va0.fsf@ruuvi.it.helsinki.fi>

Devin Jeanpierre writes:

[...]

> domain of the natural numbers.  Knuth says that thought of
> combinatorially on the naturals, x**y counts the number of mappings
> from a set of x values to a set of y values.

It's the other way around, of course: from a set of y values to a set
of x values.

Which reminds me of a question that once made me smile, even laugh,
and still does: 2**3 is almost 3**2 but not quite - what gives?

> Clearly there's only one mapping from the empty set to itself: the

[...]


From jeanpierreda at gmail.com  Fri Jan  9 04:11:21 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Fri, 9 Jan 2015 01:11:21 -0800
Subject: Decimals and other numbers
In-Reply-To: <CABicbJLjogfGFgz5zn1v-y-nQ0QJzpfrRR_ScEm7jEtiNdrMXg@mail.gmail.com>
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <54af9612$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <CABicbJLjogfGFgz5zn1v-y-nQ0QJzpfrRR_ScEm7jEtiNdrMXg@mail.gmail.com>
Message-ID: <CABicbJKJfVwGY3byHaq--sDe7JRZ5pS6O9DPAiJN3-fiQb-Nvw@mail.gmail.com>

On Fri, Jan 9, 2015 at 12:58 AM, Devin Jeanpierre
<jeanpierreda at gmail.com> wrote:
>> Arguably, *integer* 0**0 could be zero, on the basis that you can't take
>> limits of integer-valued quantities, and zero times itself zero times
>> surely has to be zero.

I should have responded in more detail here, sorry.

If you aren't performing any multiplication, why does it matter what
numbers you are "multiplying"? Doing no multiplications of five is the
same as doing no multiplications of two is the same as doing no
multiplications of... 0.

You can define it to be 0 but only if you are multiplying an empty bag
of zeroes, but it's hard to imagine what makes an empty bag of zeroes
different from an empty bag of fives. It really surely is *not* the
case.

Obviously, this kind of ridiculousness comes naturally to Java and C++
programmers, with their statically typed collections. It's no surprise
that's where the Decimal spec came from. ;)

-- Devin


From sirak2010 at gmail.com  Fri Jan  9 04:24:46 2015
From: sirak2010 at gmail.com (sirak2010 at gmail.com)
Date: Fri, 9 Jan 2015 01:24:46 -0800 (PST)
Subject: py2c - an open source Python to C/C++ is looking for developers
In-Reply-To: <16816fd5-c6b4-49df-baf0-e0bfb0d999df@googlegroups.com>
References: <16816fd5-c6b4-49df-baf0-e0bfb0d999df@googlegroups.com>
Message-ID: <f0aa8e16-7d10-410b-bfb0-c741a955717c@googlegroups.com>

On Monday, July 30, 2012 at 6:27:04 AM UTC-7, Ramchandra Apte wrote:
> I created py2c ( http://code.google.com/p/py2c )- an open source Python to C/C++ translator!
> py2c is looking for developers!
> To join create a posting in the py2c-discuss Google Group or email me!
> Thanks
> PS:I hope this is the appropiate group for this message.

this is actually a great project, because i see a lot of programmers embedding the whole python into their c++ application even the python compiler and all its libraries. and i hope this could solve that problem one day... look what matlab did  matlab to C/C++ which is great and what python was missing was that feature. python is so good for algorithm development and c/c++ is so easy for machines to execute.


From marko at pacujo.net  Fri Jan  9 04:31:09 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Fri, 09 Jan 2015 11:31:09 +0200
Subject: Decimals and other numbers
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <87a91s1kh4.fsf@elektro.pacujo.net>
 <mailman.17509.1420789074.18130.python-list@python.org>
Message-ID: <87oaq8e1wi.fsf@elektro.pacujo.net>

Chris Angelico <rosuav at gmail.com>:

> I'm not a mathematical expert, so I don't quite 'get' this. How does
> this justify 0**0 being equal to 0.5?

Many operations like this are defined in terms of some very strong
argument of uniqueness. Ultimately, the key point is safety in
mathematical deductions. One minimal requirement would be:

         lim        f(x, y)
   (x, y) -> (0, 0)

must be defined (See <URL: http://en.wikipedia.org/wiki/Limit_of_a_func
tion#Functions_of_more_than_one_variable>).

If you get sloppy, there is a real risk of terrible logical mistakes and
wrong results. I think having 0**0 return a value is as irresponsible as
having 0/0 return a value.

(The very same principle is used to define 0+0 and 0*0 as well.)


Marko


From marko at pacujo.net  Fri Jan  9 04:34:02 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Fri, 09 Jan 2015 11:34:02 +0200
Subject: Decimals and other numbers
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <54af9612$0$12995$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <87k30we1rp.fsf@elektro.pacujo.net>

Steven D'Aprano <steve+comp.lang.python at pearwood.info>:

> mathematicians with a pragmatic bent

You shouldn't call engineers and scientists mathematicians ("with a
pragmatic bent"). Rigor is an absolute requirement for any mathematics.


Marko


From marko at pacujo.net  Fri Jan  9 04:44:48 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Fri, 09 Jan 2015 11:44:48 +0200
Subject: Decimals and other numbers
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <54af9612$0$12995$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <87fvbke19r.fsf@elektro.pacujo.net>

Steven D'Aprano <steve+comp.lang.python at pearwood.info>:

> Devin Jeanpierre wrote:
> No you can't -- that would make arithmetic inconsistent. 0**1 is
> perfectly well defined as 0 however you look at it:

You *could* leave 0**1 undefined. You *could* leave 7+0 undefined.
However, that would make mathematical proofs more complex as they would
be riddled with if/else branches.

That's the whole point of silly "no-op" definitions such as a+0 or b**1;
they make mathematical proofs much more concise and feasible. It is
precious to be able to have such "ideal" cases defined, and you'd like
to do it everywhere. Unfortunately, it is not possible everywhere so you
just have to supply the necessary if/else branches in your proof.


Marko


From steve+comp.lang.python at pearwood.info  Fri Jan  9 05:20:10 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 09 Jan 2015 21:20:10 +1100
Subject: Decimals and other numbers
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <54af9612$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17513.1420793970.18130.python-list@python.org>
Message-ID: <54afab5d$0$12976$c3e8da3$5496439d@news.astraweb.com>

I think we're in violent agreement here, nevertheless I think you're right
for the wrong reasons. See below...


Devin Jeanpierre wrote:

> On Fri, Jan 9, 2015 at 12:49 AM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> Devin Jeanpierre wrote:
>>
>>> On Thu, Jan 8, 2015 at 6:43 PM, Dave Angel <davea at davea.name> wrote:
>>>> What you don't say is which behavior you actually expected.  Since 0**0
>>>> is undefined mathematically, I'd expect either an exception or a NAN
>>>> result.
>>>
>>> It can be undefined, if you choose for it to be. You can also choose
>>> to not define 0**1, of course.
>>
>> No you can't -- that would make arithmetic inconsistent. 0**1 is
>> perfectly well defined as 0 however you look at it:
>>
>> lim of x -> 0 of x**1 = 0
>> lim of y -> 1 of 0**y = 0

I should have used "x" for the variable in both expressions:

lim of x -> 0 of x**1 = 0
lim of x -> 1 of 0**x = 0

 
> This is a misunderstanding of limits. Limits are allowed to differ
> from the actual evaluated result when you substitute the limit point:
> that's what it means to be discontinuous.

That's true, if the function is discontinuous. But it's irrelevant here.
Neither x**1 nor 0**x are discontinuous, they're both continuous, and both
have the same limit for x->0 in the first place and x->1 in the second.
However you do it, 0**1 must be 0.


> What you call making  arithmetic "inconsistent", I call making the
> function inside the limit discontinuous at 0.

I don't understand what you're trying to say here. You can't just
arbitrarily declare that 0**1 equals something other than 0 (or for that
matter, doesn't equal anything at all). 

0**1 = (5-5)**1 = 5-5 = 0

If you want to say that 0**1 != 0, then you likewise have to say that 
5-5 != 0, otherwise arithmetic is inconsistent.

Can we agree that 0**1 is well-defined and get back to 0**0?


>>> If 0**0 is defined, it must be 1. I
>>> Googled around to find a mathematician to back me up, here:
>>> http://arxiv.org/abs/math/9205211 (page 6, "ripples").
>>
>> Not quite. I agree that, *generally speaking* having 0**0 equal 1 is the
>> right answer, or at least *a* right answer, but not always. It depends on
>> how you get to 0**0...
> 
> You don't "get to" a number. Those are limits. Limits and arithmetic
> are different.
> 
> (Well, sort of. :)

Yes, sort of :-)

Of course you can "get to" numbers. We start with counting, that's a way
to "get to" the natural numbers, by applying the "successor" function
repeatedly until we reach the one we want. Or you can "get to" pi by
generating an infinite sequence of closer and closer approximations. Or an
infinite series. Or an infinite product. Or an infinite continued fraction.
All of these "ways to get to pi" converge on the same result.

If 0**0 has a value, we can give that number a name. Let's call it Q. There
are different ways to evaluate Q:

lim x -> 0 of sin(x)/x  gives 1

lim x -> 0 of x**0  gives 1

lim x -> 0 of 0**x  gives 0

0**0 = 0**(5-5) = 0**5 / 0**5 = 0/0  gives indeterminate


So we have a problem. Since all these "ways to get to Q" fail to converge,
the obvious answer is to declare that Q doesn't exist and that 0**0 is
indeterminate, and that is what many mathematicians do:

http://mathworld.wolfram.com/Indeterminate.html

However, this begs the question of what we mean by 0**0.

In the case of m**n, with both m and n positive integers, there is an
intuitively obvious definition for exponentiation: repeated multiplication.
But there's no obvious meaning for exponentiation when both m and n are
zero, hence we (meaning, mathematicians) have to define what it means. So
long as that definition doesn't lead to contradiction, we can make any
choice we like.

Hence some mathematicians decide that things like the Binomial Theorem are
far more important than 0**x, and so they define 0**0 as 1. They can
justify that definition, of course, it's not just arbitrary, but the
important thing is that mathematicians working in other fields can and do
sometimes use a slightly different definition, one where 0**0 is
indeterminate.

http://www.askamathematician.com/2010/12/q-what-does-00-zero-raised-to-the-zeroth-power-equal-why-do-mathematicians-and-high-school-teachers-disagree/


>> Since you can get difference results depending on the method you use to
>> calculate it, the "technically correct" result is that 0**0 is
>> indeterminate.
> 
> No, only limits are indeterminate. Calculations not involving limits
> cannot be indeterminate.

Do tell me what 0/0 equals, if it is not indeterminate.


> -snip-
>> log(Q) = 0*-inf
>>
>> What is zero times infinity? In the real number system, that is
>> indeterminate, again because it depends on how you calculate it
> 
> In the real number system, infinity does not exist. It only exists in
> limits or extended number systems.

Yes, you are technically correct, the best kind of correct.

I'm just sketching an informal proof. If you want to make it vigorous by
using limits, be my guest. It doesn't change the conclusion.


[...]
>> Arguably, *integer* 0**0 could be zero, on the basis that you can't take
>> limits of integer-valued quantities, and zero times itself zero times
>> surely has to be zero.
> 
> No. No no no. On natural numbers no other thing makes sense than 1.

On the basis that m**n means m multiplied by itself n times:

5**4 = 5*5*5*5 = 625

that gives us:

0**0 = zero multiplied by itself zero times.

You can multiply 0 by any number you like, and the answer will always be 0,
not 1. Even if that other number is 0, the answer is still 0. 


> All of the definitions of exponentiation for natural numbers require
> it, except for those derived from analytical notions of
> exponentiation. (Integers just give you ratios of natural
> exponentials, so again no.)


As I started this post, we are in agreement that for a programming language,
having float and decimal 0**0 give different results is rather strange, and
like you I would prefer the answer given to be 1. As far as I am
concerned, "Knuth says so" is enough justification :-)



-- 
Steven



From rosuav at gmail.com  Fri Jan  9 05:39:35 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 9 Jan 2015 21:39:35 +1100
Subject: Decimals and other numbers
In-Reply-To: <54afab5d$0$12976$c3e8da3$5496439d@news.astraweb.com>
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <54af9612$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17513.1420793970.18130.python-list@python.org>
 <54afab5d$0$12976$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmqfpjUjcR8h6=6F-FHviG6QUxPB-x-HWoiUitwhNM8ySg@mail.gmail.com>

On Fri, Jan 9, 2015 at 9:20 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> On the basis that m**n means m multiplied by itself n times:
>
> 5**4 = 5*5*5*5 = 625
>
> that gives us:
>
> 0**0 = zero multiplied by itself zero times.
>
> You can multiply 0 by any number you like, and the answer will always be 0,
> not 1. Even if that other number is 0, the answer is still 0.

5 * 0 * 0 * 0 * 0 = 0

You can multiply 5 by 0 any number of times you like, and the answer
will always be 0... unless you never multiply it by 0 at all, in which
case it'll be 5. Multiplying 0 by any number, including 0, is 0... but
*not* multiplying 0 by 0 doesn't have to give 0. 0**0 is the result of
not multiplying any zeroes together, so it doesn't follow the rules of
multiplying zeroes together.

Look at it another way. 6**x modulo 10 will always be 6, right? 6, 36,
216... the rules for multiplying mean that the last digit will be
consistent. (That's how we can know what the last digits of Graham's
Number are, despite having no way to even comprehend its scale.) So
what's 6**0? Is that going to end with 6, too, to be consistent? No,
because we're not multiplying any sixes in, so the answer's simply 1.

ChrisA


From stephane at wirtel.be  Fri Jan  9 05:44:46 2015
From: stephane at wirtel.be (=?utf-8?q?St=C3=A9phane?= Wirtel)
Date: Fri, 09 Jan 2015 11:44:46 +0100
Subject: PythonFOSDEM 2015 and Plush Snake
Message-ID: <526E5C5C-A365-4778-B06E-46439B06E3EB@wirtel.be>

Hi all,

I am really happy to announce we found a correct plush snake for Python.

There is a survey and a post about this plush: 
http://pythonfosdem.tumblr.com/post/107584468521/survey-will-you-be-interested-by-a-plush-snake

If you come at PythonFOSDEM 2015 and you think you will buy this snake, 
please, fill the survey.

The minimal quantity for this item is 48 for the supplier, and I need to 
know an approximative quantity for PythonFOSDEM.

Thank you,

Stephane

--
St?phane Wirtel - http://wirtel.be - @matrixise


From steve+comp.lang.python at pearwood.info  Fri Jan  9 05:56:44 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 09 Jan 2015 21:56:44 +1100
Subject: Why do the URLs of posts here change?
Message-ID: <54afb3ed$0$12995$c3e8da3$5496439d@news.astraweb.com>

I have come across this in the past, but today it annoyed me enough that I'm
asking for an explanation.

Posts on this newsgroup/mailing list are archived on the web, but the URLs
seem to change, which leaves dead links if you search for things.

For example, today I searched for a quote about floating point equality by
William Kahan, and I came across this post by me:

https://mail.python.org/pipermail/python-list/2008-February/468598.html

But that's a dead link! Here's Google's cache of it:

http://webcache.googleusercontent.com/search?client=opera&rls=en&q=cache:i0cWb0Tjxe0J:https://mail.python.org/pipermail/python-list/2008-February/468598.html%2Bfloating+point+superstition+equality&oe=utf-8&channel=suggest&gws_rd=ssl&hl=en&&ct=clnk

And here is the actual URL, as it appears today:

https://mail.python.org/pipermail/python-list/2008-February/481374.html


Why has the URL changed? Surely this is a bug? Where can I report it?




-- 
Steven



From ben+python at benfinney.id.au  Fri Jan  9 06:01:38 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Fri, 09 Jan 2015 22:01:38 +1100
Subject: Announce: PyPrimes 0.2.1a
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <54af0564$0$2919$e4fe514c@news.xs4all.nl>
 <54af23bc$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17490.1420764635.18130.python-list@python.org>
 <RRMrw.501973$p95.379573@fx38.am4>
Message-ID: <85ppaousj1.fsf@benfinney.id.au>

alister <alister.nospam.ware at ntlworld.com> writes:

> why not simply cheat & call it V 0.2.3 :-) it is not as if there is
> any regulation concerning what can & cannot constitute a minor release
> it is all at your own discretion.

Not a regulation, but a convention which it is good etiquette to follow
<URL:http://semver.org/>. Version strings are a communication, and
communication is only useful if conventions of meaning are more or less
reliable.

-- 
 \        ?I hate it when my foot falls asleep during the day, because |
  `\            that means it's gonna be up all night.? ?Steven Wright |
_o__)                                                                  |
Ben Finney



From steve+comp.lang.python at pearwood.info  Fri Jan  9 06:03:39 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 09 Jan 2015 22:03:39 +1100
Subject: Decimals and other numbers
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <54af9612$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <87k30we1rp.fsf@elektro.pacujo.net>
Message-ID: <54afb58c$0$13010$c3e8da3$5496439d@news.astraweb.com>

Marko Rauhamaa wrote:

> Steven D'Aprano <steve+comp.lang.python at pearwood.info>:
> 
>> mathematicians with a pragmatic bent
> 
> You shouldn't call engineers and scientists mathematicians ("with a
> pragmatic bent"). Rigor is an absolute requirement for any mathematics.

I wasn't referring to engineers, scientists, short-order cooks or cat walk
models. I was referring to mathematicians.

Mathematicians with a pragmatic bent. Or to put it another way, the
intersection between the set of pragmatic people and the set of
mathematicians.




-- 
Steven



From alister.nospam.ware at ntlworld.com  Fri Jan  9 06:42:54 2015
From: alister.nospam.ware at ntlworld.com (alister)
Date: Fri, 09 Jan 2015 11:42:54 GMT
Subject: Announce: PyPrimes 0.2.1a
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <54af0564$0$2919$e4fe514c@news.xs4all.nl>
 <54af23bc$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17490.1420764635.18130.python-list@python.org>
 <RRMrw.501973$p95.379573@fx38.am4>
 <mailman.17518.1420801878.18130.python-list@python.org>
Message-ID: <29Prw.502107$p95.19363@fx38.am4>

On Fri, 09 Jan 2015 22:01:38 +1100, Ben Finney wrote:

> alister <alister.nospam.ware at ntlworld.com> writes:
> 
>> why not simply cheat & call it V 0.2.3 :-) it is not as if there is any
>> regulation concerning what can & cannot constitute a minor release it
>> is all at your own discretion.
> 
> Not a regulation, but a convention which it is good etiquette to follow
> <URL:http://semver.org/>. Version strings are a communication, and
> communication is only useful if conventions of meaning are more or less
> reliable.

true, but this is a modification to the released code so a minor release 
change could be justified, especially so early in the development cycle

it would not do to make a habit of it though



-- 
The last time I saw him he was walking down Lover's Lane holding his own 
hand.
		-- Fred Allen


From mkveee at gmail.com  Fri Jan  9 06:47:05 2015
From: mkveee at gmail.com (mubarak idris)
Date: Fri, 9 Jan 2015 03:47:05 -0800
Subject: hello please can you help me with the below problem am facing
Message-ID: <CADviZRsDr=Bbn=N8J7BF9WZPdXQzEht4ho4RcM-Vs+7g=WBCwQ@mail.gmail.com>

Please how can I make an .exe executable app out of my python script easily


From skip.montanaro at gmail.com  Fri Jan  9 07:04:33 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Fri, 9 Jan 2015 06:04:33 -0600
Subject: Why do the URLs of posts here change?
In-Reply-To: <54afb3ed$0$12995$c3e8da3$5496439d@news.astraweb.com>
References: <54afb3ed$0$12995$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CANc-5UztJsV20dRCpLs5oVrDjr131p8afV5Mp_SwFq2OihKwyQ@mail.gmail.com>

> Posts on this newsgroup/mailing list are archived on the web, but the URLs
> seem to change, which leaves dead links if you search for things.

Steven,

It's a known issue, but one which appears to be somewhat unavoidable,
at least in Mailman 2.x. The problem is that every now and then,
postmaster at python.org gets a legitimate request from someone for a
message to be deleted from the list archive. The way this is done, is
that the message is removed from the underlying mbox file, and the
archive regenerated. That changes the counter for every message after
that point - or maybe every message in the generated archive. (I have
no idea why the numerical basename of your subject message would have
changed so much. Maybe there is just a single ever incrementing
counter for a given Mailman installation.)

>From a technical standpoint, these sorts of requests are pretty
futile, since comp.lang.python/python-list at python.org is archived in
so many places, but that doesn't make the requests any less
legitimate. Consequently, when they arrive at the postmaster address,
they are generally taken care of in short order.

In my experience, they have generally fallen into two categories:

1. Safety. I recall one request where a woman accidentally posted
using an otherwise private email address. She was being stalked by her
ex-husband, and that address was unknown to him.

2. Defamation. There was a spate of recent messages (in Italian)
defaming a couple people, accusing them of being Nazis or pedophiles.

I will point out one class of messages which aren't deleted: those
which demonstrate people's stupidity. People do dumb things - e.g.,
fly off the handle during a flame war - which they sometimes later
realize reflects rather poorly on them (in future job searches and so
forth). Those sorts of message deletion requests are rejected.

That all said, I don't know if Mailman 3 (or some other archiver than
pipermail) will improve on this problem. I suggest a post to
mailman-users at python.org if you're curious about the Mailman
state-of-the-art in this area.

Skip


From __peter__ at web.de  Fri Jan  9 07:04:50 2015
From: __peter__ at web.de (Peter Otten)
Date: Fri, 09 Jan 2015 13:04:50 +0100
Subject: Why do the URLs of posts here change?
References: <54afb3ed$0$12995$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <m8og52$4nd$1@ger.gmane.org>

Steven D'Aprano wrote:

> I have come across this in the past, but today it annoyed me enough that
> I'm asking for an explanation.
> 
> Posts on this newsgroup/mailing list are archived on the web, but the URLs
> seem to change, which leaves dead links if you search for things.
> 
> For example, today I searched for a quote about floating point equality by
> William Kahan, and I came across this post by me:
> 
> https://mail.python.org/pipermail/python-list/2008-February/468598.html
> 
> But that's a dead link! Here's Google's cache of it:
> 
> 
http://webcache.googleusercontent.com/search?client=opera&rls=en&q=cache:i0cWb0Tjxe0J:https://mail.python.org/pipermail/python-list/2008-February/468598.html%2Bfloating+point+superstition+equality&oe=utf-8&channel=suggest&gws_rd=ssl&hl=en&&ct=clnk
> 
> And here is the actual URL, as it appears today:
> 
> https://mail.python.org/pipermail/python-list/2008-February/481374.html
> 
> 
> Why has the URL changed? Surely this is a bug? Where can I report it?

This is a flaw of the mailman software.

http://wiki.list.org/display/DEV/Stable+URLs

suggests that the developers are aware of it. 

I don't know if there is a version available that has stable urls...




From steve+comp.lang.python at pearwood.info  Fri Jan  9 07:24:35 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 09 Jan 2015 23:24:35 +1100
Subject: Decimals and other numbers
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <54af9612$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17513.1420793970.18130.python-list@python.org>
 <54afab5d$0$12976$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17516.1420799984.18130.python-list@python.org>
Message-ID: <54afc884$0$12985$c3e8da3$5496439d@news.astraweb.com>

I want to emphasis that I'm not really arguing that 0**0 should evaluate as
0. That's probably the least useful thing we can have out of the four
possibilities:

- return 1
- return NAN
- raise an exception
- return 0

But in the spirit of the Devil's Advocate, I mentioned that there was an
argument to be made for having integer 0**0 return 0. Intuitively, we have:

0**5 = 0
0**4 = 0
0**3 = 0
0**2 = 0
0**1 = 0
0**0 = ?

It's not hard to see that 0**n = 0 for every n except 0, so why make an
exception for 0? I stress that there are *better* arguments for making that
exception and having 0**0 defined as 1. My argument is merely that there is
*an argument* for having 0**0 return 0.

I could put it this way:

If you start with nothing and raise it to the power of nothing, then there
is nothing to exponentiate and you're left with nothing.

More below.

Chris Angelico wrote:

> On Fri, Jan 9, 2015 at 9:20 PM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> On the basis that m**n means m multiplied by itself n times:
>>
>> 5**4 = 5*5*5*5 = 625
>>
>> that gives us:
>>
>> 0**0 = zero multiplied by itself zero times.
>>
>> You can multiply 0 by any number you like, and the answer will always be
>> 0, not 1. Even if that other number is 0, the answer is still 0.
> 
> 5 * 0 * 0 * 0 * 0 = 0

Where did the 5 come from?

You're effectively saying that 0**0 becomes 5*0**0, then cancelling the 0**0
because they're all zeroes and so don't matter, leaving 5. And that simply
doesn't work. If it did work, there's nothing special about 5, we could use
18 instead:

0**0 = 5*0**0 => 5

but 0**0 = 18*0**0 => 18
therefore 5 = 18.

Yay maths! :-)


> You can multiply 5 by 0 any number of times you like, and the answer 
> will always be 0... unless you never multiply it by 0 at all, in which
> case it'll be 5. Multiplying 0 by any number, including 0, is 0... but 
> *not* multiplying 0 by 0 doesn't have to give 0. 0**0 is the result of
> not multiplying any zeroes together, so it doesn't follow the rules of
> multiplying zeroes together.

If you want to be vigorous, we're both talking nonsense. Exponentiation in
terms of repeated multiplication only works for non-zero powers. Talking
about "multiplication by itself zero times" raises the question "what the
hell do you mean by multiplication by itself zero times?"

There are ways to make this vigorous. The problem is, with 0**0, you get a
different answer depending on how you make it vigorous. Hence 0**0 is
indeterminate.


> Look at it another way. 6**x modulo 10 will always be 6, right? 6, 36, 
> 216... the rules for multiplying mean that the last digit will be
> consistent. (That's how we can know what the last digits of Graham's
> Number are, despite having no way to even comprehend its scale.) 

Oh, after going through some of the discussions on Python-ideas, I'm pretty
sure I comprehend its scale...


> So 
> what's 6**0? Is that going to end with 6, too, to be consistent? No,
> because we're not multiplying any sixes in, so the answer's simply 1.

Why 1? Why not 3? Or 0?

The answer is, it needs to be 1 to be consistent with the Index Laws such as
a**(b-c) = a**b / a**c. That's a good answer, and it works great for a=6:

6**0 = 6**(2-2) = 6**2 / 6**2 = 36/36 = 1

(There's nothing special about 2, I could have used 0 = 97-97, or any other
positive value.)

But it doesn't work when the base is zero:

0**0 = 0**(2-2) = 0**2 / 0**2 = 0/0 = ????

Oops. There's that pesky indeterminate result again.



-- 
Steven



From steve+comp.lang.python at pearwood.info  Fri Jan  9 07:27:52 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 09 Jan 2015 23:27:52 +1100
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
 <mailman.17424.1420596200.18130.python-list@python.org>
 <54ace9f0$0$2738$c3e8da3$76491128@news.astraweb.com>
 <87tx02gb9d.fsf@elektro.pacujo.net>
 <54adc53c$0$12999$c3e8da3$5496439d@news.astraweb.com>
 <877fwx3i8f.fsf@elektro.pacujo.net>
 <CALwzidkn5E3uxQ3Et9r-0_WUTjPLfHtY7mqwnhNVe2MGCi528Q@mail.gmail.com>
 <mailman.17483.1420742711.18130.python-list@python.org>
Message-ID: <54afc949$0$12985$c3e8da3$5496439d@news.astraweb.com>

Chris Kaynor wrote:

> Lately, I've been doing quite a bit of work in lua, and many times have
> wished that empty strings, tables, and 0 acted "falsey", but at the same
> time, previously working in Python, there were plenty of times I wished
> they acted "truthy". It merely depends on what algorithm I am using at the
> time...


Please do elaborate. I've never found myself in a situation where I have
wanted empty containers to be truthy, and I can't think of what such a
situation would be like.



-- 
Steven



From steve+comp.lang.python at pearwood.info  Fri Jan  9 07:28:27 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 09 Jan 2015 23:28:27 +1100
Subject: Why do the URLs of posts here change?
References: <54afb3ed$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17520.1420805082.18130.python-list@python.org>
Message-ID: <54afc96b$0$12985$c3e8da3$5496439d@news.astraweb.com>

Skip Montanaro wrote:

>> Posts on this newsgroup/mailing list are archived on the web, but the
>> URLs seem to change, which leaves dead links if you search for things.
[...]
> That all said, I don't know if Mailman 3 (or some other archiver than
> pipermail) will improve on this problem. I suggest a post to
> mailman-users at python.org if you're curious about the Mailman
> state-of-the-art in this area.

Thanks for the explanation!


-- 
Steven



From info at egenix.com  Fri Jan  9 07:32:14 2015
From: info at egenix.com (eGenix Team: M.-A. Lemburg)
Date: Fri, 09 Jan 2015 13:32:14 +0100
Subject: ANN: eGenix pyOpenSSL Distribution 0.13.7
Message-ID: <54AFCA4E.1080801@egenix.com>

________________________________________________________________________
ANNOUNCING

                   eGenix.com pyOpenSSL Distribution

                             Version 0.13.7


             An easy-to-install and easy-to-use distribution
             of the pyOpenSSL Python interface for OpenSSL -
            available for Windows, Mac OS X and Unix platforms


This announcement is also available on our web-site for online reading:
http://www.egenix.com/company/news/eGenix-pyOpenSSL-Distribution-0.13.7.html

________________________________________________________________________
INTRODUCTION

The eGenix.com pyOpenSSL Distribution includes everything you need to
get started with SSL in Python.

It comes with an easy-to-use installer that includes the most recent
OpenSSL library versions in pre-compiled form, making your application
independent of OS provided OpenSSL libraries:

    http://www.egenix.com/products/python/pyOpenSSL/

pyOpenSSL is an open-source Python add-on that allows writing SSL/TLS-
aware network applications as well as certificate management tools:

    https://launchpad.net/pyopenssl/

OpenSSL is an open-source implementation of the SSL/TLS protocol:

    http://www.openssl.org/

________________________________________________________________________
NEWS

This new release of the eGenix.com pyOpenSSL Distribution updates the
included OpenSSL version to the latest OpenSSL 1.0.1h version and adds
a few more context options:

New in OpenSSL
--------------

 * Updated included OpenSSL libraries from OpenSSL 1.0.1j to
   1.0.1k. See https://www.openssl.org/news/secadv_20150108.txt for a
   complete list of changes. The following fixes are relevant for
   pyOpenSSL applications:

   - CVE-2014-8275: OpenSSL accepts several non-DER-variations of
     certificate signature algorithm and signature encodings. OpenSSL
     also does not enforce a match between the signature algorithm
     between the signed and unsigned portions of the certificate. By
     modifying the contents of the signature algorithm or the encoding
     of the signature, it is possible to change the certificate's
     fingerprint.

   - CVE-2014-3572: An OpenSSL client will accept a handshake using an
     ephemeral ECDH ciphersuite using an ECDSA certificate if the
     server key exchange message is omitted. This effectively removes
     forward secrecy from the ciphersuite.

   - CVE-2015-0204: An OpenSSL client will accept the use of an RSA
     temporary key in a non-export RSA key exchange ciphersuite. A
     server could present a weak temporary key and downgrade the
     security of the session.

   - CVE-2014-3570: Bignum squaring (BN_sqr) may produce incorrect
     results on some platforms, including x86_64. This bug occurs at
     random with a very low probability, and is not known to be
     exploitable in any way, though its exact impact is difficult to
     determine.

   - CVE-2015-0205: An OpenSSL server will accept a DH certificate for
     client authentication without the certificate verify
     message. This effectively allows a client to authenticate without
     the use of a private key. This only affects servers which trust a
     client certificate authority which issues certificates containing
     DH keys: these are extremely rare and hardly ever encountered.

Please see the product changelog for the full set of changes:

   http://www.egenix.com/products/python/pyOpenSSL/changelog.html

pyOpenSSL / OpenSSL Binaries Included
-------------------------------------

In addition to providing sources, we make binaries available that
include both pyOpenSSL and the necessary OpenSSL libraries for all
supported platforms: Windows x86 and x64, Linux x86 and x64, Mac OS X
PPC, x86 and x64.

We've also added egg-file distribution versions of our eGenix.com
pyOpenSSL Distribution for Windows, Linux and Mac OS X to the
available download options. These make setups using e.g. zc.buildout
and other egg-file based installers a lot easier.

________________________________________________________________________
DOWNLOADS

The download archives and instructions for installing the package can
be found at:

    http://www.egenix.com/products/python/pyOpenSSL/

________________________________________________________________________
UPGRADING

Before installing this version of pyOpenSSL, please make sure that
you uninstall any previously installed pyOpenSSL version. Otherwise,
you could end up not using the included OpenSSL libs.

_______________________________________________________________________
SUPPORT

Commercial support for these packages is available from eGenix.com.
Please see

    http://www.egenix.com/services/support/

for details about our support offerings.

________________________________________________________________________
MORE INFORMATION

For more information about the eGenix pyOpenSSL Distribution, licensing
and download instructions, please visit our web-site or write to
sales at egenix.com.

Enjoy,
-- 
Marc-Andre Lemburg
eGenix.com

Professional Python Services directly from the Source  (#1, Jan 09 2015)
>>> Python Projects, Coaching and Consulting ...  http://www.egenix.com/
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           Registered at Amtsgericht Duesseldorf: HRB 46611
               http://www.egenix.com/company/contact/


From rosuav at gmail.com  Fri Jan  9 07:34:23 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 9 Jan 2015 23:34:23 +1100
Subject: Decimals and other numbers
In-Reply-To: <54afc884$0$12985$c3e8da3$5496439d@news.astraweb.com>
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <54af9612$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17513.1420793970.18130.python-list@python.org>
 <54afab5d$0$12976$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17516.1420799984.18130.python-list@python.org>
 <54afc884$0$12985$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmpSGV_JvSAdkJ5PS-YcVM0SVcCesS6PGU5=LLDqwaBvKg@mail.gmail.com>

On Fri, Jan 9, 2015 at 11:24 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
>> 5 * 0 * 0 * 0 * 0 = 0
>
> Where did the 5 come from?
>
> You're effectively saying that 0**0 becomes 5*0**0, then cancelling the 0**0
> because they're all zeroes and so don't matter, leaving 5. And that simply
> doesn't work. If it did work, there's nothing special about 5, we could use
> 18 instead:
>
> 0**0 = 5*0**0 => 5
>
> but 0**0 = 18*0**0 => 18
> therefore 5 = 18.
>
> Yay maths! :-)

To clarify, I'm following this sequence:

5 * 0**4 = 5 * 0 * 0 * 0 * 0 = 0
5 * 0**3 = 5 * 0 * 0 * 0 = 0
5 * 0**2 = 5 * 0 * 0 = 0
5 * 0**1 = 5 * 0 = 0
5 * 0**0 = 5 = ?

Multiplication by zero is idempotent; any number of multiplications
beyond the first won't change the result. But that doesn't mean that
never multiplying by zero will have the same result. I think it's
fairly obvious in this example that the pattern does NOT continue to
the case where you're multiplying in no zeroes.

ChrisA


From rosuav at gmail.com  Fri Jan  9 07:43:42 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 9 Jan 2015 23:43:42 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54afc949$0$12985$c3e8da3$5496439d@news.astraweb.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
 <mailman.17424.1420596200.18130.python-list@python.org>
 <54ace9f0$0$2738$c3e8da3$76491128@news.astraweb.com>
 <87tx02gb9d.fsf@elektro.pacujo.net>
 <54adc53c$0$12999$c3e8da3$5496439d@news.astraweb.com>
 <877fwx3i8f.fsf@elektro.pacujo.net>
 <CALwzidkn5E3uxQ3Et9r-0_WUTjPLfHtY7mqwnhNVe2MGCi528Q@mail.gmail.com>
 <mailman.17483.1420742711.18130.python-list@python.org>
 <54afc949$0$12985$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmojrOtDgNBvLZFwyoqiAkyHvJUHG7ciBSU5-w75vXpm8A@mail.gmail.com>

On Fri, Jan 9, 2015 at 11:27 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Chris Kaynor wrote:
>
>> Lately, I've been doing quite a bit of work in lua, and many times have
>> wished that empty strings, tables, and 0 acted "falsey", but at the same
>> time, previously working in Python, there were plenty of times I wished
>> they acted "truthy". It merely depends on what algorithm I am using at the
>> time...
>
>
> Please do elaborate. I've never found myself in a situation where I have
> wanted empty containers to be truthy, and I can't think of what such a
> situation would be like.

It's a matter of what you're comparing against. If you might have a
thing and might not, the obvious way to arrange things is to have the
thing be true and the non-thing be false. That works nicely if that
"thing" is an object that's always True, and the "non-thing" is None;
for instance, I might have a socket object, and I might not, so I can
use "if not self.socket: self.connect()" to ensure that I have one
(assuming that self.connect() will throw an error if it fails to
establish, blah blah, handwave away the details). This does NOT work
if a socket object might be false, so I'd have to explicitly check "if
self.socket is None:". Similarly, there are times when the user might
have entered a string or might not - say you have an optional
parameter "--name" which, if omitted, defaults to some sort of
arbitrarily-assigned name; to distinguish between "--name=" and not
providing that parameter at all, the logical way is to have name be
either a string or None. Again, "if name" would make good sense as
meaning "if the --name parameter was provided", rather than "if the
--name parameter was provided and not the empty string". If it helps,
think of a "nullable field" in databasing.

Python's truthiness model is pretty consistent (apart from a few
oddities like midnight being false), so I'm not advocating making this
change. I'm just explaining the case where the opposite choice does
make sense.

ChrisA


From gvanem at yahoo.no  Fri Jan  9 08:14:39 2015
From: gvanem at yahoo.no (Gisle Vanem)
Date: Fri, 09 Jan 2015 13:14:39 +0000
Subject: Non-unique dirs in sys.path
Message-ID: <54AFD43F.5040100@yahoo.no>

I'm having some trouble understanding why my Python 2.7.9
has the '%PYTHONHOME%\lib\site-packages' listed multiple
times.

I cooked up this .bat file to demonstrate the issue:
   @echo off
   setlocal
   set PYTHONPATH=
   python -c "import sys; [sys.stdout.write('%%s\n' %% p) for (i,p) in enumerate(sys.path)]" | sort --ignore-case

which produces:

   f:\Documents and Settings\Gisle Vanem\Programdata\Python\Python27\site-packages
   f:\windows\system32\python27.zip    << !! doesn't exist, but okay.
   G:\Programfiler\Python27
   g:\Programfiler\Python27\DLLs
   g:\Programfiler\Python27\lib
   g:\Programfiler\Python27\lib\lib-tk
   g:\Programfiler\Python27\lib\plat-win
   g:\Programfiler\Python27\lib\site-packages   << !!
   g:\programfiler\python27\lib\site-packages   << !!
   ...

Why are these listed twice with different casing? One
would assume that Python on Win32 would be case-insensitive.
Some .pth-file to blame here?

I've checked that PYTHONPATH is not defined elsewhere. Like in:
   HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment
or
   HKCU\Environment

-- 
--gv


From meiry242 at gmail.com  Fri Jan  9 08:53:33 2015
From: meiry242 at gmail.com (meiry242 at gmail.com)
Date: Fri, 9 Jan 2015 05:53:33 -0800 (PST)
Subject: Begginer Question , what i need for web app and site
Message-ID: <f769f5f9-8c7f-41e6-8d9b-227754de9564@googlegroups.com>

Hello all
coming from java and c++ now going with python 
what setup do i need to run full python stack for web application .
what i need is web framework and back-end . 
what usually be in the java world tomcat and servlets or jsp and pure java backend for processing data .
what will be the Equivalent in python world ?
Thanks!


From rustompmody at gmail.com  Fri Jan  9 09:09:38 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 9 Jan 2015 06:09:38 -0800 (PST)
Subject: Why do the URLs of posts here change?
In-Reply-To: <54afb3ed$0$12995$c3e8da3$5496439d@news.astraweb.com>
References: <54afb3ed$0$12995$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <28f970bd-188d-4455-b2b2-3320c546ad65@googlegroups.com>

On Friday, January 9, 2015 at 4:26:58 PM UTC+5:30, Steven D'Aprano wrote:
> I have come across this in the past, but today it annoyed me enough that I'm
> asking for an explanation.
> 
> Posts on this newsgroup/mailing list are archived on the web, but the URLs
> seem to change, which leaves dead links if you search for things.
> 
> For example, today I searched for a quote about floating point equality by
> William Kahan, and I came across this post by me:
> 
> https://mail.python.org/pipermail/python-list/2008-February/468598.html
> 
> But that's a dead link! Here's Google's cache of it:
> 
> http://webcache.googleusercontent.com/search?client=opera&rls=en&q=cache:i0cWb0Tjxe0J:https://mail.python.org/pipermail/python-list/2008-February/468598.html%2Bfloating+point+superstition+equality&oe=utf-8&channel=suggest&gws_rd=ssl&hl=en&&ct=clnk
> 
> And here is the actual URL, as it appears today:
> 
> https://mail.python.org/pipermail/python-list/2008-February/481374.html
> 
> 
> Why has the URL changed? Surely this is a bug? Where can I report it?

Theres a new app/service that should solve your problem:
Its from google... and called groups <wink>


From skip.montanaro at gmail.com  Fri Jan  9 09:15:46 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Fri, 9 Jan 2015 08:15:46 -0600
Subject: Why do the URLs of posts here change?
In-Reply-To: <28f970bd-188d-4455-b2b2-3320c546ad65@googlegroups.com>
References: <54afb3ed$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <28f970bd-188d-4455-b2b2-3320c546ad65@googlegroups.com>
Message-ID: <CANc-5Uxf0hOY=KdCw7KOasQmuGJvQJ8v-7=J4wUEHyXwFd7iBA@mail.gmail.com>

On Fri, Jan 9, 2015 at 8:09 AM, Rustom Mody <rustompmody at gmail.com> wrote:

> Theres a new app/service that should solve your problem:
> Its from google... and called groups <wink>
>

It solves one problem (moving archive URLs) by, I think, ignoring the other
(archive posts which should really be removed).

Skip
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From marko at pacujo.net  Fri Jan  9 09:28:24 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Fri, 09 Jan 2015 16:28:24 +0200
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
 <mailman.17424.1420596200.18130.python-list@python.org>
 <54ace9f0$0$2738$c3e8da3$76491128@news.astraweb.com>
 <87tx02gb9d.fsf@elektro.pacujo.net>
 <54adc53c$0$12999$c3e8da3$5496439d@news.astraweb.com>
 <877fwx3i8f.fsf@elektro.pacujo.net>
 <CALwzidkn5E3uxQ3Et9r-0_WUTjPLfHtY7mqwnhNVe2MGCi528Q@mail.gmail.com>
 <mailman.17483.1420742711.18130.python-list@python.org>
 <54afc949$0$12985$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17524.1420807429.18130.python-list@python.org>
Message-ID: <87bnm8do53.fsf@elektro.pacujo.net>

Chris Angelico <rosuav at gmail.com>:

> I'd have to explicitly check "if self.socket is None:".

That is the only way in Python.

Wrong:

    return f() or g() or h()

Right:

    rv = f()
    if rv is not None:
        return rv
    rv = g()
    if rv is not None:
        return rv
    return h()

> I'm not advocating making this change.

Has someone proposed a change?


Marko


From a24061 at ducksburg.com  Fri Jan  9 09:44:05 2015
From: a24061 at ducksburg.com (Adam Funk)
Date: Fri, 09 Jan 2015 14:44:05 +0000
Subject: Why does argparse return None instead of [] if an append action
 isn't used?
Message-ID: <l265obxc6d.ln2@news.ducksburg.com>

I noticed in use that if an option with the 'append' action isn't
used, argparse assigns None to it rather than an empty list, &
confirmed this interactively:

#v+
>>> import argparse
>>> parser = argparse.ArgumentParser()
>>> parser.add_argument('--foo', action='append')
_AppendAction(option_strings=['--foo'], dest='foo', nargs=None, const=None, default=None, type=None, choices=None, help=None, metavar=None)
>>> parser.add_argument('--bar', action='append')
_AppendAction(option_strings=['--bar'], dest='bar', nargs=None, const=None, default=None, type=None, choices=None, help=None, metavar=None)
>>> parser.parse_args('--foo 1 --foo 2'.split())
Namespace(bar=None, foo=['1', '2'])
#v-

This makes it a bit more trouble to use:

  if options.bar:
     for b in options:bar
        do_stuff(b)

instead of

  for b in options.bar
     do_stuff(b)

which is (of course) what I was doing when I discovered the None.  Is
there any benefit to the user from this, or is it just an "accident"
of the way argparse is written?


-- 
The history of the world is the history of a privileged few.
                                            --- Henry Miller


From skip.montanaro at gmail.com  Fri Jan  9 09:57:03 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Fri, 9 Jan 2015 08:57:03 -0600
Subject: Why does argparse return None instead of [] if an append action
 isn't used?
In-Reply-To: <l265obxc6d.ln2@news.ducksburg.com>
References: <l265obxc6d.ln2@news.ducksburg.com>
Message-ID: <CANc-5UxCFshV=9mXe6M54WbqPkjJEMzJYswSiG82EN5Z4d1uXw@mail.gmail.com>

> I noticed in use that if an option with the 'append' action isn't
> used, argparse assigns None to it rather than an empty list, &
> confirmed this interactively:

I don't use argparse (or optparse), being a getopt Luddite myself, but
can you set the default for an action in the add_argument call?

Skip


From stephen.boulet at gmail.com  Fri Jan  9 09:58:47 2015
From: stephen.boulet at gmail.com (stephen.boulet at gmail.com)
Date: Fri, 9 Jan 2015 06:58:47 -0800 (PST)
Subject: Help configuring visual studio to compile python extensions
Message-ID: <5c51c0ef-b2d0-4edd-b3cd-37759b5807e8@googlegroups.com>

I've installed Microsoft Visual Studio 10.0. Here are the steps I've been taking.

My python version is Python 3.4.2 (v3.4.2:ab2c023a9432, Oct  6 2014, 22:16:31) [MSC v.1600 64 bit (AMD64)] on win32.

(Sorry for the long output.)

>cd "c:\Program Files (x86)\Microsoft Visual Studio 10.0"\vc
>vcvarsall.bat
>
>SET VS90COMNTOOLS=%VS100COMNTOOLS%
c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC>pip install scandir
Collecting scandir
  Using cached scandir-0.9.tar.gz
Installing collected packages: scandir
  Running setup.py install for scandir
    building '_scandir' extension
    C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\BIN\cl.exe /c /nologo /Ox /MD /W3 /GS- /DNDEBUG -Ic:\Python34\include -Ic:\Python34\include /Tc_scandir.c /Fobuild\temp.win-amd64-3.4\Release
\_scandir.obj
    _scandir.c
    C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\BIN\link.exe /DLL /nologo /INCREMENTAL:NO /LIBPATH:c:\Python34\libs /LIBPATH:c:\Python34\PCbuild\amd64 /EXPORT:PyInit__scandir build\temp.win
-amd64-3.4\Release\_scandir.obj /OUT:build\lib.win-amd64-3.4\_scandir.pyd /IMPLIB:build\temp.win-amd64-3.4\Release\_scandir.lib /MANIFESTFILE:build\temp.win-amd64-3.4\Release\_scandir.pyd.manifest
       Creating library build\temp.win-amd64-3.4\Release\_scandir.lib and object build\temp.win-amd64-3.4\Release\_scandir.exp
    _scandir.obj : error LNK2001: unresolved external symbol _PyObject_SelfIter
    _scandir.obj : error LNK2001: unresolved external symbol _PyObject_GenericGetAttr
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_WarnEx referenced in function _win32_warn_bytes_api
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyExc_DeprecationWarning referenced in function _win32_warn_bytes_api
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_Occurred referenced in function _path_converter
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyBytes_FromObject referenced in function _path_converter
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_Clear referenced in function _path_converter
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyExc_ValueError referenced in function _path_converter
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyUnicode_AsUnicodeAndSize referenced in function _path_converter
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyUnicode_FromObject referenced in function _path_converter
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_Format referenced in function _path_converter
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyExc_TypeError referenced in function _path_converter
    _scandir.obj : error LNK2019: unresolved external symbol __imp___Py_NoneStruct referenced in function _path_converter
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyLong_FromUnsignedLong referenced in function _find_data_to_statresult
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyFloat_FromDouble referenced in function _find_data_to_statresult
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyLong_FromUnsignedLongLong referenced in function _find_data_to_statresult
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyLong_FromLong referenced in function _find_data_to_statresult
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyStructSequence_New referenced in function _find_data_to_statresult
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyEval_RestoreThread referenced in function __fi_close
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyEval_SaveThread referenced in function __fi_close
    _scandir.obj : error LNK2019: unresolved external symbol __imp__Py_BuildValue referenced in function __fi_next
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_SetFromWindowsErr referenced in function __fi_next
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_NoMemory referenced in function __fi_next
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_SetNone referenced in function __fi_next
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyExc_StopIteration referenced in function __fi_next
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyObject_Free referenced in function _fi_dealloc
    _scandir.obj : error LNK2019: unresolved external symbol __imp___PyObject_New referenced in function __iterfile
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyArg_ParseTupleAndKeywords referenced in function _scandir_helper
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyStructSequence_InitType referenced in function _PyInit__scandir
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyType_Ready referenced in function _PyInit__scandir
    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyModule_Create2 referenced in function _PyInit__scandir
    build\lib.win-amd64-3.4\_scandir.pyd : fatal error LNK1120: 31 unresolved externals
    error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio 10.0\\VC\\BIN\\link.exe' failed with exit status 1120
    Complete output from command c:\Python34\python.exe -c "import setuptools, tokenize;__file__='C:\\Users\\SBO010\\AppData\\Local\\Temp\\pip-build-gd_12t27\\scandir\\setup.py';exec(compile(getattr(t
okenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record C:\Users\SBO010\AppData\Local\Temp\pip-tzadruqn-record\install-record.txt --single-version-externall
y-managed --compile:
    running install

    running build

    running build_py

    creating build

    creating build\lib.win-amd64-3.4

    copying scandir.py -> build\lib.win-amd64-3.4

    running build_ext

    building '_scandir' extension

    creating build\temp.win-amd64-3.4

    creating build\temp.win-amd64-3.4\Release

    C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\BIN\cl.exe /c /nologo /Ox /MD /W3 /GS- /DNDEBUG -Ic:\Python34\include -Ic:\Python34\include /Tc_scandir.c /Fobuild\temp.win-amd64-3.4\Release
\_scandir.obj

    _scandir.c

    C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\BIN\link.exe /DLL /nologo /INCREMENTAL:NO /LIBPATH:c:\Python34\libs /LIBPATH:c:\Python34\PCbuild\amd64 /EXPORT:PyInit__scandir build\temp.win
-amd64-3.4\Release\_scandir.obj /OUT:build\lib.win-amd64-3.4\_scandir.pyd /IMPLIB:build\temp.win-amd64-3.4\Release\_scandir.lib /MANIFESTFILE:build\temp.win-amd64-3.4\Release\_scandir.pyd.manifest

       Creating library build\temp.win-amd64-3.4\Release\_scandir.lib and object build\temp.win-amd64-3.4\Release\_scandir.exp

    _scandir.obj : error LNK2001: unresolved external symbol _PyObject_SelfIter

    _scandir.obj : error LNK2001: unresolved external symbol _PyObject_GenericGetAttr

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_WarnEx referenced in function _win32_warn_bytes_api

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyExc_DeprecationWarning referenced in function _win32_warn_bytes_api

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_Occurred referenced in function _path_converter

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyBytes_FromObject referenced in function _path_converter

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_Clear referenced in function _path_converter

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyExc_ValueError referenced in function _path_converter

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyUnicode_AsUnicodeAndSize referenced in function _path_converter

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyUnicode_FromObject referenced in function _path_converter

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_Format referenced in function _path_converter

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyExc_TypeError referenced in function _path_converter

    _scandir.obj : error LNK2019: unresolved external symbol __imp___Py_NoneStruct referenced in function _path_converter

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyLong_FromUnsignedLong referenced in function _find_data_to_statresult

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyFloat_FromDouble referenced in function _find_data_to_statresult

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyLong_FromUnsignedLongLong referenced in function _find_data_to_statresult

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyLong_FromLong referenced in function _find_data_to_statresult

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyStructSequence_New referenced in function _find_data_to_statresult

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyEval_RestoreThread referenced in function __fi_close

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyEval_SaveThread referenced in function __fi_close

    _scandir.obj : error LNK2019: unresolved external symbol __imp__Py_BuildValue referenced in function __fi_next

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_SetFromWindowsErr referenced in function __fi_next

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_NoMemory referenced in function __fi_next

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_SetNone referenced in function __fi_next

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyExc_StopIteration referenced in function __fi_next

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyObject_Free referenced in function _fi_dealloc

    _scandir.obj : error LNK2019: unresolved external symbol __imp___PyObject_New referenced in function __iterfile

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyArg_ParseTupleAndKeywords referenced in function _scandir_helper

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyStructSequence_InitType referenced in function _PyInit__scandir

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyType_Ready referenced in function _PyInit__scandir

    _scandir.obj : error LNK2019: unresolved external symbol __imp__PyModule_Create2 referenced in function _PyInit__scandir

    build\lib.win-amd64-3.4\_scandir.pyd : fatal error LNK1120: 31 unresolved externals

    error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio 10.0\\VC\\BIN\\link.exe' failed with exit status 1120

    ----------------------------------------
    Command "c:\Python34\python.exe -c "import setuptools, tokenize;__file__='C:\\Users\\SBO010\\AppData\\Local\\Temp\\pip-build-gd_12t27\\scandir\\setup.py';exec(compile(getattr(tokenize, 'open', ope
n)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record C:\Users\SBO010\AppData\Local\Temp\pip-tzadruqn-record\install-record.txt --single-version-externally-managed --compile"
 failed with error code 1 in C:\Users\SBO010\AppData\Local\Temp\pip-build-gd_12t27\scandir

c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC>


From no.email at nospam.invalid  Fri Jan  9 10:06:03 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Fri, 09 Jan 2015 07:06:03 -0800
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
 <mailman.17424.1420596200.18130.python-list@python.org>
 <54ace9f0$0$2738$c3e8da3$76491128@news.astraweb.com>
 <87tx02gb9d.fsf@elektro.pacujo.net>
 <54adc53c$0$12999$c3e8da3$5496439d@news.astraweb.com>
 <877fwx3i8f.fsf@elektro.pacujo.net>
 <CALwzidkn5E3uxQ3Et9r-0_WUTjPLfHtY7mqwnhNVe2MGCi528Q@mail.gmail.com>
 <mailman.17483.1420742711.18130.python-list@python.org>
 <54afc949$0$12985$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17524.1420807429.18130.python-list@python.org>
Message-ID: <87lhlcro2s.fsf@jester.gateway.sonic.net>

Chris Angelico <rosuav at gmail.com> writes:
> for instance, I might have a socket object, and I might not, so I can
> use "if not self.socket: self.connect()" ...

This sounds like you want a Maybe or Option object.

Marko's suggestion

    rv = f()
    if rv is not None:
        return rv
    rv = g()
    if rv is not None:
        return rv
    return h()

seems unspeakably ugly.  Rather than None on failure maybe f()
and g() could return an empty list on failure, or a one-element list
containing the item on success.  That uses lists to simulate a Maybe type.

Then the above could go (Python 3, untested):

  def tries():
    yield from f()
    yield from g()
    yield [h()]
  return tries().next()


From ned at nedbatchelder.com  Fri Jan  9 10:12:39 2015
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Fri, 09 Jan 2015 10:12:39 -0500
Subject: Why does argparse return None instead of [] if an append action
 isn't used?
In-Reply-To: <l265obxc6d.ln2@news.ducksburg.com>
References: <l265obxc6d.ln2@news.ducksburg.com>
Message-ID: <m8or58$qa1$1@ger.gmane.org>

On 1/9/15 9:44 AM, Adam Funk wrote:
> This makes it a bit more trouble to use:
>
>    if options.bar:
>       for b in options:bar
>          do_stuff(b)
>
> instead of
>
>    for b in options.bar
>       do_stuff(b)

This doesn't answer why the value defaults to None, and some people may 
recoil at it, but I've used:

     for b in options.bar or ():
         do_stuff(b)

-- 
Ned Batchelder, http://nedbatchelder.com



From rosuav at gmail.com  Fri Jan  9 10:14:58 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 10 Jan 2015 02:14:58 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <87lhlcro2s.fsf@jester.gateway.sonic.net>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
 <mailman.17424.1420596200.18130.python-list@python.org>
 <54ace9f0$0$2738$c3e8da3$76491128@news.astraweb.com>
 <87tx02gb9d.fsf@elektro.pacujo.net>
 <54adc53c$0$12999$c3e8da3$5496439d@news.astraweb.com>
 <877fwx3i8f.fsf@elektro.pacujo.net>
 <CALwzidkn5E3uxQ3Et9r-0_WUTjPLfHtY7mqwnhNVe2MGCi528Q@mail.gmail.com>
 <mailman.17483.1420742711.18130.python-list@python.org>
 <54afc949$0$12985$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17524.1420807429.18130.python-list@python.org>
 <87lhlcro2s.fsf@jester.gateway.sonic.net>
Message-ID: <CAPTjJmqTxqvzyYZxoX7WUvF=0Lp_JADZ1MJ-S0=5TXC69YsG8w@mail.gmail.com>

On Sat, Jan 10, 2015 at 2:06 AM, Paul Rubin <no.email at nospam.invalid> wrote:
> Chris Angelico <rosuav at gmail.com> writes:
>> for instance, I might have a socket object, and I might not, so I can
>> use "if not self.socket: self.connect()" ...
>
> This sounds like you want a Maybe or Option object.

That's exactly what it is - a name that's always bound to either None
or a socket object. Since a socket object is always true, I can safely
use the above code.

ChrisA


From marko at pacujo.net  Fri Jan  9 10:16:46 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Fri, 09 Jan 2015 17:16:46 +0200
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com> <54ABEAD9.8070000@davea.name>
 <mailman.17424.1420596200.18130.python-list@python.org>
 <54ace9f0$0$2738$c3e8da3$76491128@news.astraweb.com>
 <87tx02gb9d.fsf@elektro.pacujo.net>
 <54adc53c$0$12999$c3e8da3$5496439d@news.astraweb.com>
 <877fwx3i8f.fsf@elektro.pacujo.net>
 <CALwzidkn5E3uxQ3Et9r-0_WUTjPLfHtY7mqwnhNVe2MGCi528Q@mail.gmail.com>
 <mailman.17483.1420742711.18130.python-list@python.org>
 <54afc949$0$12985$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17524.1420807429.18130.python-list@python.org>
 <87lhlcro2s.fsf@jester.gateway.sonic.net>
Message-ID: <877fwwdlwh.fsf@elektro.pacujo.net>

Paul Rubin <no.email at nospam.invalid>:

> Marko's suggestion
>
>     rv = f()
>     if rv is not None:
>         return rv
>     rv = g()
>     if rv is not None:
>         return rv
>     return h()
>
> seems unspeakably ugly.

Well, "unspeakably" is exaggeration IMO. It is a bit lengthy but it is
crystal clear. While the "or" pattern is neat, I wouldn't make too much
of it.

> Rather than None on failure maybe f() and g() could return an empty
> list on failure, or a one-element list containing the item on success.
> That uses lists to simulate a Maybe type.
>
> Then the above could go (Python 3, untested):
>
>   def tries():
>     yield from f()
>     yield from g()
>     yield [h()]
>   return tries().next()

I think the medicine in this case is worse than the disease.


Marko


From breamoreboy at yahoo.co.uk  Fri Jan  9 10:23:33 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Fri, 09 Jan 2015 15:23:33 +0000
Subject: Help configuring visual studio to compile python extensions
In-Reply-To: <5c51c0ef-b2d0-4edd-b3cd-37759b5807e8@googlegroups.com>
References: <5c51c0ef-b2d0-4edd-b3cd-37759b5807e8@googlegroups.com>
Message-ID: <m8orps$709$1@ger.gmane.org>

On 09/01/2015 14:58, stephen.boulet at gmail.com wrote:
> I've installed Microsoft Visual Studio 10.0. Here are the steps I've been taking.
>
> My python version is Python 3.4.2 (v3.4.2:ab2c023a9432, Oct  6 2014, 22:16:31) [MSC v.1600 64 bit (AMD64)] on win32.
>
> (Sorry for the long output.)
>
>> cd "c:\Program Files (x86)\Microsoft Visual Studio 10.0"\vc
>> vcvarsall.bat
>>
>> SET VS90COMNTOOLS=%VS100COMNTOOLS%
> c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC>pip install scandir
> Collecting scandir
>    Using cached scandir-0.9.tar.gz

See https://docs.python.org/3/extending/windows.html

I'll admit to being a little annoyed that scandir says it supports 
Python 3 but only provides a 2.7 exe on pypi.

Worse even my normal backup failed me 
http://www.lfd.uci.edu/~gohlke/pythonlibs/

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From a24061 at ducksburg.com  Fri Jan  9 10:25:59 2015
From: a24061 at ducksburg.com (Adam Funk)
Date: Fri, 09 Jan 2015 15:25:59 +0000
Subject: Why does argparse return None instead of [] if an append action
 isn't used?
References: <l265obxc6d.ln2@news.ducksburg.com>
 <mailman.17527.1420815432.18130.python-list@python.org>
Message-ID: <7h85obxhje.ln2@news.ducksburg.com>

On 2015-01-09, Skip Montanaro wrote:

>> I noticed in use that if an option with the 'append' action isn't
>> used, argparse assigns None to it rather than an empty list, &
>> confirmed this interactively:
>
> I don't use argparse (or optparse), being a getopt Luddite myself, but
> can you set the default for an action in the add_argument call?

Well, duh!  That works, thanks.  (I can't explain why I didn't think
of that.)


>>> import argparse
>>> parser = argparse.ArgumentParser()
>>> parser.add_argument('--foo', action='append',default=[])
_AppendAction(option_strings=['--foo'], dest='foo', nargs=None, const=None, default=[], type=None, choices=None, help=None, metavar=None)
>>> parser.add_argument('--bar', action='append',default=[])
_AppendAction(option_strings=['--bar'], dest='bar', nargs=None, const=None, default=[], type=None, choices=None, help=None, metavar=None)
>>> parser.parse_args('--foo 1 --foo 2'.split())
Namespace(bar=[], foo=['1', '2'])
>>> parser.parse_args('--foo 1 --bar 2'.split())
Namespace(bar=['2'], foo=['1'])
>>> parser.parse_args([])
Namespace(bar=[], foo=[])





-- 
Slade was the coolest band in England. They were the kind of guys
that would push your car out of a ditch.         --- Alice Cooper


From rosuav at gmail.com  Fri Jan  9 10:35:57 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 10 Jan 2015 02:35:57 +1100
Subject: Help configuring visual studio to compile python extensions
In-Reply-To: <m8orps$709$1@ger.gmane.org>
References: <5c51c0ef-b2d0-4edd-b3cd-37759b5807e8@googlegroups.com>
 <m8orps$709$1@ger.gmane.org>
Message-ID: <CAPTjJmqozec1kCy_a=YkkH_eXwYuYdf2mejciKN3G8S5tLMSzw@mail.gmail.com>

On Sat, Jan 10, 2015 at 2:23 AM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> I'll admit to being a little annoyed that scandir says it supports Python 3
> but only provides a 2.7 exe on pypi.

If you can wait for 3.5, you might find it in the standard library.
PEP 471 was accepted, and I believe that means scandir will be
arriving at some point. (Not sure when, though.) At that point, 2.7
will be the primary target for the PyPI distribution.

ChrisA


From wolfgang.maier at biologie.uni-freiburg.de  Fri Jan  9 10:50:07 2015
From: wolfgang.maier at biologie.uni-freiburg.de (Wolfgang Maier)
Date: Fri, 09 Jan 2015 16:50:07 +0100
Subject: Why does argparse return None instead of [] if an append action
 isn't used?
In-Reply-To: <l265obxc6d.ln2@news.ducksburg.com>
References: <l265obxc6d.ln2@news.ducksburg.com>
Message-ID: <m8otbo$2ei$1@ger.gmane.org>

On 01/09/2015 03:44 PM, Adam Funk wrote:
> I noticed in use that if an option with the 'append' action isn't
> used, argparse assigns None to it rather than an empty list, &
> confirmed this interactively:
>
> #v+
>>>> import argparse
>>>> parser = argparse.ArgumentParser()
>>>> parser.add_argument('--foo', action='append')
> _AppendAction(option_strings=['--foo'], dest='foo', nargs=None, const=None, default=None, type=None, choices=None, help=None, metavar=None)
>>>> parser.add_argument('--bar', action='append')
> _AppendAction(option_strings=['--bar'], dest='bar', nargs=None, const=None, default=None, type=None, choices=None, help=None, metavar=None)
>>>> parser.parse_args('--foo 1 --foo 2'.split())
> Namespace(bar=None, foo=['1', '2'])
> #v-
>

Isn't that the exact behaviour documented here:

https://docs.python.org/3/library/argparse.html#default

where it says that the default for the default argument is None ?

I think Skip is right: you should be able to just add

default = []

to your arguments in the add_argument call.

Wolfgang



From invalid at invalid.invalid  Fri Jan  9 11:06:46 2015
From: invalid at invalid.invalid (Grant Edwards)
Date: Fri, 9 Jan 2015 16:06:46 +0000 (UTC)
Subject: what is Jython?
References: <509995943442469175.487823bclark-es.co.nz@free.teranews.com>
 <mailman.17505.1420779030.18130.python-list@python.org>
Message-ID: <m8ouam$brp$1@reader2.panix.com>

On 2015-01-09, Chris Angelico <rosuav at gmail.com> wrote:

> Jython isn't a combination of Python and Java; it's Python,
> implemented in Java. Does that answer your question?

Just to clarify, Jython 

  1) is a Python compiler that compiles Python source code into JVM
     bytecode (class, jar, whatever) that runs on a standard Java
     runtime. Python programs compiled with Jython can call standard
     Java libraries and and can call or be called by code written in
     Java.

  2) is a Python compiler that is written in Java.

AFAK, these are in principal orthogonal.  Number 1) is the important
part and does not require that 2) be true.  The Jython compiler could
(in theory) be implemented in C, Fortran, or BASH, but there are some
practical advantages to using Java to write a compiler that generates
JVM bytecode.

-- 
Grant Edwards               grant.b.edwards        Yow! RELATIVES!!
                                  at               
                              gmail.com            


From rosuav at gmail.com  Fri Jan  9 11:15:25 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 10 Jan 2015 03:15:25 +1100
Subject: what is Jython?
In-Reply-To: <m8ouam$brp$1@reader2.panix.com>
References: <509995943442469175.487823bclark-es.co.nz@free.teranews.com>
 <mailman.17505.1420779030.18130.python-list@python.org>
 <m8ouam$brp$1@reader2.panix.com>
Message-ID: <CAPTjJmrtCLrjAa0dczp289dK_C4JVb4Zwb3H5xMehqwE-Zz9Pw@mail.gmail.com>

On Sat, Jan 10, 2015 at 3:06 AM, Grant Edwards <invalid at invalid.invalid> wrote:
> Just to clarify, Jython
>
>   1) is a Python compiler that compiles Python source code into JVM
>      bytecode (class, jar, whatever) that runs on a standard Java
>      runtime. Python programs compiled with Jython can call standard
>      Java libraries and and can call or be called by code written in
>      Java.
>
>   2) is a Python compiler that is written in Java.
>
> AFAK, these are in principal orthogonal.  Number 1) is the important
> part and does not require that 2) be true.  The Jython compiler could
> (in theory) be implemented in C, Fortran, or BASH, but there are some
> practical advantages to using Java to write a compiler that generates
> JVM bytecode.

Indeed. The point of Jython is that it compiles to Java byte-code,
putting it on par with languages like NetRexx as alternative ways to
create .class files.

ChrisA


From ian.g.kelly at gmail.com  Fri Jan  9 11:40:51 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 9 Jan 2015 09:40:51 -0700
Subject: Non-unique dirs in sys.path
In-Reply-To: <54AFD43F.5040100@yahoo.no>
References: <54AFD43F.5040100@yahoo.no>
Message-ID: <CALwzidn-TL1kazJVmeKOxjS54G-9xRfS3yZ+0qD+kyBMD0K-kg@mail.gmail.com>

On Fri, Jan 9, 2015 at 6:14 AM, Gisle Vanem <gvanem at yahoo.no> wrote:
> Why are these listed twice with different casing? One
> would assume that Python on Win32 would be case-insensitive.
> Some .pth-file to blame here?

I checked my own Python 2.7 installation and discovered that I have
the same problem, although without the different casing. Perusing the
.pth files in site-packages turns up setuptools.pth, which just
contains the site-packages path. Removing that file solves the issue
for me.


From rustompmody at gmail.com  Fri Jan  9 11:52:01 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 9 Jan 2015 08:52:01 -0800 (PST)
Subject: Why do the URLs of posts here change?
In-Reply-To: <mailman.17526.1420812949.18130.python-list@python.org>
References: <54afb3ed$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <28f970bd-188d-4455-b2b2-3320c546ad65@googlegroups.com>
 <mailman.17526.1420812949.18130.python-list@python.org>
Message-ID: <f7e24119-fd65-4525-b10c-063a7eef4ad1@googlegroups.com>

On Friday, January 9, 2015 at 7:46:42 PM UTC+5:30, Skip Montanaro wrote:
> On Fri, Jan 9, 2015 at 8:09 AM, Rustom Mody  wrote:
> 
> Theres a new app/service that should solve your problem:
> 
> Its from google... and called groups <wink>
> It solves one problem (moving archive URLs) by, I think, ignoring the other (archive posts which should really be removed).
> 
> 
> Skip

Is it?
Ok lets test that.
This is posted from google-groups.
After posting I shall remove it


From rosuav at gmail.com  Fri Jan  9 11:57:31 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 10 Jan 2015 03:57:31 +1100
Subject: Why do the URLs of posts here change?
In-Reply-To: <f7e24119-fd65-4525-b10c-063a7eef4ad1@googlegroups.com>
References: <54afb3ed$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <28f970bd-188d-4455-b2b2-3320c546ad65@googlegroups.com>
 <mailman.17526.1420812949.18130.python-list@python.org>
 <f7e24119-fd65-4525-b10c-063a7eef4ad1@googlegroups.com>
Message-ID: <CAPTjJmoYZ8jS=bk7dZx07e_Rtg3ja23BOTw_FmoXK38eGL=1zw@mail.gmail.com>

On Sat, Jan 10, 2015 at 3:52 AM, Rustom Mody <rustompmody at gmail.com> wrote:
> Is it?
> Ok lets test that.
> This is posted from google-groups.
> After posting I shall remove it

Remove it from GG, maybe, but I doubt very much it'll be removed from
the python.org archive. It's virtually impossible to remove something
from everywhere... you have to find every copy and hope none have been
web-archived yet.

ChrisA


From rustompmody at gmail.com  Fri Jan  9 12:19:01 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 9 Jan 2015 09:19:01 -0800 (PST)
Subject: Why do the URLs of posts here change?
In-Reply-To: <mailman.17537.1420822660.18130.python-list@python.org>
References: <54afb3ed$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <28f970bd-188d-4455-b2b2-3320c546ad65@googlegroups.com>
 <mailman.17526.1420812949.18130.python-list@python.org>
 <f7e24119-fd65-4525-b10c-063a7eef4ad1@googlegroups.com>
 <mailman.17537.1420822660.18130.python-list@python.org>
Message-ID: <a79802e4-dd05-4886-ba24-25567f782d84@googlegroups.com>

On Friday, January 9, 2015 at 10:27:53 PM UTC+5:30, Chris Angelico wrote:
> On Sat, Jan 10, 2015 at 3:52 AM, Rustom Mody wrote:
> > Is it?
> > Ok lets test that.
> > This is posted from google-groups.
> > After posting I shall remove it
> 
> Remove it from GG, maybe, but I doubt very much it'll be removed from
> the python.org archive. It's virtually impossible to remove something
> from everywhere... you have to find every copy and hope none have been
> web-archived yet.
> 
> ChrisA

Precisely my point.
Removing something from the web is really a meaningless activity
[apart from some moral feel-good factor]
If that gesture means something to you, GG provides it

And to the best of my knowledge it does not screw up links like mailman.
We can test in some limited way that but I dont know how to do any test which will be
reasonably exhaustive


From israel at ravnalaska.net  Fri Jan  9 12:40:25 2015
From: israel at ravnalaska.net (Israel Brewster)
Date: Fri, 9 Jan 2015 08:40:25 -0900
Subject: Track down SIGABRT
Message-ID: <B967FFA3-810A-4C9F-A353-A3C5E8C9ED6B@ravnalaska.net>

I have a long-running python/CherryPy Web App server process that I am running on Mac OS X 10.8.5. Python 2.7.2 running in 32-bit mode (for now, I have the code in place to change over to 64 bit, but need to schedule the downtime to do it). On the 6th of this month, during normal operation from what I can tell, and after around 33 days of trouble-free uptime, the python process crashed with a SIGABRT. I restarted the process, and everything looked good again until yesterday, when it again crashed with a SIGABRT. The crash dump the system gave me doesn't tell me much, other than that it looks like python is calling some C function when it crashes. I've attached the crash report, in case it can mean something more to someone else.

Can anyone give me some hints as to how to track down the cause of this crash? It's especially problematic since I can't mess with the live server for testing, and it is quite a while between crashes, making it difficult, if not impossible, to reproduce in testing. Thanks.
-----------------------------------------------
Israel Brewster
Systems Analyst II
Ravn Alaska
5245 Airport Industrial Rd
Fairbanks, AK 99709
(907) 450-7293
-----------------------------------------------



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From pkpearson at nowhere.invalid  Fri Jan  9 12:46:03 2015
From: pkpearson at nowhere.invalid (Peter Pearson)
Date: 9 Jan 2015 17:46:03 GMT
Subject: [OT] x**y == y**x
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <87a91s1kh4.fsf@elektro.pacujo.net>
 <mailman.17512.1420793559.18130.python-list@python.org>
 <qotr3v49va0.fsf@ruuvi.it.helsinki.fi>
Message-ID: <chaierFt612U1@mid.individual.net>

On 09 Jan 2015 11:07:51 +0200, Jussi Piitulainen wrote:
[snip]
> Which reminds me of a question that once made me smile, even laugh,
> and still does: 2**3 is almost 3**2 but not quite - what gives?

If you've never looked at the set of reals (x,y) satisfying x**y ==
y**x, it's worth a visit.

-- 
To email me, substitute nowhere->runbox, invalid->com.


From semeon.risom at gmail.com  Fri Jan  9 12:49:25 2015
From: semeon.risom at gmail.com (semeon.risom at gmail.com)
Date: Fri, 9 Jan 2015 09:49:25 -0800 (PST)
Subject: Generate jpg files using line length (pixels) and orientation
 (degrees)
In-Reply-To: <m8nfs8$k6e$3@dont-email.me>
References: <0f51bd21-7b0a-4ea0-8b13-27b1967d3b41@googlegroups.com>
 <m8mv27$k6e$2@dont-email.me> <m8nfs8$k6e$3@dont-email.me>
Message-ID: <1ae2a5c4-78ae-4831-ac01-b886e92c0468@googlegroups.com>

On Thursday, 8 January 2015 20:54:38 UTC-6, Denis McMahon  wrote:
> On Thu, 08 Jan 2015 22:07:03 +0000, Denis McMahon wrote:
> 
> > On Thu, 08 Jan 2015 09:09:18 -0800, semeon.risom wrote:
> > 
> >> Simple question. I hope. .....
> 
> To follow up, below is a solution to the problem you stated.
> 
> #!/usr/bin/python
> 
> import Image, ImageDraw, math
> 
> def makeimg(length, orientation):
>     """
>     Make an image file of a black 4 pixel wide line of defined length 
>     crossing and centered on a white background of 800 px square, save
>     as a png file identifying line length and orientation in the file 
>     name.
>     param length - pixels, length of the line
>     param orientation - degrees, orientation ccw of the line from +ve x 
>     axis
>     Files are saved in imgs subdir, this must already exist.
>     File name is image_lll_ooo.jpg
>     lll = length, ooo = orientation, both 0 padded to 3 digits
>     """
> 
>     # check length is +ve and not greater than 800
>     if length < 0:
>         length = length * -1
>     if length > 800:
>         length = 800
> 
>     # check orientation is positive in range 0 .. 179
>     while orientation < 0:
>         orientation = orientation + 360
>     if orientation > 179:
>         orientation = orientation % 180
> 
>     # calculate radius in pixels and orientation in radians
>     radius = length / 2
>     orient = math.radians(orientation)
> 
>     # calculate xy coords in image space of line end points
>     x1 = int(400 + (radius * math.cos(orient)))
>     y1 = int(400 - (radius * math.sin(orient)))
>     x2 = int(400 + (-radius * math.cos(orient)))
>     y2 = int(400 - (-radius * math.sin(orient)))
> 
>     # create an image
>     img = Image.new('RGB', (800,800), 'rgb(255, 255, 255)')
>     # create a draw interface
>     draw = ImageDraw.Draw(img)
> 
>     # draw the line on the image
>     draw.line([(x1, y1), (x2, y2)], fill='rgb(0, 0, 0)', width=4)
> 
>     # determine file name, save image file
>     fn = 'imgs/image_{:03d}_{:03d}.jpg'.format(length,orientation)
>     img.save(fn)
> 
> # stepping through ranges of values
> for length in range(100, 601, 100):
>     for orientation in range(0, 171, 10):
>         makeimg(length, orientation)
> 
> # using lists of values
> for length in [50, 150, 250, 350, 450, 550, 650]:
>     for orientation in [0, 15, 40, 45, 60, 75, 90, 105, 120, 135, 150, 
> 165]:
>         makeimg(length, orientation)
> 
> 
> 
> 
> -- 
> Denis McMahon, denismfmcmahon at gmail.com

Thank you for the help btw. I think I'm close to a solution, but I'm having issue feeding the coordinates from my csv file into the formula.

This is the error I get:
Traceback (most recent call last):
  File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w corr.py", line 68, in <module>
    makeimg(length, orientation)
  File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w corr.py", line 40, in makeimg
    orientation = orientation % 180
TypeError: unsupported operand type(s) for %: 'list' and 'int'
>>> 

and here's the code:

from PIL import Image, ImageDraw
from numpy import math

# import csv
import csv
f = open('C:\Users\Owner\DesktopStimuli Generation\Coordinates\file.csv', 'rb')
rdr = csv.reader(f)
f.seek(0)
i = 0
a = []
b = []
for row in rdr:
        a.append(row[0])
        b.append(row[1])

def makeimg(length, orientation):
    """
    Make an image file of a black 4 pixel wide line of defined length
    crossing and centered on a white background of 800 px square, save
    as a png file identifying line length and orientation in the file
    name.
    param length - pixels, length of the line
    param orientation - degrees, orientation ccw of the line from +ve x
    axis
    Files are saved in imgs subdir, this must already exist.
    File name is image_lll_ooo.jpg
    lll = length, ooo = orientation, both 0 padded to 3 digits
    """

    # check length is +ve and not greater than 800
    if length < 0:
        length = length * -1
    if length > 800:
        length = 800

    # check orientation is positive in range 0 .. 179
    while orientation < 0:
        orientation = orientation + 360
    if orientation > 179:
        orientation = orientation % 180

    # calculate radius in pixels and orientation in radians
    radius = length / 2
    orient = math.radians(orientation)

    # calculate xy coords in image space of line end points
    x1 = int(400 + (radius * math.cos(orient)))
    y1 = int(400 - (radius * math.sin(orient)))
    x2 = int(400 + (-radius * math.cos(orient)))
    y2 = int(400 - (-radius * math.sin(orient)))

    # create an image
    img = Image.new('RGB', (800,800), 'rgb(255, 255, 255)')
    # create a draw interface
    draw = ImageDraw.Draw(img)

    # draw the line on the image
    draw.line([(x1, y1), (x2, y2)], fill='rgb(0, 0, 0)', width=4)

    # determine file name, save image file
    fn = 'imgs/image_{:03d}_{:03d}.jpg'.format(length,orientation)
    img.save(fn)

    
# using lists of values
for length in [a]:
    for orientation in [b]:
        makeimg(length, orientation)


From stephane at wirtel.be  Fri Jan  9 13:14:18 2015
From: stephane at wirtel.be (=?utf-8?q?St=C3=A9phane?= Wirtel)
Date: Fri, 09 Jan 2015 19:14:18 +0100
Subject: PythonFOSDEM 2015 - Schedule =?utf-8?q?Updated=E2=80=A6?= We will
 start at 10:30 AM
Message-ID: <3617D6FA-103C-4936-8A44-295B79AC2866@wirtel.be>

Dear Python Community,

Because the FOSDEM will start at 10:30 AM on Saturday 31st January, the 
first talk will be at 10:30 AM.

Thus all the talks will be ajusted. The Schedule on the site of FOSDEM 
and on the PythonFOSDEM site have been updated.

https://fosdem.org/2015/schedule/track/python/

Regards,

Stephane
--
St?phane Wirtel - http://wirtel.be - @matrixise


From joel.goldstick at gmail.com  Fri Jan  9 13:18:14 2015
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Fri, 9 Jan 2015 13:18:14 -0500
Subject: Generate jpg files using line length (pixels) and orientation
 (degrees)
In-Reply-To: <1ae2a5c4-78ae-4831-ac01-b886e92c0468@googlegroups.com>
References: <0f51bd21-7b0a-4ea0-8b13-27b1967d3b41@googlegroups.com>
 <m8mv27$k6e$2@dont-email.me> <m8nfs8$k6e$3@dont-email.me>
 <1ae2a5c4-78ae-4831-ac01-b886e92c0468@googlegroups.com>
Message-ID: <CAPM-O+xSmE89naBKKRDnMTj81=xsE9LX6saWpEw-jt2=Ysyrcw@mail.gmail.com>

On Fri, Jan 9, 2015 at 12:49 PM, <semeon.risom at gmail.com> wrote:

> On Thursday, 8 January 2015 20:54:38 UTC-6, Denis McMahon  wrote:
> > On Thu, 08 Jan 2015 22:07:03 +0000, Denis McMahon wrote:
> >
> > > On Thu, 08 Jan 2015 09:09:18 -0800, semeon.risom wrote:
> > >
> > >> Simple question. I hope. .....
> >
> > To follow up, below is a solution to the problem you stated.
> >
> > #!/usr/bin/python
> >
> > import Image, ImageDraw, math
> >
> > def makeimg(length, orientation):
> >     """
> >     Make an image file of a black 4 pixel wide line of defined length
> >     crossing and centered on a white background of 800 px square, save
> >     as a png file identifying line length and orientation in the file
> >     name.
> >     param length - pixels, length of the line
> >     param orientation - degrees, orientation ccw of the line from +ve x
> >     axis
> >     Files are saved in imgs subdir, this must already exist.
> >     File name is image_lll_ooo.jpg
> >     lll = length, ooo = orientation, both 0 padded to 3 digits
> >     """
> >
> >     # check length is +ve and not greater than 800
> >     if length < 0:
> >         length = length * -1
> >     if length > 800:
> >         length = 800
> >
> >     # check orientation is positive in range 0 .. 179
> >     while orientation < 0:
> >         orientation = orientation + 360
> >     if orientation > 179:
> >         orientation = orientation % 180
> >
> >     # calculate radius in pixels and orientation in radians
> >     radius = length / 2
> >     orient = math.radians(orientation)
> >
> >     # calculate xy coords in image space of line end points
> >     x1 = int(400 + (radius * math.cos(orient)))
> >     y1 = int(400 - (radius * math.sin(orient)))
> >     x2 = int(400 + (-radius * math.cos(orient)))
> >     y2 = int(400 - (-radius * math.sin(orient)))
> >
> >     # create an image
> >     img = Image.new('RGB', (800,800), 'rgb(255, 255, 255)')
> >     # create a draw interface
> >     draw = ImageDraw.Draw(img)
> >
> >     # draw the line on the image
> >     draw.line([(x1, y1), (x2, y2)], fill='rgb(0, 0, 0)', width=4)
> >
> >     # determine file name, save image file
> >     fn = 'imgs/image_{:03d}_{:03d}.jpg'.format(length,orientation)
> >     img.save(fn)
> >
> > # stepping through ranges of values
> > for length in range(100, 601, 100):
> >     for orientation in range(0, 171, 10):
> >         makeimg(length, orientation)
> >
> > # using lists of values
> > for length in [50, 150, 250, 350, 450, 550, 650]:
> >     for orientation in [0, 15, 40, 45, 60, 75, 90, 105, 120, 135, 150,
> > 165]:
> >         makeimg(length, orientation)
> >
> >
> >
> >
> > --
> > Denis McMahon, denismfmcmahon at gmail.com
>
> Thank you for the help btw. I think I'm close to a solution, but I'm
> having issue feeding the coordinates from my csv file into the formula.
>
> This is the error I get:
> Traceback (most recent call last):
>   File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w
> corr.py", line 68, in <module>
>     makeimg(length, orientation)
>   File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w
> corr.py", line 40, in makeimg
>     orientation = orientation % 180
> TypeError: unsupported operand type(s) for %: 'list' and 'int'
> >>>
>
> and here's the code:
>
> from PIL import Image, ImageDraw
> from numpy import math
>
> # import csv
> import csv
> f = open('C:\Users\Owner\DesktopStimuli Generation\Coordinates\file.csv',
> 'rb')
> rdr = csv.reader(f)
> f.seek(0)
> i = 0
> a = []
> b = []
> for row in rdr:
>         a.append(row[0])
>         b.append(row[1])
>
> def makeimg(length, orientation):
>     """
>     Make an image file of a black 4 pixel wide line of defined length
>     crossing and centered on a white background of 800 px square, save
>     as a png file identifying line length and orientation in the file
>     name.
>     param length - pixels, length of the line
>     param orientation - degrees, orientation ccw of the line from +ve x
>     axis
>     Files are saved in imgs subdir, this must already exist.
>     File name is image_lll_ooo.jpg
>     lll = length, ooo = orientation, both 0 padded to 3 digits
>     """
>
>     # check length is +ve and not greater than 800
>     if length < 0:
>         length = length * -1
>     if length > 800:
>         length = 800
>
>     # check orientation is positive in range 0 .. 179
>     while orientation < 0:
>         orientation = orientation + 360
>     if orientation > 179:
>         orientation = orientation % 180
>
>     # calculate radius in pixels and orientation in radians
>     radius = length / 2
>     orient = math.radians(orientation)
>
>     # calculate xy coords in image space of line end points
>     x1 = int(400 + (radius * math.cos(orient)))
>     y1 = int(400 - (radius * math.sin(orient)))
>     x2 = int(400 + (-radius * math.cos(orient)))
>     y2 = int(400 - (-radius * math.sin(orient)))
>
>     # create an image
>     img = Image.new('RGB', (800,800), 'rgb(255, 255, 255)')
>     # create a draw interface
>     draw = ImageDraw.Draw(img)
>
>     # draw the line on the image
>     draw.line([(x1, y1), (x2, y2)], fill='rgb(0, 0, 0)', width=4)
>
>     # determine file name, save image file
>     fn = 'imgs/image_{:03d}_{:03d}.jpg'.format(length,orientation)
>     img.save(fn)
>
>
> # using lists of values
> for length in [a]:
>     for orientation in [b]:
>         makeimg(length, orientation)
>

above should be:
   for length in a:
      for orientation in b:


--
> https://mail.python.org/mailman/listinfo/python-list
>



-- 
Joel Goldstick
http://joelgoldstick.com
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From gcptesthp at gmail.com  Fri Jan  9 14:01:36 2015
From: gcptesthp at gmail.com (gcptesthp at gmail.com)
Date: Fri, 9 Jan 2015 11:01:36 -0800 (PST)
Subject: hello please can you help me with the below problem am facing
In-Reply-To: <mailman.17519.1420804033.18130.python-list@python.org>
References: <mailman.17519.1420804033.18130.python-list@python.org>
Message-ID: <5f77da4f-f2b6-4838-a8b4-4cad0e225582@googlegroups.com>

On Friday, January 9, 2015 at 3:47:27 AM UTC-8, mubarak idris wrote:
> Please how can I make an .exe executable app out of my python script easily

http://www.py2exe.org/


From dominic.giles at gmail.com  Fri Jan  9 14:24:48 2015
From: dominic.giles at gmail.com (Dom)
Date: Fri, 9 Jan 2015 11:24:48 -0800 (PST)
Subject: cx_Oracle, callfunc and varray
Message-ID: <db700d22-f8a0-40bb-9e01-1a9a0caba1f1@googlegroups.com>

Hi

I'm trying to return a simple array of numbers from a package using cx_oracle (5.1.2). I believe this is possible. I've not been able to find anything that suggest it isn't

create or replace TYPE NUMARRAY
-- Simple VArray of numbers
is VARRAY(3) OF NUMBER;
/

create or replace PACKAGE SIMPLEPACKAGE
AS
  FUNCTION DoSomethingSimple(
      cust_id INTEGER)
    RETURN numarray;
  FUNCTION DoSomethingSimpler(
      cust_id INTEGER)
    RETURN INTEGER;
END SIMPLEPACKAGE;
/

create or replace PACKAGE BODY SIMPLEPACKAGE
AS
FUNCTION DOSOMETHINGSIMPLE(
    cust_id INTEGER)
  RETURN numarray
AS
  simple_array numarray := numarray();
BEGIN
  simple_array.extend;
  simple_array(1) := cust_id;
  simple_array.extend;
  simple_array(2) := cust_id;
  simple_array.extend;
  simple_array(3) := cust_id;
  RETURN SIMPLE_ARRAY;
END DOSOMETHINGSIMPLE;
FUNCTION DOSOMETHINGSIMPLER(
    cust_id INTEGER)
  RETURN INTEGER
AS
BEGIN
  RETURN cust_id;
END DOSOMETHINGSIMPLER;
END SIMPLEPACKAGE;
/

The python (2.7) is very simple

import cx_Oracle

if __name__ == '__main__':
     with cx_Oracle.connect('soe', 'soe', 'oracle12c2/soe') as connection:
        try:
            cursor = connection.cursor();
            ArrayType = cursor.arrayvar(cx_Oracle.NUMBER,3)
            NumberType = cursor.var(cx_Oracle.NUMBER)
            cursor.callfunc("SIMPLEPACKAGE.DOSOMETHINGSIMPLER", NumberType, [99])
            cursor.callfunc("SIMPLEPACKAGE.DOSOMETHINGSIMPLE", ArrayType, [99])
        except cx_Oracle.DatabaseError as dberror:
            print dberror
        finally:
            cursor.close()

The call to return works just fine. The call to return the function gives the error

ORA-06550: line 1, column 13:
PLS-00382: expression is of wrong type
ORA-06550: line 1, column 7:
PL/SQL: Statement ignored

Any ideas what I'm doing wrong?

Dom





From gordon at panix.com  Fri Jan  9 16:10:58 2015
From: gordon at panix.com (John Gordon)
Date: Fri, 9 Jan 2015 21:10:58 +0000 (UTC)
Subject: cx_Oracle, callfunc and varray
References: <db700d22-f8a0-40bb-9e01-1a9a0caba1f1@googlegroups.com>
Message-ID: <m8pg52$9n8$1@reader2.panix.com>

In <db700d22-f8a0-40bb-9e01-1a9a0caba1f1 at googlegroups.com> Dom <dominic.giles at gmail.com> writes:

> create or replace PACKAGE SIMPLEPACKAGE
> AS
>   FUNCTION DoSomethingSimple(
>       cust_id INTEGER)
>     RETURN numarray;
>   FUNCTION DoSomethingSimpler(
>       cust_id INTEGER)
>     RETURN INTEGER;
> END SIMPLEPACKAGE;
> /

> Any ideas what I'm doing wrong?

Is RETURN INTEGER; allowed?

-- 
John Gordon         Imagine what it must be like for a real medical doctor to
gordon at panix.com    watch 'House', or a real serial killer to watch 'Dexter'.



From gvanem at yahoo.no  Fri Jan  9 16:24:43 2015
From: gvanem at yahoo.no (Gisle Vanem)
Date: Fri, 09 Jan 2015 21:24:43 +0000
Subject: Non-unique dirs in sys.path
In-Reply-To: <CALwzidn-TL1kazJVmeKOxjS54G-9xRfS3yZ+0qD+kyBMD0K-kg@mail.gmail.com>
References: <54AFD43F.5040100@yahoo.no>
 <CALwzidn-TL1kazJVmeKOxjS54G-9xRfS3yZ+0qD+kyBMD0K-kg@mail.gmail.com>
Message-ID: <54B0471B.7010605@yahoo.no>

Ian Kelly wrote:

> I checked my own Python 2.7 installation and discovered that I have
> the same problem, although without the different casing. Perusing the
> .pth files in site-packages turns up setuptools.pth, which just
> contains the site-packages path. Removing that file solves the issue
> for me.

That was the case here too! Deleted my setuptools.pth and the "problem"
was gone. It would be nice to know how these .pth files are involved in
extending the 'sys.path[]'. Who does that and how? Any good reference on
that?

-- 
--gv


From fomcl at yahoo.com  Fri Jan  9 16:26:52 2015
From: fomcl at yahoo.com (Albert-Jan Roskam)
Date: Fri, 9 Jan 2015 21:26:52 +0000 (UTC)
Subject: class-based class decorator
Message-ID: <879539503.1660445.1420838812525.JavaMail.yahoo@jws10784.mail.gq1.yahoo.com>



Hi,

I am trying to write a class decorator that checks whether deprecated parameters with non-default

arguments are used. More complete code is here: http://pastebin.com/ZqnMis6M. In the code below, 

how should I modify __call__ such that f.bar(old="oh no") prints "hello world"?
I thought it would be a fun way to play with the inspect module, but my head is numb now and I am thirsty for a beer!



import inspectimport functools
import warnings


class check_deprecated_args(object):
    
    """
    Class decorator that checks whether deprecated parameters with non-default
    arguments are used


    Parameters
    ----------
    deprecated_params : tuple
        tuple of strings of parameters that should raise a DeprecationWarning,
        if they are used with non-default arguments

    Raises
    ------
    DeprecationWarning : if deprecated parameters are used with 
        non-default arguments in the class's constructor.
    """

    def __init__(self, deprecated_params):
        self.deprecated_params = deprecated_params

    def __call__(self, cls):
        @functools.wraps(cls)
        def inner(*used_args, **used_kwargs):
            print "called"  
            # insert sneaky 'inspect' code here
            #pprint( dict(inspect.getmembers(cls)) )
            return cls  # --- this is wrong, it should return the Foo instance object!
        return inner

if __name__ == "__main__":
    @check_deprecated_args(deprecated_params=("old", "older"))
    class Foo(object):
        def __init__(self, old=True, older=None, new="yaay"):
            pass
        def bar(self, old=True, new=True):
            print "hello world"

    f = Foo(new="great", old="obsolete", older="stop using it")
    print repr(f)
    print f.bar(old="oh no")

 
Regards,

Albert-Jan




~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

All right, but apart from the sanitation, the medicine, education, wine, public order, irrigation, roads, a 

fresh water system, and public health, what have the Romans ever done for us?

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 


From marko at pacujo.net  Fri Jan  9 16:41:15 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Fri, 09 Jan 2015 23:41:15 +0200
Subject: [OT] x**y == y**x
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <87a91s1kh4.fsf@elektro.pacujo.net>
 <mailman.17512.1420793559.18130.python-list@python.org>
 <qotr3v49va0.fsf@ruuvi.it.helsinki.fi>
 <chaierFt612U1@mid.individual.net>
Message-ID: <87wq4vfx8k.fsf@elektro.pacujo.net>

Peter Pearson <pkpearson at nowhere.invalid>:

> If you've never looked at the set of reals (x,y) satisfying x**y ==
> y**x, it's worth a visit.

Thanks, it was. The graph's something like this:



  |         : *
  |         : *
  |         : *
  |         :  *
6 +         :  *                                              *
  |         :  *                                            **
  |         :   *                                         **
  |         :   *                                       **
  |         :    *                                    **
5 +         :    *                                  **
  |         :     *                               **
  |         :      *                            **
  |         :       *                         **
  |         :        *                      **
4 +         :         *                   **
  |         :          *                **
  |         :           *             **
  |         :            *          **
  |         :             *       **
3 +         :              *    **
  |         :               * **
  |         :               ***
  |         :             **   *****
  |         :           **          ***
2 +         :         **               *********
  |         :       **                          **
  |         :     **                              *******
  |         :   **                                       ******
  |         : **
1 +.........**.................................................
  |       **:
  |     **  :
  |   **    :
  | **      :
  +*--------+---------+---------+---------+---------+---------+
            1         2         3         4         5         6

where the line and the arc intersect at (e, e).

Where can I read more on the topic?


Marko


From semeon.risom at gmail.com  Fri Jan  9 16:51:40 2015
From: semeon.risom at gmail.com (semeon.risom at gmail.com)
Date: Fri, 9 Jan 2015 13:51:40 -0800 (PST)
Subject: Generate jpg files using line length (pixels) and orientation
 (degrees)
In-Reply-To: <mailman.17538.1420827512.18130.python-list@python.org>
References: <0f51bd21-7b0a-4ea0-8b13-27b1967d3b41@googlegroups.com>
 <m8mv27$k6e$2@dont-email.me> <m8nfs8$k6e$3@dont-email.me>
 <1ae2a5c4-78ae-4831-ac01-b886e92c0468@googlegroups.com>
 <mailman.17538.1420827512.18130.python-list@python.org>
Message-ID: <6356e045-835c-4b87-bdce-59c8f3d8bc2c@googlegroups.com>

On Friday, 9 January 2015 12:18:46 UTC-6, Joel Goldstick  wrote:
> On Fri, Jan 9, 2015 at 12:49 PM,  <semeon... at gmail.com> wrote:
> 
> 
> On Thursday, 8 January 2015 20:54:38 UTC-6, Denis McMahon? wrote:
> 
> > On Thu, 08 Jan 2015 22:07:03 +0000, Denis McMahon wrote:
> 
> >
> 
> > > On Thu, 08 Jan 2015 09:09:18 -0800, semeon.risom wrote:
> 
> > >
> 
> > >> Simple question. I hope. .....
> 
> >
> 
> > To follow up, below is a solution to the problem you stated.
> 
> >
> 
> > #!/usr/bin/python
> 
> >
> 
> > import Image, ImageDraw, math
> 
> >
> 
> > def makeimg(length, orientation):
> 
> >? ? ?"""
> 
> >? ? ?Make an image file of a black 4 pixel wide line of defined length
> 
> >? ? ?crossing and centered on a white background of 800 px square, save
> 
> >? ? ?as a png file identifying line length and orientation in the file
> 
> >? ? ?name.
> 
> >? ? ?param length - pixels, length of the line
> 
> >? ? ?param orientation - degrees, orientation ccw of the line from +ve x
> 
> >? ? ?axis
> 
> >? ? ?Files are saved in imgs subdir, this must already exist.
> 
> >? ? ?File name is image_lll_ooo.jpg
> 
> >? ? ?lll = length, ooo = orientation, both 0 padded to 3 digits
> 
> >? ? ?"""
> 
> >
> 
> >? ? ?# check length is +ve and not greater than 800
> 
> >? ? ?if length < 0:
> 
> >? ? ? ? ?length = length * -1
> 
> >? ? ?if length > 800:
> 
> >? ? ? ? ?length = 800
> 
> >
> 
> >? ? ?# check orientation is positive in range 0 .. 179
> 
> >? ? ?while orientation < 0:
> 
> >? ? ? ? ?orientation = orientation + 360
> 
> >? ? ?if orientation > 179:
> 
> >? ? ? ? ?orientation = orientation % 180
> 
> >
> 
> >? ? ?# calculate radius in pixels and orientation in radians
> 
> >? ? ?radius = length / 2
> 
> >? ? ?orient = math.radians(orientation)
> 
> >
> 
> >? ? ?# calculate xy coords in image space of line end points
> 
> >? ? ?x1 = int(400 + (radius * math.cos(orient)))
> 
> >? ? ?y1 = int(400 - (radius * math.sin(orient)))
> 
> >? ? ?x2 = int(400 + (-radius * math.cos(orient)))
> 
> >? ? ?y2 = int(400 - (-radius * math.sin(orient)))
> 
> >
> 
> >? ? ?# create an image
> 
> >? ? ?img = Image.new('RGB', (800,800), 'rgb(255, 255, 255)')
> 
> >? ? ?# create a draw interface
> 
> >? ? ?draw = ImageDraw.Draw(img)
> 
> >
> 
> >? ? ?# draw the line on the image
> 
> >? ? ?draw.line([(x1, y1), (x2, y2)], fill='rgb(0, 0, 0)', width=4)
> 
> >
> 
> >? ? ?# determine file name, save image file
> 
> >? ? ?fn = 'imgs/image_{:03d}_{:03d}.jpg'.format(length,orientation)
> 
> >? ? ?img.save(fn)
> 
> >
> 
> > # stepping through ranges of values
> 
> > for length in range(100, 601, 100):
> 
> >? ? ?for orientation in range(0, 171, 10):
> 
> >? ? ? ? ?makeimg(length, orientation)
> 
> >
> 
> > # using lists of values
> 
> > for length in [50, 150, 250, 350, 450, 550, 650]:
> 
> >? ? ?for orientation in [0, 15, 40, 45, 60, 75, 90, 105, 120, 135, 150,
> 
> > 165]:
> 
> >? ? ? ? ?makeimg(length, orientation)
> 
> >
> 
> >
> 
> >
> 
> >
> 
> > --
> 
> > Denis McMahon, denismf... at gmail.com
> 
> 
> 
> Thank you for the help btw. I think I'm close to a solution, but I'm having issue feeding the coordinates from my csv file into the formula.
> 
> 
> 
> This is the error I get:
> 
> Traceback (most recent call last):
> 
> ? File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w corr.py", line 68, in <module>
> 
> ? ? makeimg(length, orientation)
> 
> ? File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w corr.py", line 40, in makeimg
> 
> ? ? orientation = orientation % 180
> 
> TypeError: unsupported operand type(s) for %: 'list' and 'int'
> 
> >>>
> 
> 
> 
> and here's the code:
> 
> 
> 
> from PIL import Image, ImageDraw
> 
> from numpy import math
> 
> 
> 
> # import csv
> 
> import csv
> 
> f = open('C:\Users\Owner\DesktopStimuli Generation\Coordinates\file.csv', 'rb')
> 
> rdr = csv.reader(f)
> 
> f.seek(0)
> 
> i = 0
> 
> a = []
> 
> b = []
> 
> for row in rdr:
> 
> ? ? ? ? a.append(row[0])
> 
> ? ? ? ? b.append(row[1])
> 
> 
> 
> 
> 
> def makeimg(length, orientation):
> 
> ? ? """
> 
> ? ? Make an image file of a black 4 pixel wide line of defined length
> 
> ? ? crossing and centered on a white background of 800 px square, save
> 
> ? ? as a png file identifying line length and orientation in the file
> 
> ? ? name.
> 
> ? ? param length - pixels, length of the line
> 
> ? ? param orientation - degrees, orientation ccw of the line from +ve x
> 
> ? ? axis
> 
> ? ? Files are saved in imgs subdir, this must already exist.
> 
> ? ? File name is image_lll_ooo.jpg
> 
> ? ? lll = length, ooo = orientation, both 0 padded to 3 digits
> 
> ? ? """
> 
> 
> 
> ? ? # check length is +ve and not greater than 800
> 
> ? ? if length < 0:
> 
> ? ? ? ? length = length * -1
> 
> ? ? if length > 800:
> 
> ? ? ? ? length = 800
> 
> 
> 
> ? ? # check orientation is positive in range 0 .. 179
> 
> ? ? while orientation < 0:
> 
> ? ? ? ? orientation = orientation + 360
> 
> ? ? if orientation > 179:
> 
> ? ? ? ? orientation = orientation % 180
> 
> 
> 
> ? ? # calculate radius in pixels and orientation in radians
> 
> ? ? radius = length / 2
> 
> ? ? orient = math.radians(orientation)
> 
> 
> 
> ? ? # calculate xy coords in image space of line end points
> 
> ? ? x1 = int(400 + (radius * math.cos(orient)))
> 
> ? ? y1 = int(400 - (radius * math.sin(orient)))
> 
> ? ? x2 = int(400 + (-radius * math.cos(orient)))
> 
> ? ? y2 = int(400 - (-radius * math.sin(orient)))
> 
> 
> 
> ? ? # create an image
> 
> ? ? img = Image.new('RGB', (800,800), 'rgb(255, 255, 255)')
> 
> ? ? # create a draw interface
> 
> ? ? draw = ImageDraw.Draw(img)
> 
> 
> 
> ? ? # draw the line on the image
> 
> ? ? draw.line([(x1, y1), (x2, y2)], fill='rgb(0, 0, 0)', width=4)
> 
> 
> 
> ? ? # determine file name, save image file
> 
> ? ? fn = 'imgs/image_{:03d}_{:03d}.jpg'.format(length,orientation)
> 
> ? ? img.save(fn)
> 
> 
> 
> 
> 
> # using lists of values
> 
> for length in [a]:
> 
> ? ? for orientation in [b]:
> 
> ? ? ? ? makeimg(length, orientation)
> 
> 
> 
> above should be:
> ? ?for length in a:
> ? ? ? for orientation in b:
> 
> 
> 
> 
> --
> 
> https://mail.python.org/mailman/listinfo/python-list
> 
> 
> 
> 
> 
> -- 
> 
> 
> 
> Joel Goldstick
> http://joelgoldstick.com

Unfortunately getting a new error.

Traceback (most recent call last):
  File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w corr.py", line 68, in <module>
    makeimg(length, orientation)
  File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w corr.py", line 40, in makeimg
    orientation = orientation % 180
TypeError: not all arguments converted during string formatting
>>>


From stephen.boulet at gmail.com  Fri Jan  9 17:14:35 2015
From: stephen.boulet at gmail.com (stephen.boulet at gmail.com)
Date: Fri, 9 Jan 2015 14:14:35 -0800 (PST)
Subject: Help configuring visual studio to compile python extensions
In-Reply-To: <5c51c0ef-b2d0-4edd-b3cd-37759b5807e8@googlegroups.com>
References: <5c51c0ef-b2d0-4edd-b3cd-37759b5807e8@googlegroups.com>
Message-ID: <12a44355-0966-4e91-aac2-da0d8f722e3c@googlegroups.com>

This page helped me sort everything out: http://www.falatic.com/index.php/120/a-guide-to-building-python-2-x-and-3-x-extensions-for-windows.


From dan at tombstonezero.net  Fri Jan  9 17:21:19 2015
From: dan at tombstonezero.net (Dan Sommers)
Date: Fri, 9 Jan 2015 22:21:19 +0000 (UTC)
Subject: Generate jpg files using line length (pixels) and orientation
 (degrees)
References: <0f51bd21-7b0a-4ea0-8b13-27b1967d3b41@googlegroups.com>
 <m8mv27$k6e$2@dont-email.me> <m8nfs8$k6e$3@dont-email.me>
 <1ae2a5c4-78ae-4831-ac01-b886e92c0468@googlegroups.com>
 <mailman.17538.1420827512.18130.python-list@python.org>
 <6356e045-835c-4b87-bdce-59c8f3d8bc2c@googlegroups.com>
Message-ID: <m8pk8u$1mr$1@dont-email.me>


> Unfortunately getting a new error.
> 
> Traceback (most recent call last):
>   File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w corr.py", line 68, in <module>
>     makeimg(length, orientation)
>   File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w corr.py", line 40, in makeimg
>     orientation = orientation % 180
> TypeError: not all arguments converted during string formatting
>>>>

My guess is that orientation contains a string that doesn't contain a '%'
character:

Python 3.4.2 (default, Oct  8 2014, 10:45:20) 
[GCC 4.9.1] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> 'this is a string' % 180
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: not all arguments converted during string formatting



From davea at davea.name  Fri Jan  9 17:23:19 2015
From: davea at davea.name (Dave Angel)
Date: Fri, 09 Jan 2015 17:23:19 -0500
Subject: Generate jpg files using line length (pixels) and orientation
 (degrees)
In-Reply-To: <6356e045-835c-4b87-bdce-59c8f3d8bc2c@googlegroups.com>
References: <0f51bd21-7b0a-4ea0-8b13-27b1967d3b41@googlegroups.com>
 <m8mv27$k6e$2@dont-email.me> <m8nfs8$k6e$3@dont-email.me>
 <1ae2a5c4-78ae-4831-ac01-b886e92c0468@googlegroups.com>
 <mailman.17538.1420827512.18130.python-list@python.org>
 <6356e045-835c-4b87-bdce-59c8f3d8bc2c@googlegroups.com>
Message-ID: <54B054D7.8060409@davea.name>

On 01/09/2015 04:51 PM, semeon.risom at gmail.com wrote:
> On Friday, 9 January 2015 12:18:46 UTC-6, Joel Goldstick  wrote:
>> On Fri, Jan 9, 2015 at 12:49 PM,  <semeon... at gmail.com> wrote:

(double-spaced nonsense mostly trimmed)

>>
>> i = 0
>> a = []
>> b = []

What are a and b supposed to contain?   Please use more informative 
names for them.  it looks like they are intended to be lists of floats, 
but you're then stuffing them with strings.

>> for row in rdr:
>>          a.append(row[0])
>>          b.append(row[1])

perhaps something like:
             a.append(float(row[0]))
             b.append(float(row[1]))

>>
>> def makeimg(length, orientation):

Probably should add some type checking here, since you're having 
repeated errors.

         if type(length) not is float or type(orientation) not is float:
                    .....  some educational error message showing what 
the types and values actually are.....

Note I'm NOT recommending you code it this way.  Just add the check till 
you've narrowed down the errors.

>>
>>
>>
>>
.....

> Unfortunately getting a new error.
>
> Traceback (most recent call last):
>    File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w corr.py", line 68, in <module>
>      makeimg(length, orientation)
>    File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w corr.py", line 40, in makeimg
>      orientation = orientation % 180
> TypeError: not all arguments converted during string formatting
>>>>

I think that's because the % operator means an entirely different thing 
if orientation is mistakenly passed as a string.


-- 
DaveA


From breamoreboy at yahoo.co.uk  Fri Jan  9 17:36:58 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Fri, 09 Jan 2015 22:36:58 +0000
Subject: Help configuring visual studio to compile python extensions
In-Reply-To: <12a44355-0966-4e91-aac2-da0d8f722e3c@googlegroups.com>
References: <5c51c0ef-b2d0-4edd-b3cd-37759b5807e8@googlegroups.com>
 <12a44355-0966-4e91-aac2-da0d8f722e3c@googlegroups.com>
Message-ID: <m8pl6h$4sf$1@ger.gmane.org>

On 09/01/2015 22:14, stephen.boulet at gmail.com wrote:
> This page helped me sort everything out: http://www.falatic.com/index.php/120/a-guide-to-building-python-2-x-and-3-x-extensions-for-windows.
>

That's good to know both for you and me but in future could you please 
quote some context, thanks :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From breamoreboy at yahoo.co.uk  Fri Jan  9 17:41:41 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Fri, 09 Jan 2015 22:41:41 +0000
Subject: Generate jpg files using line length (pixels) and orientation
 (degrees)
In-Reply-To: <6356e045-835c-4b87-bdce-59c8f3d8bc2c@googlegroups.com>
References: <0f51bd21-7b0a-4ea0-8b13-27b1967d3b41@googlegroups.com>
 <m8mv27$k6e$2@dont-email.me> <m8nfs8$k6e$3@dont-email.me>
 <1ae2a5c4-78ae-4831-ac01-b886e92c0468@googlegroups.com>
 <mailman.17538.1420827512.18130.python-list@python.org>
 <6356e045-835c-4b87-bdce-59c8f3d8bc2c@googlegroups.com>
Message-ID: <m8plfc$b8b$1@ger.gmane.org>

On 09/01/2015 21:51, semeon.risom at gmail.com wrote:

[As per Dave Angel snip all the double spaced nonsence]

Please access this list via 
https://mail.python.org/mailman/listinfo/python-list or read and action 
this https://wiki.python.org/moin/GoogleGroupsPython to prevent us 
seeing double line spacing and single line paragraphs, thanks.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From ian.g.kelly at gmail.com  Fri Jan  9 17:49:54 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 9 Jan 2015 15:49:54 -0700
Subject: Non-unique dirs in sys.path
In-Reply-To: <54B0471B.7010605@yahoo.no>
References: <54AFD43F.5040100@yahoo.no>
 <CALwzidn-TL1kazJVmeKOxjS54G-9xRfS3yZ+0qD+kyBMD0K-kg@mail.gmail.com>
 <54B0471B.7010605@yahoo.no>
Message-ID: <CALwzidmvjRsUBC6C5dLmNf-QhsskAQvjR+17H6KsT+WJNHdthw@mail.gmail.com>

On Fri, Jan 9, 2015 at 2:24 PM, Gisle Vanem <gvanem at yahoo.no> wrote:
> Ian Kelly wrote:
>
>> I checked my own Python 2.7 installation and discovered that I have
>> the same problem, although without the different casing. Perusing the
>> .pth files in site-packages turns up setuptools.pth, which just
>> contains the site-packages path. Removing that file solves the issue
>> for me.
>
>
> That was the case here too! Deleted my setuptools.pth and the "problem"
> was gone. It would be nice to know how these .pth files are involved in
> extending the 'sys.path[]'. Who does that and how? Any good reference on
> that?

The automatically imported site module processes the .pth files.

https://docs.python.org/2/library/site.html


From stephen.boulet at gmail.com  Fri Jan  9 18:08:57 2015
From: stephen.boulet at gmail.com (stephen.boulet at gmail.com)
Date: Fri, 9 Jan 2015 15:08:57 -0800 (PST)
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
Message-ID: <2f1dd848-e075-4435-93ef-c65af9a5148b@googlegroups.com>

On Wednesday, December 31, 2014 at 4:24:50 PM UTC-6, Andr? Roberge wrote:
> EasyGUI_Qt version 0.9 has been released.  This is the first announcement about EasyGUI_Qt on this list.
> 
> Like the original EasyGUI (which used Tkinter), 
> EasyGUI_Qt seeks to provide simple GUI widgets
> that can be called in a procedural program. 
> 
> EasyGUI_Qt is NOT event-driven: all GUI interactions are invoked by simple function calls.
> 
> The archetype is get_string(message)
> which pops a box whose purpose is exactly the same as Python's input(prompt),
> that is, present the user with a question/prompt, have the user enter an
> answer, and return the provided answer as a string.  Thus
> easygui_qt.get_string() can be used as a drop-in replacement for
> input().
> 
> Similarly, instead of using a print() function to display a message,
> show_message() is used which pops a message window.
> 
> EasyGUI_Qt requires PyQt4 and is really targeted for Python 3.3+ - although it can work (possibly with some unicode problems ...) using Python 2.7.
> 
> More information can be found at 
> http://easygui-qt.readthedocs.org/en/latest/index.html
> 
> Feedback is most welcome, including reporting bugs to 
> https://github.com/aroberge/easygui_qt/issues
> 
> Happy 2015 everyone,
> 
> Andr? Roberge

Very nice, thanks.

One issue is the format returned for the calendar selection. For today, the string returned is "Fri Jan 9 2015". My script needs to convert the date to a datetime.date, and having the month returned as a string instead of an integer makes this harder.


From stephen.boulet at gmail.com  Fri Jan  9 18:16:36 2015
From: stephen.boulet at gmail.com (stephen.boulet at gmail.com)
Date: Fri, 9 Jan 2015 15:16:36 -0800 (PST)
Subject: Help configuring visual studio to compile python extensions
In-Reply-To: <5c51c0ef-b2d0-4edd-b3cd-37759b5807e8@googlegroups.com>
References: <5c51c0ef-b2d0-4edd-b3cd-37759b5807e8@googlegroups.com>
Message-ID: <7170728d-3242-4480-92d2-60cf9458abfd@googlegroups.com>

On Friday, January 9, 2015 at 8:58:59 AM UTC-6, stephen... at gmail.com wrote:
> I've installed Microsoft Visual Studio 10.0. Here are the steps I've been taking.
> 
> My python version is Python 3.4.2 (v3.4.2:ab2c023a9432, Oct  6 2014, 22:16:31) [MSC v.1600 64 bit (AMD64)] on win32.
> 
> (Sorry for the long output.)
> 
> >cd "c:\Program Files (x86)\Microsoft Visual Studio 10.0"\vc
> >vcvarsall.bat
> >
> >SET VS90COMNTOOLS=%VS100COMNTOOLS%
> c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC>pip install scandir
> Collecting scandir
>   Using cached scandir-0.9.tar.gz
> Installing collected packages: scandir
>   Running setup.py install for scandir
>     building '_scandir' extension
>     C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\BIN\cl.exe /c /nologo /Ox /MD /W3 /GS- /DNDEBUG -Ic:\Python34\include -Ic:\Python34\include /Tc_scandir.c /Fobuild\temp.win-amd64-3.4\Release
> \_scandir.obj
>     _scandir.c
>     C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\BIN\link.exe /DLL /nologo /INCREMENTAL:NO /LIBPATH:c:\Python34\libs /LIBPATH:c:\Python34\PCbuild\amd64 /EXPORT:PyInit__scandir build\temp.win
> -amd64-3.4\Release\_scandir.obj /OUT:build\lib.win-amd64-3.4\_scandir.pyd /IMPLIB:build\temp.win-amd64-3.4\Release\_scandir.lib /MANIFESTFILE:build\temp.win-amd64-3.4\Release\_scandir.pyd.manifest
>        Creating library build\temp.win-amd64-3.4\Release\_scandir.lib and object build\temp.win-amd64-3.4\Release\_scandir.exp
>     _scandir.obj : error LNK2001: unresolved external symbol _PyObject_SelfIter
>     _scandir.obj : error LNK2001: unresolved external symbol _PyObject_GenericGetAttr
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_WarnEx referenced in function _win32_warn_bytes_api
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyExc_DeprecationWarning referenced in function _win32_warn_bytes_api
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_Occurred referenced in function _path_converter
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyBytes_FromObject referenced in function _path_converter
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_Clear referenced in function _path_converter
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyExc_ValueError referenced in function _path_converter
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyUnicode_AsUnicodeAndSize referenced in function _path_converter
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyUnicode_FromObject referenced in function _path_converter
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_Format referenced in function _path_converter
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyExc_TypeError referenced in function _path_converter
>     _scandir.obj : error LNK2019: unresolved external symbol __imp___Py_NoneStruct referenced in function _path_converter
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyLong_FromUnsignedLong referenced in function _find_data_to_statresult
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyFloat_FromDouble referenced in function _find_data_to_statresult
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyLong_FromUnsignedLongLong referenced in function _find_data_to_statresult
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyLong_FromLong referenced in function _find_data_to_statresult
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyStructSequence_New referenced in function _find_data_to_statresult
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyEval_RestoreThread referenced in function __fi_close
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyEval_SaveThread referenced in function __fi_close
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__Py_BuildValue referenced in function __fi_next
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_SetFromWindowsErr referenced in function __fi_next
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_NoMemory referenced in function __fi_next
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_SetNone referenced in function __fi_next
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyExc_StopIteration referenced in function __fi_next
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyObject_Free referenced in function _fi_dealloc
>     _scandir.obj : error LNK2019: unresolved external symbol __imp___PyObject_New referenced in function __iterfile
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyArg_ParseTupleAndKeywords referenced in function _scandir_helper
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyStructSequence_InitType referenced in function _PyInit__scandir
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyType_Ready referenced in function _PyInit__scandir
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyModule_Create2 referenced in function _PyInit__scandir
>     build\lib.win-amd64-3.4\_scandir.pyd : fatal error LNK1120: 31 unresolved externals
>     error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio 10.0\\VC\\BIN\\link.exe' failed with exit status 1120
>     Complete output from command c:\Python34\python.exe -c "import setuptools, tokenize;__file__='C:\\Users\\SBO010\\AppData\\Local\\Temp\\pip-build-gd_12t27\\scandir\\setup.py';exec(compile(getattr(t
> okenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record C:\Users\SBO010\AppData\Local\Temp\pip-tzadruqn-record\install-record.txt --single-version-externall
> y-managed --compile:
>     running install
> 
>     running build
> 
>     running build_py
> 
>     creating build
> 
>     creating build\lib.win-amd64-3.4
> 
>     copying scandir.py -> build\lib.win-amd64-3.4
> 
>     running build_ext
> 
>     building '_scandir' extension
> 
>     creating build\temp.win-amd64-3.4
> 
>     creating build\temp.win-amd64-3.4\Release
> 
>     C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\BIN\cl.exe /c /nologo /Ox /MD /W3 /GS- /DNDEBUG -Ic:\Python34\include -Ic:\Python34\include /Tc_scandir.c /Fobuild\temp.win-amd64-3.4\Release
> \_scandir.obj
> 
>     _scandir.c
> 
>     C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\BIN\link.exe /DLL /nologo /INCREMENTAL:NO /LIBPATH:c:\Python34\libs /LIBPATH:c:\Python34\PCbuild\amd64 /EXPORT:PyInit__scandir build\temp.win
> -amd64-3.4\Release\_scandir.obj /OUT:build\lib.win-amd64-3.4\_scandir.pyd /IMPLIB:build\temp.win-amd64-3.4\Release\_scandir.lib /MANIFESTFILE:build\temp.win-amd64-3.4\Release\_scandir.pyd.manifest
> 
>        Creating library build\temp.win-amd64-3.4\Release\_scandir.lib and object build\temp.win-amd64-3.4\Release\_scandir.exp
> 
>     _scandir.obj : error LNK2001: unresolved external symbol _PyObject_SelfIter
> 
>     _scandir.obj : error LNK2001: unresolved external symbol _PyObject_GenericGetAttr
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_WarnEx referenced in function _win32_warn_bytes_api
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyExc_DeprecationWarning referenced in function _win32_warn_bytes_api
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_Occurred referenced in function _path_converter
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyBytes_FromObject referenced in function _path_converter
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_Clear referenced in function _path_converter
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyExc_ValueError referenced in function _path_converter
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyUnicode_AsUnicodeAndSize referenced in function _path_converter
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyUnicode_FromObject referenced in function _path_converter
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_Format referenced in function _path_converter
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyExc_TypeError referenced in function _path_converter
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp___Py_NoneStruct referenced in function _path_converter
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyLong_FromUnsignedLong referenced in function _find_data_to_statresult
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyFloat_FromDouble referenced in function _find_data_to_statresult
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyLong_FromUnsignedLongLong referenced in function _find_data_to_statresult
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyLong_FromLong referenced in function _find_data_to_statresult
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyStructSequence_New referenced in function _find_data_to_statresult
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyEval_RestoreThread referenced in function __fi_close
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyEval_SaveThread referenced in function __fi_close
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__Py_BuildValue referenced in function __fi_next
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_SetFromWindowsErr referenced in function __fi_next
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_NoMemory referenced in function __fi_next
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyErr_SetNone referenced in function __fi_next
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyExc_StopIteration referenced in function __fi_next
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyObject_Free referenced in function _fi_dealloc
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp___PyObject_New referenced in function __iterfile
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyArg_ParseTupleAndKeywords referenced in function _scandir_helper
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyStructSequence_InitType referenced in function _PyInit__scandir
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyType_Ready referenced in function _PyInit__scandir
> 
>     _scandir.obj : error LNK2019: unresolved external symbol __imp__PyModule_Create2 referenced in function _PyInit__scandir
> 
>     build\lib.win-amd64-3.4\_scandir.pyd : fatal error LNK1120: 31 unresolved externals
> 
>     error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio 10.0\\VC\\BIN\\link.exe' failed with exit status 1120
> 
>     ----------------------------------------
>     Command "c:\Python34\python.exe -c "import setuptools, tokenize;__file__='C:\\Users\\SBO010\\AppData\\Local\\Temp\\pip-build-gd_12t27\\scandir\\setup.py';exec(compile(getattr(tokenize, 'open', ope
> n)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record C:\Users\SBO010\AppData\Local\Temp\pip-tzadruqn-record\install-record.txt --single-version-externally-managed --compile"
>  failed with error code 1 in C:\Users\SBO010\AppData\Local\Temp\pip-build-gd_12t27\scandir
> 
> c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC>

This page helped me sort everything out: http://www.falatic.com/index.php/120/a-guide-to-building-python-2-x-and-3-x-extensions-for-windows. 


From andre.roberge at gmail.com  Fri Jan  9 19:21:22 2015
From: andre.roberge at gmail.com (=?ISO-8859-1?Q?Andr=E9_Roberge?=)
Date: Fri, 9 Jan 2015 16:21:22 -0800 (PST)
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <2f1dd848-e075-4435-93ef-c65af9a5148b@googlegroups.com>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
 <2f1dd848-e075-4435-93ef-c65af9a5148b@googlegroups.com>
Message-ID: <03bf997a-fd9f-4b8c-8aa9-43f421a6db8f@googlegroups.com>

On Friday, 9 January 2015 19:09:15 UTC-4, stephen... at gmail.com  wrote:

> Very nice, thanks.
> 
> One issue is the format returned for the calendar selection. For today, the string returned is "Fri Jan 9 2015". My script needs to convert the date to a datetime.date, and having the month returned as a string instead of an integer makes this harder.

Unfortunately, this is the default calendar widget from Qt - I just use the default:
 ...     def confirm(self):
        self.date = self.cal.selectedDate()

Perhaps I can find something in the docs to see if I could have the format configurable.


From andre.roberge at gmail.com  Fri Jan  9 20:02:12 2015
From: andre.roberge at gmail.com (=?ISO-8859-1?Q?Andr=E9_Roberge?=)
Date: Fri, 9 Jan 2015 17:02:12 -0800 (PST)
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <2f1dd848-e075-4435-93ef-c65af9a5148b@googlegroups.com>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
 <2f1dd848-e075-4435-93ef-c65af9a5148b@googlegroups.com>
Message-ID: <b4d90fbf-9f5a-4ffa-9013-0e70fc3e4e24@googlegroups.com>

On Friday, 9 January 2015 19:09:15 UTC-4, stephen... at gmail.com  wrote:
> On Wednesday, December 31, 2014 at 4:24:50 PM UTC-6, Andr? Roberge wrote:
> > EasyGUI_Qt version 0.9 has been released.  This is the first announcement about EasyGUI_Qt on this list.
> > 
> > Like the original EasyGUI (which used Tkinter), 
> > EasyGUI_Qt seeks to provide simple GUI widgets
> > that can be called in a procedural program. 
> > 
> > EasyGUI_Qt is NOT event-driven: all GUI interactions are invoked by simple function calls.
> > 
> > The archetype is get_string(message)
> > which pops a box whose purpose is exactly the same as Python's input(prompt),
> > that is, present the user with a question/prompt, have the user enter an
> > answer, and return the provided answer as a string.  Thus
> > easygui_qt.get_string() can be used as a drop-in replacement for
> > input().
> > 
> > Similarly, instead of using a print() function to display a message,
> > show_message() is used which pops a message window.
> > 
> > EasyGUI_Qt requires PyQt4 and is really targeted for Python 3.3+ - although it can work (possibly with some unicode problems ...) using Python 2.7.
> > 
> > More information can be found at 
> > http://easygui-qt.readthedocs.org/en/latest/index.html
> > 
> > Feedback is most welcome, including reporting bugs to 
> > https://github.com/aroberge/easygui_qt/issues
> > 
> > Happy 2015 everyone,
> > 
> > Andr? Roberge
> 
> Very nice, thanks.
> 
> One issue is the format returned for the calendar selection. For today, the string returned is "Fri Jan 9 2015". My script needs to convert the date to a datetime.date, and having the month returned as a string instead of an integer makes this harder.

Would today's date be represented as the string "09.01.2015" useful to you? (I found out how to do this.)  If so, I could perhaps add an argument like numeric_format = True.

Andr?


From rosuav at gmail.com  Fri Jan  9 20:07:44 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 10 Jan 2015 12:07:44 +1100
Subject: class-based class decorator
In-Reply-To: <879539503.1660445.1420838812525.JavaMail.yahoo@jws10784.mail.gq1.yahoo.com>
References: <879539503.1660445.1420838812525.JavaMail.yahoo@jws10784.mail.gq1.yahoo.com>
Message-ID: <CAPTjJmrV0v_SQQZkKAqVOz0nW6V_1QBxAdSfzftAVy+W2+_Xjw@mail.gmail.com>

On Sat, Jan 10, 2015 at 8:26 AM, Albert-Jan Roskam
<fomcl at yahoo.com.dmarc.invalid> wrote:
> I am trying to write a class decorator that checks whether deprecated parameters with non-default
>
> arguments are used. More complete code is here: http://pastebin.com/ZqnMis6M. In the code below,
>

Any particular reason to make this a class decorator, rather than a
function decorator on __init__? After all, __init__ is where you're
defining the deprecated parameters.

ChrisA


From jeanpierreda at gmail.com  Fri Jan  9 20:25:38 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Fri, 9 Jan 2015 17:25:38 -0800
Subject: Decimals and other numbers
In-Reply-To: <54afab5d$0$12976$c3e8da3$5496439d@news.astraweb.com>
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <54af9612$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17513.1420793970.18130.python-list@python.org>
 <54afab5d$0$12976$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CABicbJJ3e-U6wJdHbpkNVg44zyj6pzYfoVzMHrGU9euFzw5ihw@mail.gmail.com>

On Fri, Jan 9, 2015 at 2:20 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
-snip-
> I don't understand what you're trying to say here. You can't just
> arbitrarily declare that 0**1 equals something other than 0 (or for that
> matter, doesn't equal anything at all).

You can, actually. It's just silly. (Similarly, you can declare that
0**0 is something other than 1 (or for that matter, doesn't equal
anything at all), but it's silly.)

> Can we agree that 0**1 is well-defined and get back to 0**0?

Believe it or not I actually misread your whole thing and thought we
were talking about 0**0. Otherwise I would've been much briefer...

>>> Not quite. I agree that, *generally speaking* having 0**0 equal 1 is the
>>> right answer, or at least *a* right answer, but not always. It depends on
>>> how you get to 0**0...
>>
>> You don't "get to" a number. Those are limits. Limits and arithmetic
>> are different.
>>
>> (Well, sort of. :)
>
> Yes, sort of :-)

I was alluding to the definition of the reals.

> Of course you can "get to" numbers. We start with counting, that's a way
> to "get to" the natural numbers, by applying the "successor" function
> repeatedly until we reach the one we want. Or you can "get to" pi by
> generating an infinite sequence of closer and closer approximations. Or an
> infinite series. Or an infinite product. Or an infinite continued fraction.
> All of these "ways to get to pi" converge on the same result.

Yes, all numbers can be represented as a converging limit. However,
that does not mean that the way you compute the result of a function
like x**y is by taking the limit as its arguments approach the input:
that procedure works only for continuous functions. x**y is not
continuous at 0, so this style of computation cannot give you an
answer.

> If 0**0 has a value, we can give that number a name. Let's call it Q. There
> are different ways to evaluate Q:
>
> lim x -> 0 of sin(x)/x  gives 1
>
> lim x -> 0 of x**0  gives 1
>
> lim x -> 0 of 0**x  gives 0

This is a proof that f(x, y) = x**y is not continuous around 0, 0. It
is not a proof that it is undefined at 0, 0, in fact, it says nothing
about the value.

> 0**0 = 0**(5-5) = 0**5 / 0**5 = 0/0  gives indeterminate

Here is a nearly identical "proof" that 0**1 is "indeterminate": 0 =
0**1 = 0**(5 - 4) = 0**5 / 0**4 = 0/0 gives indeterminate.

The fact that you can construct a nonsensical expression from an
expression doesn't mean the original expression was nonsensical. In
this case, your proof was invalid, because 0**(X-Y) is not equivalent
to 0**X/0**Y.

> So we have a problem. Since all these "ways to get to Q" fail to converge,
> the obvious answer is to declare that Q doesn't exist and that 0**0 is
> indeterminate, and that is what many mathematicians do:

That isn't what "indeterminate" means.

> However, this begs the question of what we mean by 0**0.
>
> In the case of m**n, with both m and n positive integers, there is an
> intuitively obvious definition for exponentiation: repeated multiplication.
> But there's no obvious meaning for exponentiation when both m and n are
> zero, hence we (meaning, mathematicians) have to define what it means. So
> long as that definition doesn't lead to contradiction, we can make any
> choice we like.

Sorry, I don't follow. n**0 as repeated multiplication makes perfect
sense: we don't perform any multiplications, but if we did, we'd be
multiplying 'n's. 0**m as repeated multiplication makes perfect sense:
whatever we multiply, it's a bunch of 0s. Why doesn't 0**0 make sense?
We don't perform any multiplications, but if we did, we'd be
multiplying 0s.

If we don't perform any multiplications, the things we didn't multiply
don't matter. Whether they are fives, sevens, or zeroes, the answer is
the same: 1.

>>> Since you can get difference results depending on the method you use to
>>> calculate it, the "technically correct" result is that 0**0 is
>>> indeterminate.
>>
>> No, only limits are indeterminate. Calculations not involving limits
>> cannot be indeterminate.
>
> Do tell me what 0/0 equals, if it is not indeterminate.

0/0 is undefined, it isn't "indeterminate".

Indeterminate forms are a way of expressing limits where you have
performed a lossy substitution. That is: "the limit as x approaches a
of 0/0" is an indeterminate form.

>> In the real number system, infinity does not exist. It only exists in
>> limits or extended number systems.
>
> Yes, you are technically correct, the best kind of correct.
>
> I'm just sketching an informal proof. If you want to make it vigorous by
> using limits, be my guest. It doesn't change the conclusion.

No, the point is that limits are irrelevant.

As has been proven countlessly many times, x**y is not continuous
around the origin. This has no bearing on whether it takes a value at
the origin.

>
> [...]
>>> Arguably, *integer* 0**0 could be zero, on the basis that you can't take
>>> limits of integer-valued quantities, and zero times itself zero times
>>> surely has to be zero.
>>
>> No. No no no. On natural numbers no other thing makes sense than 1.
>
> On the basis that m**n means m multiplied by itself n times:
>
> 5**4 = 5*5*5*5 = 625
>
> that gives us:
>
> 0**0 = zero multiplied by itself zero times.
>
> You can multiply 0 by any number you like, and the answer will always be 0,
> not 1. Even if that other number is 0, the answer is still 0.

If you are performing no multiplications, you never multiplied 0 by
any number at all, so what you get from 0*X is irrelevant.

-- Devin


From steve+comp.lang.python at pearwood.info  Fri Jan  9 20:48:57 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 10 Jan 2015 12:48:57 +1100
Subject: Is anyone else unable to log into the bug tracker?
Message-ID: <54b0850a$0$13002$c3e8da3$5496439d@news.astraweb.com>

I'm having trouble logging into the bug tracker. Is anyone else having the
same problem, that is, your user name and password worked earlier but
doesn't work now?

http://bugs.python.org/

(Yes, I've checked the capslock key.)



Before I request a new password, I want to check whether it is me or
everyone.


-- 
Steven



From ethan at stoneleaf.us  Fri Jan  9 20:59:15 2015
From: ethan at stoneleaf.us (Ethan Furman)
Date: Fri, 09 Jan 2015 17:59:15 -0800
Subject: Is anyone else unable to log into the bug tracker?
In-Reply-To: <54b0850a$0$13002$c3e8da3$5496439d@news.astraweb.com>
References: <54b0850a$0$13002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <54B08773.6060009@stoneleaf.us>

On 01/09/2015 05:48 PM, Steven D'Aprano wrote:
>
> I'm having trouble logging into the bug tracker. Is anyone else having the
> same problem, that is, your user name and password worked earlier but
> doesn't work now?

I was just able to log in both using the Google short cut, and with my name/password (not Google).

--
~Ethan~

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From steve+comp.lang.python at pearwood.info  Fri Jan  9 21:24:28 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 10 Jan 2015 13:24:28 +1100
Subject: Is anyone else unable to log into the bug tracker?
References: <54b0850a$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17549.1420855163.18130.python-list@python.org>
Message-ID: <54b08d5c$0$13011$c3e8da3$5496439d@news.astraweb.com>

Ethan Furman wrote:

> On 01/09/2015 05:48 PM, Steven D'Aprano wrote:
>>
>> I'm having trouble logging into the bug tracker. Is anyone else having
>> the same problem, that is, your user name and password worked earlier but
>> doesn't work now?
> 
> I was just able to log in both using the Google short cut, and with my
> name/password (not Google).

Thanks.

Problem solved. It was just me.



-- 
Steven



From greg.ewing at canterbury.ac.nz  Fri Jan  9 22:05:52 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sat, 10 Jan 2015 16:05:52 +1300
Subject: Decimals and other numbers
In-Reply-To: <54af9612$0$12995$c3e8da3$5496439d@news.astraweb.com>
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <54af9612$0$12995$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <chbj8eF76b8U1@mid.individual.net>

Steven D'Aprano wrote:
> Arguably, *integer* 0**0 could be zero, on the basis that you can't take
> limits of integer-valued quantities, and zero times itself zero times
> surely has to be zero.

It's far from clear what *anything* multiplied by
itself zero times should be.

A better way of thinking about what x**n for integer
n means is this: Start with 1, and multiply it by
x n times. The result of this is clearly 1 when n
is 0, regardless of the value of x.

 > 5**4 = 5*5*5*5 = 625

No:

5**4 = 1*5*5*5*5
5**3 = 1*5*5*5
5**2 = 1*5*5
5**1 = 1*5
5**0 = 1

-- 
Greg


From greg.ewing at canterbury.ac.nz  Fri Jan  9 22:08:24 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sat, 10 Jan 2015 16:08:24 +1300
Subject: Decimals and other numbers
In-Reply-To: <54afab5d$0$12976$c3e8da3$5496439d@news.astraweb.com>
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <54af9612$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17513.1420793970.18130.python-list@python.org>
 <54afab5d$0$12976$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <chbjd6F76b8U2@mid.individual.net>

Steven D'Aprano wrote:
> I'm just sketching an informal proof. If you want to make it vigorous
                                                                ^^^^^^^^

I think the usual term is "rigorous", unless the mathematician
is taking some kind of stimulant... :-)

-- 
Greg


From greg.ewing at canterbury.ac.nz  Fri Jan  9 22:21:15 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sat, 10 Jan 2015 16:21:15 +1300
Subject: Why do the URLs of posts here change?
In-Reply-To: <mailman.17520.1420805082.18130.python-list@python.org>
References: <54afb3ed$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17520.1420805082.18130.python-list@python.org>
Message-ID: <chbk5cF7dv9U1@mid.individual.net>

Skip Montanaro wrote:
> The way this is done, is
> that the message is removed from the underlying mbox file, and the
> archive regenerated. That changes the counter for every message after
> that point

Would it help to replace the message with a stub
instead of deleting it altogether?

-- 
Greg


From jsf80238 at gmail.com  Fri Jan  9 22:32:19 2015
From: jsf80238 at gmail.com (Jason Friedman)
Date: Fri, 9 Jan 2015 20:32:19 -0700
Subject: Begginer Question , what i need for web app and site
In-Reply-To: <f769f5f9-8c7f-41e6-8d9b-227754de9564@googlegroups.com>
References: <f769f5f9-8c7f-41e6-8d9b-227754de9564@googlegroups.com>
Message-ID: <CANy1k1hS4q1VNDgN+xji-EYSerXJte6S_hH=JMeafZOOMzvpkg@mail.gmail.com>

> Hello all
> coming from java and c++ now going with python
> what setup do i need to run full python stack for web application .
> what i need is web framework and back-end .
> what usually be in the java world tomcat and servlets or jsp and pure java backend for processing data .
> what will be the Equivalent in python world ?
> Thanks!

Django (https://www.djangoproject.com/) is pretty popular.


From jsf80238 at gmail.com  Fri Jan  9 22:38:09 2015
From: jsf80238 at gmail.com (Jason Friedman)
Date: Fri, 9 Jan 2015 20:38:09 -0700
Subject: Array of hash table
In-Reply-To: <05c22fd5-bfae-4e09-9894-341f468e08dc@googlegroups.com>
References: <05c22fd5-bfae-4e09-9894-341f468e08dc@googlegroups.com>
Message-ID: <CANy1k1iKK-9MOMjdQ+m7xWFc-jrxsH0BneyU-y2xuwV-P+qq1Q@mail.gmail.com>

>    Can any one tell me how to create
>    graph={
>   "nodes": [
>     {
>       "id": "n0",
>       "label": "A node",
>       "x": 0,
[ ... elided ... ]
>     }
>   ]
> }


Taking a guess and guessing that graphviz might be useful for you:
https://code.google.com/p/pydot/.


From rosuav at gmail.com  Fri Jan  9 22:53:28 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 10 Jan 2015 14:53:28 +1100
Subject: Why do the URLs of posts here change?
In-Reply-To: <chbk5cF7dv9U1@mid.individual.net>
References: <54afb3ed$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17520.1420805082.18130.python-list@python.org>
 <chbk5cF7dv9U1@mid.individual.net>
Message-ID: <CAPTjJmoYy=X6qQEv10P6iQ8F_D4jJVOxuuGN9VohD0YtmtJm1Q@mail.gmail.com>

On Sat, Jan 10, 2015 at 2:21 PM, Gregory Ewing
<greg.ewing at canterbury.ac.nz> wrote:
> Skip Montanaro wrote:
>>
>> The way this is done, is
>> that the message is removed from the underlying mbox file, and the
>> archive regenerated. That changes the counter for every message after
>> that point
>
>
> Would it help to replace the message with a stub
> instead of deleting it altogether?

I had the same thought, but apparently not, according to the page
Peter Otten linked to:

http://wiki.list.org/display/DEV/Stable+URLs

ChrisA


From jeanpierreda at gmail.com  Fri Jan  9 22:57:20 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Fri, 9 Jan 2015 19:57:20 -0800
Subject: Decimals and other numbers
In-Reply-To: <chbj8eF76b8U1@mid.individual.net>
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <54af9612$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <chbj8eF76b8U1@mid.individual.net>
Message-ID: <CABicbJLJhfYFj-+mTCdrVyC2J1cw_Oq+cCi_2jyc=-gAOGNbMg@mail.gmail.com>

On Fri, Jan 9, 2015 at 7:05 PM, Gregory Ewing
<greg.ewing at canterbury.ac.nz> wrote:
> It's far from clear what *anything* multiplied by
> itself zero times should be.
>
> A better way of thinking about what x**n for integer
> n means is this: Start with 1, and multiply it by
> x n times. The result of this is clearly 1 when n
> is 0, regardless of the value of x.
>
>> 5**4 = 5*5*5*5 = 625
>
> No:
>
> 5**4 = 1*5*5*5*5
> 5**3 = 1*5*5*5
> 5**2 = 1*5*5
> 5**1 = 1*5
> 5**0 = 1

I never liked that, it seemed too arbitrary. How about this explanation:

Assume that we know how to multiply a nonempty list numbers. so
product([a]) == a, product([a, b]) = a * b, and so on.

def product(nums):
    if len(nums) == 0:
        return ???
    return reduce(operator.mul, nums)

It should be the case that given a list of factors A and B,
product(A + B) == product(A) * product(B)   (associativity).
We should let this rule apply even if A or B is the empty list,
otherwise our rules are kind of stupid.

Therefore, product([] + X) == product([]) * product(X)
But since [] + X == X, product([] + X) == product(X)

There's only one number like that: product([]) == 1

(Of course if you choose not to have the full associativity rule for
empty products, then anything is possible.)

-- Devin


From ian.g.kelly at gmail.com  Sat Jan 10 01:30:02 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 9 Jan 2015 23:30:02 -0700
Subject: class-based class decorator
In-Reply-To: <879539503.1660445.1420838812525.JavaMail.yahoo@jws10784.mail.gq1.yahoo.com>
References: <879539503.1660445.1420838812525.JavaMail.yahoo@jws10784.mail.gq1.yahoo.com>
Message-ID: <CALwzidkvGKEJtZ2f2LyfA4atY0kpaQsGrCtBro5X2TyrBe98Hw@mail.gmail.com>

On Fri, Jan 9, 2015 at 2:26 PM, Albert-Jan Roskam
<fomcl at yahoo.com.dmarc.invalid> wrote:
>
>
> Hi,
>
> I am trying to write a class decorator that checks whether deprecated parameters with non-default
>
> arguments are used. More complete code is here: http://pastebin.com/ZqnMis6M. In the code below,
>
> how should I modify __call__ such that f.bar(old="oh no") prints "hello world"?
> I thought it would be a fun way to play with the inspect module, but my head is numb now and I am thirsty for a beer!

You can use inspect.getargspec to look up the default argument values
for the target function. You can use inspect.getcallargs to map your
*args and **kwargs to a dictionary of argument names and values. Since
the target function will be the unbound __init__ method, you'll also
want to pass in a dummy value like None for the self argument. Then
you just look up each of the deprecated names in the result and flag
any where the value doesn't match the default.

If you were using Python 3.3+, then I would recommend using
inspect.signature instead, which is a lot more powerful. But your code
appears to be Python 2, so we work with what we've got.


From ian.g.kelly at gmail.com  Sat Jan 10 02:30:14 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Sat, 10 Jan 2015 00:30:14 -0700
Subject: cx_Oracle, callfunc and varray
In-Reply-To: <db700d22-f8a0-40bb-9e01-1a9a0caba1f1@googlegroups.com>
References: <db700d22-f8a0-40bb-9e01-1a9a0caba1f1@googlegroups.com>
Message-ID: <CALwzidnTfsLcLLzvK6zYBUSYhkFPH9M15kPOLom1mE5+fNYzKw@mail.gmail.com>

On Fri, Jan 9, 2015 at 12:24 PM, Dom <dominic.giles at gmail.com> wrote:
> Hi
>
> I'm trying to return a simple array of numbers from a package using cx_oracle (5.1.2). I believe this is possible. I've not been able to find anything that suggest it isn't

I'm afraid I don't have an answer for you, but you would probably have
better luck asking on the cx-oracle-users mailing list:
https://lists.sourceforge.net/lists/listinfo/cx-oracle-users


From contropinion at gmail.com  Sat Jan 10 03:12:36 2015
From: contropinion at gmail.com (contro opinion)
Date: Sat, 10 Jan 2015 16:12:36 +0800
Subject: OSError: [WinError 10022] An invalid argument was supplied in udp
 python file
Message-ID: <CA+YdQ_54x4w_GUWw6_YLwX9Mb_CgoR8VQ0E1N3oE=r-QVaiv0A@mail.gmail.com>

When i test an udp.py file on server and client in python34.


    #!/usr/bin/env python
    import socket, sys
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    MAX = 65535
    PORT = 1060
    if sys.argv[1:] == ['server']:
        s.bind(('127.0.0.1', PORT))
        print('Listening at', s.getsockname())
        while True:
              data, address = s.recvfrom(MAX)
              print('The client at', address, 'says', repr(data))
              s.sendto('Your data was %d bytes' % len(data), address)
    elif sys.argv[1:] == ['client']:
        print('Address before sending:',s.getsockname())
        s.sendto('This is my message',('127.0.0.1', PORT))
        print('Address after sending',s.getsockname())
        data, address = s.recvfrom(MAX)
        print('The server', address, 'says', repr(data))
    else:
      print('usage: udp_local.py server|client')


The command `python udp.py server`  get output:
Listening at ('127.0.0.1', 1060)

Why   `python udp.py client`  run failure:

Traceback (most recent call last):
  File "d://udp.py", line 15, in <module>
    print('Address before sending:', s.getsockname())
OSError: [WinError 10022] An invalid argument was supplied


From memilanuk at gmail.com  Sat Jan 10 04:30:55 2015
From: memilanuk at gmail.com (memilanuk)
Date: Sat, 10 Jan 2015 01:30:55 -0800
Subject: Begginer Question , what i need for web app and site
In-Reply-To: <f769f5f9-8c7f-41e6-8d9b-227754de9564@googlegroups.com>
References: <f769f5f9-8c7f-41e6-8d9b-227754de9564@googlegroups.com>
Message-ID: <54B0F14F.6080005@gmail.com>

On 01/09/2015 05:53 AM, meiry242 at gmail.com wrote:
> Hello all
> coming from java and c++ now going with python
> what setup do i need to run full python stack for web application .
> what i need is web framework and back-end .
> what usually be in the java world tomcat and servlets or jsp and pure java backend for processing data .
> what will be the Equivalent in python world ?
> Thanks!
>

http://www.fullstackpython.com/

-- 
Shiny!  Let's be bad guys.

Reach me @ memilanuk (at) gmail dot com


From memilanuk at gmail.com  Sat Jan 10 04:30:55 2015
From: memilanuk at gmail.com (memilanuk)
Date: Sat, 10 Jan 2015 01:30:55 -0800
Subject: Begginer Question , what i need for web app and site
In-Reply-To: <f769f5f9-8c7f-41e6-8d9b-227754de9564@googlegroups.com>
References: <f769f5f9-8c7f-41e6-8d9b-227754de9564@googlegroups.com>
Message-ID: <54B0F14F.6080005@gmail.com>

On 01/09/2015 05:53 AM, meiry242 at gmail.com wrote:
> Hello all
> coming from java and c++ now going with python
> what setup do i need to run full python stack for web application .
> what i need is web framework and back-end .
> what usually be in the java world tomcat and servlets or jsp and pure java backend for processing data .
> what will be the Equivalent in python world ?
> Thanks!
>

http://www.fullstackpython.com/

-- 
Shiny!  Let's be bad guys.

Reach me @ memilanuk (at) gmail dot com



From kwpolska at gmail.com  Sat Jan 10 04:32:28 2015
From: kwpolska at gmail.com (Chris Warrick)
Date: Sat, 10 Jan 2015 10:32:28 +0100
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <b4d90fbf-9f5a-4ffa-9013-0e70fc3e4e24@googlegroups.com>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
 <2f1dd848-e075-4435-93ef-c65af9a5148b@googlegroups.com>
 <b4d90fbf-9f5a-4ffa-9013-0e70fc3e4e24@googlegroups.com>
Message-ID: <CAMw+j7KA6b+rJSm6P9a=FnxRMpp1RtTuZJPs3R7E3x-a2pyAdw@mail.gmail.com>

On Sat, Jan 10, 2015 at 2:02 AM, Andr? Roberge <andre.roberge at gmail.com> wrote:
> On Friday, 9 January 2015 19:09:15 UTC-4, stephen... at gmail.com  wrote:
>> One issue is the format returned for the calendar selection. For today, the string returned is "Fri Jan 9 2015". My script needs to convert the date to a datetime.date, and having the month returned as a string instead of an integer makes this harder.
>
> Would today's date be represented as the string "09.01.2015" useful to you? (I found out how to do this.)  If so, I could perhaps add an argument like numeric_format = True.

The correct way to handle this is to use cal.date.toPyDate(), which
helpfully returns a datetime.date object ? and make this the default
output of the calendar function, because that?s the only useful output
for anyone asking for a date.

>>> date
'Sat Jan 10 2015'
>>> cal.date
PyQt4.QtCore.QDate(2015, 1, 10)
>>> cal.date.toPyDate()
datetime.date(2015, 1, 10)

-- 
Chris Warrick <https://chriswarrick.com/>
PGP: 5EAAEA16


From tjreedy at udel.edu  Sat Jan 10 04:37:14 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Sat, 10 Jan 2015 04:37:14 -0500
Subject: Non-unique dirs in sys.path
In-Reply-To: <54AFD43F.5040100@yahoo.no>
References: <54AFD43F.5040100@yahoo.no>
Message-ID: <m8qrsl$g3t$1@ger.gmane.org>

On 1/9/2015 8:14 AM, Gisle Vanem wrote:
> I'm having some trouble understanding why my Python 2.7.9
> has the '%PYTHONHOME%\lib\site-packages' listed multiple
> times.
>
> I cooked up this .bat file to demonstrate the issue:
>    @echo off
>    setlocal
>    set PYTHONPATH=
>    python -c "import sys; [sys.stdout.write('%%s\n' %% p) for (i,p) in
> enumerate(sys.path)]" | sort --ignore-case
>
> which produces:
>
>    f:\Documents and Settings\Gisle
> Vanem\Programdata\Python\Python27\site-packages
>    f:\windows\system32\python27.zip    << !! doesn't exist, but okay.
>    G:\Programfiler\Python27
>    g:\Programfiler\Python27\DLLs
>    g:\Programfiler\Python27\lib
>    g:\Programfiler\Python27\lib\lib-tk
>    g:\Programfiler\Python27\lib\plat-win
>    g:\Programfiler\Python27\lib\site-packages   << !!
>    g:\programfiler\python27\lib\site-packages   << !!
>    ...
>
> Why are these listed twice with different casing? One
> would assume that Python on Win32 would be case-insensitive.
> Some .pth-file to blame here?

To me, this is a bug, as it will, I believe, result in site-packages 
being searched twice before an import fails.

-- 
Terry Jan Reedy



From tjreedy at udel.edu  Sat Jan 10 04:41:49 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Sat, 10 Jan 2015 04:41:49 -0500
Subject: Why do the URLs of posts here change?
In-Reply-To: <CANc-5UztJsV20dRCpLs5oVrDjr131p8afV5Mp_SwFq2OihKwyQ@mail.gmail.com>
References: <54afb3ed$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <CANc-5UztJsV20dRCpLs5oVrDjr131p8afV5Mp_SwFq2OihKwyQ@mail.gmail.com>
Message-ID: <m8qs58$g3t$2@ger.gmane.org>

On 1/9/2015 7:04 AM, Skip Montanaro wrote:
>> Posts on this newsgroup/mailing list are archived on the web, but the URLs
>> seem to change, which leaves dead links if you search for things.
>
> Steven,
>
> It's a known issue, but one which appears to be somewhat unavoidable,
> at least in Mailman 2.x. The problem is that every now and then,
> postmaster at python.org gets a legitimate request from someone for a
> message to be deleted from the list archive. The way this is done, is
> that the message is removed from the underlying mbox file,

The post could be replaced by a placeholder "This message deleted'

  and the
> archive regenerated. That changes the counter for every message after

A placeholder should avoid that.

> that point - or maybe every message in the generated archive. (I have
> no idea why the numerical basename of your subject message would have
> changed so much. Maybe there is just a single ever incrementing
> counter for a given Mailman installation.)

-- 
Terry Jan Reedy



From alister.nospam.ware at ntlworld.com  Sat Jan 10 05:41:56 2015
From: alister.nospam.ware at ntlworld.com (alister)
Date: Sat, 10 Jan 2015 10:41:56 GMT
Subject: Decimals and other numbers
Message-ID: <Ul7sw.504907$c73.360611@fx27.am4>

On Fri, 09 Jan 2015 19:57:20 -0800, Devin Jeanpierre wrote:

> On Fri, Jan 9, 2015 at 7:05 PM, Gregory Ewing
> <greg.ewing at canterbury.ac.nz> wrote:
>> It's far from clear what *anything* multiplied by itself zero times
>> should be.
>>
>> A better way of thinking about what x**n for integer n means is this:
>> Start with 1, and multiply it by x n times. The result of this is
>> clearly 1 when n is 0, regardless of the value of x.
>>
>>> 5**4 = 5*5*5*5 = 625
>>
>> No:
>>
>> 5**4 = 1*5*5*5*5 5**3 = 1*5*5*5 5**2 = 1*5*5 5**1 = 1*5 5**0 = 1
> 
> I never liked that, it seemed too arbitrary. How about this explanation:
> 
> Assume that we know how to multiply a nonempty list numbers. so
> product([a]) == a, product([a, b]) = a * b, and so on.
> 
> def product(nums):
>     if len(nums) == 0:
>         return ???
>     return reduce(operator.mul, nums)
> 
> It should be the case that given a list of factors A and B,
> product(A + B) == product(A) * product(B)   (associativity).
> We should let this rule apply even if A or B is the empty list,
> otherwise our rules are kind of stupid.
> 
> Therefore, product([] + X) == product([]) * product(X)
> But since [] + X == X, product([] + X) == product(X)
> 
> There's only one number like that: product([]) == 1
> 
> (Of course if you choose not to have the full associativity rule for
> empty products, then anything is possible.)
> 
> -- Devin

The general theory behind logarithms explains why it is excepted that any 
number raised to the power of 0 =1

take  X^3 * x^ 4 = X^7 achieved simply by adding the indices
if you wanted to do X *1 using the same method what would you need to add 
to the index of X (X^1 ) to get X (X^1) - Answer 0 therefore X^0 = 1

This theoretically works regardless of the  value of x you choose for the 
base , of course in practice it is not possible to work in a number base 
of 0 which is where things get into the indeterminate as it contradicts 
the other provable fact that ) * anything is 0.

These edge case contradictions can easily cause my brain into an in 
finite recursive loop.

it is as confusing as the concept that there are different values of 
infinity (some larger than others!)





-- 
Ya'll hear about the geometer who went to the beach to catch some
rays and became a tangent ?


From ben+python at benfinney.id.au  Sat Jan 10 06:39:21 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Sat, 10 Jan 2015 22:39:21 +1100
Subject: [RELEASE] =?utf-8?Q?=E2=80=98python-daemon=E2=80=99?= version 2.0
 released
Message-ID: <85k30uvp92.fsf@benfinney.id.au>

Howdy all,

I am pleased to announce the release of version 2.0 of the
?python-daemon? library.

The current release is always available at
<URL:https://pypi.python.org/pypi/python-daemon/>.

The project's forums and VCS are hosted at Alioth
<URL:https://alioth.debian.org/projects/python-daemon/>.


Significant changes since the previous version
==============================================

* Supports Python 2 (version 2.7 or later) and Python 3 (version 3.2
  or later) with the same code base.

  This version drops support for Python earlier than Python 2.7.

  This constitutes a major re-write of large parts of the test suite,
  packaging code, and library code. Please test carefully and report any
  regressions from earlier versions.

* Full unit test coverage of all code branches.

* Add explicit credit for contributors.


What is the ?python-daemon? library?
====================================

?python-daemon? is a Python library to implement a well-behaved Unix
daemon process.

-- 
 \     ?Capitalism is the astounding belief that the most wickedest of |
  `\    men will do the most wickedest of things for the greatest good |
_o__)                               of everyone.? ?John Maynard Keynes |
Ben Finney <ben at benfinney.id.au>



From kevin.p.dwyer at gmail.com  Sat Jan 10 06:43:35 2015
From: kevin.p.dwyer at gmail.com (Kev Dwyer)
Date: Sat, 10 Jan 2015 11:43:35 +0000
Subject: OSError: [WinError 10022] An invalid argument was supplied in udp
 python file
References: <CA+YdQ_54x4w_GUWw6_YLwX9Mb_CgoR8VQ0E1N3oE=r-QVaiv0A@mail.gmail.com>
Message-ID: <m8r398$u44$1@ger.gmane.org>

contro opinion wrote:

> When i test an udp.py file on server and client in python34.
> 
> 
>     #!/usr/bin/env python
>     import socket, sys
>     s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
>     MAX = 65535
>     PORT = 1060
>     if sys.argv[1:] == ['server']:
>         s.bind(('127.0.0.1', PORT))
>         print('Listening at', s.getsockname())
>         while True:
>               data, address = s.recvfrom(MAX)
>               print('The client at', address, 'says', repr(data))
>               s.sendto('Your data was %d bytes' % len(data), address)
>     elif sys.argv[1:] == ['client']:
>         print('Address before sending:',s.getsockname())
>         s.sendto('This is my message',('127.0.0.1', PORT))
>         print('Address after sending',s.getsockname())
>         data, address = s.recvfrom(MAX)
>         print('The server', address, 'says', repr(data))
>     else:
>       print('usage: udp_local.py server|client')
> 
> 
> The command `python udp.py server`  get output:
> Listening at ('127.0.0.1', 1060)
> 
> Why   `python udp.py client`  run failure:
> 
> Traceback (most recent call last):
>   File "d://udp.py", line 15, in <module>
>     print('Address before sending:', s.getsockname())
> OSError: [WinError 10022] An invalid argument was supplied


Hello,

According to http://stackoverflow.com/questions/15638214/socket-error-invalid-argument-supplied, the client socket doesn't have an address at time
when you call s.getsocketname.  This raises an exception on Windows.

Removing the 'Address before sending' line will prevent the error.

As you're using Python3, you'll find that passing strings to s.sendto raises
a TypeError; you'll need to encode the strings as bytes.

Hope that helps,

Kev



From skip.montanaro at gmail.com  Sat Jan 10 08:57:53 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Sat, 10 Jan 2015 07:57:53 -0600
Subject: Why do the URLs of posts here change?
In-Reply-To: <m8qs58$g3t$2@ger.gmane.org>
References: <54afb3ed$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <CANc-5UztJsV20dRCpLs5oVrDjr131p8afV5Mp_SwFq2OihKwyQ@mail.gmail.com>
 <m8qs58$g3t$2@ger.gmane.org>
Message-ID: <CANc-5UwdRjDksU9A60QyAj-EBGCRFEFabrMN7ixyBk2JvVT8Tg@mail.gmail.com>

On Sat, Jan 10, 2015 at 3:41 AM, Terry Reedy <tjreedy at udel.edu> wrote:
> The post could be replaced by a placeholder "This message deleted'
>
>  and the
>>
>> archive regenerated. That changes the counter for every message after
>
>
> A placeholder should avoid that.

I suspect (though don't know for certain) that just regenerating the
archive without touching the mbox file will change the numbering.
Steven's original post mentioned two very different basenames (468598
and 481374). As I indicated in an earlier response, those might be
generated from an ever-growing counter, not just a shift as articles
slide one closer to the first one of the month.

So, you'd have to edit the mbox file carefully (might need to edit
headers) and also edit the generated HTML for the message. Neither is
an insurmountable task, but both are going to be more error-prone than
just cutting out an entire message and regenerating the archive.

I will pass along your suggestion to the postmaster folks (I don't get
involved that that level - it's mostly the folks who directly maintain
the Postfix setup who do this), though. They are a generally pretty
responsive bunch.

Skip


From ganesh1pal at gmail.com  Sat Jan 10 10:14:09 2015
From: ganesh1pal at gmail.com (Ganesh Pal)
Date: Sat, 10 Jan 2015 20:44:09 +0530
Subject: Python : writing to a file
Message-ID: <CACT3xuUW26iJOeMiF4hhRNYE11_q27G1yugB3ZaFMGyHZVwDuA@mail.gmail.com>

Please provide you input on the below questions:


(a) I was expecting  the string i.e day of week , example Saturday to be
written in the file. what Iam I missing in the below program  ?

Program:

#!/usr/bin/python

import time
f = open ('test_2.txt','w+b')
DAY = time.strftime("%A")
f.write(DAY)
f.close()

Throttling-1# cat test_2.txt

(b) Iam trying to generate a file in the below format ,

cluster1# cat test_2.txt

Saturday 0:05 0:10
Saturday 0:10 0:20
Saturday 0:20 0:30
Saturday 0:40 0:50
Saturday 0:60 0:70

(a) what is the easiest way to generate the above file fprmat ?

(b) how will I take care that the below format is repeated in the .txt file
  ( i.e column and row spacing)

    DAY OF THE WEEK  [SPACE] START TIME [ SPACE] ENDTIME{SPACE]


(c) how do I  add START TIME [ SPACE] ENDTIME{SPACE] columns



Regards,
Ganesh
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From ganesh1pal at gmail.com  Sat Jan 10 10:17:45 2015
From: ganesh1pal at gmail.com (Ganesh Pal)
Date: Sat, 10 Jan 2015 20:47:45 +0530
Subject: Playing with threads
In-Reply-To: <m8l0br$nj0$1@ger.gmane.org>
References: <CACT3xuUzuMH1CF3AsakdGMwa3U3BX3N+nA1ZVy4NhVmnA9-6gw@mail.gmail.com>
 <CACT3xuWmGF7OpoTKmEHEwzzsZNPXECn-rDKVnDtUo8-p1B1fww@mail.gmail.com>
 <m8l0br$nj0$1@ger.gmane.org>
Message-ID: <CACT3xuUkbF=Fx+A8xkFtNv6zf5GPBg0PH4zEY0dHcdQ5uuTmJA@mail.gmail.com>

Thanks I read subprocess module this answered most of my question ,thanks a
lot for the  replies

On Thu, Jan 8, 2015 at 9:46 AM, Terry Reedy <tjreedy at udel.edu> wrote:

> On 1/7/2015 9:00 PM, Ganesh Pal wrote:
>
>> Hi friends,
>>
>> I'm trying to use threads  to achieve the below work flow
>>
>> 1. Start a process , while its running grep for a string 1
>> 2. Apply the string 1 to the command in step 1 and exit step 2
>> 3. Monitor the stdout of step1 and print success if the is pattern  found
>>
>> Questions:
>>
>> 1. Can the above be achieved without threads ? I prefer keep ing code
>> simple  .threads can become confusion when this workflow grows larger
>>
>
> I do not understand the work flow either.  What I do know is that Idle
> Edit -> Find in Files is implemented in idlelib/grep.py and that the
> non-gui code could be copied and adapted to other purposes.
>
> --
> Terry Jan Reedy
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>
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From davea at davea.name  Sat Jan 10 10:37:55 2015
From: davea at davea.name (Dave Angel)
Date: Sat, 10 Jan 2015 10:37:55 -0500
Subject: Python : writing to a file
In-Reply-To: <CACT3xuUW26iJOeMiF4hhRNYE11_q27G1yugB3ZaFMGyHZVwDuA@mail.gmail.com>
References: <CACT3xuUW26iJOeMiF4hhRNYE11_q27G1yugB3ZaFMGyHZVwDuA@mail.gmail.com>
Message-ID: <54B14753.2030909@davea.name>

On 01/10/2015 10:14 AM, Ganesh Pal wrote:
> Please provide you input on the below questions:
>

For each new thread, you should specify at a minimum your Python version 
and OS.  it frequently matters, and it's better to specify than to have 
everyone try to guess.  I'll assume Python 2.7 and Linux.

>
> (a) I was expecting  the string i.e day of week , example Saturday to be
> written in the file. what Iam I missing in the below program  ?
>
> Program:
>
> #!/usr/bin/python
>
> import time
> f = open ('test_2.txt','w+b')
> DAY = time.strftime("%A")
> f.write(DAY)
> f.close()
>
> Throttling-1# cat test_2.txt

Not to belabor the obvious, but did you run the program?  I'd add at 
least one print to a minimal program to make sure you ran the same 
program as you show, and you can also use that to inspect the contents 
of variables.

Works for me on ubuntu Python 2.7

Incidentally, I'd avoid using w+b.  Just use wb if you're creating a file.

>
> (b) Iam trying to generate a file in the below format ,
>
> cluster1# cat test_2.txt
>
> Saturday 0:05 0:10
> Saturday 0:10 0:20
> Saturday 0:20 0:30
> Saturday 0:40 0:50
> Saturday 0:60 0:70
>
> (a) what is the easiest way to generate the above file fprmat ?
>
> (b) how will I take care that the below format is repeated in the .txt file
>    ( i.e column and row spacing)
>
>      DAY OF THE WEEK  [SPACE] START TIME [ SPACE] ENDTIME{SPACE]
>
>
> (c) how do I  add START TIME [ SPACE] ENDTIME{SPACE] columns
>

The use the str.format method.

line = "{} {} {}\n".format(day, start, end)

The curlies specify where the various arguments will be placed, and the 
"\n" generates a newline at the end.

-- 
DaveA


From breamoreboy at yahoo.co.uk  Sat Jan 10 10:50:44 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 10 Jan 2015 15:50:44 +0000
Subject: ftfy: fixes text for you
Message-ID: <m8rhoq$a3c$1@ger.gmane.org>

I came across ftfy via this post 
http://ianozsvald.com/2015/01/10/a-first-approach-to-automatic-text-data-cleaning/ 
and thought others here might be interested in it, so here's the direct 
link http://ftfy.readthedocs.org/en/latest/.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From pkpearson at nowhere.invalid  Sat Jan 10 11:57:14 2015
From: pkpearson at nowhere.invalid (Peter Pearson)
Date: 10 Jan 2015 16:57:14 GMT
Subject: [OT] x**y == y**x
References: <CABicbJK-5izGtet8BsS1Yqx+6AHMX7gLU4zYjjt5jULJXNVipA@mail.gmail.com>
 <54AF405C.6020609@davea.name>
 <mailman.17501.1420772593.18130.python-list@python.org>
 <87a91s1kh4.fsf@elektro.pacujo.net>
 <mailman.17512.1420793559.18130.python-list@python.org>
 <qotr3v49va0.fsf@ruuvi.it.helsinki.fi> <chaierFt612U1@mid.individual.net>
 <87wq4vfx8k.fsf@elektro.pacujo.net>
Message-ID: <chd3vaFip6hU1@mid.individual.net>

On Fri, 09 Jan 2015 23:41:15 +0200, Marko Rauhamaa <marko at pacujo.net> wrote:
> Peter Pearson <pkpearson at nowhere.invalid>:
>
>> If you've never looked at the set of reals (x,y) satisfying x**y ==
>> y**x, it's worth a visit.
>
> Thanks, it was. The graph's something like this:
[snip]
>
> Where can I read more on the topic?

Sorry, I don't know.  One Phil Rust steered me to this problem in high
school (c. 1964), and I never got much traction on it until Prof. Alfred
Roch at EPFL pointed out (c. 1981) that it's revealing to think of
horizontal lines intersecting the graph of ln(x)/x.

If you like this sort of thing, here's another cute function that
the same Phil Rust called to my attention:
http://webpages.charter.net/curryfans/peter/XtoTheXtoTheX/ode_to_e.html

-- 
To email me, substitute nowhere->runbox, invalid->com.


From steve+comp.lang.python at pearwood.info  Sat Jan 10 12:06:56 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 11 Jan 2015 04:06:56 +1100
Subject: Python : writing to a file
References: <mailman.17565.1420902853.18130.python-list@python.org>
Message-ID: <54b15c31$0$13001$c3e8da3$5496439d@news.astraweb.com>

Ganesh Pal wrote:

> Throttling-1# cat test_2.txt

Are you running these scripts as root? That could be a bad idea. If you have
a bug in your code, as often happens when coding, who knows what it might
do. E.g. if you put in the wrong pathname, you could overwrite important
files. You should always do your coding as a regular user, not root.


-- 
Steven



From michael at stroeder.com  Sat Jan 10 12:21:02 2015
From: michael at stroeder.com (=?UTF-8?Q?Michael_Str=c3=b6der?=)
Date: Sat, 10 Jan 2015 18:21:02 +0100
Subject: ANN: python-ldap 2.4.19
Message-ID: <mailman.17584.1420980140.18130.python-announce-list@python.org>

Find a new release of python-ldap:

  http://pypi.python.org/pypi/python-ldap/2.4.19

python-ldap provides an object-oriented API to access LDAP directory
servers from Python programs. It mainly wraps the OpenLDAP 2.x libs for
that purpose. Additionally it contains modules for other LDAP-related
stuff (e.g. processing LDIF, LDAP URLs and LDAPv3 schema).

Project's web site:

  http://www.python-ldap.org/

Ciao, Michael.

----------------------------------------------------------------
Released 2.4.19 2015-01-10

Changes since 2.4.18:

Lib/
* Fixed missing ReconnectLDAPObject._reconnect_lock when pickling
  (see SF#64, thanks to Dan O'Reilly)
* Added ldap.controls.pagedresults which is pure Python implementation of
  Simple Paged Results Control (see RFC 2696) and delivers the correct
  result size



From joel.goldstick at gmail.com  Sat Jan 10 12:36:58 2015
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Sat, 10 Jan 2015 12:36:58 -0500
Subject: ftfy: fixes text for you
In-Reply-To: <m8rhoq$a3c$1@ger.gmane.org>
References: <m8rhoq$a3c$1@ger.gmane.org>
Message-ID: <CAPM-O+xjUREfd4gCxL9cvox1vkzAGBYd+wU2xM4gfDYwZqncAg@mail.gmail.com>

On Sat, Jan 10, 2015 at 10:50 AM, Mark Lawrence <breamoreboy at yahoo.co.uk>
wrote:

> I came across ftfy via this post http://ianozsvald.com/2015/01/
> 10/a-first-approach-to-automatic-text-data-cleaning/ and thought others
> here might be interested in it, so here's the direct link
> http://ftfy.readthedocs.org/en/latest/.
>
> --
> My fellow Pythonistas, ask not what our language can do for you, ask
> what you can do for our language.
>
> Mark Lawrence
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>

very interesting

-- 
Joel Goldstick
http://joelgoldstick.com
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From rantingrickjohnson at gmail.com  Sat Jan 10 13:05:06 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Sat, 10 Jan 2015 10:05:06 -0800 (PST)
Subject: PyWart: Poor Documentation Examples
Message-ID: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>


============================================================
EXAMPLE 1: "Reducing Comprehension" https://docs.python.org/2/howto/doanddont.html#using-the-batteries
============================================================


    ############################################################
    #                    QUOTE: Python Docs                    #
    ############################################################
    # Another highly useful function is reduce() which can be  #
    # used to repeatly apply a binary operation to a sequence, #
    # reducing it to a single value. For example, compute a    #
    # factorial with a series of multiply operations:          #
    #                                                          #
    # py> n = 4                                                #
    # py> import operator                                      #
    # py> reduce(operator.mul, range(1, n+1))                  #
    # 24                                                       #
    ############################################################


Ignoring the obvious mis-spellings @_ at ...

How exactly does: assigning variables(n = 4),
arithmetic(n+1), and the "range" function going to help me
understand the usefulness of the reduce function? A much
better example would be:

    py> import operator
    py> reduce(operator.mul, [1,2,3,4])
    24

At *LEAST* with that example the only potential unknown
might be "operator.mul". However, a wise teacher would
recognize that this is a fine "teaching example" of how
using the operator module can prevent duplicating code --
which would lead to a better example like:

    py> def mul(x, y):
    ...     return x*y
    py> reduce(mul, [1,2,3,4])
    24

FINALLY! An example that showcases a proper usage of the
the reduce function *WITHOUT* any superfluous distractions. However,
remembering that code re-use is a good thing, and that re-
inventing the wheel is a lot of work, we should mention that
the "mul" function should be replaced with "operator.mul"

    Note: Be sure to check out the "operator" module for
    pre-defined arithmetic functions like "operator.mul",
    which would "reduce" (*wink*) the above code to this:

    py> reduce(operator.mul, [1,2,3,4])
    24


============================================================
EXAMPLE 2: "The Fibonacci Phallus Extender".
https://docs.python.org/2/tutorial/controlflow.html#defining-functions
============================================================

    #########################################################
    #                   QUOTE: Python Docs                  #
    #########################################################
    # We can create a function that writes the Fibonacci    #
    # series to an arbitrary boundary:                      #
    #                                                       #
    # py> def fib(n):    # write Fibonacci series up to n   #
    # ...     """Print a Fibonacci series up to n."""       #
    # ...     a, b = 0, 1                                   #
    # ...     while a < n:                                  #
    # ...         print a,                                  #
    # ...         a, b = b, a+b                             #
    # ...                                                   #
    # py> # Now call the function we just defined:          #
    # ... fib(2000)                                         #
    # 0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 #
    #########################################################


No, No, *NO*! This is the most horrible example i have ever
encountered. Why would you introduction functions with an
example of calculating Fibonacci series? How are
"doc-strings" and "multiple assignment" and "loops" and
"conditions" the "print function" and "comments" going to
help me understand "defining a python function"?

Listen, if your primary goal is to teach, then *BEFORE* you
provide *ANY* examples of "defining functions", you should
*FIRST* explain what a function *IS* and *WHY* you would
want to use one.

    Next we going to learn about defining functions, but
    before we do, we need to understand *WHAT* a function
    *IS* and *WHY* we should use them ...

    [LAZY DOC WRITERS CAN INSERT EXTERNAL LINK HERE!]

Now that we've explained the *what* and *why* of functions,
we need to provide an example of the most *BASIC* of python
function definitions:

    py> def add(x, y):
        return x + y
    py> add(1,1)
    2

*SCHOOL-BELL-RINGS*



From rosuav at gmail.com  Sat Jan 10 13:26:16 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 11 Jan 2015 05:26:16 +1100
Subject: PyWart: Poor Documentation Examples
In-Reply-To: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>
References: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>
Message-ID: <CAPTjJmoQ9ABAB=g34MQU=JZHnLG3nhb+a3WvBLX7agokU8ip7g@mail.gmail.com>

On Sun, Jan 11, 2015 at 5:05 AM, Rick Johnson
<rantingrickjohnson at gmail.com> wrote:
> ============================================================
> EXAMPLE 1: "Reducing Comprehension" https://docs.python.org/2/howto/doanddont.html#using-the-batteries
> ============================================================

1) Why are you focusing on the /2/ docs, rather than /3/?
2) Why are you ranting, rather than submitting docs patches?

Your school bell is muted.

ChrisA


From ben+python at benfinney.id.au  Sat Jan 10 13:56:14 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Sun, 11 Jan 2015 05:56:14 +1100
Subject: [RELEASE] =?utf-8?Q?=E2=80=98python-daemon=E2=80=99?= version 2.0.1
 released
Message-ID: <85fvbiv50x.fsf@benfinney.id.au>

Howdy all,

I am pleased to announce the release of version 2.0.1 of the
?python-daemon? library.

The current release is always available at
<URL:https://pypi.python.org/pypi/python-daemon/>.

The project's forums and VCS are hosted at Alioth
<URL:https://alioth.debian.org/projects/python-daemon/>.


Significant changes since the previous version
==============================================

This is a bug fix release, addressing a packaging bug:

* Include the ?version? module with source distribution.

Many thanks to users who promptly reported this omission.


What is the ?python-daemon? library?
====================================

?python-daemon? is a Python library to implement a well-behaved Unix
daemon process.

-- 
 \       ?It is wrong to think that the task of physics is to find out |
  `\         how nature *is*. Physics concerns what we can *say* about |
_o__)                                             nature?? ?Niels Bohr |
Ben Finney <ben at benfinney.id.au>



From breamoreboy at yahoo.co.uk  Sat Jan 10 14:13:58 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 10 Jan 2015 19:13:58 +0000
Subject: PyWart: Poor Documentation Examples
In-Reply-To: <CAPTjJmoQ9ABAB=g34MQU=JZHnLG3nhb+a3WvBLX7agokU8ip7g@mail.gmail.com>
References: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>
 <CAPTjJmoQ9ABAB=g34MQU=JZHnLG3nhb+a3WvBLX7agokU8ip7g@mail.gmail.com>
Message-ID: <m8rtlt$12v$1@ger.gmane.org>

On 10/01/2015 18:26, Chris Angelico wrote:
> On Sun, Jan 11, 2015 at 5:05 AM, Rick Johnson
> <rantingrickjohnson at gmail.com> wrote:
>> ============================================================
>> EXAMPLE 1: "Reducing Comprehension" https://docs.python.org/2/howto/doanddont.html#using-the-batteries
>> ============================================================
>
> 1) Why are you focusing on the /2/ docs, rather than /3/?
> 2) Why are you ranting, rather than submitting docs patches?
>
> Your school bell is muted.
>
> ChrisA
>

Ooh, I say old chap, isn't that going a bit too far?  Users submitting 
patches, whatever next?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From abdul.sw84 at gmail.com  Sat Jan 10 16:36:21 2015
From: abdul.sw84 at gmail.com (Abdul Abdul)
Date: Sat, 10 Jan 2015 22:36:21 +0100
Subject: Syntax error
Message-ID: <CAA+hu4XUKqk1oopamcqdCU_=TYaA8Xpgadu8u2qWmBE8DYsLrA@mail.gmail.com>

Hello,

I have the following program that employs the dcm2jpg.exe software:

import os
os.system(?dcm2jpg.exe IM-0004-0004.dcm?)
exit

When I tried to run it, I got the following error:

SyntaxError: Non-ASCII character '\xe2' in file dicomjpg.py on line 2, but
no en
coding declared; see http://python.org/dev/peps/pep-0263/ for details

Why is that? How can this error be solved?

Thanks.
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From joel.goldstick at gmail.com  Sat Jan 10 16:56:42 2015
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Sat, 10 Jan 2015 16:56:42 -0500
Subject: Syntax error
In-Reply-To: <CAA+hu4XUKqk1oopamcqdCU_=TYaA8Xpgadu8u2qWmBE8DYsLrA@mail.gmail.com>
References: <CAA+hu4XUKqk1oopamcqdCU_=TYaA8Xpgadu8u2qWmBE8DYsLrA@mail.gmail.com>
Message-ID: <CAPM-O+xAMftegHayYzMuK+fCFqn7eGn0NgiMUF67YxPndtDu1Q@mail.gmail.com>

On Sat, Jan 10, 2015 at 4:36 PM, Abdul Abdul <abdul.sw84 at gmail.com> wrote:
>
> Hello,
>
> I have the following program that employs the dcm2jpg.exe software:
>
> import os
> os.system(?dcm2jpg.exe IM-0004-0004.dcm?)
> exit
>
It may be that your actual code has ascii quote characters, but you
have sent your question as rtf.  Please copy your code and paste it in
message using text only mail.  If you are using curly quotes, its not
ascii

>
> When I tried to run it, I got the following error:
>
> SyntaxError: Non-ASCII character '\xe2' in file dicomjpg.py on line 2, but no en
> coding declared; see http://python.org/dev/peps/pep-0263/ for details
>
> Why is that? How can this error be solved?
>
> Thanks.
>
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>



-- 
Joel Goldstick
http://joelgoldstick.com


From __peter__ at web.de  Sat Jan 10 17:02:11 2015
From: __peter__ at web.de (Peter Otten)
Date: Sat, 10 Jan 2015 23:02:11 +0100
Subject: Syntax error
References: <CAA+hu4XUKqk1oopamcqdCU_=TYaA8Xpgadu8u2qWmBE8DYsLrA@mail.gmail.com>
Message-ID: <m8s7h4$dj5$1@ger.gmane.org>

Abdul Abdul wrote:

> Hello,
> 
> I have the following program that employs the dcm2jpg.exe software:
> 
> import os
> os.system(?dcm2jpg.exe IM-0004-0004.dcm?)
> exit
> 
> When I tried to run it, I got the following error:
> 
> SyntaxError: Non-ASCII character '\xe2' in file dicomjpg.py on line 2, but
> no en
> coding declared; see http://python.org/dev/peps/pep-0263/ for details
> 
> Why is that? 

As the error message says, you are using non-ascii characters (the ? and ?) 
in your code.

> How can this error be solved?

But even if you were to read the linked document and would add the line

# -*- coding: utf-8 -*

at the beginning of your script you would run into the next SyntaxError.

You are trying to quote a string literal with

?...?

but Python only understands

"..."

or 

'...'

Change the os.system() call to

os.system("dcm2jpg.exe IM-0004-0004.dcm")

and your script should work.

An unrelated issue:

> exit

to call a function the () is required -- to end the script at an arbitrary 
point use

exit()

However, as execution also ends automatically when the last line of the 
script is reached it is better to remove the

> exit

line completely.



From davea at davea.name  Sat Jan 10 19:02:12 2015
From: davea at davea.name (Dave Angel)
Date: Sat, 10 Jan 2015 19:02:12 -0500
Subject: Syntax error
In-Reply-To: <CAA+hu4XUKqk1oopamcqdCU_=TYaA8Xpgadu8u2qWmBE8DYsLrA@mail.gmail.com>
References: <CAA+hu4XUKqk1oopamcqdCU_=TYaA8Xpgadu8u2qWmBE8DYsLrA@mail.gmail.com>
Message-ID: <54B1BD84.6050503@davea.name>

On 01/10/2015 04:36 PM, Abdul Abdul wrote:
> Hello,
>
> I have the following program that employs the dcm2jpg.exe software:
>
> import os
> os.system(?dcm2jpg.exe IM-0004-0004.dcm?)
> exit
>
> When I tried to run it, I got the following error:
>
> SyntaxError: Non-ASCII character '\xe2' in file dicomjpg.py on line 2, but
> no en
> coding declared; see http://python.org/dev/peps/pep-0263/ for details
>
> Why is that? How can this error be solved?
>

Peter and Joel have the answer exactly right.

But I'd point out that it's also very important to use the right editor 
for writing your programs.  In order to get those curly quotes, you 
probably used a word processor to write the file, then saved it as text. 
  Use a good text editor, and you're much less likely to have it change 
your keystrokes out from under you.

Similarly when posting here, use text mode in your email, not html.

here's what the html you posted looks like:

<div dir=3D"ltr"><div><div>Hello,<br><br></div>I have the following program=
  that employs the dcm2jpg.exe software:<br><br>import os<br>os.system(=E2=
=80=9Cdcm2jpg.exe IM-0004-0004.dcm=E2=80=9D)<br>exit<br><br></div>When I tr=
ied to run it, I got the following error:<br><div><div><div><br>SyntaxError=
: Non-ASCII character &#39;\xe2&#39; in file dicomjpg.py on line 2, but no =
en<br>coding declared; see <a href=3D"http://python.org/dev/peps/pep-0263/"=
 >http://python.org/dev/peps/pep-0263/</a> for 
details<br><br></div><div>Why=
  is that? How can this error be 
solved?<br><br>Thanks.<br></div><div><br></=
div></div></div></div>


-- 
DaveA


From denismfmcmahon at gmail.com  Sat Jan 10 19:32:18 2015
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Sun, 11 Jan 2015 00:32:18 +0000 (UTC)
Subject: Generate jpg files using line length (pixels) and orientation
 (degrees)
References: <0f51bd21-7b0a-4ea0-8b13-27b1967d3b41@googlegroups.com>
 <m8mv27$k6e$2@dont-email.me> <m8nfs8$k6e$3@dont-email.me>
 <1ae2a5c4-78ae-4831-ac01-b886e92c0468@googlegroups.com>
Message-ID: <m8sgai$k48$1@dont-email.me>

On Fri, 09 Jan 2015 09:49:25 -0800, semeon.risom wrote:

> Thank you for the help btw. I think I'm close to a solution, but I'm
> having issue feeding the coordinates from my csv file into the formula.
> 
> This is the error I get:
> Traceback (most recent call last):
>   File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w
>   corr.py", line 68, in <module>
>     makeimg(length, orientation)
>   File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w
>   corr.py", line 40, in makeimg
>     orientation = orientation % 180
> TypeError: unsupported operand type(s) for %: 'list' and 'int'
>>>> 
>>>> 
> and here's the code:
> 
> from PIL import Image, ImageDraw from numpy import math
> 
> # import csv import csv f = open('C:\Users\Owner\DesktopStimuli
> Generation\Coordinates\file.csv', 'rb')
> rdr = csv.reader(f)
> f.seek(0)
> i = 0 a = []
> b = []
> for row in rdr:
>         a.append(row[0]) 
>         b.append(row[1])

This makes a and b both lists

Having read some other errors that you are having, you need to make sure 
that these items are numeric and not string data

for row in rdr:
        a.append(int(row[0]))
        b.append(int(row[1]))

> # using lists of values for length in [a]:
>     for orientation in [b]:
>         makeimg(length, orientation)

This puts list a inside another list, and puts list b inside another 
list, and then passes the whole of lists a and b in the first call to 
makeimg.

makeimg expects 2 integer parameters on each call, not two lists!

As you have already created lists, you don't need to wrap them inside 
another list.

# using lists of values 
for length in a:
    for orientation in b:
        makeimg(length, orientation)

-- 
Denis McMahon, denismfmcmahon at gmail.com


From steve+comp.lang.python at pearwood.info  Sat Jan 10 21:32:37 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 11 Jan 2015 13:32:37 +1100
Subject: PyWart: Poor Documentation Examples
References: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>
Message-ID: <54b1e0c5$0$13012$c3e8da3$5496439d@news.astraweb.com>

Rick Johnson wrote:


> ============================================================
> EXAMPLE 1: "Reducing Comprehension"
> https://docs.python.org/2/howto/doanddont.html#using-the-batteries
> ============================================================
> 
> 
>     ############################################################
>     #                    QUOTE: Python Docs                    #
>     ############################################################
>     # Another highly useful function is reduce() which can be  #
>     # used to repeatly apply a binary operation to a sequence, #
>     # reducing it to a single value. For example, compute a    #
>     # factorial with a series of multiply operations:          #
>     #                                                          #
>     # py> n = 4                                                #
>     # py> import operator                                      #
>     # py> reduce(operator.mul, range(1, n+1))                  #
>     # 24                                                       #
>     ############################################################

> How exactly does: assigning variables(n = 4),
> arithmetic(n+1), and the "range" function going to help me
> understand the usefulness of the reduce function?

Obviously they don't, duh. They're mere incidentals.


> A much better example would be:
> 
>     py> import operator
>     py> reduce(operator.mul, [1,2,3,4])
>     24

"But Rick, my o-so-wise teacher, what's this stuff with the square brackets
and commas? And the round brackets (or parentheses as the Americans call
them)?"

At the point you are demonstrating reduce(), if the reader doesn't
understand or can't guess the meaning of "n = 4", "n+1" or range(), they
won't understand anything you say.

Teachers need to understand that education is a process of building upon
that which has come before. If the teacher talks down to the student by
assuming that the student knows nothing, and tries to go back to first
principles for every little thing, they will never get anywhere.

In this case, it is perfectly acceptable to assume that by the time the
beginner gets to a document about "Dos and Don'ts" they are comfortable
with such basic concepts as assigning values to variables "n=4",
addition "n+1", importing, and can interpret from the context that
operator.mul multiplies without needing to be explicitly told.

If you treat your readers as idiots, only idiots will read your writing.


> At *LEAST* with that example the only potential unknown
> might be "operator.mul". However, a wise teacher would
> recognize that this is a fine "teaching example" of how
> using the operator module can prevent duplicating code --

And the version on the docs demonstrates this by example, instead of
patronising the reader and treating them as an eight year old who needs to
have the most trivial things explained to them.


> which would lead to a better example like:
> 
>     py> def mul(x, y):
>     ...     return x*y
>     py> reduce(mul, [1,2,3,4])
>     24

"But Rick, my o-so-wise teacher! What is the meaning of 'def', 'return' and
the asterisk between the x and y? What's with the three dots and the
spaces?"



> FINALLY! An example that showcases a proper usage of the
> the reduce function *WITHOUT* any superfluous distractions.

Apart from having to define your own function. Given that this is a document
intended to show-case best practice (as in Do this, Don't do that) it is
completely inappropriate to encourage the reader to re-invent the wheel by
creating their own (slow) mul function instead of importing the (fast)
pre-built one in the operator module.


> However, 
> remembering that code re-use is a good thing, and that re-
> inventing the wheel is a lot of work, we should mention that
> the "mul" function should be replaced with "operator.mul"

No, we should not "mention" it as an aside. We should demonstrate best
practice from the start. Unless you are writing for beginners who haven't
been introduced to importing yet (in which case, why are you teaching them
reduce() so early?) there is no benefit at all in showing people how *not*
to do it, then jokingly give them a little nudge-nudge-wink-wink "by the
way, this is better" aside.


>     Note: Be sure to check out the "operator" module for
>     pre-defined arithmetic functions like "operator.mul",
>     which would "reduce" (*wink*) the above code to this:
> 
>     py> reduce(operator.mul, [1,2,3,4])
>     24
> 
> 
> ============================================================
> EXAMPLE 2: "The Fibonacci Phallus Extender".


And that's where I stopped reading. I'm sure it will be overflowing with
insights of your usual quality, but I hurt myself laughing so hard at your
wit ("ha ha, phallus, that means the D") that I simply couldn't continue.



-- 
Steven



From steve+comp.lang.python at pearwood.info  Sat Jan 10 21:42:53 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 11 Jan 2015 13:42:53 +1100
Subject: Syntax error
References: <mailman.17573.1420925784.18130.python-list@python.org>
Message-ID: <54b1e32e$0$12993$c3e8da3$5496439d@news.astraweb.com>

Abdul Abdul wrote:

> Hello,
> 
> I have the following program that employs the dcm2jpg.exe software:
> 
> import os
> os.system(?dcm2jpg.exe IM-0004-0004.dcm?)
> exit
> 
> When I tried to run it, I got the following error:
> 
> SyntaxError: Non-ASCII character '\xe2' in file dicomjpg.py on line 2, but
> no en
> coding declared; see http://python.org/dev/peps/pep-0263/ for details
> 
> Why is that? 

You have curly quotes ?? instead of typewriter quotes "" in your source
code.


> How can this error be solved? 

Don't use Microsoft Office to write code. Use a programmer's text editor:


https://duckduckgo.com/?q=python+text+editors

If you absolutely must use MS Office, turn "Smart Quotes" off.



-- 
Steven



From rramesh1 at gmail.com  Sat Jan 10 22:07:58 2015
From: rramesh1 at gmail.com (Ramesh)
Date: Sat, 10 Jan 2015 19:07:58 -0800 (PST)
Subject: Help running python tests on MIPS
Message-ID: <1058401f-bb43-4805-bab5-0613e6dd21c8@googlegroups.com>

I am new to python.

I downloaded python 2.7.8 tarball, successfully cross compiled it, to make sure that the subsystems are correctly built, I tried running the python test scripts on the MIPS based target board. I hit the below error while I do so,

==
# /opt/Python-2.7.8/bin/python2.7 /opt/Python-2.7.8/lib/python2.7/test/test___al
l__.py
Traceback (most recent call last):
  File "/opt/Python-2.7.8/lib/python2.7/test/test___all__.py", line 3, in <module>
    import unittest
  File "/opt/Python-2.7.8/lib/python2.7/unittest/__init__.py", line 58, in <module>
    from .result import TestResult
  File "/opt/Python-2.7.8/lib/python2.7/unittest/result.py", line 9, in <module>
    from . import util
  File "/opt/Python-2.7.8/lib/python2.7/unittest/util.py", line 2, in <module>
    from collections import namedtuple, OrderedDict
  File "/opt/Python-2.7.8/lib/python2.7/collections.py", line 8, in <module>
    from _collections import deque, defaultdict
ImportError: No module named _collections
# 
===

I tried setting PATH & PYTHONPATH, but it doesn't seem to fix the issue. Can someone please advice on what possibly is causing this problem / how to fix this?

Regards
Ramesh


From nobody at nowhere.invalid  Sat Jan 10 23:12:54 2015
From: nobody at nowhere.invalid (Nobody)
Date: Sun, 11 Jan 2015 04:12:54 +0000
Subject: Can numpy do better than this?
References: <71ecb9ec-5d8c-4503-a75b-1d4aeca79b08@googlegroups.com>
Message-ID: <pan.2015.01.11.04.12.53.470000@nowhere.invalid>

On Thu, 08 Jan 2015 09:56:50 -0800, Rustom Mody wrote:

> Given a matrix I want to shift the 1st column 0 (ie leave as is) 2nd by
> one place, 3rd by 2 places etc.
> 
> This code works.
> But I wonder if numpy can do it shorter and simpler.

def shiftcols(mat):
    iy,ix = np.indices(mat.shape)
    return mat[(iy+ix)%mat.shape[0],ix]



From rustompmody at gmail.com  Sat Jan 10 23:42:26 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Sat, 10 Jan 2015 20:42:26 -0800 (PST)
Subject: PyWart: Poor Documentation Examples
In-Reply-To: <54b1e0c5$0$13012$c3e8da3$5496439d@news.astraweb.com>
References: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>
 <54b1e0c5$0$13012$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <0fede8f4-1174-457e-adc1-06baafe88d5a@googlegroups.com>

On Sunday, January 11, 2015 at 8:02:50 AM UTC+5:30, Steven D'Aprano wrote:
> Rick Johnson wrote:
> 
> 
> > ============================================================
> > EXAMPLE 1: "Reducing Comprehension"
> > https://docs.python.org/2/howto/doanddont.html#using-the-batteries
> > ============================================================
> > 
> > 
> >     ############################################################
> >     #                    QUOTE: Python Docs                    #
> >     ############################################################
> >     # Another highly useful function is reduce() which can be  #
> >     # used to repeatly apply a binary operation to a sequence, #
> >     # reducing it to a single value. For example, compute a    #
> >     # factorial with a series of multiply operations:          #
> >     #                                                          #
> >     # py> n = 4                                                #
> >     # py> import operator                                      #
> >     # py> reduce(operator.mul, range(1, n+1))                  #
> >     # 24                                                       #
> >     ############################################################
> 
> > How exactly does: assigning variables(n = 4),
> > arithmetic(n+1), and the "range" function going to help me
> > understand the usefulness of the reduce function?
> 
> Obviously they don't, duh. They're mere incidentals.
> 
> 
> > A much better example would be:
> > 
> >     py> import operator
> >     py> reduce(operator.mul, [1,2,3,4])
> >     24
> 
> "But Rick, my o-so-wise teacher, what's this stuff with the square brackets
> and commas? And the round brackets (or parentheses as the Americans call
> them)?"
> 
> At the point you are demonstrating reduce(), if the reader doesn't
> understand or can't guess the meaning of "n = 4", "n+1" or range(), they
> won't understand anything you say.
> 
> Teachers need to understand that education is a process of building upon
> that which has come before. If the teacher talks down to the student by
> assuming that the student knows nothing, and tries to go back to first
> principles for every little thing, they will never get anywhere.
> 
> In this case, it is perfectly acceptable to assume that by the time the
> beginner gets to a document about "Dos and Don'ts" they are comfortable
> with such basic concepts as assigning values to variables "n=4",
> addition "n+1", importing, and can interpret from the context that
> operator.mul multiplies without needing to be explicitly told.
> 
> If you treat your readers as idiots, only idiots will read your writing.
> 
> 
> > At *LEAST* with that example the only potential unknown
> > might be "operator.mul". However, a wise teacher would
> > recognize that this is a fine "teaching example" of how
> > using the operator module can prevent duplicating code --
> 
> And the version on the docs demonstrates this by example, instead of
> patronising the reader and treating them as an eight year old who needs to
> have the most trivial things explained to them.
> 
> 
> > which would lead to a better example like:
> > 
> >     py> def mul(x, y):
> >     ...     return x*y
> >     py> reduce(mul, [1,2,3,4])
> >     24
> 
> "But Rick, my o-so-wise teacher! What is the meaning of 'def', 'return' and
> the asterisk between the x and y? What's with the three dots and the
> spaces?"
> 
> 
> 
> > FINALLY! An example that showcases a proper usage of the
> > the reduce function *WITHOUT* any superfluous distractions.
> 
> Apart from having to define your own function. Given that this is a document
> intended to show-case best practice (as in Do this, Don't do that) it is
> completely inappropriate to encourage the reader to re-invent the wheel by
> creating their own (slow) mul function instead of importing the (fast)
> pre-built one in the operator module.
> 
> 
> > However, 
> > remembering that code re-use is a good thing, and that re-
> > inventing the wheel is a lot of work, we should mention that
> > the "mul" function should be replaced with "operator.mul"
> 
> No, we should not "mention" it as an aside. We should demonstrate best
> practice from the start. Unless you are writing for beginners who haven't
> been introduced to importing yet (in which case, why are you teaching them
> reduce() so early?) there is no benefit at all in showing people how *not*
> to do it, then jokingly give them a little nudge-nudge-wink-wink "by the
> way, this is better" aside.
> 
> 
> >     Note: Be sure to check out the "operator" module for
> >     pre-defined arithmetic functions like "operator.mul",
> >     which would "reduce" (*wink*) the above code to this:
> > 
> >     py> reduce(operator.mul, [1,2,3,4])
> >     24
> > 
> > 
> > ============================================================
> > EXAMPLE 2: "The Fibonacci Phallus Extender".
> 
> 
> And that's where I stopped reading. I'm sure it will be overflowing with
> insights of your usual quality, but I hurt myself laughing so hard at your
> wit ("ha ha, phallus, that means the D") that I simply couldn't continue.
> 
> 
> 
> -- 
> Steven

Rick:
Your style beyond irritating to just plain ridiculous.
As it happens I find your reduce example better than the given one.
Unfortunately dunno how to agree the one and not the other :-)


From jeanpierreda at gmail.com  Sun Jan 11 00:25:10 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Sat, 10 Jan 2015 21:25:10 -0800
Subject: PyWart: Poor Documentation Examples
In-Reply-To: <54b1e0c5$0$13012$c3e8da3$5496439d@news.astraweb.com>
References: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>
 <54b1e0c5$0$13012$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CABicbJ+aDseN-dpUyxnO+D_9b40viOHnpjGCA92fKT60698miQ@mail.gmail.com>

On Sat, Jan 10, 2015 at 6:32 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> At the point you are demonstrating reduce(), if the reader doesn't
> understand or can't guess the meaning of "n = 4", "n+1" or range(), they
> won't understand anything you say.
>
> Teachers need to understand that education is a process of building upon
> that which has come before. If the teacher talks down to the student by
> assuming that the student knows nothing, and tries to go back to first
> principles for every little thing, they will never get anywhere.

Agree wholeheartedly. That said, I do think reduce(operator.mul, [1,
2, 3, 4]) actually _is_ a better example, since it cuts right to the
point.

-- Devin


From ethan at stoneleaf.us  Sun Jan 11 02:10:15 2015
From: ethan at stoneleaf.us (Ethan Furman)
Date: Sat, 10 Jan 2015 23:10:15 -0800
Subject: PyWart: Poor Documentation Examples
In-Reply-To: <54b1e0c5$0$13012$c3e8da3$5496439d@news.astraweb.com>
References: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>
 <54b1e0c5$0$13012$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <54B221D7.1070609@stoneleaf.us>

On 01/10/2015 06:32 PM, Steven D'Aprano wrote:
> 
> If you treat your readers as idiots, only idiots will read your writing.

Or the morbidly curious, which I presume covers your case (along with a handful of others ;) .

--
~Ethan~

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From davea at davea.name  Sun Jan 11 03:47:42 2015
From: davea at davea.name (Dave Angel)
Date: Sun, 11 Jan 2015 03:47:42 -0500
Subject: Python : writing to a file
In-Reply-To: <CACT3xuXXhi6oj4Ha2HfftGQ=o_Eo0N-w9pP2gKOXSEkTc7km7g@mail.gmail.com>
References: <CACT3xuUW26iJOeMiF4hhRNYE11_q27G1yugB3ZaFMGyHZVwDuA@mail.gmail.com>	<54B14753.2030909@davea.name>
 <CACT3xuXXhi6oj4Ha2HfftGQ=o_Eo0N-w9pP2gKOXSEkTc7km7g@mail.gmail.com>
Message-ID: <54B238AE.5060401@davea.name>

You accidentally did a Reply instead of a Reply-List.  So the email came 
to me and not to the list.  if your mail program doesn't support 
reply-list, do a reply-all and remove the personal addresses.  The list 
is what's important here.

On 01/11/2015 12:20 AM, Ganesh Pal wrote:
> On Sat, Jan 10, 2015 at 9:07 PM, Dave Angel <davea at davea.name> wrote:
>
<snip>
>
> I did execute the program multiple times, It appeared that it was not
> working because I was trying to view the contents of the file using
> cat commad and cat didn't display the data.
>
> case (a) output with cat:
>
> node- 1# file test_2.txt
> test_2.txt: ASCII text, with no line terminators
>
> node-1# cat test_2.txt
>

You chopped off the output there.  It probably looked like this:


node-1# cat test_2.txt
Sundaynode-1#


Your output is there, right before the prompt.  Since you neglected the 
newline in your code, that's what you'd expect, wouldn't you?

Incidentally, in most systems that prompt would mean you're running as 
root.  Bad idea, especially when you're learning to program.

--
DaveA



From steve+comp.lang.python at pearwood.info  Sun Jan 11 04:31:50 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 11 Jan 2015 20:31:50 +1100
Subject: PyWart: Poor Documentation Examples
References: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>
 <54b1e0c5$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17578.1420960254.18130.python-list@python.org>
Message-ID: <54b24306$0$12989$c3e8da3$5496439d@news.astraweb.com>

Ethan Furman wrote:

> On 01/10/2015 06:32 PM, Steven D'Aprano wrote:
>> 
>> If you treat your readers as idiots, only idiots will read your writing.
> 
> Or the morbidly curious, which I presume covers your case (along with a
> handful of others ;) .


Reading Rick is like taking bad drugs. Every time I've had it in the past,
it was a bad trip. I know that this time it's going to be a bad trip. And
yet I just can't help myself.

If that isn't a form of stupidity, I don't know what is.



-- 
Steven



From steve+comp.lang.python at pearwood.info  Sun Jan 11 04:39:08 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 11 Jan 2015 20:39:08 +1100
Subject: Help running python tests on MIPS
References: <1058401f-bb43-4805-bab5-0613e6dd21c8@googlegroups.com>
Message-ID: <54b244bd$0$13010$c3e8da3$5496439d@news.astraweb.com>

Ramesh wrote:

> I am new to python.
> 
> I downloaded python 2.7.8 tarball, successfully cross compiled it, to make
> sure that the subsystems are correctly built, I tried running the python
> test scripts on the MIPS based target board. I hit the below error while I
> do so,
[...]
> I tried setting PATH & PYTHONPATH, but it doesn't seem to fix the issue.

Tried setting them to what?


> Can someone please advice on what possibly is causing this problem / how
> to fix this?

Try running these commands from the operating system's shell, and report on
the output:


ls -ld /opt/Python-2.7.8/lib/python2.7/lib-dynload/

ls -l /opt/Python-2.7.8/lib/python2.7/lib-dynload/*coll*

python -c "import collections; print collections.__file__"



That will help diagnose the problem.



-- 
Steven



From steve+comp.lang.python at pearwood.info  Sun Jan 11 04:45:21 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 11 Jan 2015 20:45:21 +1100
Subject: Help running python tests on MIPS
References: <1058401f-bb43-4805-bab5-0613e6dd21c8@googlegroups.com>
Message-ID: <54b24632$0$13008$c3e8da3$5496439d@news.astraweb.com>

Ramesh wrote:

> I am new to python.
> 
> I downloaded python 2.7.8 tarball, successfully cross compiled it, to make
> sure that the subsystems are correctly built, I tried running the python
> test scripts on the MIPS based target board. I hit the below error while I
> do so,


On second thoughts, how are you doing this? If I'm reading the next line
correctly:

> # /opt/Python-2.7.8/bin/python2.7
> /opt/Python-2.7.8/lib/python2.7/test/test___all__.py

you haven't installed Python, you've just compiled it and are now trying to
run the test suite manually.

If you read the README file, you should see instructions that tell you to
run the following commands:

    ./configure
    make
    make test
    sudo make install


I recommend following those instructions if you can.


-- 
Steven



From ganesh1pal at gmail.com  Sun Jan 11 05:01:46 2015
From: ganesh1pal at gmail.com (Ganesh Pal)
Date: Sun, 11 Jan 2015 15:31:46 +0530
Subject: Python : writing to a file
In-Reply-To: <54B238AE.5060401@davea.name>
References: <CACT3xuUW26iJOeMiF4hhRNYE11_q27G1yugB3ZaFMGyHZVwDuA@mail.gmail.com>
 <54B14753.2030909@davea.name>
 <CACT3xuXXhi6oj4Ha2HfftGQ=o_Eo0N-w9pP2gKOXSEkTc7km7g@mail.gmail.com>
 <54B238AE.5060401@davea.name>
Message-ID: <CACT3xuW5xDYPNs4dBSgxxdJjZ9Ko2EASxVgrNihZwXTdqqD4wA@mail.gmail.com>

On Sun, Jan 11, 2015 at 2:17 PM, Dave Angel <davea at davea.name> wrote:
>
>
> You chopped off the output there.  It probably looked like this:
>
>
> node-1# cat test_2.txt
> Sundaynode-1#
>
>
> Your output is there, right before the prompt.  Since you neglected the
> newline in your code, that's what you'd expect, wouldn't you?
>
> Incidentally, in most systems that prompt would mean you're running as root.
> Bad idea, especially when you're learning to program.
>

I didn't get the output before the prompt ,I actually didn't chop off
the output . below is the complete flow.

# cat get_day.py
#!/usr/bin/python

import time
f = open ('test_a.txt','wb+')
DAY = time.strftime("%A")
f.write(DAY)
f.close()
Throttling-1# python get_day.py


node-1# cat test_a.txt   // This didn't give any result

node-1# less test_a.txt //  I can see the text here
Sunday
test_a.txt (END)



Regards,
Ganesh


From __peter__ at web.de  Sun Jan 11 05:32:34 2015
From: __peter__ at web.de (Peter Otten)
Date: Sun, 11 Jan 2015 11:32:34 +0100
Subject: Python : writing to a file
References: <CACT3xuUW26iJOeMiF4hhRNYE11_q27G1yugB3ZaFMGyHZVwDuA@mail.gmail.com>
 <54B14753.2030909@davea.name>
 <CACT3xuXXhi6oj4Ha2HfftGQ=o_Eo0N-w9pP2gKOXSEkTc7km7g@mail.gmail.com>
 <54B238AE.5060401@davea.name>
 <CACT3xuW5xDYPNs4dBSgxxdJjZ9Ko2EASxVgrNihZwXTdqqD4wA@mail.gmail.com>
Message-ID: <m8tjg5$bgm$1@ger.gmane.org>

Ganesh Pal wrote:

> On Sun, Jan 11, 2015 at 2:17 PM, Dave Angel <davea at davea.name> wrote:
>>
>>
>> You chopped off the output there.  It probably looked like this:
>>
>>
>> node-1# cat test_2.txt
>> Sundaynode-1#
>>
>>
>> Your output is there, right before the prompt.  Since you neglected the
>> newline in your code, that's what you'd expect, wouldn't you?
>>
>> Incidentally, in most systems that prompt would mean you're running as
>> root. Bad idea, especially when you're learning to program.
>>
> 
> I didn't get the output before the prompt ,I actually didn't chop off
> the output . below is the complete flow.
> 
> # cat get_day.py
> #!/usr/bin/python
> 
> import time
> f = open ('test_a.txt','wb+')
> DAY = time.strftime("%A")
> f.write(DAY)
> f.close()
> Throttling-1# python get_day.py
> 
> 
> node-1# cat test_a.txt   // This didn't give any result
> 
> node-1# less test_a.txt //  I can see the text here
> Sunday
> test_a.txt (END)

What does

$ echo $PS1

print? If there's a \r (carriage return) you should change it to avoid this 
confusion.



From wxjmfauth at gmail.com  Sun Jan 11 05:38:30 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Sun, 11 Jan 2015 02:38:30 -0800 (PST)
Subject: ftfy: fixes text for you
In-Reply-To: <mailman.17568.1420905356.18130.python-list@python.org>
References: <mailman.17568.1420905356.18130.python-list@python.org>
Message-ID: <82f472c0-b8ce-4295-b58f-3451571e328c@googlegroups.com>

Le samedi 10 janvier 2015 16:56:08 UTC+1, Mark Lawrence a ?crit?:
> I came across ftfy via this post 
> http://ianozsvald.com/2015/01/10/a-first-approach-to-automatic-text-data-cleaning/ 
> and thought others here might be interested in it, so here's the direct 
> link http://ftfy.readthedocs.org/en/latest/.
> 

----
??? !!!
jmf



From ganesh1pal at gmail.com  Sun Jan 11 06:44:35 2015
From: ganesh1pal at gmail.com (Ganesh Pal)
Date: Sun, 11 Jan 2015 17:14:35 +0530
Subject: Few coding suggestions
Message-ID: <CACT3xuVSQVM-mkQ0SuSBPA4KuujhSeEx_PE_Of6zujayB-+WUw@mail.gmail.com>

Hello Team,

Iam trying to generate a file which would will should the contents in
the below format

# cat  /root/schedule.conf

Sunday 10:20 10:30
Sunday 10:30 10:40
Sunday 10:50  10:60


I have to build the above format on the local linux machine using
python 2.7 version and then copy the file to the remote machine.

Here is the progress and few questions on the same ,

Program :

node-1# cat time_range.py
def yield_times():
    from datetime import date, time, datetime, timedelta
    start = datetime.combine(date.today(), time(23, 50))
    yield start.strftime("%A %H:%M")
    while True:
        start += timedelta(minutes=10)
        yield start.strftime("%A %H:%M")
gen = yield_times()
for ii in range(05):
     print gen.next()

node-1# python time_range.py
Sunday 23:50
Monday 00:00
Monday 00:10
Monday 00:20
Monday 00:30

(a)  How do I modify the output to have an another column with a
difference of 5 mins

Example :

node-1# python time_range.py

Sunday 23:50 23:05
Monday 00:00 00:05
Monday 00:10 00:05
Monday 00:20 00:15
Monday 00:30 00: 20

(b)  how to copy the above output (i.e with the new column to a file.)


(c)  The  final output should be a file , having the entries  day ,
start , end time of the remote file. how do  i pass the  this to
yeild-times()

import time

/* Assuming I retrive the below values h,m,d from the remote machine*/

h = time.strftime("%H")
m = time.strftime("%M")
d = date.today()


def yield_times():
      global h,m,d
    from datetime import date, time, datetime, timedelta
    start = datetime.combine(date.today(), time(int(h),int(m))) /*
converting string to int)
    yield start.strftime("%A %H:%M")
    while True:
        start += timedelta(minutes=10)
        yield start.strftime("%A %H:%M")
gen = yield_times()
for ii in range(15):
     print gen.next()


Regards,
Ganesh


From ganesh1pal at gmail.com  Sun Jan 11 06:47:44 2015
From: ganesh1pal at gmail.com (Ganesh Pal)
Date: Sun, 11 Jan 2015 17:17:44 +0530
Subject: Few Coding suggestions - resending
Message-ID: <CACT3xuWwYDoj-oMU1dPoRo8Xv_qHRx4JYBXPJcm3T1QfSWjgGw@mail.gmail.com>

Hello Team,

Iam trying to generate a file which should have the  contents in the
below format

# cat  /root/schedule.conf

Sunday 10:20 10:30
Sunday 10:30 10:40
Sunday 10:50  10:60


I have to build the above format on the local linux machine using
python 2.7 version and then copy the file to the remote machine.

Here is the progress and few questions on the same ,

Program :

node-1# cat time_range.py
def yield_times():
    from datetime import date, time, datetime, timedelta
    start = datetime.combine(date.today(), time(23, 50))
    yield start.strftime("%A %H:%M")
    while True:
        start += timedelta(minutes=10)
        yield start.strftime("%A %H:%M")
gen = yield_times()
for ii in range(05):
     print gen.next()

node-1# python time_range.py
Sunday 23:50
Monday 00:00
Monday 00:10
Monday 00:20
Monday 00:30

(a)  How do I modify the output to have an another column with a
difference of 5 mins

Example :

node-1# python time_range.py

Sunday 23:50 23:05
Monday 00:00 00:05
Monday 00:10 00:05
Monday 00:20 00:15
Monday 00:30 00: 20

(b)  how to copy the above output (i.e with the new column to a file.)


(c)  The  final output should be a file , having the entries  day ,
start , end time of the remote file. how do  i pass the  this to
yeild-times()

import time

/* Assuming I retrive the below values h,m,d from the remote machine*/

h = time.strftime("%H")
m = time.strftime("%M")
d = date.today()


def yield_times():
      global h,m,d
    from datetime import date, time, datetime, timedelta
    start = datetime.combine(date.today(), time(int(h),int(m))) /*
converting string to int)
    yield start.strftime("%A %H:%M")
    while True:
        start += timedelta(minutes=10)
        yield start.strftime("%A %H:%M")
gen = yield_times()
for ii in range(15):
     print gen.next()


Regards,
Ganesh


From abdul.sw84 at gmail.com  Sun Jan 11 08:01:59 2015
From: abdul.sw84 at gmail.com (Abdul Abdul)
Date: Sun, 11 Jan 2015 14:01:59 +0100
Subject: DICOM to jpg
Message-ID: <CAA+hu4XvMgXdZswa3X8hTCk9RD2sLuCgXuoz-DwayS7ouMhJJA@mail.gmail.com>

Hello,

Is there a way to convert a DICOM file to an image using Python?

Thanks.
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From tavares at fe.up.pt  Sun Jan 11 08:21:22 2015
From: tavares at fe.up.pt (tavares at fe.up.pt)
Date: Sun, 11 Jan 2015 05:21:22 -0800 (PST)
Subject: VipIMAGE 2015 - ANNOUNCEMENT & CALL FOR CONTRIBUTIONS
Message-ID: <326f5c9e-10f1-4ba7-9f33-0e50916c4caf@googlegroups.com>

Dear Colleague,

We are pleased to announce the International Conference VipIMAGE 2015 - V ECCOMAS THEMATIC CONFERENCE ON COMPUTATIONAL VISION AND MEDICAL IMAGE PROCESSING (www.fe.up.pt/~vipimage) to be held October 19-21, 2015, in H10 Costa Adeje Palace, Costa Adeje, Tenerife, Spain.

Possible Topics (not limited to)
- Signal and Image Processing
- Computational Vision
- Medical Imaging
- Physics of Medical Imaging
- Tracking and Analysis of Movement
- Simulation and Modeling
- Image Acquisition
- Industrial Applications
- Shape Reconstruction
- Segmentation, Matching, Simulation
- Data Interpolation, Registration, Acquisition and Compression
- 3D Vision
- Virtual Reality
- Visual Inspection
- Software Development for Image Processing and Analysis
- Computer Aided Diagnosis, Surgery, Therapy, and Treatment
- Computational Bioimaging and Visualization
- Telemedicine Systems and Applications

Invited Lecturers
- Alexandre Xavier Falc?o, Universidade de Campinas, Brazil
- Cristian A. Linte, Mayo Clinic, USA
- Da-Chuan Cheng, China Medical University, Taiwan
- Fiorella Sgallari, University of Bologna, Italy
- Yongjie Zhang, Carnegie Mellon University, USA
- Xue-cheng Tai, University of Bergen, Norway

Thematic Sessions
Proposals to organize Thematic Sessions under the auspicious of VipIMAGE 2015 are welcome.
Proposals for Thematic Sessions should be submitted by email to the conference co-chairs (tavares at fe.up.pt, rnatal at fe.up.pt).

Publications
Proceedings: The proceedings book will be published by the Taylor & Francis Group and indexed by Thomson Reuters Conference Proceedings Citation Index, IET Inspect and Elsevier Scopus.
Springer Book: A book with 20 invited works from the ones presented in the conference will be published by Springer under the book series "Lecture Notes in Computational Vision and Biomechanics".
Journal Publication: A dedicated special issue of the Taylor & Francis International Journal "Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization" will be published with extended versions of the best works presented in the conference.

Important Dates
- Deadline for Thematic Session Proposals: February 28, 2015
- Deadline for Extended Abstracts: March 15, 2015
- Authors Notification: April 15, 2015
- Deadline for Papers: June 15, 2015
 

We are looking forward to see you in Tenerife next October,
Jo?o Manuel R. S. Tavares
Renato Natal Jorge
(VipIMAGE 2015 co-chairs)


For further details, please, have a look in the conference website at: www.fe.up.pt/~vipimage, the Facebook page at: www.facebook.com/pages/Vipimage/237980719665456, or join the LinkedIn group at: http://www.linkedin.com/groups?gid=4752820&trk=hb_side_g.


From rustompmody at gmail.com  Sun Jan 11 09:20:34 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Sun, 11 Jan 2015 06:20:34 -0800 (PST)
Subject: PyWart: Poor Documentation Examples
In-Reply-To: <mailman.17577.1420953959.18130.python-list@python.org>
References: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>
 <54b1e0c5$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17577.1420953959.18130.python-list@python.org>
Message-ID: <985d05dc-3764-4d12-a641-b4d124cdb457@googlegroups.com>

On Sunday, January 11, 2015 at 10:56:11 AM UTC+5:30, Devin Jeanpierre wrote:
> On Sat, Jan 10, 2015 at 6:32 PM, Steven D'Aprano wrote:
> > At the point you are demonstrating reduce(), if the reader doesn't
> > understand or can't guess the meaning of "n = 4", "n+1" or range(), they
> > won't understand anything you say.
> >
> > Teachers need to understand that education is a process of building upon
> > that which has come before. If the teacher talks down to the student by
> > assuming that the student knows nothing, and tries to go back to first
> > principles for every little thing, they will never get anywhere.
> 
> Agree wholeheartedly. That said, I do think reduce(operator.mul, [1,
> 2, 3, 4]) actually _is_ a better example, since it cuts right to the
> point.

In keeping with Rick's super-polite suggestion to remove
irreleventia like range and variables(!), if we are about to
improve that doc, I would remove the
1,2,3,4
pattern as well and replace with something more random.

The mathematically minded student may think that this has something
to do with arithmetic progressions,
that it does clever algebraic simplifications like
? i = n(n+1)/2

A favorite example of mine is automata-acceptance:
If 
? : Q ? ? ? Q is a transition function
F is the set of final states
q? is the start state
and s is a string

then
reduce(?,q?,s) ? F
expresses "automaton accepts string s"

Should that go into the doc??
I'll leave that to somebody else whose name starts with 'R' :-)


From davea at davea.name  Sun Jan 11 09:27:23 2015
From: davea at davea.name (Dave Angel)
Date: Sun, 11 Jan 2015 09:27:23 -0500
Subject: Few Coding suggestions - resending
In-Reply-To: <CACT3xuWwYDoj-oMU1dPoRo8Xv_qHRx4JYBXPJcm3T1QfSWjgGw@mail.gmail.com>
References: <CACT3xuWwYDoj-oMU1dPoRo8Xv_qHRx4JYBXPJcm3T1QfSWjgGw@mail.gmail.com>
Message-ID: <54B2884B.90301@davea.name>

On 01/11/2015 06:47 AM, Ganesh Pal wrote:
> Hello Team,
>
> Iam trying to generate a file which should have the  contents in the
> below format
>
> # cat  /root/schedule.conf
>
> Sunday 10:20 10:30
> Sunday 10:30 10:40
> Sunday 10:50  10:60
>
>
> I have to build the above format on the local linux machine using
> python 2.7 version and then copy the file to the remote machine.
>
> Here is the progress and few questions on the same ,
>
> Program :
>
> node-1# cat time_range.py
> def yield_times():
>      from datetime import date, time, datetime, timedelta
>      start = datetime.combine(date.today(), time(23, 50))
>      yield start.strftime("%A %H:%M")
>      while True:
>          start += timedelta(minutes=10)
>          yield start.strftime("%A %H:%M")
> gen = yield_times()
> for ii in range(05):
>       print gen.next()
>
> node-1# python time_range.py
> Sunday 23:50
> Monday 00:00
> Monday 00:10
> Monday 00:20
> Monday 00:30
>
> (a)  How do I modify the output to have an another column with a
> difference of 5 mins
>
> Example :
>
> node-1# python time_range.py
>
> Sunday 23:50 23:05
> Monday 00:00 00:05
> Monday 00:10 00:05
> Monday 00:20 00:15
> Monday 00:30 00: 20

No idea how that represents "a difference of 5 minutes".  So I'll take a 
totally wild guess that you meant:

Sunday 23:50 23:55
Monday 00:00 00:05
Monday 00:10 00:15
Monday 00:20 00:25
Monday 00:30 00:35

which would have the 2nd column 5 minutes after the first.

You need another datetime object, let's call it 'end'

end = start + timedelta(minutes=5)

and now you want to yield three things, in a tuple:

yield (start.strftime("%A"), start.strftime("%H:%M"),
    end.strftime("%H:%M"))

Of course that's a pain to do twice, as you have two yields in that 
function.  I'll leave you to reorder the loop to make that unnecessary. 
  Hint, do the yield first, THEN increment the start variable.

and in the other loop, you want
     res = "{} {} {}\n".format(gen.next)
     print res,

>
> (b)  how to copy the above output (i.e with the new column to a file.)
>

Instead of printing, just do f.write(res).  Or do both. Notice that to 
make this easy, i avoided doing any formatting in the print statement. 
I used a trailing comma on it to avoid print adding a newline, and 
instead put it explicitly in the format method call.

>
> (c)  The  final output should be a file , having the entries  day ,
> start , end time of the remote file. how do  i pass the  this to
> yeild-times()
>
> import time
>
> /* Assuming I retrive the below values h,m,d from the remote machine*/
>
> h = time.strftime("%H")
> m = time.strftime("%M")
> d = date.today()
>

Those first two are strings, but the third is a datetime object.  That 
last can be painful to pass between machines.

>
> def yield_times():
>        global h,m,d

No idea what that's all about.  If you want to pass arguments to 
yield_times(), put them inside the parens.

>      from datetime import date, time, datetime, timedelta
>      start = datetime.combine(date.today(), time(int(h),int(m))) /*
> converting string to int)

Got some C code in there?  Use # for comments.

You don't seem to be honoring the 'd' value from the other machine.

>      yield start.strftime("%A %H:%M")
>      while True:
>          start += timedelta(minutes=10)
>          yield start.strftime("%A %H:%M")
> gen = yield_times()
> for ii in range(15):
>       print gen.next()
>
>
> Regards,
> Ganesh
>


-- 
DaveA


From dan at tombstonezero.net  Sun Jan 11 09:38:21 2015
From: dan at tombstonezero.net (Dan Sommers)
Date: Sun, 11 Jan 2015 14:38:21 +0000 (UTC)
Subject: PyWart: Poor Documentation Examples
References: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>
 <54b1e0c5$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17577.1420953959.18130.python-list@python.org>
 <985d05dc-3764-4d12-a641-b4d124cdb457@googlegroups.com>
Message-ID: <m8u1st$igp$1@dont-email.me>

On Sun, 11 Jan 2015 06:20:34 -0800, Rustom Mody wrote:


> A favorite example of mine is automata-acceptance:
> If 
> ? : Q ? ? ? Q is a transition function
> F is the set of final states
> q? is the start state
> and s is a string
> 
> then
> reduce(?,q?,s) ? F
> expresses "automaton accepts string s"
> 
> Should that go into the doc??

Absolutely.  :-)  If the docs had explained that reduce is
actually a finite state machine framework, then I wouldn't
have written my such framework.

> I'll leave that to somebody else whose name starts with 'R' :-)

Uh, oh.  Sorry.

-- 
Dan Sommers, neither of which begins with an 'R'


From invalid at invalid.invalid  Sun Jan 11 11:04:50 2015
From: invalid at invalid.invalid (Grant Edwards)
Date: Sun, 11 Jan 2015 16:04:50 +0000 (UTC)
Subject: PyWart: Poor Documentation Examples
References: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>
 <mailman.17570.1420914384.18130.python-list@python.org>
Message-ID: <m8u6v2$bqa$1@reader2.panix.com>

On 2015-01-10, Chris Angelico <rosuav at gmail.com> wrote:
> On Sun, Jan 11, 2015 at 5:05 AM, Rick Johnson
><rantingrickjohnson at gmail.com> wrote:
>> ============================================================
>> EXAMPLE 1: "Reducing Comprehension" https://docs.python.org/2/howto/doanddont.html#using-the-batteries
>> ============================================================
>
> 1) Why are you focusing on the /2/ docs, rather than /3/?
> 2) Why are you ranting, rather than submitting docs patches?

3) There are still people who read RR posts?

-- 
Grant





From rosuav at gmail.com  Sun Jan 11 11:18:33 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 12 Jan 2015 03:18:33 +1100
Subject: PyWart: Poor Documentation Examples
In-Reply-To: <m8u6v2$bqa$1@reader2.panix.com>
References: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>
 <mailman.17570.1420914384.18130.python-list@python.org>
 <m8u6v2$bqa$1@reader2.panix.com>
Message-ID: <CAPTjJmpnremMhKWnBu93zL=S+uirdneq+JFUNVHrm0_98S826w@mail.gmail.com>

On Mon, Jan 12, 2015 at 3:04 AM, Grant Edwards <invalid at invalid.invalid> wrote:
> On 2015-01-10, Chris Angelico <rosuav at gmail.com> wrote:
>> 1) Why are you focusing on the /2/ docs, rather than /3/?
>> 2) Why are you ranting, rather than submitting docs patches?
>
> 3) There are still people who read RR posts?

Yeah, there are. Steven summarized it thus, although I can't
personally speak to the accuracy of the specifics:

On Sun, Jan 11, 2015 at 8:31 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Reading Rick is like taking bad drugs. Every time I've had it in the past,
> it was a bad trip. I know that this time it's going to be a bad trip. And
> yet I just can't help myself.
>
> If that isn't a form of stupidity, I don't know what is.

ChrisA


From torriem at gmail.com  Sun Jan 11 12:11:13 2015
From: torriem at gmail.com (Michael Torrie)
Date: Sun, 11 Jan 2015 10:11:13 -0700
Subject: PyWart: Poor Documentation Examples
In-Reply-To: <m8u6v2$bqa$1@reader2.panix.com>
References: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>
 <mailman.17570.1420914384.18130.python-list@python.org>
 <m8u6v2$bqa$1@reader2.panix.com>
Message-ID: <54B2AEB1.70105@gmail.com>

On 01/11/2015 09:04 AM, Grant Edwards wrote:
> 3) There are still people who read RR posts?

The last post by RR helping someone with a tk problem was very helpful,
and rather elucidating, as are most of his post on tk.  It was rather
refreshing to see several posts like this.  I thought perhaps this would
signify a new era.  But alas, no, he's slipped back into his lazy ways.
 Too bad really. He seems to be a smart person.  He could contribute to
Python in positive ways if he chose (like patching the documentation, or
contributing code).  Unfortunately when he gets like this he can't even
get up the energy to open bug reports.  Easier to just rant on the list
apparently.  Now perhaps there are two RRs, in some sort of conflict in
the same person.  Sad to see this one winning out.



From rosuav at gmail.com  Sun Jan 11 12:18:56 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 12 Jan 2015 04:18:56 +1100
Subject: PyWart: Poor Documentation Examples
In-Reply-To: <54B2AEB1.70105@gmail.com>
References: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>
 <mailman.17570.1420914384.18130.python-list@python.org>
 <m8u6v2$bqa$1@reader2.panix.com> <54B2AEB1.70105@gmail.com>
Message-ID: <CAPTjJmoim9ZBr4R9zWqiXtn_mTGLx8n89p2-D4JSfh-fNA8oOw@mail.gmail.com>

On Mon, Jan 12, 2015 at 4:11 AM, Michael Torrie <torriem at gmail.com> wrote:
> The last post by RR helping someone with a tk problem was very helpful,
> and rather elucidating, as are most of his post on tk.  ...
> Now perhaps there are two RRs, in some sort of conflict in
> the same person.  Sad to see this one winning out.

Doubtful. Even when he's answering tkinter questions (and is imparting
useful information), he still has the same abrasive style. It reflects
badly on Python that the help is provided in such a way, but unless
there's someone else with as much expertise as Rick has, that's not
going to change. (Either that, or we just all start recommending PyQT
or GTK or something.)

ChrisA


From rustompmody at gmail.com  Sun Jan 11 12:29:12 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Sun, 11 Jan 2015 09:29:12 -0800 (PST)
Subject: PyWart: Poor Documentation Examples
In-Reply-To: <mailman.17589.1420996739.18130.python-list@python.org>
References: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>
 <mailman.17570.1420914384.18130.python-list@python.org>
 <m8u6v2$bqa$1@reader2.panix.com> <54B2AEB1.70105@gmail.com>
 <mailman.17589.1420996739.18130.python-list@python.org>
Message-ID: <21c06058-f370-4bf0-ad31-818d49c08510@googlegroups.com>

On Sunday, January 11, 2015 at 10:49:11 PM UTC+5:30, Chris Angelico wrote:
> On Mon, Jan 12, 2015 at 4:11 AM, Michael Torrie  wrote:
> > The last post by RR helping someone with a tk problem was very helpful,
> > and rather elucidating, as are most of his post on tk.  ...
> > Now perhaps there are two RRs, in some sort of conflict in
> > the same person.  Sad to see this one winning out.
> 
> Doubtful. Even when he's answering tkinter questions (and is imparting
> useful information), he still has the same abrasive style. It reflects
> badly on Python that the help is provided in such a way, but unless
> there's someone else with as much expertise as Rick has, that's not
> going to change. (Either that, or we just all start recommending PyQT
> or GTK or something.)

You can always tell the unwitting new questioner that Rick's 
content is useful [when it is] whereas his style is ignorable.


From denismfmcmahon at gmail.com  Sun Jan 11 12:37:26 2015
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Sun, 11 Jan 2015 17:37:26 +0000 (UTC)
Subject: Few coding suggestions
References: <mailman.17582.1420976683.18130.python-list@python.org>
Message-ID: <m8uccm$i2o$2@dont-email.me>

On Sun, 11 Jan 2015 17:14:35 +0530, Ganesh Pal wrote:

> (a)  How do I modify the output to have an another column with a
> difference of 5 mins

I'm not sure I understand the problem you're trying to solve, and it 
seems to me that you are presenting your problem in terms of your partial 
solution.

Try stating the actual problem.

Some hints, based on my best guess of what you're actually trying to do.

If you want a program to execute every n minutes, the easiest way to do 
this is normally to use the cron scheduler to start your program every n 
minutes.

If you want to append the output of a program to an existing file, open 
the file in append mode.

You normally add lines to a file, not columns.

You my want to investigate various ways of serialising data inside a 
file, eg csv, json etc. Also things like date and time formats if this is 
some sort of log file.

It would however be much easier to help you with your problem if you 
stated the problem you're trying to solve, eg "I wish to create a 
snapshot of process memory and cpu use every 5 minutes and send it to 
another server."

-- 
Denis McMahon, denismfmcmahon at gmail.com


From breamoreboy at yahoo.co.uk  Sun Jan 11 12:46:57 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 11 Jan 2015 17:46:57 +0000
Subject: PyWart: Poor Documentation Examples
In-Reply-To: <m8u6v2$bqa$1@reader2.panix.com>
References: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>
 <mailman.17570.1420914384.18130.python-list@python.org>
 <m8u6v2$bqa$1@reader2.panix.com>
Message-ID: <m8ucup$qnr$1@ger.gmane.org>

On 11/01/2015 16:04, Grant Edwards wrote:
> On 2015-01-10, Chris Angelico <rosuav at gmail.com> wrote:
>> On Sun, Jan 11, 2015 at 5:05 AM, Rick Johnson
>> <rantingrickjohnson at gmail.com> wrote:
>>> ============================================================
>>> EXAMPLE 1: "Reducing Comprehension" https://docs.python.org/2/howto/doanddont.html#using-the-batteries
>>> ============================================================
>>
>> 1) Why are you focusing on the /2/ docs, rather than /3/?
>> 2) Why are you ranting, rather than submitting docs patches?
>
> 3) There are still people who read RR posts?
>

Admittedly this was a bad one but his contributions to tkinter/IDLE are 
useful.  Contrast that to our former Resident Unicode Expert or our 
Greek Web Design Expert.  Then years ago there was Xah Lee telling us 
how to write docs, it was so funny the way he was torn to shreds.  As 
for Ilias Lazaridu what can I say, except that I beat all when having a 
day that starts with me getting out of bed on the wrong side, and worse 
later on when my hair do gets ruined!!! :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From steve+comp.lang.python at pearwood.info  Sun Jan 11 13:17:10 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Mon, 12 Jan 2015 05:17:10 +1100
Subject: Using a ChangeLog as a canonical source of package metadata (was:
 Announce: PyPrimes 0.2.1a)
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17488.1420762070.18130.python-list@python.org>
Message-ID: <54b2be27$0$13000$c3e8da3$5496439d@news.astraweb.com>

Ben Finney wrote:
[...]
> The perils of duplicate sources of information: a Changelog makes claims
> about which version is latest, but the packaging metadata comes from
> somewhere else.
> 
> This problem is addressed quite well, in my opinion, by the Debian
> packaging tools. The tools by default read the following information:
> 
> * release version string
> * maintainer name
> * maintainer email address
> * target suite (a conceptual ?which Debian version should this go into?)
> 
> from the Changelog document, automatically. This means that the
> Changelog document, as well as being directly useful to the recipient as
> a text document, becomes the canonical place to record all those fields
> for the packaging tools to read. No need to maintain duplicate records.

A very interesting way to handle this, and one which deserves further
configuration.

I currently read this metadata from the Python code itself. The advantages
of putting the metadata into the source code include:

- the source code is the definitive source of information about itself;
- even if the user deletes the README and CHANGELOG files, they can 
  still find the metadata;
- if your application wants to report a version number (as many apps 
  do) then it is easy for them to do so.


But the disadvantages include:

- it's a bit sad to have to put such metadata into the source code;
- the risk of the changelog getting out of date.


> I would like Python's packaging tools to have the same capability.
> 
> This requires recording the Changelog document in a machine-parseable
> format, with specified locations for each of the fields to be read for
> each version.

I wonder whether it would be better to have setup.py check the CHANGELOG and
halt if it isn't up to date? 



> I have recently gone through a process of converting the Changelog for a
> package I maintain (?python-daemon?) to reStructuredText [0]. This has
> all the above features: machine-parseable, a well-defined way to attach
> fields to a section, etc.
> 
> [0] reStructuredText: <URL:http://docutils.sourceforge.net/rst.html>
> 
> I've now produced a small Python library which knows how to transform a
> reST Changelog to package metadata; and how to get that package metadata
> into and out of a Python distribution with Distutils.

Sounds interesting. Where can we see this?

> The result is that I will never again upload the package with a mismatch
> between what the Changelog claims is the latest version, and what the
> package metadata says.
> 
> 
> This may be generally useful to others. I'm interested to know how
> people would expect to use this. As an extension to Distutils? As a
> third-party library? Something else?

Offering it as a third-party library is a good start, but perhaps you could
discuss this on the packaging mailing list and see whether they have any
interest in it?

https://mail.python.org/mailman/listinfo/distutils-sig/


-- 
Steven



From rramesh1 at gmail.com  Sun Jan 11 13:43:55 2015
From: rramesh1 at gmail.com (rramesh1 at gmail.com)
Date: Sun, 11 Jan 2015 10:43:55 -0800 (PST)
Subject: Help running python tests on MIPS
In-Reply-To: <54b24632$0$13008$c3e8da3$5496439d@news.astraweb.com>
References: <1058401f-bb43-4805-bab5-0613e6dd21c8@googlegroups.com>
 <54b24632$0$13008$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <c887a737-15ab-4dad-9ecc-78bda9906540@googlegroups.com>

On Sunday, January 11, 2015 at 1:45:33 AM UTC-8, Steven D'Aprano wrote:
> Ramesh wrote:
> 
> > I am new to python.
> > 
> > I downloaded python 2.7.8 tarball, successfully cross compiled it, to make
> > sure that the subsystems are correctly built, I tried running the python
> > test scripts on the MIPS based target board. I hit the below error while I
> > do so,
> 
> 
> On second thoughts, how are you doing this? If I'm reading the next line
> correctly:
> 
> > # /opt/Python-2.7.8/bin/python2.7
> > /opt/Python-2.7.8/lib/python2.7/test/test___all__.py
> 
> you haven't installed Python, you've just compiled it and are now trying to
> run the test suite manually.
> 
> If you read the README file, you should see instructions that tell you to
> run the following commands:
> 
>     ./configure
>     make
>     make test
>     sudo make install
> 
> 
> I recommend following those instructions if you can.
> 
> 
> -- 
> Steven

Thank you for the response.

I did see the README, here is what I am doing

configure
#Make hostpython & hostpgen
make python
make test
mv python hostpython 
mv Parser/hostpgen hostpgen
# Do a distclean before cross compiling
make distclean

# Configure with cross toolchain options
# gcc, g++, ar & ranlib for MIPS
# prefix pointing to /usr/lib on the target file system (MIPS)
configure 
#Build python for MIPS
make
make install

Actually I hit a problem in install (I got it worked around by doing -i (ignore errors), but later found the issue & fixed by a patch, after which - there were no errors in make install as well).

After the install, I am removing (rm -rf) certain files that I think are of no use as the target has limited flash space. 

==
       /bin/rm -rf ${PYTHON_ROOTFS_DEPLOY_DIR}/lib/python2.7/lib2to3
        /bin/rm -rf ${PYTHON_ROOTFS_DEPLOY_DIR}/lib/python2.7/email
        /bin/rm -rf ${PYTHON_ROOTFS_DEPLOY_DIR}/lib/python2.7/bsddb
        /bin/rm -rf ${PYTHON_ROOTFS_DEPLOY_DIR}/lib/python2.7/xml
        /bin/rm -rf ${PYTHON_ROOTFS_DEPLOY_DIR}/lib/python2.7/pydoc_data
        /bin/rm -rf ${PYTHON_ROOTFS_DEPLOY_DIR}/lib/python2.7/lib-tk
        /bin/rm -rf ${PYTHON_ROOTFS_DEPLOY_DIR}/lib/python2.7/sqlite3
        /bin/rm -rf ${PYTHON_ROOTFS_DEPLOY_DIR}/lib/python2.7/idlelib
        /bin/rm -rf ${PYTHON_ROOTFS_DEPLOY_DIR}/share
        /bin/rm -rf ${PYTHON_ROOTFS_DEPLOY_DIR}/lib/python2.7/config/libpython2.7.a
        /bin/rm -rf ${PYTHON_ROOTFS_DEPLOY_DIR}/lib/python2.7/test/audiodata

==

I set the PYTHONPATH point to /opt/Python-2.7.8/lib/python2.7

Still hit the same error. Am I missing something else?

 


From profesor.fir at gmail.com  Sun Jan 11 13:46:36 2015
From: profesor.fir at gmail.com (fir)
Date: Sun, 11 Jan 2015 10:46:36 -0800 (PST)
Subject: ]beginer] what i need to code simple graphics?
Message-ID: <719b1592-a8a6-4f95-836b-d2be8a1c6e22@googlegroups.com>

what i need to code simple graphic in python?
Im totally new in python, though im moderately experienced in c

2d perpixel graphic probably, or other kind of graphic too


From rramesh1 at gmail.com  Sun Jan 11 14:01:49 2015
From: rramesh1 at gmail.com (rramesh1 at gmail.com)
Date: Sun, 11 Jan 2015 11:01:49 -0800 (PST)
Subject: Help running python tests on MIPS
In-Reply-To: <54b244bd$0$13010$c3e8da3$5496439d@news.astraweb.com>
References: <1058401f-bb43-4805-bab5-0613e6dd21c8@googlegroups.com>
 <54b244bd$0$13010$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <462bf362-d698-41c7-a28d-35199d96dd51@googlegroups.com>

On Sunday, January 11, 2015 at 1:39:20 AM UTC-8, Steven D'Aprano wrote:
> Ramesh wrote:
> 
> > I am new to python.
> > 
> > I downloaded python 2.7.8 tarball, successfully cross compiled it, to make
> > sure that the subsystems are correctly built, I tried running the python
> > test scripts on the MIPS based target board. I hit the below error while I
> > do so,
> [...]
> > I tried setting PATH & PYTHONPATH, but it doesn't seem to fix the issue.
> 
> Tried setting them to what?
> 
> 
> > Can someone please advice on what possibly is causing this problem / how
> > to fix this?
> 
> Try running these commands from the operating system's shell, and report on
> the output:
> 
> 
> ls -ld /opt/Python-2.7.8/lib/python2.7/lib-dynload/
> 
> ls -l /opt/Python-2.7.8/lib/python2.7/lib-dynload/*coll*
> 
> python -c "import collections; print collections.__file__"
> 
> 
> 
> That will help diagnose the problem.
> 
> 
> 
> -- 
> Steven

For the above commands, here is the output 

# ls -ld /opt/Python-2.7.8/lib/python2.7/lib-dynload/ 
drwxr-xr-x    2 root     root          681 Jan 10  2015 /opt/Python-2.7.8/lib/python2.7/lib-dynload/
# ls -l /opt/Python-2.7.8/lib/python2.7/lib-dynload/*coll*
ls: /opt/Python-2.7.8/lib/python2.7/lib-dynload/*coll*: No such file or directory
# /opt/Python-2.7.8/bin/python2.7 -c "import collections; print collections.__fi
le__" 
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/opt/Python-2.7.8/lib/python2.7/collections.py", line 8, in <module>
    from _collections import deque, defaultdict
ImportError: No module named _collections
# 



From store0a at gmail.com  Sun Jan 11 14:31:04 2015
From: store0a at gmail.com (Store Makhzan)
Date: Sun, 11 Jan 2015 11:31:04 -0800 (PST)
Subject: extracting numbers with decimal places from a string
Message-ID: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>

I have this script which can calculate the total of numbers given in a string
---- script -----
total = 0
for c in '0123456789':
   total += int(c)
print total
---- script -----

How should I modify this script to find the total of if the numbers given in the string form have decimal places? That is, how do I need to modify this line:
----- script -----
for c in '1.32, 5.32, 4.4, 3.78':
----- script -----
to find the total of these given numbers.


From semeon.risom at gmail.com  Sun Jan 11 14:41:28 2015
From: semeon.risom at gmail.com (semeon.risom at gmail.com)
Date: Sun, 11 Jan 2015 11:41:28 -0800 (PST)
Subject: Generate jpg files using line length (pixels) and orientation
 (degrees)
In-Reply-To: <m8sgai$k48$1@dont-email.me>
References: <0f51bd21-7b0a-4ea0-8b13-27b1967d3b41@googlegroups.com>
 <m8mv27$k6e$2@dont-email.me> <m8nfs8$k6e$3@dont-email.me>
 <1ae2a5c4-78ae-4831-ac01-b886e92c0468@googlegroups.com>
 <m8sgai$k48$1@dont-email.me>
Message-ID: <70bd0c94-9336-4ab2-adc0-3fd93af25e2d@googlegroups.com>

On Saturday, 10 January 2015 21:31:25 UTC-6, Denis McMahon  wrote:
> On Fri, 09 Jan 2015 09:49:25 -0800, semeon.risom wrote:
> 
> > Thank you for the help btw. I think I'm close to a solution, but I'm
> > having issue feeding the coordinates from my csv file into the formula.
> > 
> > This is the error I get:
> > Traceback (most recent call last):
> >   File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w
> >   corr.py", line 68, in <module>
> >     makeimg(length, orientation)
> >   File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w
> >   corr.py", line 40, in makeimg
> >     orientation = orientation % 180
> > TypeError: unsupported operand type(s) for %: 'list' and 'int'
> >>>> 
> >>>> 
> > and here's the code:
> > 
> > from PIL import Image, ImageDraw from numpy import math
> > 
> > # import csv import csv f = open('C:\Users\Owner\DesktopStimuli
> > Generation\Coordinates\file.csv', 'rb')
> > rdr = csv.reader(f)
> > f.seek(0)
> > i = 0 a = []
> > b = []
> > for row in rdr:
> >         a.append(row[0]) 
> >         b.append(row[1])
> 
> This makes a and b both lists
> 
> Having read some other errors that you are having, you need to make sure 
> that these items are numeric and not string data
> 
> for row in rdr:
>         a.append(int(row[0]))
>         b.append(int(row[1]))
> 
> > # using lists of values for length in [a]:
> >     for orientation in [b]:
> >         makeimg(length, orientation)
> 
> This puts list a inside another list, and puts list b inside another 
> list, and then passes the whole of lists a and b in the first call to 
> makeimg.
> 
> makeimg expects 2 integer parameters on each call, not two lists!
> 
> As you have already created lists, you don't need to wrap them inside 
> another list.
> 
> # using lists of values 
> for length in a:
>     for orientation in b:
>         makeimg(length, orientation)
> 
> -- 
> Denis McMahon, denismfmcmahon at gmail.com

The code is working correctly. Thank you! The only change I had to make was referring to it as a float instead of an integer. 

The images are generating, however I'm noticing that it's making an image for every possible pair in each list (i.e. Image 1: a1 and b1; Image 2: a1 and b2; Image 3: a1 and b3....) instead of an image for each row (e.g. Image 1: a1 and b1; Image 2: a2 and b2; Image 3: a3 and b3...).


From denismfmcmahon at gmail.com  Sun Jan 11 14:56:57 2015
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Sun, 11 Jan 2015 19:56:57 +0000 (UTC)
Subject: Generate jpg files using line length (pixels) and orientation
 (degrees)
References: <0f51bd21-7b0a-4ea0-8b13-27b1967d3b41@googlegroups.com>
 <m8mv27$k6e$2@dont-email.me> <m8nfs8$k6e$3@dont-email.me>
 <1ae2a5c4-78ae-4831-ac01-b886e92c0468@googlegroups.com>
 <m8sgai$k48$1@dont-email.me>
 <70bd0c94-9336-4ab2-adc0-3fd93af25e2d@googlegroups.com>
Message-ID: <m8uki9$d0s$1@dont-email.me>

On Sun, 11 Jan 2015 11:41:28 -0800, semeon.risom wrote:

> The code is working correctly. Thank you! The only change I had to make
> was referring to it as a float instead of an integer.
> 
> The images are generating, however I'm noticing that it's making an
> image for every possible pair in each list (i.e. Image 1: a1 and b1;
> Image 2: a1 and b2; Image 3: a1 and b3....) instead of an image for each
> row (e.g. Image 1: a1 and b1; Image 2: a2 and b2; Image 3: a3 and
> b3...).

Try these changes:

# before the csv reader, declare a single list
params = []

# in the csv reader, append each pair of params to the list as
# a tuple

for row in rdr:
    params.append( ( int(row[0]), int(row[1]) ) )


# use the lists of tuples to generate one image per tuple

for item in params:
    makeimg(item[0], item[1])

#####################################################

You could also skip the list generation entirely.

After the main function definition:

f = open(filename, 'r')
rdr = csv.reader(f)
for row in rdr:
    makeimg(int(row[0]), int(row[1]))

Also please note that you only need to quote the bits of the post that 
you are replying to to give context, not the whole post.

-- 
Denis McMahon, denismfmcmahon at gmail.com


From joel.goldstick at gmail.com  Sun Jan 11 15:06:34 2015
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Sun, 11 Jan 2015 15:06:34 -0500
Subject: extracting numbers with decimal places from a string
In-Reply-To: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
Message-ID: <CAPM-O+w1ree8o-tc8rwh+JeSuQSSiQw5ic920X3DTbbcw7Ch3g@mail.gmail.com>

On Sun, Jan 11, 2015 at 2:31 PM, Store Makhzan <store0a at gmail.com> wrote:
> I have this script which can calculate the total of numbers given in a string
> ---- script -----
> total = 0
> for c in '0123456789':
>    total += int(c)
> print total
> ---- script -----
>
> How should I modify this script to find the total of if the numbers given in the string form have decimal places? That is, how do I need to modify this line:
> ----- script -----
> for c in '1.32, 5.32, 4.4, 3.78':
> ----- script -----
> to find the total of these given numbers.
> --
> https://mail.python.org/mailman/listinfo/python-list

split the string on ',' to get a list of strings.  loop thru list
using float(s), add float values


-- 
Joel Goldstick
http://joelgoldstick.com


From davea at davea.name  Sun Jan 11 15:16:58 2015
From: davea at davea.name (Dave Angel)
Date: Sun, 11 Jan 2015 15:16:58 -0500
Subject: Generate jpg files using line length (pixels) and orientation
 (degrees)
In-Reply-To: <70bd0c94-9336-4ab2-adc0-3fd93af25e2d@googlegroups.com>
References: <0f51bd21-7b0a-4ea0-8b13-27b1967d3b41@googlegroups.com>
 <m8mv27$k6e$2@dont-email.me> <m8nfs8$k6e$3@dont-email.me>
 <1ae2a5c4-78ae-4831-ac01-b886e92c0468@googlegroups.com>
 <m8sgai$k48$1@dont-email.me>
 <70bd0c94-9336-4ab2-adc0-3fd93af25e2d@googlegroups.com>
Message-ID: <54B2DA3A.4070305@davea.name>

On 01/11/2015 02:41 PM, semeon.risom at gmail.com wrote:
> On Saturday, 10 January 2015 21:31:25 UTC-6, Denis McMahon  wrote:

>> # using lists of values
>> for length in a:
>>      for orientation in b:
>>          makeimg(length, orientation)
>>
>> --
>> Denis McMahon, denismfmcmahon at gmail.com
>
> The code is working correctly. Thank you! The only change I had to make was referring to it as a float instead of an integer.
>
> The images are generating, however I'm noticing that it's making an image for every possible pair in each list (i.e. Image 1: a1 and b1; Image 2: a1 and b2; Image 3: a1 and b3....) instead of an image for each row (e.g. Image 1: a1 and b1; Image 2: a2 and b2; Image 3: a3 and b3...).
>

The minimum change for that would be to zip the lists together:

for length, orientation in zip(a,b):
     makeimg(length, orientation)


-- 
DaveA


From ben+python at benfinney.id.au  Sun Jan 11 15:21:25 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Mon, 12 Jan 2015 07:21:25 +1100
Subject: Using a ChangeLog as a canonical source of package metadata
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17488.1420762070.18130.python-list@python.org>
 <54b2be27$0$13000$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <85bnm5ukze.fsf@benfinney.id.au>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:

> I currently read this metadata from the Python code itself. The
> advantages of putting the metadata into the source code include:
>
> - the source code is the definitive source of information about itself;

The Changelog document should be in the same source tree and maintained
by the same people, so I don't count that as a difference between the
two approaches.

> - even if the user deletes the README and CHANGELOG files, they can 
>   still find the metadata;

Perhaps I didn't emphasise it, but: The approach I'm advocating (as
inspired by Debian packaging tools) has the version metadata
*canonically* recorded in the Changelog, but not *only* stored there.

The packaging tools parse the version metadata from the Changelog, then
duplicate whatever metadata is needed in various other places ? such as
for programmatic access by the package's own code.

> - if your application wants to report a version number (as many apps 
>   do) then it is easy for them to do so.

The idea is to parse from the Changelog the version metadata, and record
it in Setuptools metadata. Then the ?pkg_resources? module of Setuptools
allows programmatic access to that metadata.

Thanks for enumerating those points, I think they are adequately
addressed by this approach.


> > I've now produced a small Python library which knows how to
> > transform a reST Changelog to package metadata; and how to get that
> > package metadata into and out of a Python distribution with
> > Distutils.
>
> Sounds interesting. Where can we see this?

It is the approach used in ?python-daemon? version 2. Find the source at
<URL:https://alioth.debian.org/projects/python-daemon/>. The
?ChangeLog?, ?setup.py?, ?version.py?, ?daemon/_metadata.py? files are
the relevant ones to examine.

Since this is a new approach I'm trying, I flubbed a couple of versions:
you'll need version 2.0.1 or later (I omitted the ?version? module
entirely from the earlier distribution), and you'll need ?docutils?
already installed (a future ?python-daemon? distribution will declare
this dependency).

I'll be interested to see how Python developers like this.

-- 
 \      ?The process by which banks create money is so simple that the |
  `\     mind is repelled.? ?John Kenneth Galbraith, _Money: Whence It |
_o__)                                       Came, Where It Went_, 1975 |
Ben Finney



From store0a at gmail.com  Sun Jan 11 15:26:32 2015
From: store0a at gmail.com (Store Makhzan)
Date: Sun, 11 Jan 2015 12:26:32 -0800 (PST)
Subject: extracting numbers with decimal places from a string
In-Reply-To: <mailman.17591.1421006803.18130.python-list@python.org>
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
 <mailman.17591.1421006803.18130.python-list@python.org>
Message-ID: <3bfeea22-cded-4363-92fa-6f1b33ddae16@googlegroups.com>

On Sunday, January 11, 2015 at 2:06:54 PM UTC-6, Joel Goldstick wrote:
> On Sun, Jan 11, 2015 at 2:31 PM, Store Makhzan wrote:
> > I have this script which can calculate the total of numbers given in a string
> > ---- script -----
> > total = 0
> > for c in '0123456789':
> >    total += int(c)
> > print total
> > ---- script -----
> >
> > How should I modify this script to find the total of if the numbers given in the string form have decimal places? That is, how do I need to modify this line:
> > ----- script -----
> > for c in '1.32, 5.32, 4.4, 3.78':
> > ----- script -----
> > to find the total of these given numbers.
> > --
> > https://mail.python.org/mailman/listinfo/python-list
> 
> split the string on ',' to get a list of strings.  loop thru list
> using float(s), add float values
> 
> 
> -- 
> Joel Goldstick
> http://joelgoldstick.com

Thank you
Here is what I did:

----- script -----
#Check if a perfect cube
total = 0
for c in ('1.23', '2.4', '3.123'):
   print float(c)
   total += float(c)
print total
----- script -----

Which gave me the result I wanted.
Since I am new to Python, I used () as a guess, and it worked.


From bv8bv8bv8 at gmail.com  Sun Jan 11 15:27:33 2015
From: bv8bv8bv8 at gmail.com (BV BV)
Date: Sun, 11 Jan 2015 12:27:33 -0800 (PST)
Subject: Muhammad (saws): A Role Model for a New Millennium
Message-ID: <4679aa9c-ae9b-499a-8285-41b5b33b7ab2@googlegroups.com>

Muhammad (saws): A Role Model for a New Millennium


The human need for role models

Have you ever heard of Moses, Jesus, Confucius, Krishna or the Buddha? How about Gandhi, Mother Theresa or Martin Luther King? If you live in the West, there's a good chance that you know a bit about these people and their accomplishments. In man's eternal search for immortality and meaning, many leaders and heroes, both true and false, have made their appearance on the world stage. The respect and reverence shown to such figures among people of every nationality, in every age, points to a deep human need to believe in someone greater than oneself, in an attempt to transcend the confines of one's own limited existence. We see this theme recur in world myths, legends, hero stories, and in the idealisation of people who have been raised by their followers to superhuman or godly status.
 
Most educated people today are sceptics,

and view such stories as the charming remnants of a simpler age. And with globalisation and the steady stream of new religions and ideologies that people are exposed to, it may be hard to know what to believe. Some find it easier to ignore spiritual questions altogether, focusing instead on their relationships, careers and 'getting ahead'. Yet we know that excessive materialism stifles the mind and spirit; despite technological advances, the deep yearning to believe in a Higher Power, true leadership, and an ultimate purpose in life remains. In this day and age, who can be trusted as a guide in both spiritual and worldly matters?
 
There is one leader,

still largely unknown to the West, who is an extraordinary role model that people of all backgrounds can relate to: the Prophet Muhammad. The details of Muhammad's remarkable life have been carefully preserved and have been subjected to the scrutiny of historians, east and west. In contrast to others who have achieved renown for their accomplishments in a limited sphere of activity, Muhammad's achievements span all major areas of life. The historian Michael H. Hart wrote:
My choice of Muhammad to lead the list of the world's most influential persons may surprise some readers and be questioned by others, but he was the only man in history who was supremely successful on both the religious and secular levels. Hart, Michael, The 100: A Ranking of the Most Influential Persons in History.
 
Why does the average European or American
 
know so little about a man whose life was so exceptional? Irrational fears and negative propaganda, dating back to the Crusades and exaggerated by the media, have created a 'mental block' for many people against all things Arab or Islamic, and the two terms are often mistakenly confused. As we enter the age of the global village, is it not time for those who pride themselves on being unprejudiced, independent thinkers to put aside these mental relics from a bygone era? We invite you to take a few minutes to explore a new understanding of religious leadership, and in so doing, to catch a glimpse of a man who is loved by one-fifth of the people on this planet.
 
The concept of Prophethood in Islam

For a Muslim, a Prophet does not primarily imply someone able to foretell the future - although most of Muhammad's predictions have already been fulfilled in astonishing ways - but a man sent by God to call people to repent, have faith, and dedicate their lives to doing good, thereby helping them rediscover the purpose for which they were created. Prophets are not considered to be Divine, and are not prayed to or worshipped - though they were men of outstanding character and spirituality who were protected from committing sins, performed miracles, received revelation and communed with God. Islam teaches that God is One, without partner or associate; no human being can share in any of the qualities that are unique to the Intelligent Creator and Sustainer of our vast and complex universe. Muhammad was no more than God's honoured servant and Messenger, yet he embodied the best of human potential, and that is what continues to make him so appealing and accessible today. Last in a line of Prophets and Messengers sent by God to all people on earth - including Noah, Abraham, Moses and Jesus - who effected the large-scale transformation of individuals and society, Muhammad was unsurpassed as teacher and guide. Speaking of his own role as the last true Prophet before Judgement Day, he said:
'The parable of me in relation to the Prophets who came before me is that of a man who built a house beautifully and well, except that one brick in its corner was missing. The people went around it and wondered at its beauty, but said: "If only that brick were put in its place!" I am that brick, and I am the last of the Prophets.'
 
Muhammad's personal life
 
Muhammad was born in 570 AD to a noble family of Makkah, and was a descendant of the Prophet Abraham. Orphaned at six, Muhammad was a thoughtful youth who worked as a shepherd and helped his uncle with the trade caravans. As a teenager he rejected the immoral customs of his people, who had become steeped in idolatry, and joined a chivalrous order, earning the nickname 'The Trustworthy'. At age 25 he found employment with a wealthy widow of 40 named Khadijah, managing her business. Impressed by his honesty and character, Khadijah proposed marriage and he accepted. Despite their age difference, they were happily married for 25 years, and were blessed with six children. After Khadijah's death Muhammad married several women for political and humanitarian reasons, as was expected of a man of his position; all but one were widows and divorcees. He was a loving and considerate husband and father, and his family was devoted to him despite his voluntary poverty, for he put into practice his own advice, 'the best of you is the one who is best to his own family.'
 
Muhammad, the Prophet
 
Muhammad received his first revelation from God at 40, through the Angel Gabriel. He continued to receive revelations for 23 years, on topics ranging from the Oneness of God and His wondrous handiwork, to stories of earlier prophets, morality and ethics, and life after death. These revelations became collectively known as the Qur'an, and are considered by Muslims to be the literal word of God; the Prophet's own words were collected separately. Muhammad's call to monotheism and social reform was heavily opposed by the Makkan elite; after enduring thirteen years of intense persecution, he and his followers were invited to relocate to Madinah, a town to the north that had been torn apart by generations of intertribal warfare. Muhammad successfully settled their differences and forged a bond of brotherhood between the two warring factions, as well as between the locals and the new emigrants. For Arab tribal society, this was an amazing accomplishment. The early Muslims learned to implement the golden rule under the Prophet's tutelage: 'No one truly believes until he desires for his brother what he desires for himself.'
 
Muhammad's legacy: the Madinan model
 
For Muhammad, religion was not a matter of personal conviction alone but a complete way of life, and Madinah flourished under his leadership. The Madinan model of government, based on justice, respect for human dignity and God-consciousness, became the template to which Muslims have looked for guidance and inspiration ever since. The Prophet drew up the world's first constitution in which the rights of religious minorities were protected, and entered into treaties and alliances with neighbouring tribes. He sent letters to the rulers of the Persians, Egyptians, Abyssinians and Byzantines, announcing his message of pure monotheism and inviting them to accept Islam. For the first time in history, women, children, orphans, foreigners and slaves were granted extensive rights and protection. Many of the Prophet's concerns seem surprisingly 'modern': he condemned racism and nationalism, saying 'there is no superiority of an Arab over a non-Arab, or a white man over a black man, except in righteousness.' He established laws protecting animals, trees and the environment. He encouraged free trade and ethical investments, but secured workers' rights and forbade usury. He worked for peace, but defined the parameters of the judicious use of force, when force was needed. He convinced people to give up alcohol, drugs, prostitution and crime, and promoted healthy living. He condemned domestic violence, encouraged his wives to speak their own mind, and granted Muslim women many rights not dreamed of in Europe until centuries later, including the right to own property, reject arranged marriages, and seek divorce because of incompatibility. And the Prophet encouraged his followers to seek beneficial knowledge wherever it could be found, with the result that Muslims never experienced a conflict between science and religion, and led the world in many fields of learning for centuries afterwards. Although his enduring legacy can be observed in everything from art to politics, Muhammad's greatest achievement by far was to re-establish pure monotheism. As simple and straightforward to understand as the nucleus at the centre of an atom, the concept of One God lies at the heart of Islamic culture. Muslims turn to their Creator for guidance, without the need for intermediaries, or the loss of dignity that idolatry and superstition bring.
The Prophet accomplished all this through the strength of his character and personal example; he inspired in his followers a love, devotion and sense of awe that was unparalleled. While other men would have been corrupted by the absolute power that he wielded in his later years, Muhammad remained humble, ever aware of the Source of his blessings. 'I am just God's servant,' he said, and 'I have only been sent as a teacher.' Although he spent his days in serving people and his nights in prayer, he preached religious moderation and balance; he forbade his followers to adopt a monastic lifestyle and preferred that they establish strong families and engage themselves in bettering the world around them, while remaining deeply conscious of God.
In the brief space of one generation and during his own lifetime, the Prophet Muhammad* successfully transformed the faith, mentality and culture of the people of Arabia; within 100 years his message had touched the hearts and lives of millions in Africa, Asia and parts of Europe. The Prophet foretold that each succeeding generation would be worse than the one before it, and true to his prediction, Muslims have not always understood or honoured his example. But Muhammad's teachings, speeches and customs were carefully noted down by his Companions, and compiled into books of authentic sayings which are available in translation. Along with the Qur'an, they form the holistic foundation of a satisfying way of life for practising Muslims, while for others, they provide a fascinating glimpse into the heart and mind of an exceptional man and role model from whom much can be learned.

http://www.islamhouse.com/401719/en/en/articles/Muhammad_Peace_be_Upon_Him:_A_Role_Model_for_a_New_Millennium


From drsalists at gmail.com  Sun Jan 11 15:36:06 2015
From: drsalists at gmail.com (Dan Stromberg)
Date: Sun, 11 Jan 2015 12:36:06 -0800
Subject: DICOM to jpg
In-Reply-To: <CAA+hu4XvMgXdZswa3X8hTCk9RD2sLuCgXuoz-DwayS7ouMhJJA@mail.gmail.com>
References: <CAA+hu4XvMgXdZswa3X8hTCk9RD2sLuCgXuoz-DwayS7ouMhJJA@mail.gmail.com>
Message-ID: <CAGGBd_qQLY18f7s4Z9Z_yV8=YCm4mamVwB=VHOXtV3F7_WsYsg@mail.gmail.com>

On Sun, Jan 11, 2015 at 5:01 AM, Abdul Abdul <abdul.sw84 at gmail.com> wrote:
> Hello,
>
> Is there a way to convert a DICOM file to an image using Python?
>
> Thanks.

Does GDCM do what you need?

http://gdcm.sourceforge.net/wiki/index.php/Main_Page


From wxjmfauth at gmail.com  Sun Jan 11 15:37:03 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Sun, 11 Jan 2015 12:37:03 -0800 (PST)
Subject: Using a ChangeLog as a canonical source of package metadata
In-Reply-To: <mailman.17593.1421007692.18130.python-list@python.org>
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17488.1420762070.18130.python-list@python.org>
 <54b2be27$0$13000$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17593.1421007692.18130.python-list@python.org>
Message-ID: <d0131022-c085-411e-a554-ec45f1ed4021@googlegroups.com>

1) I downloaded pyprimes-0.2.1a.tar.gz
2) I extracted the relevant part, the py files, the pyprimes
subdirectory,
awful.py, compat23.py, factors.py, test.py, ..........
and put in d:\junk

Then, I cd to d:\junk

D:\junk>
D:\junk>c:\python32\python.exe
Python 3.2.5 (default, May 15 2013, 23:06:03) [MSC v.1500 32 bit (Intel)] on win
32
Type "help", "copyright", "credits" or "license" for more information.
>>> quit()

D:\junk>c:\python32\python.exe tests.py
Traceback (most recent call last):
  File "tests.py", line 35, in <module>
    import pyprimes
ImportError: No module named pyprimes

D:\junk>c:\python32\python.exe d:\junk\tests.py
Traceback (most recent call last):
  File "d:\junk\tests.py", line 35, in <module>
    import pyprimes
ImportError: No module named pyprimes

D:\junk>

Normally it should work.

All the software I wrote works indipendently
from the location.






From joel.goldstick at gmail.com  Sun Jan 11 16:42:57 2015
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Sun, 11 Jan 2015 16:42:57 -0500
Subject: extracting numbers with decimal places from a string
In-Reply-To: <3bfeea22-cded-4363-92fa-6f1b33ddae16@googlegroups.com>
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
 <mailman.17591.1421006803.18130.python-list@python.org>
 <3bfeea22-cded-4363-92fa-6f1b33ddae16@googlegroups.com>
Message-ID: <CAPM-O+yKPFJfvs1h3yZ8r87xwE=--opEhDTGhKSXUve2811UqQ@mail.gmail.com>

On Sun, Jan 11, 2015 at 3:26 PM, Store Makhzan <store0a at gmail.com> wrote:
> On Sunday, January 11, 2015 at 2:06:54 PM UTC-6, Joel Goldstick wrote:
>> On Sun, Jan 11, 2015 at 2:31 PM, Store Makhzan wrote:
>> > I have this script which can calculate the total of numbers given in a string
>> > ---- script -----
>> > total = 0
>> > for c in '0123456789':
>> >    total += int(c)
>> > print total
>> > ---- script -----
>> >
>> > How should I modify this script to find the total of if the numbers given in the string form have decimal places? That is, how do I need to modify this line:
>> > ----- script -----
>> > for c in '1.32, 5.32, 4.4, 3.78':
>> > ----- script -----
>> > to find the total of these given numbers.
>> > --
>> > https://mail.python.org/mailman/listinfo/python-list
>>
>> split the string on ',' to get a list of strings.  loop thru list
>> using float(s), add float values
>>
>>
>> --
>> Joel Goldstick
>> http://joelgoldstick.com
>
> Thank you
> Here is what I did:
>
> ----- script -----
> #Check if a perfect cube
> total = 0
> for c in ('1.23', '2.4', '3.123'):
>    print float(c)
>    total += float(c)
> print total
> ----- script -----
>
> Which gave me the result I wanted.
> Since I am new to Python, I used () as a guess, and it worked.

That's fine, but its different than your original question.  In your
original question you had a string of floats separated by commas.  To
solve that problem you need to first split the string on the commas:

my_list = "1.23, 2.4, 3.123".split(",")

that will give you ['1.23', '2.4', '3.123']

>From there do what you did starting with your for loop



> --
> https://mail.python.org/mailman/listinfo/python-list



-- 
Joel Goldstick
http://joelgoldstick.com


From jenaceerowens at gmail.com  Sun Jan 11 17:13:18 2015
From: jenaceerowens at gmail.com (Jenacee Owens)
Date: Sun, 11 Jan 2015 14:13:18 -0800 (PST)
Subject: MS-DOS Commands
Message-ID: <9c3445d2-8ce6-491a-b240-5c71f91d3fc1@googlegroups.com>

I'm new to python and every time i type a command into the MS-DOS Commands it looks like this.

>>>strings

Traceback<most recent call last:
   file "<stdin>";line 1 in <module>
name error:name strings'is not defined

how can i fix this?


From PointedEars at web.de  Sun Jan 11 17:20:49 2015
From: PointedEars at web.de (Thomas 'PointedEars' Lahn)
Date: Sun, 11 Jan 2015 23:20:49 +0100
Subject: extracting numbers with decimal places from a string
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
 <mailman.17591.1421006803.18130.python-list@python.org>
 <3bfeea22-cded-4363-92fa-6f1b33ddae16@googlegroups.com>
 <mailman.17595.1421012580.18130.python-list@python.org>
Message-ID: <8077448.xvuXrbCisO@PointedEars.de>

Joel Goldstick wrote:

> my_list = "1.23, 2.4, 3.123".split(",")
> 
> that will give you ['1.23', '2.4', '3.123']

No, it gives

| $ python
| Python 2.7.9 (default, Dec 11 2014, 08:58:12) 
| [GCC 4.9.2] on linux2
| Type "help", "copyright", "credits" or "license" for more information.
| >>> my_list = "1.23, 2.4, 3.123".split(",")
| >>> my_list
| ['1.23', ' 2.4', ' 3.123']
| >>>

| $ python3
| Python 3.4.2 (default, Dec 27 2014, 13:16:08) 
| [GCC 4.9.2] on linux
| Type "help", "copyright", "credits" or "license" for more information.
| >>> my_list = "1.23, 2.4, 3.123".split(",")
| >>> my_list
| ['1.23', ' 2.4', ' 3.123']
| >>> 

In order to get the result you described, one needs at least

| >>> '1.23, 2.4, 3.123'.split(', ')
| ['1.23', '2.4', '3.123']

This is safer:

| >>> from re import split
| >>> split(r'\s*,\s*', '1.23, 2.4, 3.123')
| ['1.23', '2.4', '3.123']

-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.


From ian.g.kelly at gmail.com  Sun Jan 11 17:32:03 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Sun, 11 Jan 2015 15:32:03 -0700
Subject: MS-DOS Commands
In-Reply-To: <9c3445d2-8ce6-491a-b240-5c71f91d3fc1@googlegroups.com>
References: <9c3445d2-8ce6-491a-b240-5c71f91d3fc1@googlegroups.com>
Message-ID: <CALwzidnKuY8MgvdJEumm04QQF-wxqY+UOU9JsDe-4gMfof-_3Q@mail.gmail.com>

On Sun, Jan 11, 2015 at 3:13 PM, Jenacee Owens <jenaceerowens at gmail.com> wrote:
> I'm new to python and every time i type a command into the MS-DOS Commands it looks like this.
>
>>>>strings
>
> Traceback<most recent call last:
>    file "<stdin>";line 1 in <module>
> name error:name strings'is not defined

That error is from the Python interpreter, not MS-DOS (by which I
assume you mean the Windows command prompt; nobody seriously uses
MS-DOS any more).

> how can i fix this?

That depends on what it is you're trying to do. If you're actually
trying to run some program called 'strings' from the command prompt
then you'll need to exit the Python interpreter first (or open a
second command prompt window).


From gary.herron at islandtraining.com  Sun Jan 11 17:33:45 2015
From: gary.herron at islandtraining.com (Gary Herron)
Date: Sun, 11 Jan 2015 14:33:45 -0800
Subject: MS-DOS Commands
In-Reply-To: <9c3445d2-8ce6-491a-b240-5c71f91d3fc1@googlegroups.com>
References: <9c3445d2-8ce6-491a-b240-5c71f91d3fc1@googlegroups.com>
Message-ID: <54B2FA49.60707@islandtraining.com>

On 01/11/2015 02:13 PM, Jenacee Owens wrote:
> I'm new to python and every time i type a command into the MS-DOS Commands it looks like this.
>
>>>> strings
> Traceback<most recent call last:
>     file "<stdin>";line 1 in <module>
> name error:name strings'is not defined
>
> how can i fix this?

What where you trying to accomplish, and what did you expect that to 
do?  It's not a valid Python statement, so an error message that says as 
much is to be expected.

You really should start with a Python tutorial.

More comments:

  * You did not type that "into the MS-DOS Commands", but rather to
    Python (or more accurately, to the Python interpreter).
  * Python does not have "commands", but rather "statements".
  * There is a module named strings, and you could import it (to use
    Python's terminology) with the "import strings" statement, but
    there's probably not much need to do so.  But then the "strings"
    statement you typed would not produce an error message, but would
    just print out a line informing you that strings is a module -- not
    very useful.
  * Rather than using Python in an MS-DOS window, you should consider
    trying statements and programs in Idle -- A reasonable GUI
    environment to experiment with Python.  It came with your
    installation of Python.
  * In the future, questions should be accompanied with information
    about your version of Python (Python2 or Python3) and the platform
    you are running it on. (Apparently Windows in your case.)

Gary Herron





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From joel.goldstick at gmail.com  Sun Jan 11 17:50:40 2015
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Sun, 11 Jan 2015 17:50:40 -0500
Subject: MS-DOS Commands
In-Reply-To: <9c3445d2-8ce6-491a-b240-5c71f91d3fc1@googlegroups.com>
References: <9c3445d2-8ce6-491a-b240-5c71f91d3fc1@googlegroups.com>
Message-ID: <CAPM-O+x7QQG6=gk-u-VjDfTadPe2E8QPrQ7m4VDqQ-dhezh6Hw@mail.gmail.com>

On Sun, Jan 11, 2015 at 5:13 PM, Jenacee Owens <jenaceerowens at gmail.com> wrote:
> I'm new to python and every time i type a command into the MS-DOS Commands it looks like this.
>
>>>>strings
>
> Traceback<most recent call last:
>    file "<stdin>";line 1 in <module>
> name error:name strings'is not defined
>
> how can i fix this?

Nothing to do with DOS, there is no strings

Try this:
>>>my_string = "hi there"
>>>print my_string
> --
> https://mail.python.org/mailman/listinfo/python-list



-- 
Joel Goldstick
http://joelgoldstick.com


From joel.goldstick at gmail.com  Sun Jan 11 17:54:52 2015
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Sun, 11 Jan 2015 17:54:52 -0500
Subject: extracting numbers with decimal places from a string
In-Reply-To: <8077448.xvuXrbCisO@PointedEars.de>
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
 <mailman.17591.1421006803.18130.python-list@python.org>
 <3bfeea22-cded-4363-92fa-6f1b33ddae16@googlegroups.com>
 <mailman.17595.1421012580.18130.python-list@python.org>
 <8077448.xvuXrbCisO@PointedEars.de>
Message-ID: <CAPM-O+zaGUhszen1KGDXQ=NrPqOy=MJHUSaxu6V0SOdk8cV1rg@mail.gmail.com>

On Sun, Jan 11, 2015 at 5:20 PM, Thomas 'PointedEars' Lahn
<PointedEars at web.de> wrote:
> Joel Goldstick wrote:
>
>> my_list = "1.23, 2.4, 3.123".split(",")
>>
>> that will give you ['1.23', '2.4', '3.123']
>
> No, it gives
>
> | $ python
> | Python 2.7.9 (default, Dec 11 2014, 08:58:12)
> | [GCC 4.9.2] on linux2
> | Type "help", "copyright", "credits" or "license" for more information.
> | >>> my_list = "1.23, 2.4, 3.123".split(",")
> | >>> my_list
> | ['1.23', ' 2.4', ' 3.123']
> | >>>
>
> | $ python3
> | Python 3.4.2 (default, Dec 27 2014, 13:16:08)
> | [GCC 4.9.2] on linux
> | Type "help", "copyright", "credits" or "license" for more information.
> | >>> my_list = "1.23, 2.4, 3.123".split(",")
> | >>> my_list
> | ['1.23', ' 2.4', ' 3.123']
> | >>>
>
> In order to get the result you described, one needs at least
>
> | >>> '1.23, 2.4, 3.123'.split(', ')
> | ['1.23', '2.4', '3.123']
>
> This is safer:
>
> | >>> from re import split
> | >>> split(r'\s*,\s*', '1.23, 2.4, 3.123')
> | ['1.23', '2.4', '3.123']
>

I'm not sure what you are trying to point out as your examples confirm
my code.  Am I missing something.

As for feeding a beginner regex solutions, I'm on the side that this
is a terrible idea.  Regex is not something a beginner should worry
about!
> --
> PointedEars
>
> Twitter: @PointedEars2
> Please do not cc me. / Bitte keine Kopien per E-Mail.
> --
> https://mail.python.org/mailman/listinfo/python-list



-- 
Joel Goldstick
http://joelgoldstick.com


From invalid at invalid.invalid  Sun Jan 11 18:06:49 2015
From: invalid at invalid.invalid (Grant Edwards)
Date: Sun, 11 Jan 2015 23:06:49 +0000 (UTC)
Subject: extracting numbers with decimal places from a string
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
 <mailman.17591.1421006803.18130.python-list@python.org>
 <3bfeea22-cded-4363-92fa-6f1b33ddae16@googlegroups.com>
 <mailman.17595.1421012580.18130.python-list@python.org>
Message-ID: <m8uvm8$omu$1@reader1.panix.com>

On 2015-01-11, Joel Goldstick <joel.goldstick at gmail.com> wrote:

> That's fine, but its different than your original question.  In your
> original question you had a string of floats separated by commas.  To
> solve that problem you need to first split the string on the commas:
>
> my_list = "1.23, 2.4, 3.123".split(",")
>
> that will give you ['1.23', '2.4', '3.123']

Well, almost:

$ python
Python 2.7.9 (default, Jan 11 2015, 15:39:24) 
[GCC 4.7.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> "1.23, 2.4, 3.123".split(",")
['1.23', ' 2.4', ' 3.123']

Note the leating whitespace in two of the elements. In this case, the
leading whitespace is ignored if you pass the values to float():

>>>map(float,"1.23, 2.4, 3.123".split(","))
[1.23, 2.4, 3.123]

Or for you young folks who prefer the more long-winded version:

>>> [float(s) for s in "1.23, 2.4, 3.123".split(",")]
[1.23, 2.4, 3.123]

In other situations, the leading whitespace might matter.

-- 
Grant





From PointedEars at web.de  Sun Jan 11 18:07:57 2015
From: PointedEars at web.de (Thomas 'PointedEars' Lahn)
Date: Mon, 12 Jan 2015 00:07:57 +0100
Subject: extracting numbers with decimal places from a string
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
Message-ID: <3233082.KAWmNIKqbW@PointedEars.de>

Store Makhzan wrote:

> I have this script which can calculate the total of numbers given in a
> string [?]
> total = 0
> for c in '0123456789':
>    total += int(c)
> print total
> 
> [?]
> How should I modify this script to find the total of if the numbers given
> in the string form have decimal places? That is, how do I need to modify
> this line: [?]
> 
> for c in '1.32, 5.32, 4.4, 3.78':
> 
> [?] to find the total of these given numbers.

The original script already does not do what it advertises.  Instead, it 
iterates over the characters of the string, attempts to convert each to an 
integer and then computes the sum.  That is _not_ ?calculate the total of 
numbers given in a string?.

A solution has been presented, but it is not very pythonic because the 
original code was not; that should have been

### Ahh, Gau? ;-)
print(sum(map(lambda x: int(x), list('0123456789'))))
### --------------------------------------------------------------------

Also, it cannot handle non-numeric strings well.  Consider this instead:

### --------------------------------------------------------------------
from re import findall

s = '1.32, 5.32, 4.4, 3.78'
print(sum(map(lambda x: float(x), findall(r'-?\d+\.\d+', s))))
### --------------------------------------------------------------------

But if you are sure that except for the comma separator there are only 
numeric strings, it is more efficient to use re.split() instead of 
re.findall() here.


Aside:

I thought I had more than a fair grasp of regular expressions, but I am 
puzzled by

| $ python3
| Python 3.4.2 (default, Dec 27 2014, 13:16:08) 
| [GCC 4.9.2] on linux
| >>> from re import findall
| >>> s = '1.32, 5.32, 4.4, 3.78'
| >>> findall(r'-?\d+(\.\d+)?', s)
| ['.32', '.32', '.4', '.78']

Why does this more flexible pattern not work as I expected in Python 3.x, 
but virtually everywhere else?

And why this?

| >>> findall(r'-?\d+\.\d+', s)
| ['1.32', '5.32', '4.4', '3.78']
| >>> findall(r'-?\d+(\.\d+)', s)
| ['.32', '.32', '.4', '.78']

Feature?  Bug?

-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.


From PointedEars at web.de  Sun Jan 11 18:12:28 2015
From: PointedEars at web.de (Thomas 'PointedEars' Lahn)
Date: Mon, 12 Jan 2015 00:12:28 +0100
Subject: extracting numbers with decimal places from a string
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
 <mailman.17591.1421006803.18130.python-list@python.org>
 <3bfeea22-cded-4363-92fa-6f1b33ddae16@googlegroups.com>
 <mailman.17595.1421012580.18130.python-list@python.org>
 <8077448.xvuXrbCisO@PointedEars.de>
 <mailman.17599.1421016900.18130.python-list@python.org>
Message-ID: <2182977.fJl0o3iPdP@PointedEars.de>

Joel Goldstick wrote:

> Thomas 'PointedEars' Lahn wrote:
>> Joel Goldstick wrote:
>>> my_list = "1.23, 2.4, 3.123".split(",")
>>>
>>> that will give you ['1.23', '2.4', '3.123']
>>
>> No, it gives
>>
>> [?]
>> | >>> my_list = "1.23, 2.4, 3.123".split(",")
>> | >>> my_list
>> | ['1.23', ' 2.4', ' 3.123']
               ^       ^
>> | >>>
>>
>> In order to get the result you described, one needs at least
>>
>> | >>> '1.23, 2.4, 3.123'.split(', ')
>> | ['1.23', '2.4', '3.123']
>>
>> [?]
> 
> I'm not sure what you are trying to point out as your examples confirm
> my code.

No, they don't.

> Am I missing something.
                        ^
(Is that a question.)

You are missing a leading space character because in the string the comma 
was followed by one.

> As for feeding a beginner regex solutions, I'm on the side that this
> is a terrible idea.  Regex is not something a beginner should worry
> about!

NAK.

-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.


From joel.goldstick at gmail.com  Sun Jan 11 18:35:22 2015
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Sun, 11 Jan 2015 18:35:22 -0500
Subject: extracting numbers with decimal places from a string
In-Reply-To: <2182977.fJl0o3iPdP@PointedEars.de>
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
 <mailman.17591.1421006803.18130.python-list@python.org>
 <3bfeea22-cded-4363-92fa-6f1b33ddae16@googlegroups.com>
 <mailman.17595.1421012580.18130.python-list@python.org>
 <8077448.xvuXrbCisO@PointedEars.de>
 <mailman.17599.1421016900.18130.python-list@python.org>
 <2182977.fJl0o3iPdP@PointedEars.de>
Message-ID: <CAPM-O+z+1KQM3Ta1OLjBkfjsrUYymn=aumBEaTWPbOkuQZYFmA@mail.gmail.com>

On Sun, Jan 11, 2015 at 6:12 PM, Thomas 'PointedEars' Lahn
<PointedEars at web.de> wrote:
> Joel Goldstick wrote:
>
>> Thomas 'PointedEars' Lahn wrote:
>>> Joel Goldstick wrote:
>>>> my_list = "1.23, 2.4, 3.123".split(",")
>>>>
>>>> that will give you ['1.23', '2.4', '3.123']
>>>
>>> No, it gives
>>>
>>> [?]
>>> | >>> my_list = "1.23, 2.4, 3.123".split(",")
>>> | >>> my_list
>>> | ['1.23', ' 2.4', ' 3.123']
>                ^       ^
>>> | >>>
>>>
>>> In order to get the result you described, one needs at least
>>>
>>> | >>> '1.23, 2.4, 3.123'.split(', ')
>>> | ['1.23', '2.4', '3.123']
>>>
>>> [?]
>>
>> I'm not sure what you are trying to point out as your examples confirm
>> my code.
>
> No, they don't.
>
>> Am I missing something.
>                         ^
> (Is that a question.)
>
> You are missing a leading space character because in the string the comma
> was followed by one.

I see that now.  Performing float on each element of the list will
take care of that, or I guess .strip() on each first.
>
>> As for feeding a beginner regex solutions, I'm on the side that this
>> is a terrible idea.  Regex is not something a beginner should worry
>> about!
>
> NAK.
>
> --
> PointedEars
>
> Twitter: @PointedEars2
> Please do not cc me. / Bitte keine Kopien per E-Mail.
> --
> https://mail.python.org/mailman/listinfo/python-list



-- 
Joel Goldstick
http://joelgoldstick.com


From PointedEars at web.de  Sun Jan 11 18:46:07 2015
From: PointedEars at web.de (Thomas 'PointedEars' Lahn)
Date: Mon, 12 Jan 2015 00:46:07 +0100
Subject: extracting numbers with decimal places from a string
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
 <mailman.17591.1421006803.18130.python-list@python.org>
 <3bfeea22-cded-4363-92fa-6f1b33ddae16@googlegroups.com>
 <mailman.17595.1421012580.18130.python-list@python.org>
 <8077448.xvuXrbCisO@PointedEars.de>
 <mailman.17599.1421016900.18130.python-list@python.org>
 <2182977.fJl0o3iPdP@PointedEars.de>
 <mailman.17600.1421019325.18130.python-list@python.org>
Message-ID: <1786463.stBbe1naGD@PointedEars.de>

Joel Goldstick wrote:

> On Sun, Jan 11, 2015 at 6:12 PM, Thomas 'PointedEars' Lahn
> <PointedEars at web.de> wrote:
>> Joel Goldstick wrote:
>>> Am I missing something.
>>                        ^
>> [?]
>> You are missing a leading space character because in the string the comma
>> was followed by one.
> 
> I see that now.  Performing float on each element of the list will
> take care of that, or I guess .strip() on each first.

As I showed, .strip() is unnecessary.  But float() is always necessary for 
computing the sum and suffices indeed together with s.split() if s is just a 
comma-separated list of numeric strings with optional whitespace leading and 
trailing the comma:

  print(sum(map(lambda x: float(x), s.split(',')))

Please trim your quotes to the relevant minimum.

-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.


From breamoreboy at yahoo.co.uk  Sun Jan 11 18:57:03 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 11 Jan 2015 23:57:03 +0000
Subject: MS-DOS Commands
In-Reply-To: <9c3445d2-8ce6-491a-b240-5c71f91d3fc1@googlegroups.com>
References: <9c3445d2-8ce6-491a-b240-5c71f91d3fc1@googlegroups.com>
Message-ID: <m8v2kf$3rt$1@ger.gmane.org>

On 11/01/2015 22:13, Jenacee Owens wrote:
> I'm new to python and every time i type a command into the MS-DOS Commands it looks like this.
>
>>>> strings
>
> Traceback<most recent call last:
>     file "<stdin>";line 1 in <module>
> name error:name strings'is not defined
>
> how can i fix this?
>

Others have already commented, so I'll just ask would you be more 
comfortable on the tutor mailing list 
https://mail.python.org/mailman/listinfo/tutor ?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From breamoreboy at yahoo.co.uk  Sun Jan 11 19:04:49 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 12 Jan 2015 00:04:49 +0000
Subject: extracting numbers with decimal places from a string
In-Reply-To: <3233082.KAWmNIKqbW@PointedEars.de>
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
 <3233082.KAWmNIKqbW@PointedEars.de>
Message-ID: <m8v332$aq2$1@ger.gmane.org>

On 11/01/2015 23:07, Thomas 'PointedEars' Lahn wrote:
> Store Makhzan wrote:
>
>> I have this script which can calculate the total of numbers given in a
>> string [?]
>> total = 0
>> for c in '0123456789':
>>     total += int(c)
>> print total
>>
>> [?]
>> How should I modify this script to find the total of if the numbers given
>> in the string form have decimal places? That is, how do I need to modify
>> this line: [?]
>>
>> for c in '1.32, 5.32, 4.4, 3.78':
>>
>> [?] to find the total of these given numbers.
>
> The original script already does not do what it advertises.  Instead, it
> iterates over the characters of the string, attempts to convert each to an
> integer and then computes the sum.  That is _not_ ?calculate the total of
> numbers given in a string?.
>
> A solution has been presented, but it is not very pythonic because the
> original code was not; that should have been
>
> ### Ahh, Gau? ;-)
> print(sum(map(lambda x: int(x), list('0123456789'))))
> ### --------------------------------------------------------------------
>
> Also, it cannot handle non-numeric strings well.  Consider this instead:
>
> ### --------------------------------------------------------------------
> from re import findall
>
> s = '1.32, 5.32, 4.4, 3.78'
> print(sum(map(lambda x: float(x), findall(r'-?\d+\.\d+', s))))
> ### --------------------------------------------------------------------
>
> But if you are sure that except for the comma separator there are only
> numeric strings, it is more efficient to use re.split() instead of
> re.findall() here.
>
>
> Aside:
>
> I thought I had more than a fair grasp of regular expressions, but I am
> puzzled by
>
> | $ python3
> | Python 3.4.2 (default, Dec 27 2014, 13:16:08)
> | [GCC 4.9.2] on linux
> | >>> from re import findall
> | >>> s = '1.32, 5.32, 4.4, 3.78'
> | >>> findall(r'-?\d+(\.\d+)?', s)
> | ['.32', '.32', '.4', '.78']
>
> Why does this more flexible pattern not work as I expected in Python 3.x,
> but virtually everywhere else?
>
> And why this?
>
> | >>> findall(r'-?\d+\.\d+', s)
> | ['1.32', '5.32', '4.4', '3.78']
> | >>> findall(r'-?\d+(\.\d+)', s)
> | ['.32', '.32', '.4', '.78']
>
> Feature?  Bug?
>

I can't tell you as I avoid regexes like I avoid the plague.  Having 
said that I do know that there loads of old bugs on the bug tracker, 
many of which are fixed in the "new" regex module that's available here 
https://pypi.python.org/pypi/regex/

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From __peter__ at web.de  Sun Jan 11 19:09:21 2015
From: __peter__ at web.de (Peter Otten)
Date: Mon, 12 Jan 2015 01:09:21 +0100
Subject: extracting numbers with decimal places from a string
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
 <mailman.17591.1421006803.18130.python-list@python.org>
 <3bfeea22-cded-4363-92fa-6f1b33ddae16@googlegroups.com>
 <mailman.17595.1421012580.18130.python-list@python.org>
 <8077448.xvuXrbCisO@PointedEars.de>
 <mailman.17599.1421016900.18130.python-list@python.org>
 <2182977.fJl0o3iPdP@PointedEars.de>
 <mailman.17600.1421019325.18130.python-list@python.org>
 <1786463.stBbe1naGD@PointedEars.de>
Message-ID: <m8v3bh$1vh$1@ger.gmane.org>

Thomas 'PointedEars' Lahn wrote:

> Joel Goldstick wrote:
> 
>> On Sun, Jan 11, 2015 at 6:12 PM, Thomas 'PointedEars' Lahn
>> <PointedEars at web.de> wrote:
>>> Joel Goldstick wrote:
>>>> Am I missing something.
>>>                        ^
>>> [?]
>>> You are missing a leading space character because in the string the
>>> comma was followed by one.
>> 
>> I see that now.  Performing float on each element of the list will
>> take care of that, or I guess .strip() on each first.
> 
> As I showed, .strip() is unnecessary.  But float() is always necessary for
> computing the sum and suffices indeed together with s.split() if s is just
> a comma-separated list of numeric strings with optional whitespace leading
> and trailing the comma:
> 
>   print(sum(map(lambda x: float(x), s.split(',')))
> 
> Please trim your quotes to the relevant minimum.

Hm, can you explain what this

lambda x: float(x)

is supposed to achieve? I mean other than to confuse a newbie...




From rosuav at gmail.com  Sun Jan 11 19:17:29 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 12 Jan 2015 11:17:29 +1100
Subject: extracting numbers with decimal places from a string
In-Reply-To: <m8v3bh$1vh$1@ger.gmane.org>
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
 <mailman.17591.1421006803.18130.python-list@python.org>
 <3bfeea22-cded-4363-92fa-6f1b33ddae16@googlegroups.com>
 <mailman.17595.1421012580.18130.python-list@python.org>
 <8077448.xvuXrbCisO@PointedEars.de>
 <mailman.17599.1421016900.18130.python-list@python.org>
 <2182977.fJl0o3iPdP@PointedEars.de>
 <mailman.17600.1421019325.18130.python-list@python.org>
 <1786463.stBbe1naGD@PointedEars.de> <m8v3bh$1vh$1@ger.gmane.org>
Message-ID: <CAPTjJmrF5dGLfHKYitMMo=j9tLpvvh2FZnWrO8fK=k2chP2r8A@mail.gmail.com>

On Mon, Jan 12, 2015 at 11:09 AM, Peter Otten <__peter__ at web.de> wrote:
>>
>>   print(sum(map(lambda x: float(x), s.split(',')))
>>
>> Please trim your quotes to the relevant minimum.
>
> Hm, can you explain what this
>
> lambda x: float(x)
>
> is supposed to achieve? I mean other than to confuse a newbie...

Maybe he gets paid by the character.

ChrisA


From PointedEars at web.de  Sun Jan 11 19:45:16 2015
From: PointedEars at web.de (Thomas 'PointedEars' Lahn)
Date: Mon, 12 Jan 2015 01:45:16 +0100
Subject: extracting numbers with decimal places from a string
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
 <mailman.17591.1421006803.18130.python-list@python.org>
 <3bfeea22-cded-4363-92fa-6f1b33ddae16@googlegroups.com>
 <mailman.17595.1421012580.18130.python-list@python.org>
 <8077448.xvuXrbCisO@PointedEars.de>
 <mailman.17599.1421016900.18130.python-list@python.org>
 <2182977.fJl0o3iPdP@PointedEars.de>
 <mailman.17600.1421019325.18130.python-list@python.org>
 <1786463.stBbe1naGD@PointedEars.de>
 <mailman.17603.1421021375.18130.python-list@python.org>
Message-ID: <2606109.fVWkh9SoWk@PointedEars.de>

Peter Otten wrote:

> Thomas 'PointedEars' Lahn wrote:
>> [?]  But float() is always necessary for computing the sum and suffices 
>> indeed together with s.split() if s is just a comma-separated list of 
>> numeric strings with optional whitespace leading and trailing the comma:
>> 
>>   print(sum(map(lambda x: float(x), s.split(',')))
>> 
>> Please trim your quotes to the relevant minimum.
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> Hm, can you explain what this
> 
> lambda x: float(x)
> 
> is supposed to achieve? I mean other than to confuse a newbie...

  print(sum(map(float, s.split(','))))

suffices in this case, of course.

I could have done without the snide remarks.

-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.


From steve+comp.lang.python at pearwood.info  Sun Jan 11 19:45:28 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Mon, 12 Jan 2015 11:45:28 +1100
Subject: extracting numbers with decimal places from a string
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
 <mailman.17591.1421006803.18130.python-list@python.org>
 <3bfeea22-cded-4363-92fa-6f1b33ddae16@googlegroups.com>
 <mailman.17595.1421012580.18130.python-list@python.org>
 <8077448.xvuXrbCisO@PointedEars.de>
Message-ID: <54b31929$0$13014$c3e8da3$5496439d@news.astraweb.com>

Thomas 'PointedEars' Lahn wrote:

> This is safer:
> 
> | >>> from re import split
> | >>> split(r'\s*,\s*', '1.23, 2.4, 3.123')
> | ['1.23', '2.4', '3.123']

Safer, slower, and unnecessary.

There is no need for the nuclear-powered bulldozer of regular expressions
just to crack this tiny peanut. We can split on commas, and then strip
whitespace:

py> values = "    1.234   ,    4.5678,   9.0123  ,4.321,0.9876  "
py> [s.strip() for s in values.split(',')]
['1.234', '4.5678', '9.0123', '4.321', '0.9876']


but in fact, we don't even need that, since float is perfectly happy to
accept strings with leading and trailing spaces:

py> float('            1.2345              ')
1.2345


-- 
Steven



From python at mrabarnett.plus.com  Sun Jan 11 19:59:12 2015
From: python at mrabarnett.plus.com (MRAB)
Date: Mon, 12 Jan 2015 00:59:12 +0000
Subject: extracting numbers with decimal places from a string
In-Reply-To: <m8v332$aq2$1@ger.gmane.org>
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
 <3233082.KAWmNIKqbW@PointedEars.de> <m8v332$aq2$1@ger.gmane.org>
Message-ID: <54B31C60.8010409@mrabarnett.plus.com>

On 2015-01-12 00:04, Mark Lawrence wrote:
> On 11/01/2015 23:07, Thomas 'PointedEars' Lahn wrote:
>> Store Makhzan wrote:
>>
>>> I have this script which can calculate the total of numbers given in a
>>> string [?]
>>> total = 0
>>> for c in '0123456789':
>>>     total += int(c)
>>> print total
>>>
>>> [?]
>>> How should I modify this script to find the total of if the numbers given
>>> in the string form have decimal places? That is, how do I need to modify
>>> this line: [?]
>>>
>>> for c in '1.32, 5.32, 4.4, 3.78':
>>>
>>> [?] to find the total of these given numbers.
>>
>> The original script already does not do what it advertises.  Instead, it
>> iterates over the characters of the string, attempts to convert each to an
>> integer and then computes the sum.  That is _not_ ?calculate the total of
>> numbers given in a string?.
>>
>> A solution has been presented, but it is not very pythonic because the
>> original code was not; that should have been
>>
>> ### Ahh, Gau? ;-)
>> print(sum(map(lambda x: int(x), list('0123456789'))))
>> ### --------------------------------------------------------------------
>>
>> Also, it cannot handle non-numeric strings well.  Consider this instead:
>>
>> ### --------------------------------------------------------------------
>> from re import findall
>>
>> s = '1.32, 5.32, 4.4, 3.78'
>> print(sum(map(lambda x: float(x), findall(r'-?\d+\.\d+', s))))
>> ### --------------------------------------------------------------------
>>
>> But if you are sure that except for the comma separator there are only
>> numeric strings, it is more efficient to use re.split() instead of
>> re.findall() here.
>>
>>
>> Aside:
>>
>> I thought I had more than a fair grasp of regular expressions, but I am
>> puzzled by
>>
>> | $ python3
>> | Python 3.4.2 (default, Dec 27 2014, 13:16:08)
>> | [GCC 4.9.2] on linux
>> | >>> from re import findall
>> | >>> s = '1.32, 5.32, 4.4, 3.78'
>> | >>> findall(r'-?\d+(\.\d+)?', s)
>> | ['.32', '.32', '.4', '.78']
>>
>> Why does this more flexible pattern not work as I expected in Python 3.x,
>> but virtually everywhere else?
>>
>> And why this?
>>
>> | >>> findall(r'-?\d+\.\d+', s)
>> | ['1.32', '5.32', '4.4', '3.78']
>> | >>> findall(r'-?\d+(\.\d+)', s)
>> | ['.32', '.32', '.4', '.78']
>>
>> Feature?  Bug?
>>
>
> I can't tell you as I avoid regexes like I avoid the plague.  Having
> said that I do know that there loads of old bugs on the bug tracker,
> many of which are fixed in the "new" regex module that's available here
> https://pypi.python.org/pypi/regex/
>
It's not a bug.

re.findall returns the capture groups, if present, or the entire match
if there are no capture groups.

In this instance, it's better to use a non-capture group:

findall(r'-?\d+(?:\.\d+)', s)

It's all in the docs! :-)


From PointedEars at web.de  Sun Jan 11 20:00:19 2015
From: PointedEars at web.de (Thomas 'PointedEars' Lahn)
Date: Mon, 12 Jan 2015 02:00:19 +0100
Subject: extracting numbers with decimal places from a string
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
 <3233082.KAWmNIKqbW@PointedEars.de>
 <mailman.17602.1421021101.18130.python-list@python.org>
Message-ID: <1596579.yx7AUifxch@PointedEars.de>

Mark Lawrence wrote:

> On 11/01/2015 23:07, Thomas 'PointedEars' Lahn wrote:
>> I thought I had more than a fair grasp of regular expressions, but I am
>> puzzled by
>>
>> | $ python3
>> | Python 3.4.2 (default, Dec 27 2014, 13:16:08)
>> | [GCC 4.9.2] on linux
>> | >>> from re import findall
>> | >>> s = '1.32, 5.32, 4.4, 3.78'
>> | >>> findall(r'-?\d+(\.\d+)?', s)
>> | ['.32', '.32', '.4', '.78']
>>
>> Why does this more flexible pattern not work as I expected in Python 3.x,
>> but virtually everywhere else?
>>
>> And why this?
>>
>> | >>> findall(r'-?\d+\.\d+', s)
>> | ['1.32', '5.32', '4.4', '3.78']
>> | >>> findall(r'-?\d+(\.\d+)', s)
>> | ['.32', '.32', '.4', '.78']
>>
>> Feature?  Bug?
> 
> I can't tell you

I know now why I get this result.  It is a feature, not a bug:

<https://docs.python.org/3/library/re.html?highlight=findall#re.findall>
|
| re.findall(pattern, string, flags=0)
|   Return all non-overlapping matches of pattern in string, as a list of 
|   strings. The string is scanned left-to-right, and matches are returned 
|   in the order found. If one or more groups are present in the pattern,
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|   return a list of groups; this will be a list of tuples if the pattern
    ^^^^^^^^^^^^^^^^^^^^^^^   
|   has more than one group. Empty matches are included in the result unless 
|   they touch the beginning of another match.

A solution is to use non-capturing parentheses:

| >>> findall(r'-?\d+(?:\.\d+)?', '1.32, 5.32, 4.4, 3.78')
| ['1.32', '5.32', '4.4', '3.78']

> as I avoid regexes like I avoid the plague.

You should reconsider.  Regular expressions are a powerful tool.

> Having said that I do know that there loads of old bugs on the bug 
> tracker, many of which are fixed in the "new" regex module that's 
> available here https://pypi.python.org/pypi/regex/

Interesting, thank you.

Please trim your quotes to the relevant minimum next time, though.

-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.


From steve+comp.lang.python at pearwood.info  Sun Jan 11 20:13:21 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Mon, 12 Jan 2015 12:13:21 +1100
Subject: extracting numbers with decimal places from a string
References: <7240a574-dfd7-46c3-80eb-0657b41894bb@googlegroups.com>
 <3233082.KAWmNIKqbW@PointedEars.de>
Message-ID: <54b31fb2$0$12978$c3e8da3$5496439d@news.astraweb.com>

Thomas 'PointedEars' Lahn wrote:

> The original script already does not do what it advertises.  Instead, it
> iterates over the characters of the string, attempts to convert each to an
> integer and then computes the sum.  That is _not_ ?calculate the total of
> numbers given in a string?.

Yes, and the second piece of code the Original Poster provided is even
worse:

#Check if a perfect cube
total = 0
for c in ('1.23', '2.4', '3.123'):
   print float(c)
   total += float(c)
print total


I don't see how adding up some numbers checks whether it is a perfect cube.
I guess this is a good example of this:

    At Resolver we've found it useful to short-circuit any doubt 
    and just refer to comments in code as 'lies'.

http://import-that.dreamwidth.org/956.html



> A solution has been presented, but it is not very pythonic because the
> original code was not; that should have been
> 
> ### Ahh, Gau? ;-)
> print(sum(map(lambda x: int(x), list('0123456789'))))

That can be simplified to:

sum(map(int, '0123456789'))

which can then be passed to print() if required.



> Also, it cannot handle non-numeric strings well.  Consider this instead:

The OP hasn't specified whether or not he has to deal with non-numeric
strings, or how he wants to deal with them. But my guess is that he
actually doesn't want strings at all, and needs to be taught how to work
with lists of floats and/or ints.


> ### --------------------------------------------------------------------
> from re import findall
> 
> s = '1.32, 5.32, 4.4, 3.78'
> print(sum(map(lambda x: float(x), findall(r'-?\d+\.\d+', s))))
> ### --------------------------------------------------------------------

Consider this:

py> s = '123^%#@1.2abc, %#$@2.1&*%^'
py> print(sum(map(lambda x: float(x), findall(r'-?\d+\.\d+', s))))
3.3

If your aim is just to hide the fact that you have bad data, then the regex
solution "works". Many beginners think that their job as a programmer is to
stop the program from raising an exception no matter what. But I suggest
that Postel's Law:

    Be conservative in what you emit, and liberal in what you accept.

shouldn't apply here. I don't think any reasonable person would expect that
the string "123^%#@1.2abc" should be treated as 1.2.


> Aside:
> 
> I thought I had more than a fair grasp of regular expressions, but I am
> puzzled by
> 
> | $ python3
> | Python 3.4.2 (default, Dec 27 2014, 13:16:08)
> | [GCC 4.9.2] on linux
> | >>> from re import findall
> | >>> s = '1.32, 5.32, 4.4, 3.78'
> | >>> findall(r'-?\d+(\.\d+)?', s)
> | ['.32', '.32', '.4', '.78']
> 
> Why does this more flexible pattern not work as I expected in Python 3.x,
> but virtually everywhere else?

This is documented by findall:


py> help(findall)
Help on function findall in module re:

findall(pattern, string, flags=0)
    Return a list of all non-overlapping matches in the string.

    If one or more groups are present in the pattern, return a
    list of groups; this will be a list of tuples if the pattern
    has more than one group.

    Empty matches are included in the result.



-- 
Steven



From ganesh1pal at gmail.com  Sun Jan 11 22:12:17 2015
From: ganesh1pal at gmail.com (Ganesh Pal)
Date: Mon, 12 Jan 2015 08:42:17 +0530
Subject: Few Coding suggestions - resending
In-Reply-To: <54B2884B.90301@davea.name>
References: <CACT3xuWwYDoj-oMU1dPoRo8Xv_qHRx4JYBXPJcm3T1QfSWjgGw@mail.gmail.com>
 <54B2884B.90301@davea.name>
Message-ID: <CACT3xuVeYdRWhONP6eb8F9chOYcow=ZQyv7Sw3aKjCAg3pdbHA@mail.gmail.com>

On Sun, Jan 11, 2015 at 7:57 PM, Dave Angel <davea at davea.name> wrote:
>>
>>
> No idea how that represents "a difference of 5 minutes".  So I'll take a totally wild guess that you meant:
>
> Sunday 23:50 23:55
> Monday 00:00 00:05
> Monday 00:10 00:15
> Monday 00:20 00:25
> Monday 00:30 00:35
>
> which would have the 2nd column 5 minutes after the first.
>
> You need another datetime object, let's call it 'end'
>
> end = start + timedelta(minutes=5)
>
> and now you want to yield three things, in a tuple:
>
> yield (start.strftime("%A"), start.strftime("%H:%M"),
>    end.strftime("%H:%M"))
>
> Of course that's a pain to do twice, as you have two yields in that function.  I'll leave you to reorder the loop to make that unnecessary.  Hint, do the yield first, THEN increment the start variable.

Thanks for the inputs , I tried doing the increments and decrements
first and then Yield

 Program:

  Login-1 at SNAP-BOX-1 new]$ cat time_range_01.py
#!/usr/bin/python
import time
from datetime import date, time, datetime, timedelta
#h = datetime.strftime("%H")
#m = datetime.strftime("%M")
h=23
m=50
d = date.today()
print d

def yield_times():
    global  h,m,d
    start = datetime.combine(d, time(int(h),int(m)))
    end = datetime.combine(d, time(int(h),int(m)))
    while True:
        start += timedelta(minutes=10)
        end = start + timedelta(minutes=5)
        yield(start.strftime("%A"),start.strftime("%H:%M"),end.strftime("%H:%M"))
gen = yield_times()
for i in range(10):
    print gen.next()

output :
[Login-1 at SNAP-BOX-1 new]$ python time_range_01.py
2015-01-12
('Tuesday', '00:00', '00:05')
('Tuesday', '00:10', '00:15')
('Tuesday', '00:20', '00:25')
('Tuesday', '00:30', '00:35')
('Tuesday', '00:40', '00:45')
('Tuesday', '00:50', '00:55')
('Tuesday', '01:00', '01:05')
('Tuesday', '01:10', '01:15')
('Tuesday', '01:20', '01:25')
('Tuesday', '01:30', '01:35')

PS :   Except formatting the results looks pretty much what i was
expecting .I was pretty much happy to see this last night :) .


> and in the other loop, you want
>     res = "{} {} {}\n".format(gen.next)
>     print res,
>
>>

Thanks ,  I will have to modify for the new output

>> (b)  how to copy the above output (i.e with the new column to a file.)
>>
>
> Instead of printing, just do f.write(res).  Or do both. Notice that to make this easy, i avoided doing any formatting in the print statement. I used a trailing comma on it to avoid print adding a newline, and instead put it explicitly in the format method call.
>
>>

Sure

>> (c)  The  final output should be a file , having the entries  day ,
>> start , end time of the remote file. how do  i pass the  this to
>> yeild-times()
>>
>> import time
>>
>> /* Assuming I retrive the below values h,m,d from the remote machine*/
>>
>> h = time.strftime("%H")
>> m = time.strftime("%M")
>> d = date.today()
>>
>
> Those first two are strings, but the third is a datetime object.  That last can be painful to pass between machines.

Correct , also looks like I have another issue , if I happen to pass
the first two strings

#  instead hard coded value i.e h = 23 and y =50 , i try using the
string directly I end up getting the below error :

h = datetime.strftime("%H")
m = datetime.strftime("%M")

[Login-1 at SNAP-BOX-1 new]$ python  time_range_01.py
Traceback (most recent call last):
  File "time_range_01.py", line 4, in <module>
    h = datetime.strftime("%H")
TypeError: descriptor 'strftime' requires a 'datetime.date' object but
received a 'str'

The date time object is retrieved once once from the remote machine
and just for building the file in the required format.
Do you foresee any problems using this ?

>
>>
>> def yield_times():
>>        global h,m,d
>
>
> No idea what that's all about.  If you want to pass arguments to yield_times(), put them inside the parens.
>
sure .

Regards,
Gpal


From wuwei23 at gmail.com  Sun Jan 11 23:03:05 2015
From: wuwei23 at gmail.com (alex23)
Date: Mon, 12 Jan 2015 14:03:05 +1000
Subject: PyWart: Poor Documentation Examples
In-Reply-To: <54b24306$0$12989$c3e8da3$5496439d@news.astraweb.com>
References: <3a0471c5-3cbe-4d1d-816d-3de76d35efa6@googlegroups.com>
 <54b1e0c5$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17578.1420960254.18130.python-list@python.org>
 <54b24306$0$12989$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <m8vh0t$dn2$1@dont-email.me>

On 11/01/2015 7:31 PM, Steven D'Aprano wrote:
> If that isn't a form of stupidity, I don't know what is.

Maybe you're just eternally optimistic that people can change for the 
better.



From miki.tebeka at gmail.com  Sun Jan 11 23:17:48 2015
From: miki.tebeka at gmail.com (Miki Tebeka)
Date: Sun, 11 Jan 2015 20:17:48 -0800 (PST)
Subject: List of "python -m" tools
Message-ID: <9d6346ee-b29d-45a8-bde0-29072a9dca73@googlegroups.com>

Greetings,

I've compiled a list of "python -m" tools at pythonwise.blogspot.com/2015/01/python-m.html.

Did I miss something? What are your favorite "python -m" tools?

Thanks,
--
Miki


From gordianknot1981 at gmail.com  Sun Jan 11 23:20:35 2015
From: gordianknot1981 at gmail.com (gordianknot1981 at gmail.com)
Date: Sun, 11 Jan 2015 20:20:35 -0800 (PST)
Subject: annoying doctest problem
Message-ID: <0e9e5a03-2291-490e-9220-fa6744c9e2e5@googlegroups.com>

#!/usr/bin/python
# -*- coding: utf-8 -*-

import re
kivy_class_ptn      = re.compile(r"<\b[\w_.\@\+]+>:?")


def test_kivy_class(s):
    """
    >>> s = "<MYBT at ToggleButton+Button>:"
    >>> test_kivy_class(s)
    "<MYBT at ToggleButton+Button>:"
    >>> s = "<MYBT>"
    >>> test_kivy_class(s)
    "<MYBT>"
    """
    ret =  re.search(kivy_class_ptn, s)
    if ret: return ret.group()
    else:   return ''




if __name__ == "__main__":

    import doctest
    doctest.testmod()



output:

**********************************************************************
File "F:/MyDocument/[Programing]/Python/PhotoshopAsGui/python3_branch/regexSnippet.py", line 19, in __main__.test_kivy_class
Failed example:
    test_kivy_class(s)
Expected:
    "<MYBT at ToggleButton+Button>:"
Got:
    '<MYBT at ToggleButton+Button>:'
**********************************************************************
File "F:/MyDocument/[Programing]/Python/PhotoshopAsGui/python3_branch/regexSnippet.py", line 22, in __main__.test_kivy_class
Failed example:
    test_kivy_class(s)
Expected:
    "<MYBT>"
Got:
    '<MYBT>'
**********************************************************************
1 items had failures:
   2 of   8 in __main__.test_kivy_class
***Test Failed*** 2 failures.




It failed with an unknown reason that evaluate two expected equal value but got an unexpected result! I'm struggling with this problem for a long time. Did I did something wrong? And how do I to fix it?

any help is appreciated. :)








From gordianknot1981 at gmail.com  Sun Jan 11 23:30:44 2015
From: gordianknot1981 at gmail.com (gordianknot1981 at gmail.com)
Date: Sun, 11 Jan 2015 20:30:44 -0800 (PST)
Subject: annoying doctest problem
In-Reply-To: <0e9e5a03-2291-490e-9220-fa6744c9e2e5@googlegroups.com>
References: <0e9e5a03-2291-490e-9220-fa6744c9e2e5@googlegroups.com>
Message-ID: <8ea370e0-21f2-4b54-88ba-f3efc44a48da@googlegroups.com>

gordian... at gmail.com? 2015?1?12???? UTC+8??12?20?46????
> #!/usr/bin/python
> # -*- coding: utf-8 -*-
> 
> import re
> kivy_class_ptn      = re.compile(r"<\b[\w_.\@\+]+>:?")
> 
> 
> def test_kivy_class(s):
>     """
>     >>> s = "<MYBT at ToggleButton+Button>:"
>     >>> test_kivy_class(s)
>     "<MYBT at ToggleButton+Button>:"
>     >>> s = "<MYBT>"
>     >>> test_kivy_class(s)
>     "<MYBT>"
>     """
>     ret =  re.search(kivy_class_ptn, s)
>     if ret: return ret.group()
>     else:   return ''
> 
> 
> 
> 
> if __name__ == "__main__":
> 
>     import doctest
>     doctest.testmod()
> 
> 
> 
> output:
> 
> **********************************************************************
> File "F:/MyDocument/[Programing]/Python/PhotoshopAsGui/python3_branch/regexSnippet.py", line 19, in __main__.test_kivy_class
> Failed example:
>     test_kivy_class(s)
> Expected:
>     "<MYBT at ToggleButton+Button>:"
> Got:
>     '<MYBT at ToggleButton+Button>:'
> **********************************************************************
> File "F:/MyDocument/[Programing]/Python/PhotoshopAsGui/python3_branch/regexSnippet.py", line 22, in __main__.test_kivy_class
> Failed example:
>     test_kivy_class(s)
> Expected:
>     "<MYBT>"
> Got:
>     '<MYBT>'
> **********************************************************************
> 1 items had failures:
>    2 of   8 in __main__.test_kivy_class
> ***Test Failed*** 2 failures.
> 
> 
> 
> 
> It failed with an unknown reason that evaluate two expected equal value but got an unexpected result! I'm struggling with this problem for a long time. Did I did something wrong? And how do I to fix it?
> 
> any help is appreciated. :)


Sorry for asking a dummy problem. I just solve it by changing the string quote from double to single. The problem is that doctest treat double quote string and single quote string as different value!


    >>> s = "<MYBT at ToggleButton+Button>:"
    >>> test_kivy_class(s)
    '<MYBT at ToggleButton+Button>:'   < change from double quote to single
    >>> s = "<MYBT>"             
    >>> test_kivy_class(s)
    '<MYBT>'                        < change from double quote to single






From steve at pearwood.info  Mon Jan 12 00:22:27 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 12 Jan 2015 05:22:27 GMT
Subject: List of "python -m" tools
References: <9d6346ee-b29d-45a8-bde0-29072a9dca73@googlegroups.com>
Message-ID: <54b35a12$0$2738$c3e8da3$76491128@news.astraweb.com>

On Sun, 11 Jan 2015 20:17:48 -0800, Miki Tebeka wrote:

> Greetings,
> 
> I've compiled a list of "python -m" tools at
> pythonwise.blogspot.com/2015/01/python-m.html.
> 
> Did I miss something? What are your favorite "python -m" tools?

The three I use all the time are:

- doctools
- unittest
- my own custom test suites



-- 
Steven


From steve at pearwood.info  Mon Jan 12 00:24:44 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 12 Jan 2015 05:24:44 GMT
Subject: annoying doctest problem
References: <0e9e5a03-2291-490e-9220-fa6744c9e2e5@googlegroups.com>
Message-ID: <54b35a9c$0$2738$c3e8da3$76491128@news.astraweb.com>

On Sun, 11 Jan 2015 20:20:35 -0800, gordianknot1981 wrote:
[...]
> Expected:
>     "<MYBT at ToggleButton+Button>:"
> Got:
>     '<MYBT at ToggleButton+Button>:'

doctest is *very* fussy about the strings matching exactly. You have to 
use single quotes.

I've been burned by this once or twice...


-- 
Steve


From sushanthece at gmail.com  Mon Jan 12 00:27:16 2015
From: sushanthece at gmail.com (Sushanth)
Date: Mon, 12 Jan 2015 05:27:16 +0000
Subject: Reg: scrappring error
Message-ID: <CAL7yq01BANKQdQ7Nmt3jHfu1+JgwHDA8EsCS-cyy9hjfdLk70w@mail.gmail.com>

?Traceback (most recent call last):
  File "sample.py", line 28, in <module>
    scrape_data(row['All Samples'],row['URL'])
  File "sample.py", line 13, in scrape_data
    html = etree.HTML(urllib2.urlopen(url).read())
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 127, in urlopen
    return _opener.open(url, data, timeout)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 410, in open
    response = meth(req, response)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 523, in http_response
    'http', request, response, code, msg, hdrs)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 442, in error
    result = self._call_chain(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 382, in _call_chain
    result = func(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 629, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 410, in open
    response = meth(req, response)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 523, in http_response
    'http', request, response, code, msg, hdrs)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 442, in error
    result = self._call_chain(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 382, in _call_chain
    result = func(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 629, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 410, in open
    response = meth(req, response)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 523, in http_response
    'http', request, response, code, msg, hdrs)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 442, in error
    result = self._call_chain(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 382, in _call_chain
    result = func(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 629, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 410, in open
    response = meth(req, response)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 523, in http_response
    'http', request, response, code, msg, hdrs)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 442, in error
    result = self._call_chain(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 382, in _call_chain
    result = func(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 629, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 410, in open
    response = meth(req, response)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 523, in http_response
    'http', request, response, code, msg, hdrs)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 442, in error
    result = self._call_chain(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 382, in _call_chain
    result = func(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 629, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 410, in open
    response = meth(req, response)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 523, in http_response
    'http', request, response, code, msg, hdrs)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 442, in error
    result = self._call_chain(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 382, in _call_chain
    result = func(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 629, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 410, in open
    response = meth(req, response)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 523, in http_response
    'http', request, response, code, msg, hdrs)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 442, in error
    result = self._call_chain(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 382, in _call_chain
    result = func(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 629, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 410, in open
    response = meth(req, response)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 523, in http_response
    'http', request, response, code, msg, hdrs)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 442, in error
    result = self._call_chain(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 382, in _call_chain
    result = func(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 629, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 410, in open
    response = meth(req, response)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 523, in http_response
    'http', request, response, code, msg, hdrs)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 442, in error
    result = self._call_chain(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 382, in _call_chain
    result = func(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 629, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 410, in open
    response = meth(req, response)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 523, in http_response
    'http', request, response, code, msg, hdrs)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 442, in error
    result = self._call_chain(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 382, in _call_chain
    result = func(*args)
  File
"C:\Users\sushanth.thangamani\AppData\Local\Continuum\Anaconda\lib\urllib
2.py", line 619, in http_error_302
    self.inf_msg + msg, headers, fp)
urllib2.HTTPError: HTTP Error 302: The HTTP server returned a redirect
error tha
t would lead to an infinite loop.
The last 30x error message was:
Found
?

-- 
*Regards*
*Sushanth*
*ph : 91-9949472210*
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From steve at pearwood.info  Mon Jan 12 00:31:41 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 12 Jan 2015 05:31:41 GMT
Subject: importing os.path -- why does it work?
Message-ID: <54b35c3d$0$2738$c3e8da3$76491128@news.astraweb.com>

Using the `spam.eggs` syntax for modules only works if spam is a package 
and eggs is a sub-package or module. For example, this fails:


py> import glob.fnmatch
Traceback (most recent call last):
  File "<frozen importlib._bootstrap>", line 1516, in 
_find_and_load_unlocked
AttributeError: 'module' object has no attribute '__path__'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named 'glob.fnmatch'; glob is not a package



even though fnmatch is a module in glob's namespace:

py> import glob
py> glob.fnmatch
<module 'fnmatch' from '/usr/local/lib/python3.3/fnmatch.py'>



On the other hand, if you have a proper package, it works:

py> import collections.abc
py> collections.__package__
'collections'



But bizarrely, you can import os.path this way!

py> import os.path
py> os.path
<module 'posixpath' from '/usr/local/lib/python3.3/posixpath.py'>
py> os.__package__
''



By what wizardry does this work?


-- 
Steve


From steve at pearwood.info  Mon Jan 12 00:44:19 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 12 Jan 2015 05:44:19 GMT
Subject: Using a ChangeLog as a canonical source of package metadata
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17488.1420762070.18130.python-list@python.org>
 <54b2be27$0$13000$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17593.1421007692.18130.python-list@python.org>
 <d0131022-c085-411e-a554-ec45f1ed4021@googlegroups.com>
Message-ID: <54b35f33$0$2738$c3e8da3$76491128@news.astraweb.com>

On Sun, 11 Jan 2015 12:37:03 -0800, wxjmfauth wrote:

> 1) I downloaded pyprimes-0.2.1a.tar.gz 
> 2) I extracted the relevant part,
> the py files, the pyprimes subdirectory,
> awful.py, compat23.py, factors.py, test.py, .......... and put in
> d:\junk

That is not the way packages work.

pyprimes is a package, which means it has to stay together in a single 
directory called "pyprimes", with a file called "__init__.py" inside it. 
It is not a set of independent modules.

Please read the README file, it explains the correct way to install 
pyprimes. You should use the setup.py installer script.

If you insist on manually doing this, you can copy the *entire* pyprimes 
package directory. That is, unpack the tar.gz file to something like this:


pyprimes/
+-- CHANGES.txt  
+-- LICENCE.txt
+-- MANIFEST  
+-- README.txt
+-- setup.py
+-- src/
    +-- pyprimes/
        +-- __init__.py
        +-- awful.py
        +-- factors.py
        +-- test.py
        etc.


Copy the *entire* folder pyprimes/src/pyprimes/ and move that somewhere 
into your PYTHONPATH. 

Or instead you can:

cd pyprimes/src  # ***NOT*** pyprimes/src/pyprimes !!!


and run python from there.


-- 
Steve


From ian.g.kelly at gmail.com  Mon Jan 12 01:00:45 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Sun, 11 Jan 2015 23:00:45 -0700
Subject: importing os.path -- why does it work?
In-Reply-To: <54b35c3d$0$2738$c3e8da3$76491128@news.astraweb.com>
References: <54b35c3d$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <CALwzidn7Vb=7UANWrLFAL4W85=40Eeq17404zpAaght0DdRigg@mail.gmail.com>

On Sun, Jan 11, 2015 at 10:31 PM, Steven D'Aprano <steve at pearwood.info> wrote:
> But bizarrely, you can import os.path this way!
>
> py> import os.path
> py> os.path
> <module 'posixpath' from '/usr/local/lib/python3.3/posixpath.py'>
> py> os.__package__
> ''
>
>
>
> By what wizardry does this work?

By the wizardry of adding an entry to sys.modules.

https://hg.python.org/cpython/file/8b3c609f3f73/Lib/os.py#l112


From christian at python.org  Mon Jan 12 01:08:46 2015
From: christian at python.org (Christian Heimes)
Date: Mon, 12 Jan 2015 07:08:46 +0100
Subject: List of "python -m" tools
In-Reply-To: <9d6346ee-b29d-45a8-bde0-29072a9dca73@googlegroups.com>
References: <9d6346ee-b29d-45a8-bde0-29072a9dca73@googlegroups.com>
Message-ID: <m8vodc$4hb$1@ger.gmane.org>

On 12.01.2015 05:17, Miki Tebeka wrote:
> Greetings,
> 
> I've compiled a list of "python -m" tools at pythonwise.blogspot.com/2015/01/python-m.html.
> 
> Did I miss something? What are your favorite "python -m" tools?

My all time favorite is "python -me", https://pypi.python.org/pypi/e.
It's a small yet elegant tool for the command line.

Christian





From rosuav at gmail.com  Mon Jan 12 01:26:32 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 12 Jan 2015 17:26:32 +1100
Subject: List of "python -m" tools
In-Reply-To: <m8vodc$4hb$1@ger.gmane.org>
References: <9d6346ee-b29d-45a8-bde0-29072a9dca73@googlegroups.com>
 <m8vodc$4hb$1@ger.gmane.org>
Message-ID: <CAPTjJmrLRCv1ftgMFgqMeL+hCfTPsaOqby6844F45+jtLUSm5Q@mail.gmail.com>

On Mon, Jan 12, 2015 at 5:08 PM, Christian Heimes <christian at python.org> wrote:
> My all time favorite is "python -me", https://pypi.python.org/pypi/e.
> It's a small yet elegant tool for the command line.

That's cool!

ChrisA


From steve at pearwood.info  Mon Jan 12 02:21:10 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 12 Jan 2015 07:21:10 GMT
Subject: importing os.path -- why does it work?
References: <54b35c3d$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17607.1421042495.18130.python-list@python.org>
Message-ID: <54b375e6$0$2738$c3e8da3$76491128@news.astraweb.com>

On Sun, 11 Jan 2015 23:00:45 -0700, Ian Kelly wrote:

> On Sun, Jan 11, 2015 at 10:31 PM, Steven D'Aprano <steve at pearwood.info>
> wrote:
>> But bizarrely, you can import os.path this way!
>>
>> py> import os.path
>> py> os.path
>> <module 'posixpath' from '/usr/local/lib/python3.3/posixpath.py'> py>
>> os.__package__
>> ''
>>
>>
>>
>> By what wizardry does this work?
> 
> By the wizardry of adding an entry to sys.modules.
> 
> https://hg.python.org/cpython/file/8b3c609f3f73/Lib/os.py#l112


/head-desk

It's always the simplest thing... 

Thanks.

-- 
Steve


From ganesh1pal at gmail.com  Mon Jan 12 04:53:48 2015
From: ganesh1pal at gmail.com (Ganesh Pal)
Date: Mon, 12 Jan 2015 15:23:48 +0530
Subject: Few Coding suggestions - resending
In-Reply-To: <CACT3xuVeYdRWhONP6eb8F9chOYcow=ZQyv7Sw3aKjCAg3pdbHA@mail.gmail.com>
References: <CACT3xuWwYDoj-oMU1dPoRo8Xv_qHRx4JYBXPJcm3T1QfSWjgGw@mail.gmail.com>
 <54B2884B.90301@davea.name>
 <CACT3xuVeYdRWhONP6eb8F9chOYcow=ZQyv7Sw3aKjCAg3pdbHA@mail.gmail.com>
Message-ID: <CACT3xuVSCakm8GPPMZfhGUbC4P+LFj+mt5Agh=SCZaxgPm7GSQ@mail.gmail.com>

On Mon, Jan 12, 2015 at 8:42 AM, Ganesh Pal <ganesh1pal at gmail.com> wrote:
> On Sun, Jan 11, 2015 at 7:57 PM, Dave Angel <davea at davea.name> wrote:
>>>
>>>
>> No idea how that represents "a difference of 5 minutes".  So I'll take a totally wild guess that you meant:
>>
>> Sunday 23:50 23:55
>> Monday 00:00 00:05
>> Monday 00:10 00:15
>> Monday 00:20 00:25
>> Monday 00:30 00:35
>>
>> which would have the 2nd column 5 minutes after the first.
>>
>> You need another datetime object, let's call it 'end'
>>
>> end = start + timedelta(minutes=5)
>>
>> and now you want to yield three things, in a tuple:
>>
>> yield (start.strftime("%A"), start.strftime("%H:%M"),
>>    end.strftime("%H:%M"))
>>
>> Of course that's a pain to do twice, as you have two yields in that function.  I'll leave you to reorder the loop to make that unnecessary.  Hint, do the yield first, THEN increment the start variable.
>
> Thanks for the inputs , I tried doing the increments and decrements
> first and then Yield
>
>  Program:
>
>   Login-1 at SNAP-BOX-1 new]$ cat time_range_01.py
> #!/usr/bin/python
> import time
> from datetime import date, time, datetime, timedelta
> #h = datetime.strftime("%H")
> #m = datetime.strftime("%M")
> h=23
> m=50
> d = date.today()
> print d
>
> def yield_times():
>     global  h,m,d
>     start = datetime.combine(d, time(int(h),int(m)))
>     end = datetime.combine(d, time(int(h),int(m)))
>     while True:
>         start += timedelta(minutes=10)
>         end = start + timedelta(minutes=5)
>         yield(start.strftime("%A"),start.strftime("%H:%M"),end.strftime("%H:%M"))
> gen = yield_times()
> for i in range(10):
>     print gen.next()
>
> output :
> [Login-1 at SNAP-BOX-1 new]$ python time_range_01.py
> 2015-01-12
> ('Tuesday', '00:00', '00:05')
> ('Tuesday', '00:10', '00:15')
> ('Tuesday', '00:20', '00:25')
> ('Tuesday', '00:30', '00:35')
> ('Tuesday', '00:40', '00:45')
> ('Tuesday', '00:50', '00:55')
> ('Tuesday', '01:00', '01:05')
> ('Tuesday', '01:10', '01:15')
> ('Tuesday', '01:20', '01:25')
> ('Tuesday', '01:30', '01:35')
>
> PS :   Except formatting the results looks pretty much what i was
> expecting .I was pretty much happy to see this last night :) .
>
>
>> and in the other loop, you want
>>     res = "{} {} {}\n".format(gen.next)
>>     print res,
>>
>>>
>
> Thanks ,  I will have to modify for the new output
>
>>> (b)  how to copy the above output (i.e with the new column to a file.)
>>>
>>
>> Instead of printing, just do f.write(res).  Or do both. Notice that to make this easy, i avoided doing any formatting in the print statement. I used a trailing comma on it to avoid print adding a newline, and instead put it explicitly in the format method call.
>>
>>>
>
> Sure
>
>>> (c)  The  final output should be a file , having the entries  day ,
>>> start , end time of the remote file. how do  i pass the  this to
>>> yeild-times()
>>>
>>> import time
>>>
>>> /* Assuming I retrive the below values h,m,d from the remote machine*/
>>>
>>> h = time.strftime("%H")
>>> m = time.strftime("%M")
>>> d = date.today()
>>>
>>
>> Those first two are strings, but the third is a datetime object.  That last can be painful to pass between machines.
>
> Correct , also looks like I have another issue , if I happen to pass
> the first two strings
>
> #  instead hard coded value i.e h = 23 and y =50 , i try using the
> string directly I end up getting the below error :
>
> h = datetime.strftime("%H")
> m = datetime.strftime("%M")
>
> [Login-1 at SNAP-BOX-1 new]$ python  time_range_01.py
> Traceback (most recent call last):
>   File "time_range_01.py", line 4, in <module>
>     h = datetime.strftime("%H")
> TypeError: descriptor 'strftime' requires a 'datetime.date' object but
> received a 'str'
>
> The date time object is retrieved once once from the remote machine
> and just for building the file in the required format.
> Do you foresee any problems using this ?
>
>>
>>>
>>> def yield_times():
>>>        global h,m,d
>>
>>
>> No idea what that's all about.  If you want to pass arguments to yield_times(), put them inside the parens.
>>
> sure .
>
> Regards,
> Gpal


From skip.montanaro at gmail.com  Mon Jan 12 07:15:42 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Mon, 12 Jan 2015 06:15:42 -0600
Subject: annoying doctest problem
In-Reply-To: <54b35a9c$0$2738$c3e8da3$76491128@news.astraweb.com>
References: <0e9e5a03-2291-490e-9220-fa6744c9e2e5@googlegroups.com>
 <54b35a9c$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <CANc-5UzRvYBGmERK71sf2gxOCioTPGQpCA5BVe=qF9SF4x=+aw@mail.gmail.com>

ISTR that when Tim Peters first implemented first, the typical way you were
expected to get tests into a doc string was to copy from an interactive
session, which would not have this problem.

Also, to Steven's comment about fussiness, it isn't so much that it's
fussy. It's more that it's dumb. I just does a simple string comparison of
the expected and actual outputs. It would be impossible for doctest to know
whether the expected output was something like repr or str output, and thus
safe to exchange single for double (don't forget to escape other embedded
quotes!), or was some sort of user-generated string, perhaps intended to be
text in  another programming language which has different quoting rules
than Python. Therefore, fussy (or dumb) is exactly what you want.

I-said-what-I-meant-ly y'rs,

Skip
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From jacob at blindza.co.za  Mon Jan 12 07:31:15 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Mon, 12 Jan 2015 14:31:15 +0200
Subject: unidecode
Message-ID: <E8F66B1E436D455AA5DC4FE6A03C337C@JakesPC>

Along lines of recent queries/questions, which had mostly sorted out, but, which was still trying to fine tune with regards to text file formats, in terms of writing as strings, or as binary files, and where was still trying to decide if wanted to worry about maybe specifically just handling forms of manual/hard-coded translations of certain accented characters which might relate to some of them that might get used quite often in names, etc., I just came across the following unidecode module:
https://pypi.python.org/pypi/Unidecode/

Seems to just take any unicode value, and 'translate' it into a string value, and will apparently try handle some forms of character substitution - but will play around with it a bit more, and let's see...

Stay well

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."

----- Original Message ----- 
From: Jacob Kruger 
To: Jacob Kruger 
Sent: Monday, January 12, 2015 2:15 PM
Subject: unidecode


https://pypi.python.org/pypi/Unidecode/

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."
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From skip.montanaro at gmail.com  Mon Jan 12 07:32:20 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Mon, 12 Jan 2015 06:32:20 -0600
Subject: annoying doctest problem
In-Reply-To: <CANc-5UzRvYBGmERK71sf2gxOCioTPGQpCA5BVe=qF9SF4x=+aw@mail.gmail.com>
References: <0e9e5a03-2291-490e-9220-fa6744c9e2e5@googlegroups.com>
 <54b35a9c$0$2738$c3e8da3$76491128@news.astraweb.com>
 <CANc-5UzRvYBGmERK71sf2gxOCioTPGQpCA5BVe=qF9SF4x=+aw@mail.gmail.com>
Message-ID: <CANc-5UwLQ-jLY_dQw0-cUBAWESKGtVFjR_n=0OEkAKzB+hU6Ng@mail.gmail.com>

On Mon, Jan 12, 2015 at 6:15 AM, Skip Montanaro
<skip.montanaro at gmail.com> wrote:
> ... first implemented first ...

s/first/doctest/

Darn auto-correct...

Skip


From steve+comp.lang.python at pearwood.info  Mon Jan 12 08:00:21 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 13 Jan 2015 00:00:21 +1100
Subject: annoying doctest problem
References: <0e9e5a03-2291-490e-9220-fa6744c9e2e5@googlegroups.com>
 <54b35a9c$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17618.1421064945.18130.python-list@python.org>
Message-ID: <54b3c566$0$13004$c3e8da3$5496439d@news.astraweb.com>

Skip Montanaro wrote:

> ISTR that when Tim Peters first implemented first, the typical way you
> were expected to get tests into a doc string was to copy from an
> interactive session, which would not have this problem.

I believe that is still documented as the way to generate doctests.
 
> Also, to Steven's comment about fussiness, it isn't so much that it's
> fussy. It's more that it's dumb. I just does a simple string comparison of
> the expected and actual outputs. It would be impossible for doctest to
> know whether the expected output was something like repr or str output,
> and thus safe to exchange single for double (don't forget to escape other
> embedded quotes!), or was some sort of user-generated string, perhaps
> intended to be
> text in  another programming language which has different quoting rules
> than Python. Therefore, fussy (or dumb) is exactly what you want.

I didn't mean to give the impression that doctest was wrong to be fussy, or
dumb if you prefer. I think it's exactly the right behaviour.



-- 
Steven



From wxjmfauth at gmail.com  Mon Jan 12 08:24:00 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Mon, 12 Jan 2015 05:24:00 -0800 (PST)
Subject: Using a ChangeLog as a canonical source of package metadata
In-Reply-To: <54b35f33$0$2738$c3e8da3$76491128@news.astraweb.com>
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17488.1420762070.18130.python-list@python.org>
 <54b2be27$0$13000$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17593.1421007692.18130.python-list@python.org>
 <d0131022-c085-411e-a554-ec45f1ed4021@googlegroups.com>
 <54b35f33$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <c82ac862-9f9a-41b6-b774-a8506e0a4f88@googlegroups.com>

Le lundi 12 janvier 2015 06:46:20 UTC+1, Steven D'Aprano a ?crit?:
> On Sun, 11 Jan 2015 12:37:03 -0800, wxjmfauth wrote:
> 
> > 1) I downloaded pyprimes-0.2.1a.tar.gz 
> > 2) I extracted the relevant part,
> > the py files, the pyprimes subdirectory,
> > awful.py, compat23.py, factors.py, test.py, .......... and put in
> > d:\junk
> 
> That is not the way packages work.
> 
> pyprimes is a package, which means it has to stay together in a single 
> directory called "pyprimes", with a file called "__init__.py" inside it. 
> It is not a set of independent modules.
> 
> Please read the README file, it explains the correct way to install 
> pyprimes. You should use the setup.py installer script.
> 
> If you insist on manually doing this, you can copy the *entire* pyprimes 
> package directory. That is, unpack the tar.gz file to something like this:
> 
> 
> pyprimes/
> +-- CHANGES.txt  
> +-- LICENCE.txt
> +-- MANIFEST  
> +-- README.txt
> +-- setup.py
> +-- src/
>     +-- pyprimes/
>         +-- __init__.py
>         +-- awful.py
>         +-- factors.py
>         +-- test.py
>         etc.
> 
> 
> Copy the *entire* folder pyprimes/src/pyprimes/ and move that somewhere 
> into your PYTHONPATH. 
> 
> Or instead you can:
> 
> cd pyprimes/src  # ***NOT*** pyprimes/src/pyprimes !!!
> 
> 
> and run python from there.
> 
> 
> -- 
> Steve

To tell you the truth, I'm unable to
put your product to work.



From ganesh1pal at gmail.com  Mon Jan 12 08:39:45 2015
From: ganesh1pal at gmail.com (Ganesh Pal)
Date: Mon, 12 Jan 2015 19:09:45 +0530
Subject: Few Coding suggestions - resending
In-Reply-To: <CACT3xuVSCakm8GPPMZfhGUbC4P+LFj+mt5Agh=SCZaxgPm7GSQ@mail.gmail.com>
References: <CACT3xuWwYDoj-oMU1dPoRo8Xv_qHRx4JYBXPJcm3T1QfSWjgGw@mail.gmail.com>
 <54B2884B.90301@davea.name>
 <CACT3xuVeYdRWhONP6eb8F9chOYcow=ZQyv7Sw3aKjCAg3pdbHA@mail.gmail.com>
 <CACT3xuVSCakm8GPPMZfhGUbC4P+LFj+mt5Agh=SCZaxgPm7GSQ@mail.gmail.com>
Message-ID: <CACT3xuVpPAi7Gwr_NWXhjW49bxtBzw9febi3BJD=3fXGSbdG4w@mail.gmail.com>

Thanks to all and  dear Dave Angel, I got this working :)  , using
your valuable  inputs .

Here is the final program:
Throttling-1# cat sleep_schedule_file.py
#!/usr/bin/python
import time
import pdb
from datetime import date, time, datetime, timedelta

#'''run these on the remote commmand '''

n = datetime.now()
h = n.strftime("%H")
m = n.strftime("%M")
d = date.today()

#''' get the sleep_schedule_structure '''

def yield_times():
    start = datetime.combine(d, time(int(h),int(m)))
    end = datetime.combine(d, time(int(h),int(m)))
    while True:
        start += timedelta(minutes=4)
        end = start + timedelta(minutes=2)
        yield(start.strftime("%A"),start.strftime("%H:%M"),end.strftime("%H:%M"))
gen = yield_times()

f = open('/tmp/sleep_sched.conf','wb')
for ii in range(10):
     a,b,c = gen.next()
     res = "{0} {1} {2} \n".format(a,b,c)
     print res,
     f.write(res)

f.close()

Gpal

On Mon, Jan 12, 2015 at 3:23 PM, Ganesh Pal <ganesh1pal at gmail.com> wrote:
> On Mon, Jan 12, 2015 at 8:42 AM, Ganesh Pal <ganesh1pal at gmail.com> wrote:
>> On Sun, Jan 11, 2015 at 7:57 PM, Dave Angel <davea at davea.name> wrote:
>>>>
>>>>
>>> No idea how that represents "a difference of 5 minutes".  So I'll take a totally wild guess that you meant:
>>>
>>> Sunday 23:50 23:55
>>> Monday 00:00 00:05
>>> Monday 00:10 00:15
>>> Monday 00:20 00:25
>>> Monday 00:30 00:35
>>>
>>> which would have the 2nd column 5 minutes after the first.
>>>
>>> You need another datetime object, let's call it 'end'
>>>
>>> end = start + timedelta(minutes=5)
>>>
>>> and now you want to yield three things, in a tuple:
>>>
>>> yield (start.strftime("%A"), start.strftime("%H:%M"),
>>>    end.strftime("%H:%M"))
>>>
>>> Of course that's a pain to do twice, as you have two yields in that function.  I'll leave you to reorder the loop to make that unnecessary.  Hint, do the yield first, THEN increment the start variable.
>>
>> Thanks for the inputs , I tried doing the increments and decrements
>> first and then Yield
>>
>>  Program:
>>
>>   Login-1 at SNAP-BOX-1 new]$ cat time_range_01.py
>> #!/usr/bin/python
>> import time
>> from datetime import date, time, datetime, timedelta
>> #h = datetime.strftime("%H")
>> #m = datetime.strftime("%M")
>> h=23
>> m=50
>> d = date.today()
>> print d
>>
>> def yield_times():
>>     global  h,m,d
>>     start = datetime.combine(d, time(int(h),int(m)))
>>     end = datetime.combine(d, time(int(h),int(m)))
>>     while True:
>>         start += timedelta(minutes=10)
>>         end = start + timedelta(minutes=5)
>>         yield(start.strftime("%A"),start.strftime("%H:%M"),end.strftime("%H:%M"))
>> gen = yield_times()
>> for i in range(10):
>>     print gen.next()
>>
>> output :
>> [Login-1 at SNAP-BOX-1 new]$ python time_range_01.py
>> 2015-01-12
>> ('Tuesday', '00:00', '00:05')
>> ('Tuesday', '00:10', '00:15')
>> ('Tuesday', '00:20', '00:25')
>> ('Tuesday', '00:30', '00:35')
>> ('Tuesday', '00:40', '00:45')
>> ('Tuesday', '00:50', '00:55')
>> ('Tuesday', '01:00', '01:05')
>> ('Tuesday', '01:10', '01:15')
>> ('Tuesday', '01:20', '01:25')
>> ('Tuesday', '01:30', '01:35')
>>
>> PS :   Except formatting the results looks pretty much what i was
>> expecting .I was pretty much happy to see this last night :) .
>>
>>
>>> and in the other loop, you want
>>>     res = "{} {} {}\n".format(gen.next)
>>>     print res,
>>>
>>>>
>>
>> Thanks ,  I will have to modify for the new output
>>
>>>> (b)  how to copy the above output (i.e with the new column to a file.)
>>>>
>>>
>>> Instead of printing, just do f.write(res).  Or do both. Notice that to make this easy, i avoided doing any formatting in the print statement. I used a trailing comma on it to avoid print adding a newline, and instead put it explicitly in the format method call.
>>>
>>>>
>>
>> Sure
>>
>>>> (c)  The  final output should be a file , having the entries  day ,
>>>> start , end time of the remote file. how do  i pass the  this to
>>>> yeild-times()
>>>>
>>>> import time
>>>>
>>>> /* Assuming I retrive the below values h,m,d from the remote machine*/
>>>>
>>>> h = time.strftime("%H")
>>>> m = time.strftime("%M")
>>>> d = date.today()
>>>>
>>>
>>> Those first two are strings, but the third is a datetime object.  That last can be painful to pass between machines.
>>
>> Correct , also looks like I have another issue , if I happen to pass
>> the first two strings
>>
>> #  instead hard coded value i.e h = 23 and y =50 , i try using the
>> string directly I end up getting the below error :
>>
>> h = datetime.strftime("%H")
>> m = datetime.strftime("%M")
>>
>> [Login-1 at SNAP-BOX-1 new]$ python  time_range_01.py
>> Traceback (most recent call last):
>>   File "time_range_01.py", line 4, in <module>
>>     h = datetime.strftime("%H")
>> TypeError: descriptor 'strftime' requires a 'datetime.date' object but
>> received a 'str'
>>
>> The date time object is retrieved once once from the remote machine
>> and just for building the file in the required format.
>> Do you foresee any problems using this ?
>>
>>>
>>>>
>>>> def yield_times():
>>>>        global h,m,d
>>>
>>>
>>> No idea what that's all about.  If you want to pass arguments to yield_times(), put them inside the parens.
>>>
>> sure .
>>
>> Regards,
>> Gpal


From fomcl at yahoo.com  Mon Jan 12 08:44:36 2015
From: fomcl at yahoo.com (Albert-Jan Roskam)
Date: Mon, 12 Jan 2015 13:44:36 +0000 (UTC)
Subject: class-based class decorator
In-Reply-To: <CALwzidkvGKEJtZ2f2LyfA4atY0kpaQsGrCtBro5X2TyrBe98Hw@mail.gmail.com>
References: <CALwzidkvGKEJtZ2f2LyfA4atY0kpaQsGrCtBro5X2TyrBe98Hw@mail.gmail.com>
Message-ID: <1098350771.199383.1421070276837.JavaMail.yahoo@jws10769.mail.gq1.yahoo.com>



----- Original Message -----

> From: Ian Kelly <ian.g.kelly at gmail.com>
> To: Python <python-list at python.org>
> Cc: 
> Sent: Saturday, January 10, 2015 7:30 AM
> Subject: Re: class-based class decorator
> 
> On Fri, Jan 9, 2015 at 2:26 PM, Albert-Jan Roskam
> 
> <fomcl at yahoo.com.dmarc.invalid> wrote:
>> 
>> 
>>  Hi,
>> 
>>  I am trying to write a class decorator that checks whether deprecated 
> parameters with non-default
>> 
>>  arguments are used. More complete code is here: 

> http://pastebin.com/ZqnMis6M.

Oops, the period was included in the url. It was 
http://pastebin.com/ZqnMis6M

>> In the code below,>>  how should I modify __call__ such that f.bar(old="oh no") prints 
> "hello world"?
>>  I thought it would be a fun way to play with the inspect module, but my 
> head is numb now and I am thirsty for a beer!
> 
> You can use inspect.getargspec to look up the default argument values
> for the target function. You can use inspect.getcallargs to map your
> *args and **kwargs to a dictionary of argument names and values. Since
> the target function will be the unbound __init__ method, you'll also
> want to pass in a dummy value like None for the self argument. Then
> you just look up each of the deprecated names in the result and flag
> any where the value doesn't match the default.
> 
> If you were using Python 3.3+, then I would recommend using
> inspect.signature instead, which is a lot more powerful. But your code
> appears to be Python 2, so we work with what we've got.


Hi Ian, Chris,

Thanks for your replies. I changed it into a regular decorator (not a class decorator). It would have been even nicer if I only needed to specify it once per class, but, well, in my case this hardly matters. The code below works as intended. One problem (not specific to the code): the decorator destroys the signature: it always becomes "*args, **kwargs"). This is annoying with help(), but what worries me most is that my Sphinx documentation is also affected. The information about the defaults gets lost (the parameters are decribed in the docstring, but not the defaults). That kind of sucks. Is there a builtin way around this (in other words: I am aware of this package: https://pypi.python.org/pypi/decorator). I am hoping to get the code working on Python 2.7 and 3.3 and up.

import functools
import inspect
import warnings

warnings.simplefilter("always")

class check_deprecated_args(object):

    def __init__(self, deprecated_params, msg=None):
        self.deprecated_params = deprecated_params
        self.msg = msg

    def __call__(self, func):
        @functools.wraps(func)
        def inner(*args, **kwargs):
            argspec = inspect.getargspec(func)
            default_signature = dict(zip(argspec.args[1:], argspec.defaults))
            callargs = inspect.getcallargs(func, *args, **kwargs)
            deprecated_calls = [(p, a) for p, a in callargs.items() if 
                                 p in self.deprecated_params and 
                                 a != default_signature[p]]
            for (param, arg) in deprecated_calls:
                msg = "you're using obsolete parameters in %s: [%s:%s]" 
                msg = msg % (func.__name__, param, arg)
                msg = msg + " " + self.msg if self.msg else msg 
                warnings.warn(msg, DeprecationWarning, stacklevel=2)
            return func(*args, **kwargs)
        functools.update_wrapper(inner, func)
        return inner

if __name__ == "__main__":
    class Foo(object):

        @check_deprecated_args(["old", "older"], "use 'brand_new' param instead")
        def __init__(self, old="old", older="ancient"):
            print "hello"

        @check_deprecated_args(deprecated_params=["old", "older"])
        def bar(self, old="default"):
            print "world"    

    f = Foo(old="old", older="dino era")
    f.bar("gnarly")

    help(f)  # now the signature is *args, **kwargs, which makes my Sphinx documentation less readable!

Best wishes,
Albert-Jan


From breamoreboy at yahoo.co.uk  Mon Jan 12 09:59:49 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 12 Jan 2015 14:59:49 +0000
Subject: annoying doctest problem
In-Reply-To: <54b3c566$0$13004$c3e8da3$5496439d@news.astraweb.com>
References: <0e9e5a03-2291-490e-9220-fa6744c9e2e5@googlegroups.com>
 <54b35a9c$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17618.1421064945.18130.python-list@python.org>
 <54b3c566$0$13004$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <m90nh5$g56$1@ger.gmane.org>

On 12/01/2015 13:00, Steven D'Aprano wrote:
> Skip Montanaro wrote:
>
>> ISTR that when Tim Peters first implemented first, the typical way you
>> were expected to get tests into a doc string was to copy from an
>> interactive session, which would not have this problem.
>
> I believe that is still documented as the way to generate doctests.
>
>> Also, to Steven's comment about fussiness, it isn't so much that it's
>> fussy. It's more that it's dumb. I just does a simple string comparison of
>> the expected and actual outputs. It would be impossible for doctest to
>> know whether the expected output was something like repr or str output,
>> and thus safe to exchange single for double (don't forget to escape other
>> embedded quotes!), or was some sort of user-generated string, perhaps
>> intended to be
>> text in  another programming language which has different quoting rules
>> than Python. Therefore, fussy (or dumb) is exactly what you want.
>
> I didn't mean to give the impression that doctest was wrong to be fussy, or
> dumb if you prefer. I think it's exactly the right behaviour.
>

If doctest is dumb then that's clearly down to the author.  Perhaps we 
should refer him or her to the Zen of Python so they don't repeat the 
mistake with future design decisions?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From jeanmichel at sequans.com  Mon Jan 12 10:20:51 2015
From: jeanmichel at sequans.com (Jean-Michel Pichavant)
Date: Mon, 12 Jan 2015 16:20:51 +0100 (CET)
Subject: class-based class decorator
In-Reply-To: <1098350771.199383.1421070276837.JavaMail.yahoo@jws10769.mail.gq1.yahoo.com>
Message-ID: <2047794092.9155299.1421076051020.JavaMail.root@sequans.com>

----- Original Message -----
> From: "Albert-Jan Roskam" <fomcl at yahoo.com.dmarc.invalid>
> import functools
> import inspect
> import warnings
> 
> warnings.simplefilter("always")
> 
> class check_deprecated_args(object):
> 
>     def __init__(self, deprecated_params, msg=None):
>         self.deprecated_params = deprecated_params
>         self.msg = msg
> 
>     def __call__(self, func):
>         @functools.wraps(func)
>         def inner(*args, **kwargs):
>             argspec = inspect.getargspec(func)
>             default_signature = dict(zip(argspec.args[1:],
>             argspec.defaults))
>             callargs = inspect.getcallargs(func, *args, **kwargs)
>             deprecated_calls = [(p, a) for p, a in callargs.items()
>             if
>                                  p in self.deprecated_params and
>                                  a != default_signature[p]]
>             for (param, arg) in deprecated_calls:
>                 msg = "you're using obsolete parameters in %s:
>                 [%s:%s]"
>                 msg = msg % (func.__name__, param, arg)
>                 msg = msg + " " + self.msg if self.msg else msg
>                 warnings.warn(msg, DeprecationWarning, stacklevel=2)
>             return func(*args, **kwargs)
>         functools.update_wrapper(inner, func)
>         return inner
> 
> if __name__ == "__main__":
>     class Foo(object):
> 
>         @check_deprecated_args(["old", "older"], "use 'brand_new'
>         param instead")
>         def __init__(self, old="old", older="ancient"):
>             print "hello"
> 
>         @check_deprecated_args(deprecated_params=["old", "older"])
>         def bar(self, old="default"):
>             print "world"
> 
>     f = Foo(old="old", older="dino era")
>     f.bar("gnarly")
> 
>     help(f)  # now the signature is *args, **kwargs, which makes my
>     Sphinx documentation less readable!
> 
> Best wishes,
> Albert-Jan

I don't really understand how you successfuly manage positional parameters, since the caller may not name them.
I'm asking because if your intend to check only the keyword parameters, there's a much simplier solution.

JM


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From ned at nedbatchelder.com  Mon Jan 12 10:47:25 2015
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Mon, 12 Jan 2015 10:47:25 -0500
Subject: annoying doctest problem
In-Reply-To: <0e9e5a03-2291-490e-9220-fa6744c9e2e5@googlegroups.com>
References: <0e9e5a03-2291-490e-9220-fa6744c9e2e5@googlegroups.com>
Message-ID: <m90qad$ua8$1@ger.gmane.org>

On 1/11/15 11:20 PM, gordianknot1981 at gmail.com wrote:
>
> It failed with an unknown reason that evaluate two expected equal value but got an unexpected result! I'm struggling with this problem for a long time. Did I did something wrong? And how do I to fix it?
>
> any help is appreciated. :)
>

My recommendation is to use doctest to test the code samples that 
naturally occur in your docstrings, but not to use it as a 
general-purpose testing tool.  It has too many limitations and quirks, 
and if you're going to write separate test methods anyway, why not just 
write actual code?

More detail here: 
http://nedbatchelder.com/blog/200811/things_i_dont_like_about_doctest.html


-- 
Ned Batchelder, http://nedbatchelder.com



From steve+comp.lang.python at pearwood.info  Mon Jan 12 10:58:42 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 13 Jan 2015 02:58:42 +1100
Subject: annoying doctest problem
References: <0e9e5a03-2291-490e-9220-fa6744c9e2e5@googlegroups.com>
 <54b35a9c$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17618.1421064945.18130.python-list@python.org>
 <54b3c566$0$13004$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17624.1421074803.18130.python-list@python.org>
Message-ID: <54b3ef32$0$13008$c3e8da3$5496439d@news.astraweb.com>

Mark Lawrence wrote:

> If doctest is dumb then that's clearly down to the author. ?Perhaps we
> should refer him or her to the Zen of Python so they don't repeat the
> mistake with future design decisions?

o_O


I don't even ... 

wait ... 

[starts typing]

[stops typing]

... okay.

-- 
Steven



From breamoreboy at yahoo.co.uk  Mon Jan 12 11:46:54 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 12 Jan 2015 16:46:54 +0000
Subject: annoying doctest problem
In-Reply-To: <54b3ef32$0$13008$c3e8da3$5496439d@news.astraweb.com>
References: <0e9e5a03-2291-490e-9220-fa6744c9e2e5@googlegroups.com>
 <54b35a9c$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17618.1421064945.18130.python-list@python.org>
 <54b3c566$0$13004$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17624.1421074803.18130.python-list@python.org>
 <54b3ef32$0$13008$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <m90tpv$sdo$2@ger.gmane.org>

On 12/01/2015 15:58, Steven D'Aprano wrote:
> Mark Lawrence wrote:
>
>> If doctest is dumb then that's clearly down to the author.  Perhaps we
>> should refer him or her to the Zen of Python so they don't repeat the
>> mistake with future design decisions?
>
> o_O
>
>
> I don't even ...
>
> wait ...
>
> [starts typing]
>
> [stops typing]
>
> ... okay.
>

Drat, drat and double drat, for just one minute I thought I'd hooked a 
large, highly respected Antipodean :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From ark at acm.org  Mon Jan 12 13:02:04 2015
From: ark at acm.org (Andrew Koenig)
Date: Mon, 12 Jan 2015 10:02:04 -0800 (PST)
Subject: I must be missing something obvious in installing Python 3.4.2...
Message-ID: <ec7b8633-3b02-42b3-89e4-ef002ebd78e6@googlegroups.com>

Downloaded and installed 64-bit Python 3.4 and pywin32-219. Both installed smoothly on my 64-bit Win7 machine. I added C:\Python34 to the search path.

If I launch a Windows command window and run

        python -m ensurepip

I get the following:

Ignoring indexes: https://pypi.python.org/simple/
Downloading/unpacking setuptools
Cleaning up...
Exception:
Traceback (most recent call last):
  File "C:\Users\ark\AppData\Local\Temp\tmpe3ckts9f\pip-1.5.6-py2.py3-none-any.w
hl\pip\basecommand.py", line 122, in main
    status = self.run(options, args)
  File "C:\Users\ark\AppData\Local\Temp\tmpe3ckts9f\pip-1.5.6-py2.py3-none-any.w
hl\pip\commands\install.py", line 278, in run
    requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundl
e=self.bundle)
  File "C:\Users\ark\AppData\Local\Temp\tmpe3ckts9f\pip-1.5.6-py2.py3-none-any.w
hl\pip\req.py", line 1177, in prepare_files
    url = finder.find_requirement(req_to_install, upgrade=self.upgrade)
  File "C:\Users\ark\AppData\Local\Temp\tmpe3ckts9f\pip-1.5.6-py2.py3-none-any.w
hl\pip\index.py", line 209, in find_requirement
    file_locations, url_locations = self._sort_locations(locations)
  File "C:\Users\ark\AppData\Local\Temp\tmpe3ckts9f\pip-1.5.6-py2.py3-none-any.w
hl\pip\index.py", line 128, in _sort_locations
    sort_path(os.path.join(path, item))
  File "C:\Users\ark\AppData\Local\Temp\tmpe3ckts9f\pip-1.5.6-py2.py3-none-any.w
hl\pip\index.py", line 109, in sort_path
    if mimetypes.guess_type(url, strict=False)[0] == 'text/html':
  File "C:\Python34\lib\mimetypes.py", line 287, in guess_type
    init()
  File "C:\Python34\lib\mimetypes.py", line 348, in init
    db.read_windows_registry()
  File "C:\Python34\lib\mimetypes.py", line 255, in read_windows_registry
    with _winreg.OpenKey(hkcr, subkeyname) as subkey:
TypeError: OpenKey() argument 2 must be str without null characters or None, not
 str

The pip.log file contains the same text.

I'm sure I'm doing something obviously wrong here--but what?


From jbailey at emerytelcom.com  Mon Jan 12 13:03:49 2015
From: jbailey at emerytelcom.com (Jason Bailey)
Date: Mon, 12 Jan 2015 11:03:49 -0700
Subject: Python 3 regex?
Message-ID: <54B40C85.5000806@emerytelcom.com>

Hi all,

I'm working on a Python _3_ project that will be used to parse ISC DHCPD 
configuration files for statistics and alarming purposes (IP address 
pools, etc). Anyway, I'm hung up on this one section and was hoping 
someone could provide me with some insight.

My script first reads the DHCPD configuration file into memory - 
variable "filebody". It then utilizes the re module to find the 
configuration details for the wanted "shared network".

The config file might look something like this:

######################################

shared-network My-Network-MOHE {
   subnet 192.168.0.0 netmask 255.255.248.0 {
     option routers 192.168.0.1;
     option tftp-server-name "192.168.90.12";
     pool {
       deny dynamic bootp clients;
       range 192.168.0.20 192.168.7.254;
     }
   }
}

shared-network My-Network-CDCO {
   subnet 192.168.8.0 netmask 255.255.248.0 {
     option routers 10.101.8.1;
     option tftp-server-name "192.168.90.12";
     pool {
       deny dynamic bootp clients;
       range 192.168.8.20 192.168.15.254;
     }
   }
}

shared-network My-Network-FECO {
   subnet 192.168.16.0 netmask 255.255.248.0 {
     option routers 192.168.16.1;
     option tftp-server-name "192.168.90.12";
     pool {
       deny dynamic bootp clients;
       range 192.168.16.20 192.168.23.254;
     }
   }
}

######################################

Suppose I'm trying to grab the shared network called "My-Network-FECO" 
from the above config file stored in the variable 'filebody'.

First I have my variable 'shared_network' which contains the string 
"My-Network-FECO".

I compile my regex:
m = re.compile(r"^(shared\-network (" + re.escape(shared_network) + r") 
\{((\n|.|\r\n)*?)(^\}))", re.MULTILINE|re.UNICODE)

I search for regex matches in my config file:
m.search(filebody)

Unfortunately, I get no matches. From output on the command line, I can 
see that Python is adding extra backslashes to my re.compile string. I 
have added the raw 'r' in front of the strings to prevent it, but to no 
avail.

Thoughts on this?

Thanks




From skip.montanaro at gmail.com  Mon Jan 12 13:15:23 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Mon, 12 Jan 2015 12:15:23 -0600
Subject: annoying doctest problem
In-Reply-To: <54b3c566$0$13004$c3e8da3$5496439d@news.astraweb.com>
References: <0e9e5a03-2291-490e-9220-fa6744c9e2e5@googlegroups.com>
 <54b35a9c$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17618.1421064945.18130.python-list@python.org>
 <54b3c566$0$13004$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CANc-5UzfUTBSy5AimVqDJr8kBiUmdQcj7rjm--hpZto5fZ9Cnw@mail.gmail.com>

On Mon, Jan 12, 2015 at 7:00 AM, Steven D'Aprano <
steve+comp.lang.python at pearwood.info> wrote:

> I didn't mean to give the impression that doctest was wrong to be fussy, or
> dumb if you prefer. I think it's exactly the right behaviour.
>

I wasn't actually concerned that Steven might have misunderstood how
doctest works, just that other less experienced programmers might interpret
his statement as suggesting that doctest's comparisons were somehow wrong
or might be made less "fussy". That word suggests to me that there is some
sort of critical evaluation by the fussy party going on (doctest, in this
case), when there is none. Which is why I chose the word "dumb."

Skip
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-list/attachments/20150112/0ea073fe/attachment.html>

From jbailey at emerytelcom.com  Mon Jan 12 13:20:35 2015
From: jbailey at emerytelcom.com (Jason Bailey)
Date: Mon, 12 Jan 2015 11:20:35 -0700
Subject: Python 3 regex woes (parsing ISC DHCPD config)
Message-ID: <54B41073.30902@emerytelcom.com>

Hi all,

I'm working on a Python _3_ project that will be used to parse ISC DHCPD 
configuration files for statistics and alarming purposes (IP address 
pools, etc). Anyway, I'm hung up on this one section and was hoping 
someone could provide me with some insight.

My script first reads the DHCPD configuration file into memory - 
variable "filebody". It then utilizes the re module to find the 
configuration details for the wanted "shared network".

The config file might look something like this:

######################################

shared-network My-Network-MOHE {
   subnet 192.168.0.0 netmask 255.255.248.0 {
     option routers 192.168.0.1;
     option tftp-server-name "192.168.90.12";
     pool {
       deny dynamic bootp clients;
       range 192.168.0.20 192.168.7.254;
     }
   }
}

shared-network My-Network-CDCO {
   subnet 192.168.8.0 netmask 255.255.248.0 {
     option routers 10.101.8.1;
     option tftp-server-name "192.168.90.12";
     pool {
       deny dynamic bootp clients;
       range 192.168.8.20 192.168.15.254;
     }
   }
}

shared-network My-Network-FECO {
   subnet 192.168.16.0 netmask 255.255.248.0 {
     option routers 192.168.16.1;
     option tftp-server-name "192.168.90.12";
     pool {
       deny dynamic bootp clients;
       range 192.168.16.20 192.168.23.254;
     }
   }
}

######################################

Suppose I'm trying to grab the shared network called "My-Network-FECO" 
from the above config file stored in the variable 'filebody'.

First I have my variable 'shared_network' which contains the string 
"My-Network-FECO".

I compile my regex:
m = re.compile(r"^(shared\-network (" + re.escape(shared_network) + r") 
\{((\n|.|\r\n)*?)(^\}))", re.MULTILINE|re.UNICODE)

I search for regex matches in my config file:
m.search(filebody)

Unfortunately, I get no matches. From output on the command line, I can 
see that Python is adding extra backslashes to my re.compile string. I 
have added the raw 'r' in front of the strings to prevent it, but to no 
avail.

Thoughts on this?

Thanks




From Charles at CharlesWeitzer.com  Mon Jan 12 13:33:25 2015
From: Charles at CharlesWeitzer.com (Charles Weitzer)
Date: Mon, 12 Jan 2015 10:33:25 -0800
Subject: Machine Learning Startup Hiring
Message-ID: <00a401d02e96$41533a90$c3f9afb0$@CharlesWeitzer.com>

Hello,

My name is Charles Weitzer. I do recruiting with a focus on quantitative sciences. One of my clients is a machine learning startup
located in Northern California. The founders include a successful veteran entrepreneur with a PhD in CS from Stanford, while the
other founder is on the faculty at UC Berkeley. Their team has made unpublished discoveries in the field of Machine Learning and in
other areas as well.  

My client would like to hire an extremely talented Senior Data Infrastructure Software Engineer as soon as possible. Their job
description can be found below. This group is going to be the next big thing in terms of quantitative strategies and systems.  They
are rebuilding their current system and also designing a new system.  You could work on either or both. I would love to speak with
you or anyone else you might highly recommend about this opportunity.

Thank you,

Charles Weitzer

CEO/Senior Recruiter
Charles Weitzer and Associates, Inc.
Global Financial Recruiting Services
Email: Charles at CharlesWeitzer.com
Phone: (USA) 510 558-9182

*********************************
Senior Data Infrastructure Software Engineer

Fast-growing science and technology-driven startup seeks a Senior Data Infrastructure Software Engineer. You will be a core member
working with the RnD, Software, Infrastructure, and Trading teams to develop, test, deploy, and manage research, operational and
production software. 

The firm researches and deploys machine learning and statistical trading strategies that are designed to generate attractive returns
without being dependent on the performance of the overall market.  Join a team of people that includes a professor at a premier
university as well as over ten PhDs and two MBAs from top schools, led by the founder and CEO of a successful Internet
Infrastructure technology firm. We have a casual and collegial office environment, weekly catered lunches, and offer competitive
benefits packages. 

Focus areas for the position include creating software infrastructure for our research department and production trading systems,
implementing and automating back office and reporting systems, as well as supporting the next generation of our compute and storage
hardware systems. We seek a candidate who can bring both development and operations skills to rework existing software
infrastructure and guide test/automation of new and ongoing deployments.

Qualifications:

.	Experience writing Python code in a *nix environment
.	Experience working with mission critical RDBMS, performance and fault tolerance
.	Industry experience as a software engineer
.	Automation deployment and virtualization (Ansible, KVM, Jenkins, etc.)
.	Experience with debugging and performance profiling, including the use of tools such as strace, valgrind, gdb, tcpdump, etc.

Useful Skills (Desirable, but not required):

.	Monitor and network management (Nagios, Logstash, Graphite, Cacti, etc.)
.	Knowledge of distributed systems, cluster computing, and fault tolerance
.	Experience making commits on open-source technology
.	Familiarity with cluster management and job queuing systems (Chronos, Luigi, Oracle grid engine, Mesos, etc.)
.	Experience in operations for highly available services

Please note that a background in finance is not required.

*********************************
To apply for this position, please send your resume to Charles at CharlesWeitzer.com.

Thank you,

Charles Weitzer

CEO/Senior Recruiter
Charles Weitzer and Associates, Inc.
Global Financial Recruiting Services
Email: Charles at CharlesWeitzer.com
Phone: (USA) 510 558-9182





From gordianknot1981 at gmail.com  Mon Jan 12 13:34:51 2015
From: gordianknot1981 at gmail.com (gordianknot1981 at gmail.com)
Date: Mon, 12 Jan 2015 10:34:51 -0800 (PST)
Subject: annoying doctest problem
In-Reply-To: <mailman.17626.1421077657.18130.python-list@python.org>
References: <0e9e5a03-2291-490e-9220-fa6744c9e2e5@googlegroups.com>
 <mailman.17626.1421077657.18130.python-list@python.org>
Message-ID: <a57c835b-6820-4af2-986e-9a4083d22408@googlegroups.com>

----------------------------------------------------------
> My recommendation is to use doctest to test the code samples that 
> naturally occur in your docstrings, but not to use it as a 
> general-purpose testing tool.  It has too many limitations and quirks, 
> and if you're going to write separate test methods anyway, why not just 
> write actual code?
> 
> More detail here: 
> http://nedbatchelder.com/blog/200811/things_i_dont_like_about_doctest.html
------------------------------------------------------------
"Docstrings may be good ways to explain what code does, but explaining and testing are two different tasks"......That's really to the point, and make sense. anyway, thanks for your article I benefit a lot from it.


From Charles at CharlesWeitzer.com  Mon Jan 12 13:35:35 2015
From: Charles at CharlesWeitzer.com (Charles Weitzer)
Date: Mon, 12 Jan 2015 10:35:35 -0800
Subject: Design and Build Software Engineer Opportunity
Message-ID: <00a501d02e96$8e918d20$abb4a760$@CharlesWeitzer.com>

My name is Charles Weitzer.  I do recruiting for machine learning teams worldwide. One of my clients is a startup quantitative hedge
fund located in Northern, California. The founders previous worked together at one of the most successful quantitative hedge funds
in the world in New York City. Now they are ready to do it again. The team would like to hire an extremely talented design and build
software engineer as soon as possible..  They are rebuilding their current trading strategy and system and also designing a new
strategy.  You could work on either or both.  The title and level of seniority are very flexible. Their team has made unpublished
discoveries in the field of machine learning and in other areas as well.  This is an opportunity to leverage these discoveries in a
real world environment.

Here is their description of the position:

**********************************************************
Design and Build Software Engineer

Fast-growing quantitative trading firm seeks an exceptional software engineer. You will design and build new production trading
systems, machine learning infrastructure, data integration pipelines, and large-scale storage systems.

We seek a candidate with a proven track record of building correct, well-designed software, solving hard problems, and delivering
complex projects on time. You should preferably have experience designing and implementing fault-tolerant distributed systems.
Experience with building large-scale data infrastructure, stream processing systems, or latency-sensitive programs is a bonus. We
are getting big fast. Willingness to take initiative, and a gritty determination to productize, are essential.

Join a team that includes faculty at premier universities and PhD's from top-tier schools, led by the founder and CEO of a
successful Internet infrastructure startup. You will have a high impact, and you can expect frequent interaction with the
researchers, officers, and founders.

Compensation and benefits are highly competitive.

Qualifications:

* Experience developing with C/C++/Python/Go in a Linux environment with a focus on performance, concurrency, and correctness.
* Experience working in TCP/IP networking, multithreading and server development.
* Experience working with common Internet protocols (IP, TCP/UDP, SSL/TLS, HTTP, SNMP, etc.)
* Experience architecting and designing highly-available critical systems.
* Experience architecting and designing large-scale data management infrastructure.
* Experience working in large codebases and building modular, manageable code.

Useful Skills:

* Experience with debugging and performance profiling, including the use of tools such as strace, valgrind, gdb, tcpdump, etc.
* Experience with build and test automation tools.
* Experience working with well-defined change management processes.
* Has experience hunting down RDBMS performance problems, understands indexing options, can read an execution/explain plan, has some
experience with ORM and optimization at the code layer, etc.
* Experience with messaging queues (such as RabbitMQ and Redis), as well as distributed caching systems.
**********************************************************
This group is currently managing a very healthy amount of capital. And their job description above is really just a starting point
in terms of possible responsibilities and seniority.  They can be very flexible for the right person.

If you are interested, let me know the best way to get in touch and we can discuss details.

Talk soon,

Charles Weitzer

CEO\Senior Recruiter
Charles Weitzer and Associates, Inc.
Global Financial Recruiting Services
Charles at CharlesWeitzer.com
Voice: USA (510) 558-9182







From rosuav at gmail.com  Mon Jan 12 13:36:55 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 13 Jan 2015 05:36:55 +1100
Subject: I must be missing something obvious in installing Python 3.4.2...
In-Reply-To: <ec7b8633-3b02-42b3-89e4-ef002ebd78e6@googlegroups.com>
References: <ec7b8633-3b02-42b3-89e4-ef002ebd78e6@googlegroups.com>
Message-ID: <CAPTjJmojydauft=r2fHfNx0ASoEk43ODwxDrVTW_V97hU8swAg@mail.gmail.com>

On Tue, Jan 13, 2015 at 5:02 AM, Andrew Koenig <ark at acm.org> wrote:
> Downloaded and installed 64-bit Python 3.4 and pywin32-219. Both installed smoothly on my 64-bit Win7 machine. I added C:\Python34 to the search path.
>
> If I launch a Windows command window and run
>
>         python -m ensurepip

Do you have any other Pythons in PATH? Try:

python --version

Is it what you expect? If it is, see if there's a PYTHONPATH or
somesuch from a different version of Python.

ChrisA


From rosuav at gmail.com  Mon Jan 12 13:48:10 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 13 Jan 2015 05:48:10 +1100
Subject: Python 3 regex?
In-Reply-To: <54B40C85.5000806@emerytelcom.com>
References: <54B40C85.5000806@emerytelcom.com>
Message-ID: <CAPTjJmoB5qH8MF1FZQSCVPjCNencJbCbsu+f7o1odDH1NGBjLg@mail.gmail.com>

On Tue, Jan 13, 2015 at 5:03 AM, Jason Bailey <jbailey at emerytelcom.com> wrote:
> Unfortunately, I get no matches. From output on the command line, I can see
> that Python is adding extra backslashes to my re.compile string. I have
> added the raw 'r' in front of the strings to prevent it, but to no avail.
>

Regexes are notoriously hard to debug. Is there any particular reason
you _have_ to use one here? ISTM you could simplify it enormously by
just looking for the opening string:

shared_network = "My-Network-FECO"
network = filebody.split("\nshared-network "+shared_network+"
{",1)[1].split("\n}\n")[0]

Assuming your file is always correctly indented, and assuming you
don't have any other instances of that header string, you should be
fine.

ChrisA


From hobson42 at gmail.com  Mon Jan 12 14:48:18 2015
From: hobson42 at gmail.com (Ian)
Date: Mon, 12 Jan 2015 19:48:18 +0000
Subject: Python 3 regex?
In-Reply-To: <54B40C85.5000806@emerytelcom.com>
References: <54B40C85.5000806@emerytelcom.com>
Message-ID: <54B42502.6050702@gmail.com>

On 12/01/2015 18:03, Jason Bailey wrote:
> Hi all,
>
> I'm working on a Python _3_ project that will be used to parse ISC 
> DHCPD configuration files for statistics and alarming purposes (IP 
> address pools, etc). Anyway, I'm hung up on this one section and was 
> hoping someone could provide me with some insight.
>
> My script first reads the DHCPD configuration file into memory - 
> variable "filebody". It then utilizes the re module to find the 
> configuration details for the wanted "shared network".
>
Hi Jason,

If you actually look at the syntax of what you are parsing, it is very 
simple.

My recommendation would be to write a recursive decent parser for your 
files.

That way will be easier to write, much easier to modify and almost 
certainly faster that a RE solution - and it can easily give you all the 
information in the file thus future proofing it.

'Some people, when confronted with a problem, think "I know, I'll use 
regular expressions." Now they have two problems.' -  Jamie Zawinski.

Regards

Ian




From davea at davea.name  Mon Jan 12 15:17:08 2015
From: davea at davea.name (Dave Angel)
Date: Mon, 12 Jan 2015 15:17:08 -0500
Subject: Python 3 regex woes (parsing ISC DHCPD config)
In-Reply-To: <54B41073.30902@emerytelcom.com>
References: <54B41073.30902@emerytelcom.com>
Message-ID: <54B42BC4.8090204@davea.name>

On 01/12/2015 01:20 PM, Jason Bailey wrote:
> Hi all,
>

What changed between 1:03 and 1:20 that made you post a nearly identical 
second message, as a new thread?

>
> Unfortunately, I get no matches. From output on the command line, I can
> see that Python is adding extra backslashes to my re.compile string. I
> have added the raw 'r' in front of the strings to prevent it, but to no
> avail.
>

What makes you think that?  Please isolate this part of your problem 
with a simple short program, so we can diagnose it.  You're probably 
getting confused between str() and repr().  The latter adds backslash 
escape sequences for good reason, and if you don't understand it, you 
might think the strings are getting corrupted.


-- 
DaveA


From john_ladasky at sbcglobal.net  Mon Jan 12 15:25:40 2015
From: john_ladasky at sbcglobal.net (John Ladasky)
Date: Mon, 12 Jan 2015 12:25:40 -0800 (PST)
Subject: Namespace puzzle, list comprehension fails within class definition
Message-ID: <af9bb2fd-f0b9-4efb-874e-78f30ac65b7e@googlegroups.com>

I've never come across this before.  Here's a minimal example (in Python 3.4):


Code:
---------------------------------------------------------------------

d = {0:"a", 1:"b", 2:"c", 3:"d"}
e = [d[x] for x in (0,2)]

class Foo:
    f = {0:"a", 1:"b", 2:"c", 3:"d"}
    print(f)
    g = [f[x] for x in (0,2)]

foo = Foo()


Output:
---------------------------------------------------------------------

{0: 'a', 1: 'b', 2: 'c', 3: 'd'}

Traceback (most recent call last):
  File "minimal example.py", line 6, in <module>
    class Foo:
  File "minimal example.py", line 9, in Foo
    g = [f[x] for x in (0,2)]
  File "minimal example.py", line 9, in <listcomp>
    g = [f[x] for x in (0,2)]
NameError: name 'f' is not defined

---------------------------------------------------------------------

When I am working in the top-level namespace, I get no errors when referencing the dictionary, d, inside the list comprehension which generates e.

When I am working inside the class namespace, the print function call on line 8 recognizes the name f and prints the dictionary bound to that name.

However, the LIST COMPREHENSION defined inside the class namespace generates a NameError.

In all my years of Python programming, I guess that I have never tried to define a class attribute using a list comprehension.  Why doesn't it work?  Any advice, and suggestions for Pythonic workarounds, are appreciated.


From rosuav at gmail.com  Mon Jan 12 15:32:06 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 13 Jan 2015 07:32:06 +1100
Subject: Python 3 regex?
In-Reply-To: <54B42502.6050702@gmail.com>
References: <54B40C85.5000806@emerytelcom.com>
	<54B42502.6050702@gmail.com>
Message-ID: <CAPTjJmrEy40EckCsVbV2fmrYxGRR=dr3EiMjdXXZ6pdmpsLpcA@mail.gmail.com>

On Tue, Jan 13, 2015 at 6:48 AM, Ian <hobson42 at gmail.com> wrote:
> My recommendation would be to write a recursive decent parser for your
> files.
>
> That way will be easier to write, much easier to modify and almost certainly
> faster that a RE solution - and it can easily give you all the information
> in the file thus future proofing it.

Generally, even a recursive descent parser will be overkill. It's
pretty easy to do simple string manipulation to get the info you want;
maybe that means restricting the syntax some, but for a personal-use
script, that's usually no big cost. The example I gave requires that
the indentation be correct, and on this mailing list, I think people
agree that that's not a deal-breaker :)

ChrisA


From ethan at stoneleaf.us  Mon Jan 12 15:40:13 2015
From: ethan at stoneleaf.us (Ethan Furman)
Date: Mon, 12 Jan 2015 12:40:13 -0800
Subject: Namespace puzzle, list comprehension fails within class definition
In-Reply-To: <af9bb2fd-f0b9-4efb-874e-78f30ac65b7e@googlegroups.com>
References: <af9bb2fd-f0b9-4efb-874e-78f30ac65b7e@googlegroups.com>
Message-ID: <54B4312D.90009@stoneleaf.us>

On 01/12/2015 12:25 PM, John Ladasky wrote:
> d = {0:"a", 1:"b", 2:"c", 3:"d"}
> e = [d[x] for x in (0,2)]
> 
> class Foo:
>     f = {0:"a", 1:"b", 2:"c", 3:"d"}
>     print(f)
>     g = [f[x] for x in (0,2)]

In Foo 'f' is part of an unnamed namespace; the list comp 'g' has its own namespace, effectively making be a nonlocal;
class name lookup skips nonlocal namespaces.

Workaround:  use an actual for loop.

--
~Ethan~

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From john_ladasky at sbcglobal.net  Mon Jan 12 15:43:27 2015
From: john_ladasky at sbcglobal.net (John Ladasky)
Date: Mon, 12 Jan 2015 12:43:27 -0800 (PST)
Subject: Namespace puzzle, list comprehension fails within class definition
In-Reply-To: <af9bb2fd-f0b9-4efb-874e-78f30ac65b7e@googlegroups.com>
References: <af9bb2fd-f0b9-4efb-874e-78f30ac65b7e@googlegroups.com>
Message-ID: <74df17fd-b129-4207-86d8-965a93fa5ef9@googlegroups.com>

Following up to myself: I finally did the right keyword search, and found a relevant article:

http://stackoverflow.com/questions/13905741/accessing-class-variables-from-a-list-comprehension-in-the-class-definition

Maybe I HAVE tried to define a list comprehension inside a class definition before.  What I tried to do would have apparently worked in Python 2.  But in Python 3, the namespace behavior has changed (and I'm still reading the article to understand how and why).

I guess that I could define my objects as globals... now, why would Python force me into doing that? :^(


From john_ladasky at sbcglobal.net  Mon Jan 12 15:49:45 2015
From: john_ladasky at sbcglobal.net (John Ladasky)
Date: Mon, 12 Jan 2015 12:49:45 -0800 (PST)
Subject: Namespace puzzle, list comprehension fails within class definition
In-Reply-To: <mailman.17638.1421095249.18130.python-list@python.org>
References: <af9bb2fd-f0b9-4efb-874e-78f30ac65b7e@googlegroups.com>
 <mailman.17638.1421095249.18130.python-list@python.org>
Message-ID: <1ec8bc0a-9391-483b-9bea-a468f97d6798@googlegroups.com>

On Monday, January 12, 2015 at 12:41:30 PM UTC-8, Ethan Furman wrote:

> In Foo 'f' is part of an unnamed namespace; the list comp 'g' has its own namespace, effectively making be a nonlocal;
> class name lookup skips nonlocal namespaces.
> 
> Workaround:  use an actual for loop.

Thanks, Ethan.  That works.

As you can see from my other post, I've just discovered that the scoping rules for list comprehensions were changed between Py2 and Py3.


From rosuav at gmail.com  Mon Jan 12 15:51:23 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 13 Jan 2015 07:51:23 +1100
Subject: Namespace puzzle, list comprehension fails within class definition
In-Reply-To: <af9bb2fd-f0b9-4efb-874e-78f30ac65b7e@googlegroups.com>
References: <af9bb2fd-f0b9-4efb-874e-78f30ac65b7e@googlegroups.com>
Message-ID: <CAPTjJmodTbzWNLeqkN6QK2FVJOSKWcoNneoNKaG=56_YuaO=hA@mail.gmail.com>

On Tue, Jan 13, 2015 at 7:25 AM, John Ladasky
<john_ladasky at sbcglobal.net> wrote:
> When I am working inside the class namespace, the print function call on line 8 recognizes the name f and prints the dictionary bound to that name.
>
> However, the LIST COMPREHENSION defined inside the class namespace generates a NameError.

A list comp is defined with a function call:

>>> def f():
...  return [x*x for x in range(4)]
...
>>> dis.dis(f)
  2           0 LOAD_CONST               1 (<code object <listcomp> at
0x7fdf25981420, file "<stdin>", line 2>)
              3 LOAD_CONST               2 ('f.<locals>.<listcomp>')
              6 MAKE_FUNCTION            0
              9 LOAD_GLOBAL              0 (range)
             12 LOAD_CONST               3 (4)
             15 CALL_FUNCTION            1 (1 positional, 0 keyword pair)
             18 GET_ITER
             19 CALL_FUNCTION            1 (1 positional, 0 keyword pair)
             22 RETURN_VALUE

This prevents leakage of the iterator into the enclosing scope.
Personally, I think it's a hack to get around the fact that Python
doesn't have any concept of sub-function-scope (similar to the weird
hack in try/except); if it weren't for that, true nesting would be
easier. As it is, function definitions in class scope have a special
meaning, and that interferes a bit with list comps.

ChrisA


From ark at acm.org  Mon Jan 12 15:51:34 2015
From: ark at acm.org (Andrew Koenig)
Date: Mon, 12 Jan 2015 12:51:34 -0800 (PST)
Subject: I must be missing something obvious in installing Python 3.4.2...
In-Reply-To: <mailman.17632.1421087826.18130.python-list@python.org>
References: <ec7b8633-3b02-42b3-89e4-ef002ebd78e6@googlegroups.com>
 <mailman.17632.1421087826.18130.python-list@python.org>
Message-ID: <cd0407d9-33f4-4608-a29a-9103f491a6ad@googlegroups.com>

python --version reports 3.4.2, which is what I expected. I see no PYTHONPATH variable, or any environment variable with a name beginning PY (either upper or lower case).


From mail at timgolden.me.uk  Mon Jan 12 15:52:08 2015
From: mail at timgolden.me.uk (Tim Golden)
Date: Mon, 12 Jan 2015 20:52:08 +0000
Subject: I must be missing something obvious in installing Python 3.4.2...
In-Reply-To: <ec7b8633-3b02-42b3-89e4-ef002ebd78e6@googlegroups.com>
References: <ec7b8633-3b02-42b3-89e4-ef002ebd78e6@googlegroups.com>
Message-ID: <54B433F8.4020606@timgolden.me.uk>



On 12/01/2015 18:02, Andrew Koenig wrote:
> Downloaded and installed 64-bit Python 3.4 and pywin32-219. Both installed smoothly on my 64-bit Win7 machine. I added C:\Python34 to the search path.
>
> If I launch a Windows command window and run
>
>          python -m ensurepip
>
> I get the following:
>
> Ignoring indexes: https://pypi.python.org/simple/
> Downloading/unpacking setuptools
> Cleaning up...
> Exception:
> Traceback (most recent call last):
>    File "C:\Users\ark\AppData\Local\Temp\tmpe3ckts9f\pip-1.5.6-py2.py3-none-any.w
> hl\pip\basecommand.py", line 122, in main
>      status = self.run(options, args)
>    File "C:\Users\ark\AppData\Local\Temp\tmpe3ckts9f\pip-1.5.6-py2.py3-none-any.w
> hl\pip\commands\install.py", line 278, in run
>      requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundl
> e=self.bundle)
>    File "C:\Users\ark\AppData\Local\Temp\tmpe3ckts9f\pip-1.5.6-py2.py3-none-any.w
> hl\pip\req.py", line 1177, in prepare_files
>      url = finder.find_requirement(req_to_install, upgrade=self.upgrade)
>    File "C:\Users\ark\AppData\Local\Temp\tmpe3ckts9f\pip-1.5.6-py2.py3-none-any.w
> hl\pip\index.py", line 209, in find_requirement
>      file_locations, url_locations = self._sort_locations(locations)
>    File "C:\Users\ark\AppData\Local\Temp\tmpe3ckts9f\pip-1.5.6-py2.py3-none-any.w
> hl\pip\index.py", line 128, in _sort_locations
>      sort_path(os.path.join(path, item))
>    File "C:\Users\ark\AppData\Local\Temp\tmpe3ckts9f\pip-1.5.6-py2.py3-none-any.w
> hl\pip\index.py", line 109, in sort_path
>      if mimetypes.guess_type(url, strict=False)[0] == 'text/html':
>    File "C:\Python34\lib\mimetypes.py", line 287, in guess_type
>      init()
>    File "C:\Python34\lib\mimetypes.py", line 348, in init
>      db.read_windows_registry()
>    File "C:\Python34\lib\mimetypes.py", line 255, in read_windows_registry
>      with _winreg.OpenKey(hkcr, subkeyname) as subkey:
> TypeError: OpenKey() argument 2 must be str without null characters or None, not
>   str

Ouch! That looks like another variation on a bug of which we've fixed at 
least two variations to do with reading mimetypes from the Windows 
registry. Can you see what the following code produces, please:

<code>
import winreg as _winreg

hkcr = _winreg.OpenKey(_winreg.HKEY_CLASSES_ROOT, "")

with open("classes.txt", "w") as f:
     i = 0
     while True:
         try:
             ctype = _winreg.EnumKey(hkcr, i)
         except EnvironmentError:
             break
         else:
             f.write("%s -> %r\n" % (type(ctype), ctype))

         i += 1

</code>

TJG


From joboppsgpp at gmail.com  Mon Jan 12 16:19:18 2015
From: joboppsgpp at gmail.com (joboppsgpp at gmail.com)
Date: Mon, 12 Jan 2015 13:19:18 -0800 (PST)
Subject: Broken IF statement
Message-ID: <dd384c6d-17c0-4850-ad5b-6b073c80bdb8@googlegroups.com>

https://bpaste.net/show/93be9e15634b <--- Line 19 through 22

At all times, my program is assigning the object priority of 0, even if one already exists in the database with a priority of 0 (it's supposed to be assigning it a priority of 1 in those cases).

I'm a non developer trying to fix a freelancer's code. Would anybody be able to suggest changes to the IF logic that might be able to fix it, assuming the statements in the code provided look flawed?

Thanks...


From rosuav at gmail.com  Mon Jan 12 16:40:49 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 13 Jan 2015 08:40:49 +1100
Subject: Broken IF statement
In-Reply-To: <dd384c6d-17c0-4850-ad5b-6b073c80bdb8@googlegroups.com>
References: <dd384c6d-17c0-4850-ad5b-6b073c80bdb8@googlegroups.com>
Message-ID: <CAPTjJmr4-mG9gRNZYpXM16UsgwG0K07noevCebw9sAwt6wAc2w@mail.gmail.com>

On Tue, Jan 13, 2015 at 8:19 AM,  <joboppsgpp at gmail.com> wrote:
> https://bpaste.net/show/93be9e15634b <--- Line 19 through 22
>
> At all times, my program is assigning the object priority of 0, even if one already exists in the database with a priority of 0 (it's supposed to be assigning it a priority of 1 in those cases).
>
> I'm a non developer trying to fix a freelancer's code. Would anybody be able to suggest changes to the IF logic that might be able to fix it, assuming the statements in the code provided look flawed?

Normally, I would suggest talking to the freelancer who wrote the
code, unless you're no longer working with him/her. Changing someone's
code out from under them is a great way to annoy and confuse.

Including the text in-line as it's short enough for that:

def create_socialaccount(profile, urls, twitters, facebooks, statuses=None):
    """
    Add or update all the social accounts linked to the 'profile'
    """
    results = []
    l = [(urls, SocialAccount.HOMEPAGE, HOMEPAGE_COL_START),
         (twitters, SocialAccount.TWITTER, TWITTER_COL_START),
         (facebooks, SocialAccount.FACEBOOK, FACEBOOK_COL_START)]
    for objs, service, offset in l:
        for i, value in enumerate(objs):
            if value:
                obj, created = SocialAccount.objects.get_or_create(
                    social_profile=profile,
                    service=service,
                    value=value,
                )
                # The first object added/updated gets a priority of 0, all
                # others get a 1
                if i == 0:
                    obj.priority = 0
                else:
                    obj.priority = 1


What kind of object is this 'obj'? After you make a change to it, do
you need to tell it to write to a database or something?

What you could try is changing the priority assignments to, say, 2 and
3. That would tell you that it's making the change. But if the
intention is to have the first successful one at priority 0 and all
others at priority 1 (which is what the comment implies), then I'd
write it like this:

def create_socialaccount(profile, urls, twitters, facebooks, statuses=None):
    """
    Add or update all the social accounts linked to the 'profile'
    """
    l = [(urls, SocialAccount.HOMEPAGE, HOMEPAGE_COL_START),
         (twitters, SocialAccount.TWITTER, TWITTER_COL_START),
         (facebooks, SocialAccount.FACEBOOK, FACEBOOK_COL_START)]
    for objs, service, offset in l:
        prio = 0
        for value in objs:
            if value:
                obj, created = SocialAccount.objects.get_or_create(
                    social_profile=profile,
                    service=service,
                    value=value,
                )
                # The first object added/updated gets a priority of 0, all
                # others get a 1
                obj.priority = prio
                prio = 1

It's not clear whether "first" means "first of each type" or "first
overall". For instance, if someone has three twitters and two
facebooks, should one twitter and one facebook be given priority 0, or
should one twitter get prio 0 and everything else prio 1? I've coded
it for the former, but you could easily make it the latter by simply
shifting the "prio = 0" statement one line further up (and unindenting
it), thus putting it before the entire loop.

Does that help, at all?

ChrisA


From ark at acm.org  Mon Jan 12 16:45:25 2015
From: ark at acm.org (Andrew Koenig)
Date: Mon, 12 Jan 2015 13:45:25 -0800 (PST)
Subject: I must be missing something obvious in installing Python 3.4.2...
In-Reply-To: <mailman.17640.1421095928.18130.python-list@python.org>
References: <ec7b8633-3b02-42b3-89e4-ef002ebd78e6@googlegroups.com>
 <mailman.17640.1421095928.18130.python-list@python.org>
Message-ID: <4723ce7c-53ec-463b-b270-63241305f867@googlegroups.com>

It runs and creates a classes.txt file with 803 lines. The first few:

<class 'str'> -> '$cpfile12'
<class 'str'> -> '$crfile12'
<class 'str'> -> '$cxfile12'
<class 'str'> -> '*'
<class 'str'> -> '.$cp'
<class 'str'> -> '.$cr'
<class 'str'> -> '.$cx'
<class 'str'> -> '.386'
<class 'str'> -> '.3ds'

A few lines in the middle that might be relevant:

<class 'str'> -> '.py'
<class 'str'> -> '.pyc'
<class 'str'> -> '.pyo'
<class 'str'> -> '.pys'
<class 'str'> -> '.pyw'

And the last few:

<class 'str'> -> '{C7A40493-BF23-4B53-AB2A-4A923B3EE34B}\x00'
<class 'str'> -> '{E14E55A7-29C8-4389-8E5A-3EF964510FCA}\x00'
<class 'str'> -> '{F5E30566-7C8F-4037-A8FF-A7382E251C56}\x00'

Anything in particular I should be looking for?


From joboppsgpp at gmail.com  Mon Jan 12 16:55:30 2015
From: joboppsgpp at gmail.com (joboppsgpp at gmail.com)
Date: Mon, 12 Jan 2015 13:55:30 -0800 (PST)
Subject: Broken IF statement
In-Reply-To: <mailman.17641.1421099337.18130.python-list@python.org>
References: <dd384c6d-17c0-4850-ad5b-6b073c80bdb8@googlegroups.com>
 <mailman.17641.1421099337.18130.python-list@python.org>
Message-ID: <ae5a458e-2914-4cd3-81f0-a3b93eab1a14@googlegroups.com>

Thanks Chris. This definitely helps. I will test it and see what happens. In terms of the previous code, what it was intended to do wasn't actually happening. 


From fomcl at yahoo.com  Mon Jan 12 16:58:25 2015
From: fomcl at yahoo.com (Albert-Jan Roskam)
Date: Mon, 12 Jan 2015 21:58:25 +0000 (UTC)
Subject: Python 3 regex woes (parsing ISC DHCPD config)
In-Reply-To: <54B41073.30902@emerytelcom.com>
References: <54B41073.30902@emerytelcom.com>
Message-ID: <2048656795.13463.1421099905222.JavaMail.yahoo@jws10748.mail.gq1.yahoo.com>



----- Original Message -----

> From: Jason Bailey <jbailey at emerytelcom.com>
> To: python-list at python.org
> Cc: 
> Sent: Monday, January 12, 2015 7:20 PM
> Subject: Python 3 regex woes (parsing ISC DHCPD config)
> 
> Hi all,
> 
> I'm working on a Python _3_ project that will be used to parse ISC DHCPD 
> configuration files for statistics and alarming purposes (IP address 
> pools, etc). Anyway, I'm hung up on this one section and was hoping 
> someone could provide me with some insight.
> 
> My script first reads the DHCPD configuration file into memory - 
> variable "filebody". It then utilizes the re module to find the 
> configuration details for the wanted "shared network".
> 
> The config file might look something like this:
> 
> ######################################
> 
> shared-network My-Network-MOHE {
>    subnet 192.168.0.0 netmask 255.255.248.0 {
>      option routers 192.168.0.1;
>      option tftp-server-name "192.168.90.12";
>      pool {
>        deny dynamic bootp clients;
>        range 192.168.0.20 192.168.7.254;
>      }
>    }
> }
> 
> shared-network My-Network-CDCO {
>    subnet 192.168.8.0 netmask 255.255.248.0 {
>      option routers 10.101.8.1;
>      option tftp-server-name "192.168.90.12";
>      pool {
>        deny dynamic bootp clients;
>        range 192.168.8.20 192.168.15.254;
>      }
>    }
> }
> 
> shared-network My-Network-FECO {
>    subnet 192.168.16.0 netmask 255.255.248.0 {
>      option routers 192.168.16.1;
>      option tftp-server-name "192.168.90.12";
>      pool {
>        deny dynamic bootp clients;
>        range 192.168.16.20 192.168.23.254;
>      }
>    }
> }
> 
> ######################################
> 
> Suppose I'm trying to grab the shared network called 
> "My-Network-FECO" 
> from the above config file stored in the variable 'filebody'.
> 
> First I have my variable 'shared_network' which contains the string 
> "My-Network-FECO".
> 
> I compile my regex:
> m = re.compile(r"^(shared\-network (" + re.escape(shared_network) 
> + r") 
> \{((\n|.|\r\n)*?)(^\}))", re.MULTILINE|re.UNICODE)
> 
> I search for regex matches in my config file:
> m.search(filebody)
> 
> Unfortunately, I get no matches. From output on the command line, I can 
> see that Python is adding extra backslashes to my re.compile string. I 
> have added the raw 'r' in front of the strings to prevent it, but to no 
> avail.
> 
> Thoughts on this?


Will the following work for you? My brain shuts down when I try to read your regex, but I believe you also used a non-greedy match.


Python 3.4.2 (default, Nov 20 2014, 13:01:11) 
[GCC 4.7.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> cfg = """shared-network My-Network-MOHE {
...   subnet 192.168.0.0 netmask 255.255.248.0 {
...     option routers 192.168.0.1;
...     option tftp-server-name "192.168.90.12";
...     pool {
...       deny dynamic bootp clients;
...       range 192.168.0.20 192.168.7.254;
...     }
...   }
... }
... 
... shared-network My-Network-CDCO {
...   subnet 192.168.8.0 netmask 255.255.248.0 {
...     option routers 10.101.8.1;
...     option tftp-server-name "192.168.90.12";
...     pool {
...       deny dynamic bootp clients;
...       range 192.168.8.20 192.168.15.254;
...     }
...   }
... }
... 
... shared-network My-Network-FECO {
...   subnet 192.168.16.0 netmask 255.255.248.0 {
...     option routers 192.168.16.1;
...     option tftp-server-name "192.168.90.12";
...     pool {
...       deny dynamic bootp clients;
...       range 192.168.16.20 192.168.23.254;
...     }
...   }
... }"""
>>> import re
>>> re.findall(r"shared\-network (.+) \{?", cfg)
['My-Network-MOHE', 'My-Network-CDCO', 'My-Network-FECO']
>>> 


From mail at timgolden.me.uk  Mon Jan 12 17:00:22 2015
From: mail at timgolden.me.uk (Tim Golden)
Date: Mon, 12 Jan 2015 22:00:22 +0000
Subject: I must be missing something obvious in installing Python 3.4.2...
In-Reply-To: <4723ce7c-53ec-463b-b270-63241305f867@googlegroups.com>
References: <ec7b8633-3b02-42b3-89e4-ef002ebd78e6@googlegroups.com>
 <mailman.17640.1421095928.18130.python-list@python.org>
 <4723ce7c-53ec-463b-b270-63241305f867@googlegroups.com>
Message-ID: <54B443F6.6060309@timgolden.me.uk>



On 12/01/2015 21:45, Andrew Koenig wrote:
> It runs and creates a classes.txt file with 803 lines. The first few:
>
> <class 'str'> -> '$cpfile12'
> <class 'str'> -> '$crfile12'
> <class 'str'> -> '$cxfile12'
> <class 'str'> -> '*'
> <class 'str'> -> '.$cp'
> <class 'str'> -> '.$cr'
> <class 'str'> -> '.$cx'
> <class 'str'> -> '.386'
> <class 'str'> -> '.3ds'
>
> A few lines in the middle that might be relevant:
>
> <class 'str'> -> '.py'
> <class 'str'> -> '.pyc'
> <class 'str'> -> '.pyo'
> <class 'str'> -> '.pys'
> <class 'str'> -> '.pyw'
>
> And the last few:
>
> <class 'str'> -> '{C7A40493-BF23-4B53-AB2A-4A923B3EE34B}\x00'
> <class 'str'> -> '{E14E55A7-29C8-4389-8E5A-3EF964510FCA}\x00'
> <class 'str'> -> '{F5E30566-7C8F-4037-A8FF-A7382E251C56}\x00'
>
> Anything in particular I should be looking for?
>

I was actually expecting to see something like a byestring, but in fact 
those last few items look suspicious with their trailing NULs. The 
mimetypes code tries to open each key to find its associated mimetype(s) 
and would probably fail on those.

The PyArg_ParseTupleAndKeywords in OpenKey is using the "Z" pattern for 
its first parameter which disallows embedded NULs. Obviously we can 
trap-and-skip within the mimetypes code but that won't help you 
immediately (short of your patching your own lib/mimetypes).

Is it possible to temporarily rename those keys out of the way, or to 
strip their trailing NULs to see if the problem goes away?

TJG



From andrew3 at r3dsolutions.com  Mon Jan 12 17:27:48 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Mon, 12 Jan 2015 14:27:48 -0800
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54ADC99F.3020405@stoneleaf.us>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
Message-ID: <54B44A64.7010105@r3dsolutions.com>


On 01/07/2015 04:04 PM, Ethan Furman wrote:
> On 01/06/2015 07:37 PM, Andrew Robinson wrote:
>
>> Explain; How does mere subclassing of bool break the contract that bool has?
>> eg: What method or data would the superclass have that my subclass would not?
> bool's contract is that there are only two values (True and False) and only one instance each of those two values (True
> and False).  If bool were subclassable, new values could be added with either completely different values (PartTrue) or
> with more of the same value (True, ReallyTrue, AbsolutelyTrue) -- hence, broken contract.
>
> --
> ~Ethan~
>
>
>
Huh? I'm not adding any values when I merely subclass bool ; and even if 
the subclass could be instantiated -- that's doesn't mean a new value or 
instance of the base class (bool) must exist.  For I could happily work 
with a new subclass that contains no new data, but only an already 
_existing instance_ of 'True' or 'False_'_ as its value source.   That 
means there is no new value...  but at most (and even that could be 
worked around) a new instance of a subclass containing an existing 
instance of it's base class.

Note:  Guido only mentioned that he didn't want multiple instances of 
the base class bool -- But that's not technically the same as objecting 
to a subclass having an instance which CONTAINS an original bool 
instance and not a new one.

There are other ways Guido could have modified the Python language to 
prevent creation of new values without preventing the creation of a 
subclass --  if that's what he was really after....    So -- no -- I 
disagree with you.

Subclassing is allowed in many other OOP languages (not just C++) when 
working with singletons, and dualtons, n-tons... and the very PURPOSE of 
those objects is to prevent multiple instances, or spreading of 
control.  BUT -- Most object oriented languages I know of -- allow as 
standard practice, subclassing of n-tons -- while (often) simultaneously 
controlling or even eliminating the number of instances a subclass may 
have / and or the values it may take.  eg: depending on how flexible the 
type/class definition of a language is -- languages handle sub-classing 
of singletons differently.

Besides, a contract for a class can only be assumed to be valid for code 
designed for that specific class -- not code made for a subclass;  The 
contract for bool simply says nothing about programs designed for any 
other classes that bool is found inside of -- either as a subclass or a 
subelement;  eg:  I can still put bool inside another object with 
different methods: eg: I just write: (False,) as proof -- so Guido 
couldn't possibly have been trying to limit the methods which can 
operate on bool or the number of links to bool.

So I don't understand why Guido cared to restrict subclassing of bool -- 
and what the contract you mention has to do with it --  eg: what was his 
actual goal ?  Was it memory conservation, or compatability of built-in 
return types -- or what ?  There is no written 'contract' saying exactly 
what Guido's design objectives were in detail and more importantly 
'WHY';  but Guido only said that subclassing instances allowed a 'back 
door' (not that subclassiing itself was bad, just that it allowed some 
side effect...) to whatever Guido really didn't want to happen.

Python generally allows subclassing of singleton instances; so that 
makes 'bool' is an arbitrary exception to the general rule which Guido 
decided  to make... and he did so without any very clear explanation as 
to why.  eg: he cited what C/C++ *must *do as part of his reasoning -- 
but C/C++ can apparently do something that Guido  thought it couldn't 
(Guido was flat wrong).... and for that reason, I really wonder if 
Guido's decision was some kind of spur of the moment erroneous epiphany 
-- bolstered by the fact that he said "I realized last night..." like 
something he had never thought of before, or thought through carefully....

https://mail.python.org/pipermail/python-dev/2002-March/020822.html


And worse, Guido's problem even apparently extends to making 'duck 
types' which other writers in this thread have been proposing I do. eg: 
They, too, are going against canonical Guido's epiphany night...

Of course, you can define your own subclass of int similar to the bool
class I show in the PEP, and you can give it any semantics you want --
but that_would also defeat the purpose of having a standard bool_.

Not to mention, that Charles Bool's two initial values True and False 
are NOT the only ones used in computer engineering and science; for 
boolean logic only became useful at a time when engineers and 
mathematicians realized that at least a third type, AKA: 'Don't care' -- 
was necessary for doing correctness testing of logic in a tractable 
way.   So -- Guido arbitrarily chose to make bool based on a historical 
curiosity that never has been mainstream in logic analysis.  eg: He 
based it on a beta quality revision of boolean theory....    Look at any 
logic design and testing package -- such as silos Three, or verilog, or 
VHDL, UHDL, etc.  and all of them support tri-state logic with at least 
one 'don't care' state for boolean logic.

But setting that all aside....

I've already said that I don't actually need an instance of the 
subclass... but you (and others) repeatedly ignore what I'm saying. So, 
let me try to give a crude example of alternative routes an OOP language 
like Python COULD take....

Consider -- There are generic alternatives to class instances in many 
OOP languages; eg: making proxy or wrapper objects.

These are not foreign ideas in Python; though it implements them too 
crudely for my use or else there is a trick to the Python versions I 
haven't figured out yet -- but none the less, Python already creates 
proxy objects ( CF: super() ) ; so it's not a foreign idea.

For my purposes;  At minimum I need a wrapper and proxy object (both) 
which can be passed in lieu of a an actual bool or subclass of bool; eg: 
it holds an actual False or True object (the super), and can pass the 
test whenever a user attempts an 'isinstance( mybinding, bool )' for 
type checking; but fails whenever it is examined by  'is' True or 'is' 
False;  Python can almost do what I want -- but not quite -- because the 
existing proxys are not quite as transparent as they need to be; but 
it's very close:

 >>> a=super(True,int)
 >>> isinstance( a.__self__, bool )
True
 >>> a is bool
False

So -- since it can't be done, the next best thing is some kind of 
wrapper object acting as a proxy;
As a first attempt -- I'll override the comparison operators in a 
generic way to 'make' a more generic proxy:

def _op(op,other): # Call an operation, insuring iterable is second arg.
         try: other[0]
         except: return op((other,))
         return op(other)

class ETuple(tuple):
     """
     Enhanced Tuple.
     A tuple which does rich comparisons even when the item being
     compared against is not an iterable by converting non iterables to
     tuples of length, exactly one.
     """
     def __new__(cls, data):return super(ETuple,cls).__new__(cls,data)
     def __eq__(self,other):return _op(super(ETuple,self).__eq__,other)
     def __ne__(self,other):return _op(super(ETuple,self).__ne__,other)
     def __lt__(self,other):return _op(super(ETuple,self).__lt__,other)
     def __le__(self,other):return _op(super(ETuple,self).__le__,other)
     def __gt__(self,other):return _op(super(ETuple,self).__gt__,other)
     def __ge__(self,other):return _op(super(ETuple,self).__ge__,other)
     def __cmp__(self,other):return _op(super(ETuple,self).__cmp__,other)
     def __nonzero__(self,other):return 
_op(super(ETuple,self).__cmp__,other)


Now, I can do:
 >>> (False,) == False
True
and:
 >>> (False,) is False
False
 >>> PartFalse = (False,)
 >>> PartFalse == False
True
 >>> PartFalse == PartTrue
False

and, it's clear that I am not creating a new instance of 'bool;' -- for 
PartFalse is not a new instance of bool, it is (under rich comparison), 
exactly equivalent to a bool.  eg: a duck type under rich comparison.
Therefore, RBool acts exactly like a bool for traditional code in a 
nearly transparent way (proxy idea) -- but still allows detection of the 
wrapper by 'is' so that newer code can take advantage of a refined 
definition of falseness...

So,  If Etuple was a subclass of 'bool', instead of just tuple -- and 
was restricted to wrap ONLY an existing bool (perhaps as an enhancement 
to the class definition...) -- it would achieve all my design goals;  so 
your objection that it is a new value would simply be false.  It would 
merely be a wrapper of an existing bool that passes the type check 
isinstance( bool, ETuple(False) ) --> True .

Why was it so important to Guido to make this impossible???
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From fabien.maussion at gmail.com  Mon Jan 12 17:35:01 2015
From: fabien.maussion at gmail.com (Fabien)
Date: Mon, 12 Jan 2015 23:35:01 +0100
Subject: What does "pip install" do?
Message-ID: <m91i6i$3ft$1@speranza.aioe.org>

Folks,

I've learned a lot today about python packaging and stuff, thanks to a 
couple of good websites. I've learned how to install a package from PyPi 
with pip, choose which version, upgrade it, uninstall it, use 
virtualenv, BUT I'm still asking myself: what does "pip install" 
*concretely* do on my virtual environment?

It seems to add a directory in the /site-packages directory, but what 
does it do when for example command-line scripts are shipped with it? Is 
something else happening in the background?

Neither does the "Python Packaging Authority" website 
(https://pip.pypa.io/en/latest/user_guide.html) nor the 
"python-packaging-user-guide" 
(http://python-packaging-user-guide.readthedocs.org/en/latest/installing.html) 
nor the "Installing python packages" from the python docs 
(https://docs.python.org/3/installing/) seem to provide an answer to 
this question.

Or did I simply miss it?

Thanks!

Fabien


From ark at acm.org  Mon Jan 12 17:35:33 2015
From: ark at acm.org (Andrew Koenig)
Date: Mon, 12 Jan 2015 14:35:33 -0800 (PST)
Subject: I must be missing something obvious in installing Python 3.4.2...
In-Reply-To: <mailman.17642.1421100022.18130.python-list@python.org>
References: <ec7b8633-3b02-42b3-89e4-ef002ebd78e6@googlegroups.com>
 <mailman.17640.1421095928.18130.python-list@python.org>
 <4723ce7c-53ec-463b-b270-63241305f867@googlegroups.com>
 <mailman.17642.1421100022.18130.python-list@python.org>
Message-ID: <6474bfec-ce53-4967-8a76-5bedda9110a8@googlegroups.com>

Not sure that would be a good idea: There are 22 such keys, as opposed to only two keys with Windows ID strings that don't end in nulls. I found this article:

http://www.swarley.me.uk/blog/2014/04/23/python-pip-and-windows-registry-corruption/

with the comment "If you are happy to completely remove any problematic keys, and accept any associated breakages that may occur, then this is the easiest solution."

I am concerned that if I change these keys, something else might break and I have no easy way of figuring out what.


From rosuav at gmail.com  Mon Jan 12 17:35:43 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 13 Jan 2015 09:35:43 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54B44A64.7010105@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
Message-ID: <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>

On Tue, Jan 13, 2015 at 9:27 AM, Andrew Robinson
<andrew3 at r3dsolutions.com> wrote:
> Huh? I'm not adding any values when I merely subclass bool ; and even if the
> subclass could be instantiated -- that's doesn't mean a new value or
> instance of the base class (bool) must exist.  For I could happily work with
> a new subclass that contains no new data, but only an already existing
> instance of 'True' or 'False' as its value source.   That means there is no
> new value...  but at most (and even that could be worked around) a new
> instance of a subclass containing an existing instance of it's base class.

If you subclass bool and instantiate your subclass, you have made a
new instance of bool, because every instance of a subclass is an
instance of its superclass. The Python bool type has the following
invariant, for any object x:

assert not isinstance(x, bool) or x is True or x is False

(You can fiddle with this in Py2 by rebinding the names True and
False, but you could replace those names with (1==1) and (1==0) if you
want to be completely safe. Likewise, the name "bool" could be
replaced with (1==1).__class__ to avoid any stupidities there. But
conceptually, that's the invariant.)

Subclassing bool breaks this invariant, unless you never instantiate
the subclass, in which case it's completely useless.

ChrisA


From rosuav at gmail.com  Mon Jan 12 17:46:46 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 13 Jan 2015 09:46:46 +1100
Subject: What does "pip install" do?
In-Reply-To: <m91i6i$3ft$1@speranza.aioe.org>
References: <m91i6i$3ft$1@speranza.aioe.org>
Message-ID: <CAPTjJmpUO7pnXrEk3qo29Qz=dXWFRoV4VhbuNeub1hpz3QOyjA@mail.gmail.com>

On Tue, Jan 13, 2015 at 9:35 AM, Fabien <fabien.maussion at gmail.com> wrote:
>
> I've learned a lot today about python packaging and stuff, thanks to a
> couple of good websites. I've learned how to install a package from PyPi
> with pip, choose which version, upgrade it, uninstall it, use virtualenv,
> BUT I'm still asking myself: what does "pip install" *concretely* do on my
> virtual environment?

As far as I know, it's equivalent to three steps:

1) Download the appropriate version of a package (the latest, if you
didn't say otherwise)
2) Extract that package
3) Run 'python setup.py'.

What setup.py does is up to the package, but for a pure-Python package
it should simply create something in site-packages. It might do a lot
more, though - compiling C or Fortran code, for instance.

ChrisA


From emile at fenx.com  Mon Jan 12 18:10:39 2015
From: emile at fenx.com (Emile van Sebille)
Date: Mon, 12 Jan 2015 15:10:39 -0800
Subject: Reg: scrappring error
In-Reply-To: <CAL7yq01BANKQdQ7Nmt3jHfu1+JgwHDA8EsCS-cyy9hjfdLk70w@mail.gmail.com>
References: <CAL7yq01BANKQdQ7Nmt3jHfu1+JgwHDA8EsCS-cyy9hjfdLk70w@mail.gmail.com>
Message-ID: <m91k9n$h76$1@ger.gmane.org>

On 1/11/2015 9:27 PM, Sushanth wrote:
<SNIP>

> urllib2.HTTPError: HTTP Error 302: The HTTP server returned a redirect
> error that would lead to an infinite loop.

Looks like the server has a link on this page pointing back to itself or 
somesuch.

Does this help?

Emile




From ark at acm.org  Mon Jan 12 18:12:33 2015
From: ark at acm.org (Andrew Koenig)
Date: Mon, 12 Jan 2015 15:12:33 -0800 (PST)
Subject: I must be missing something obvious in installing Python 3.4.2...
In-Reply-To: <6474bfec-ce53-4967-8a76-5bedda9110a8@googlegroups.com>
References: <ec7b8633-3b02-42b3-89e4-ef002ebd78e6@googlegroups.com>
 <mailman.17640.1421095928.18130.python-list@python.org>
 <4723ce7c-53ec-463b-b270-63241305f867@googlegroups.com>
 <mailman.17642.1421100022.18130.python-list@python.org>
 <6474bfec-ce53-4967-8a76-5bedda9110a8@googlegroups.com>
Message-ID: <f49c0c9c-09ab-4aec-8dbc-253d78170f9f@googlegroups.com>

Fixed it!

The aforementioned article is correct. I downloaded the RegDelNull program mentioned in the article (http://technet.microsoft.com/en-us/sysinternals/bb897448.aspx) and ran it on hkcr, hkcu, hklm, hku, and hkcc (short for HKEY_CLASSES_ROOT, HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, HKEY_USERS, and HKEY_CURRENT_CONFIG), respectively. It deleted a bunch of keys. Rerunning the program you posted earlier revealed no keys with embedded nulls in their names, and ensurepip now works.

I have no idea how these keys got there. For all I know they are the result of malware.

I think it would be worthwhile changing the Python code to detect nulls and perhaps issue a warning that directs people to this article or something like it.


From rantingrickjohnson at gmail.com  Mon Jan 12 18:47:08 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Mon, 12 Jan 2015 15:47:08 -0800 (PST)
Subject: Python 3 regex?
In-Reply-To: <mailman.17635.1421092112.18130.python-list@python.org>
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
Message-ID: <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>

> 'Some people, when confronted with a problem, think "I
> know, I'll use regular expressions." Now they have two
> problems.' -  Jamie Zawinski.

This statement is one of my favorite examples of "powerful
propaganda", which has scared more folks away from regexps
than even the "Upright Citizens Brigade" could manage with
their "Journey through the center of gas giant #7" and it's
resulting "aggravated assault" on American coinage!

I wonder if Jamie's conclusions are a result of careful
study, or merely, an attempt to resolve his own cognitive
dissonance? Of course, if the latter is true, then i give
him bonus points for his use of the third person to veil his
own inadequacies -- nice Jamie, *verrrrry* nice!

    "Rick it sounds like you're accusing Jamie of cowardice
    resulting in "sour grapes"?"

Indeed! The problem with statements like his is that, the
ironic humor near the end *fortifies* the argument so much
that the reader forgets the limits of the harm (quantified
as: "some people") and immediately accepts the consequences
as effecting "all people who choose to use regexps", or more
generally, accepts the argument as a "universal unbounded
truth". Besides, who would want to be a member of a group
for which the individuals are too stupid to know good
choices from bad choices?

    HA, PEER PRESSURE, IT'S A POWERFUL THING!

But there is more going on here than just mere "slight of
forked tongue" my friends, because, even the most
accomplished propagandist cannot fool *most* of the people.
No, this type of "powerful propaganda" only succeeds when
the subject matter is both cryptic *AND* esoteric.

For instance, in the following example, i contrive a
similarly ironic statement to showcase the effects of such
propaganda, but one that covers a subject matter in which
laymen either: already understand, or, can easily attain
"enough knowledge" to appreciate the humor.

    ############################################################
    #                       Ironic Twist                       #
    ############################################################
    # Some diabetics, when confronted with hunger, think "I    #
    # know, I'll eat a box of sugar cookies." -- now they have #
    # two problems!'                                           #
    ############################################################

    "Wait a minute Rick! After eating the cookies the
    diabetic would not longer be hungry, so how could he
    have two problems? Your logic is flawed!

    Au Contraire! Read the statement carefully, I said:
    "When *CONFRONTED* with hunger" -- the two problems
    (and the eventual side effect) exist at the *MOMENT* the
    diabetic considers eating the cookies.

        PROBLEM1: Need to eat!
        PROBLEM2: Cookies raise glucose too quickly

In this example, even a layman would understand that the
statement is meant to showcase the irony of resolving a
problem (hunger) with a solution (eating a box of cookies)
that results in the undesirable outcome of (hyperglycemia).

And while this statement, and the one about regexps, both
contain a "factual underlying truth" (basically that
negative side effects should be avoided) the layman will
lack the esoteric knowledge of regexps to confirm the
factual basis for himself, and will instead blindly adopt
the propagandist assertion as truth, based solely on the
humorous prowess of the propagandist.

The most effective propaganda utilizes the sub-conscience.
You see, the role of propaganda is to "modify behavior", and
it is a more prevalent and powerful tool than most people
realize! The propagandist will seek to control you; he'll
use your ignorance against you; but you didn't notice
because he made you laugh!

    WHO'S LAUGHING NOW? -- YOU MINDLESS ROBOTS!

    "But what's so evil about that Rick? He scared away a
    few feeble minded folks. SO WHAT!

I argue that we are all "feeble minded" in any subject we
have not yet mastered. His propaganda (be it intentional or
not) is so powerful that it defeats the neophyte before they
can even begin. Because it gives them the false impression
that regexps are only used by foolish people.

Yes, i'll admit, regexps are very cryptic, but once you
grasp their intricacies, you appreciate the succinctness of
there syntax, because, what makes them so powerful is not
only the extents of their pattern matching abilities, but
their conciseness.



From rosuav at gmail.com  Mon Jan 12 18:52:23 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 13 Jan 2015 10:52:23 +1100
Subject: Python 3 regex?
In-Reply-To: <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
Message-ID: <CAPTjJmpeY=TsKxp=xvJEea__Y0Yc__up0vFK_PDcJr8keyfwLA@mail.gmail.com>

On Tue, Jan 13, 2015 at 10:47 AM, Rick Johnson
<rantingrickjohnson at gmail.com> wrote:
>     WHO'S LAUGHING NOW? -- YOU MINDLESS ROBOTS!

It's very satisfying when mindless robots laugh.

ChrisA


From breamoreboy at yahoo.co.uk  Mon Jan 12 20:54:55 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Tue, 13 Jan 2015 01:54:55 +0000
Subject: Python 3 regex?
In-Reply-To: <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
Message-ID: <m91ttg$fio$1@ger.gmane.org>

On 12/01/2015 23:47, Rick Johnson wrote:
>> 'Some people, when confronted with a problem, think "I
>> know, I'll use regular expressions." Now they have two
>> problems.' -  Jamie Zawinski.
>

[normal cobblers snipped]

If you wish to use a hydrogen bomb instead of a tooth pick feel free, I 
won't lose any sleep over it.  Meanwhile I'll get on with writing code, 
and for the simple jobs that can be completed with string methods I'll 
carry on using them.  When that gets too complicated I'll reach for the 
regex manual, knowing full well that there's enough data in books and 
online to help even a novice such as myself get over all the hurdles. 
If that isn't good enough then maybe a full blown parser, such as the 
pile listed here http://nedbatchelder.com/text/python-parsers.html ?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From andrew3 at r3dsolutions.com  Mon Jan 12 20:59:42 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Mon, 12 Jan 2015 17:59:42 -0800
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
Message-ID: <54B47C0E.208@r3dsolutions.com>


On 01/12/2015 02:35 PM, Chris Angelico wrote:
> On Tue, Jan 13, 2015 at 9:27 AM, Andrew Robinson
> <andrew3 at r3dsolutions.com> wrote:
>> Huh? I'm not adding any values when I merely subclass bool ; and even if the
>> subclass could be instantiated -- that's doesn't mean a new value or
>> instance of the base class (bool) must exist.  For I could happily work with
>> a new subclass that contains no new data, but only an already existing
>> instance of 'True' or 'False' as its value source.   That means there is no
>> new value...  but at most (and even that could be worked around) a new
>> instance of a subclass containing an existing instance of it's base class.
Hmmm....
That may be true in python, as it is now, but that doesn't mean that 
Guido had to leave it that way when he decided to change the language to 
single out bool, and make it's subclassing rules abnormal in the first 
place.
He was changing the language when he made the decision after all !!

What I am wanting to know is WHY did Guido think it so important to do 
that ?   Why was he so focused on a strict inability to have any 
instances of a bool subclass at all -- that he made a very arbitrary 
exception to the general rule that base types in Python can be subclassed ?

There's no reason in object oriented programming principles in general 
that requires a new subclass instance to be a COMPLETELY DISTINCT 
instance from an already existing superclass instance.... nor, have I 
ever seen Guido say that Python is designed intentionally to force this 
to always be the case... so I'm not sure that's its anything more than a 
non guaranteed implementation detail that Python acts the way you say it 
does....

I don't see, within Python, an intrinsic reason (other than lack of 
support/foresight in the historical evolution of Python to date), as to 
why a subclass couldn't be instanted with the data coming from an 
*already* existing instance of it's superclass.

There is no need to copy data from an initialized superclass instance 
into a subclass instance that has no new data, but only rebind -- or add 
a binding/proxy object -- to bind the superclass instance to the 
subclass methods.

eg: what is now standard practice to create a new copy of the superclass:

class myFalse( bool ): __new__( self, data ): return super( myFalse, 
self ).__new__(self,data)

Could be replaced by a general purpose proxy meant to handle singleton 
subclassing:

class myFalse( bool ):  __new__( self ): return 
bind_superinstance_to_subclass( False, myFalse )

> he Python bool type has the following
> invariant, for any object x:
>
> assert not isinstance(x, bool) or x is True or x is False
Really !???
Where, in the language definition, did Guido explicitly guarantee this 
invariant ?

> (You can fiddle with this in Py2 by rebinding the names True and
> False, but you could replace those names with (1==1) and (1==0) if you
> want to be completely safe. Likewise, the name "bool" could be
> replaced with (1==1).__class__ to avoid any stupidities there. But
> conceptually, that's the invariant.)
Interesting ... but rebinding True and False, won't extend the new 
capabilities to modules which are imported.  They will still, I think, 
be bound to the old True and False values.   I know, for example -- I 
can redefine the class bool altogether; although the type string becomes 
'main.bool' -- none the less, it does not exist in default scope when I 
switch namespaces; eg: in a module being imported 'bool' still means the 
old version of class bool.

I have to do something more drastic, like __builtins__.bool = class 
bool(int): ...  And then, even modules will recognize the changed class 
definition.

Hmmm.....
 >>> __builtins__.True='yes'
 >>> True
'yes'

However, such actions -- I think -- are rather drastic; because they 
produce situations where another third party library in competition with 
mine might also have need of subclassing 'bool' and then we are in a 
fight for a static binding name with winner takes all ... rather than 
sharing dynamically compatible definitions based on subclasses.

> Subclassing bool breaks this invariant, unless you never instantiate
> the subclass, in which case it's completely useless.

Well we can't subclass bool now -- and the language would have to change 
in order for us to be able to subclass it; So -- I don't think your 
assert statement guarantees anything if case the language changes... On 
the other hand, I also don't see that your assert statement would ever 
return False even as it is written --- even if the object (x) was 
sub-classed or a totally different object than True or False .... and so 
I *definitely* don't see why your assert statement would Fail if the 
language changed in one of several subtle ways I think it could.

I mean, even right now -- with the language as-is -- let's define 
something that blatantly creates a new instance of something neither an 
actual instance of True nor False, and make that x -- and see if your 
assertion catches it:

Python 2.7.5 (default, May 29 2013, 02:28:51)
[GCC 4.8.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
 >>> x=(False,)
 >>> assert not isinstance(x, bool) or x is True or x is False
 >>>

LOL ... no exception was raised... and we know if the assertion Failed, 
an exception ought to be raised:

 >>> assert False
Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
AssertionError
 >>>

And I'll prove my object is neither the instance True nor False itself, 
but a tupple wrap of it:

 >>> (False,)==False
False
 >>>

So -- your assertion, at least as shown, is pretty useless in helping 
determine why subclassing is not allowed, or instances of subclasses 
that are not distinct from their superclasses existing instance.





From rosuav at gmail.com  Mon Jan 12 21:11:12 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 13 Jan 2015 13:11:12 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54B47C0E.208@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <54B47C0E.208@r3dsolutions.com>
Message-ID: <CAPTjJmpX-Y++Uv=pMT6xVTpPk5-dkJd6BwUD0RFqLtON4XRm=Q@mail.gmail.com>

On Tue, Jan 13, 2015 at 12:59 PM, Andrew Robinson
<andrew3 at r3dsolutions.com> wrote:
> There is no need to copy data from an initialized superclass instance into a
> subclass instance that has no new data, but only rebind -- or add a
> binding/proxy object -- to bind the superclass instance to the subclass
> methods.
>
> eg: what is now standard practice to create a new copy of the superclass:
>
> class myFalse( bool ): __new__( self, data ): return super( myFalse, self
> ).__new__(self,data)
>
> Could be replaced by a general purpose proxy meant to handle singleton
> subclassing:
>
> class myFalse( bool ):  __new__( self ): return
> bind_superinstance_to_subclass( False, myFalse )

I don't understand. What do you expect this to be doing? Are you
trying to replace the original False with your new subclass?

>> he Python bool type has the following
>> invariant, for any object x:
>>
>> assert not isinstance(x, bool) or x is True or x is False
> I mean, even right now -- with the language as-is -- let's define something
> that blatantly creates a new instance of something neither an actual
> instance of True nor False, and make that x -- and see if your assertion
> catches it:
>
> Python 2.7.5 (default, May 29 2013, 02:28:51)
> [GCC 4.8.0] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
>>>> x=(False,)
>>>> assert not isinstance(x, bool) or x is True or x is False
>>>>
>
> LOL ... no exception was raised... and we know if the assertion Failed, an
> exception ought to be raised:

The assertion did not fail. There are three parts, and as long as one
of them is true, the assertion will pass:

1) x isn't an instance of bool
2) x is the object known as True
3) x is the object known as False

You just gave an example of the first part of the invariant. That's an
instance of tuple, which is not a subclass of bool, ergo isinstance(x,
bool) returns False, negating that makes True, and the assertion
passes. [1]

> So -- your assertion, at least as shown, is pretty useless in helping
> determine why subclassing is not allowed, or instances of subclasses that
> are not distinct from their superclasses existing instance.

It exactly defines the nature of Python's bool type: there are
precisely two instances of it.

ChrisA

[1] Which puts me in mind of https://www.youtube.com/watch?v=D0yYwBzKAyY


From jsf80238 at gmail.com  Mon Jan 12 21:51:07 2015
From: jsf80238 at gmail.com (Jason Friedman)
Date: Mon, 12 Jan 2015 19:51:07 -0700
Subject: Track down SIGABRT
In-Reply-To: <B967FFA3-810A-4C9F-A353-A3C5E8C9ED6B@ravnalaska.net>
References: <B967FFA3-810A-4C9F-A353-A3C5E8C9ED6B@ravnalaska.net>
Message-ID: <CANy1k1jiNGXSJVJjCAh4xEw9eiS=hdswEhhioONqsLRvxeSdTw@mail.gmail.com>

> I have a long-running python/CherryPy Web App server process that I am
> running on Mac OS X 10.8.5. Python 2.7.2 running in 32-bit mode (for now, I
> have the code in place to change over to 64 bit, but need to schedule the
> downtime to do it). On the 6th of this month, during normal operation from
> what I can tell, and after around 33 days of trouble-free uptime, the python
> process crashed with a SIGABRT. I restarted the process, and everything
> looked good again until yesterday, when it again crashed with a SIGABRT.

Can you monitor disk and memory on the host?  Perhaps it is climbing
towards an unacceptable value right before crashing.

Do you have the option of stopping and starting your process every
night or every week?


From rantingrickjohnson at gmail.com  Mon Jan 12 21:53:32 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Mon, 12 Jan 2015 18:53:32 -0800 (PST)
Subject: Python 3 regex?
In-Reply-To: <mailman.17649.1421114112.18130.python-list@python.org>
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
 <mailman.17649.1421114112.18130.python-list@python.org>
Message-ID: <7c648fa2-4a59-4d1a-923f-d29f4f2dc8f7@googlegroups.com>

On Monday, January 12, 2015 at 7:55:32 PM UTC-6, Mark Lawrence wrote:
> On 12/01/2015 23:47, Rick Johnson wrote:
> >> 'Some people, when confronted with a problem, think "I
> >> know, I'll use regular expressions." Now they have two
> >> problems.' -  Jamie Zawinski.
> >
>
> [snip]
>
> If you wish to use a hydrogen bomb instead of a tooth pick
> feel free, I won't lose any sleep over it.  Meanwhile I'll
> get on with writing code, and for the simple jobs that can
> be completed with string methods I'll carry on using them.
> When that gets too complicated I'll reach for the regex
> manual, knowing full well that there's enough data in
> books and online to help even a novice such as myself get
> over all the hurdles. If that isn't good enough then maybe
> a full blown parser, such as the pile listed here [snip]

Mark, if you're going to quote me, then at least quote me in
a manner that does not confuse the content of my post. The
snippet you posted was not a statement of mine, rather, it
was a quote that i was responding to, and without any
context of my response, what is the point of quoting
anything at all? It would be better to quote nothing and
just say @Rick, then to quote something which does not have
any context.

Every python programmer worth his *SALT* should master the
following three text processing capabilities of Python, and
he should know how and when to apply them (for they all have
strengths and weaknesses):

    (1) String methods: Simplistic API, but with limited
        capabilities -- but never underestimate the
        possibilities!

    (2) Regexps: Great for pattern matching with a powerful
        and concise syntax, but highly cryptic and unintuitive
        for the neophyte (and sometimes even the guru! *wink*).

    (3) Parsers: Great for extracting deeper meaning from text,
        but if pattern matching is all you need, then why not
        use (1) or (2) -- are you scared or uninformed?

    "We can easily forgive a child who is afraid of the
    dark; the real tragedy of life is when men are afraid of
    the light. -- Plato

IMHO, if you seek to only match patterns, then string
methods should be your first choice, however, if the pattern
is too difficult for string methods, then graduate to
regexps. If you need to extract deeper meaning from
text, by all means utilize a parser.

But above all, don't fall for these "religious teachings"
about how regexps are too difficult for mortals -- that's
just hysteria. If you follow the outline i provided above,
you should find Python's "text processing Nirvana".



From andrew3 at r3dsolutions.com  Mon Jan 12 23:16:52 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Mon, 12 Jan 2015 20:16:52 -0800
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <CAPTjJmpX-Y++Uv=pMT6xVTpPk5-dkJd6BwUD0RFqLtON4XRm=Q@mail.gmail.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <54B47C0E.208@r3dsolutions.com>
 <CAPTjJmpX-Y++Uv=pMT6xVTpPk5-dkJd6BwUD0RFqLtON4XRm=Q@mail.gmail.com>
Message-ID: <54B49C34.6050900@r3dsolutions.com>

Hmm....
>> LOL ... no exception was raised... and we know if the assertion Failed, an
>> exception ought to be raised:
> The assertion did not fail. There are three parts, and as long as one
> of them is true, the assertion will pass:
>
> 1) x isn't an instance of bool
> 2) x is the object known as True
> 3) x is the object known as False
>
> You just gave an example of the first part of the invariant. That's an
> instance of tuple, which is not a subclass of bool, ergo isinstance(x,
> bool) returns False, negating that makes True, and the assertion
> passes. [1]

Uh ... yeah... and so an assertion meant to test if something is or is 
not a bool let a non-bool pass the assertion.  That seems rather ... 
silly, and useless, ... and so I really doubt the assertion -- based on 
it's behavior --can distinguish an actual bool from a subclassed one or 
a totally unrelated object ...

I mean, let's start by testing if x as an actual boolean will cause the 
assertion to act differently from a fake-non bool object which we 
already tried.

x=True
 >>> x=True
 >>> assert not isinstance(x, bool) or x is True or x is False
 >>>
Wow. No difference in behavior.

So (as a test) it can't distinguish between an actual boolean and a 
faked one.
They both pass the assertion.  So -- What good is this assertion? It 
tells us nothing useful when executed.

Also what if we put in a subclass....

Instead of pretending what if -- let's actually REPLACE python's built 
in bool class with an emulation that ALLOWS subclassing and THEN let's 
TEST my hypothesis that the assert statement you gave me can't tell the 
difference between bools any anthing else by it's actions...  ( ooooh 
... another back-door that Guido forgot about... or perhaps purposely 
left open...)

class bool( int ):
     def __new__(self,data): return super( bool, self).__new__(self, 
[0,1][data!=0] )
     def __repr__(self): return [ 'True', 'False' ][self>0]

__builtins__.bool=bool
__builtins__.True=bool( 1==1 )
__builtins__.False=bool( 1==0 )

And, running it in the python interpreter...

 >>> class bool( int ):
...     def __new__(self,data): return super( bool, self).__new__(self, 
[0,1][data!=0] )
...     def __repr__(self): return [ 'True', 'False' ][self>0]
...
 >>> __builtins__.bool=bool
 >>> __builtins__.True=bool( 1==1 )
 >>> __builtins__.False=bool( 1==0 )
 >>>
 >>> type(True)
<class '__main__.bool'>

I now have proof that the replacement succeeded.
So let's subclass bool !!!

 >>> class subBool(bool): pass
...
 >>>

and now, let's see if your assertion believes a subclass of bool is a 
bool...
 >>> x=subBool(0)
 >>> assert not isinstance(x, bool) or x is True or x is False
 >>>

Wow. No change.
So -- it doesn't fail when the object ISN'T a bool, it doesn't fail when 
the object IS a bool, and it doesn't fail when the object is a subclass 
of bool; and #1 matches that of a True bool! or if #1 doesn't match that 
of a true bool.

 >>> isinstance( x, bool ) ,
True
 >>> isinstance( True, bool )
True

Therefore, your explantion ( so far ) of how to interpret the invariant, 
is consistent with it explicitly and *precisely* 'passing'  all possible 
instances of subclasses of bool, all instances of non-bools, and all 
instances of bools.  Yes, the assertion you chose passes precisely 
ANYTHING! (facetous use of precise.).

It's a worthless assertion in the sense that it has no explicit logic to 
DISTINGUISH what Guido/Python does want a bool to be from what you have 
said and implied Guido doesn't want (even though I've never seen Guido 
agree with you on this assertion thing...) .
>> So -- your assertion, at least as shown, is pretty useless in helping
>> determine why subclassing is not allowed, or instances of subclasses that
>> are not distinct from their superclasses existing instance.
> It exactly defines the nature of Python's bool type: there are
> precisely two instances of it.
>
> ChrisA
>
> [1] Which puts me in mind of https://www.youtube.com/watch?v=D0yYwBzKAyY

Uh, no, -- your assertion excludes nothing you've been telling me is not 
a bool by contract -- so it doesn't 'define' anything precisely because 
it's by definition inaccurate.  it's simply an invariant form of spam 
with three terms you can interpret any way you like.

Where did you get that assertion from anyway and how is it related to 
Guido and formal definitions of the python language ???  Are you really 
trying to imply that Guido wrote that assertion ?

> On Tue, Jan 13, 2015 at 12:59 PM, Andrew Robinson
> <andrew3 at r3dsolutions.com>  wrote:
>> There is no need to copy data from an initialized superclass instance into a
>> subclass instance that has no new data, but only rebind -- or add a
>> binding/proxy object -- to bind the superclass instance to the subclass
>> methods.
>>
>> eg: what is now standard practice to create a new copy of the superclass:
>>
>> class myFalse( bool ): __new__( self, data ): return super( myFalse, self
>> ).__new__(self,data)
>>
>> Could be replaced by a general purpose proxy meant to handle singleton
>> subclassing:
>>
>> class myFalse( bool ):  __new__( self ): return
>> bind_superinstance_to_subclass( False, myFalse )
> I don't understand. What do you expect this to be doing? Are you
> trying to replace the original False with your new subclass?
>
No.  I'm trying to make a subclass be a wrapper for an existing 
superclass's instance's data.
It is creating something equivalent to a proxy object ; since singletons 
have no need of data, there is no reason to create a new instance; 
Therefore a fake instance will do.  In C++ (Which Guido quoted in his 
reasoning though he was wrong about what it can do), a fake instance 
would generally be created by typecasting a base class instance as a 
subclass instance... but in python, a proxy object is generally used for 
the same task.

eg: when wanting to access super objects in C++, you could typecast a 
pointer to the subclass object as a pointer to the superclass object; 
but in python, typecasts don't exist so the same job is done -- via 
super(), by returning a proxy object.

To understand what a subclass of bool would do without an instance; Here 
is an example of a C-Python interpreter session after the python source 
code of the super() proxy type was modified to allow binding subclass 
methods to an existing superclass instance:

 >>> x=myFalse( False )
 >>> print x is False
 >>> False
 >>> print x==False
 >>> True
 >>> print isinstance( x, myFalse)
 >>> True
 >>> print isinstance( x, bool )
 >>> True
 >>> print isinstance( x, int )
 >>> True
 >>> print super( x, int ).__self__  # Revert the proxy object to the 
superclass instance,this is a kludge.
 >>> False

Note: False is the actual False object being returned as __self__, 
because the instance False was chosen to be bound to the proxy object 
and I thought that __self__ degenerating to the bound instance would be 
a reasonable action;  If I had set x=myFalse( True ), it should return 
the singleton 'True' instead.

 >>> print x
 >>> False
 >>> print type(x) # This could return various things, depending on how 
the proxy is implemented...
 >>> <super>

So, you see -- The subclass is implemented as a transparent proxy object 
to an instance of bool; it's NOT an instance of the subclass myFalse in 
reality -- but it acts 100% like an instance of myFalse would, except 
for '__self__' and type().

There are probably other ways to achieve this same goal, but one is 
enough for explanation.  This is taking too much time...





From steve at pearwood.info  Mon Jan 12 23:36:38 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 13 Jan 2015 04:36:38 GMT
Subject: Python 3 regex?
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
Message-ID: <54b4a0d6$0$2738$c3e8da3$76491128@news.astraweb.com>

On Mon, 12 Jan 2015 19:48:18 +0000, Ian wrote:

> My recommendation would be to write a recursive decent parser for your
> files.
> 
> That way will be easier to write,

I know that writing parsers is a solved problem in computer science, and 
that doing so is allegedly one of the more trivial things computer 
scientists are supposed to be able to do, but the learning curve to write 
parsers is if anything even higher than the learning curve to write a 
regex.

I wish that Python made it as easy to use EBNF to write a parser as it 
makes to use a regex :-(

http://en.wikipedia.org/wiki/Extended_Backus?Naur_Form



-- 
Steven


From steve at pearwood.info  Mon Jan 12 23:49:34 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 13 Jan 2015 04:49:34 GMT
Subject: Namespace puzzle, list comprehension fails within class definition
References: <af9bb2fd-f0b9-4efb-874e-78f30ac65b7e@googlegroups.com>
 <mailman.17638.1421095249.18130.python-list@python.org>
Message-ID: <54b4a3dd$0$2738$c3e8da3$76491128@news.astraweb.com>

On Mon, 12 Jan 2015 12:40:13 -0800, Ethan Furman wrote:

> On 01/12/2015 12:25 PM, John Ladasky wrote:
>> d = {0:"a", 1:"b", 2:"c", 3:"d"}
>> e = [d[x] for x in (0,2)]
>> 
>> class Foo:
>>     f = {0:"a", 1:"b", 2:"c", 3:"d"}
>>     print(f)
>>     g = [f[x] for x in (0,2)]
> 
> In Foo 'f' is part of an unnamed namespace; the list comp 'g' has its
> own namespace, effectively making be a nonlocal; class name lookup skips
> nonlocal namespaces.


Actually, no it doesn't.

py> def factory():
...     x = 23
...     class Inner(object):
...             print('x is', x)
...     return Inner
... 
py> o = factory()
x is 23


The "problem" is that *functions* lookup don't include the class body in 
their scope. This is by design, and goes back to Python 1.5 or older:

[steve at ando ~]$ python1.5
Python 1.5.2 (#1, Aug 27 2012, 09:09:18)  [GCC 4.1.2 20080704 (Red Hat 
4.1.2-52)] on linux2
Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam
>>> class Outer:
... 	x = 23
... 	f = lambda: x+1
... 	y = f()
... 
Traceback (innermost last):
  File "<stdin>", line 1, in ?
  File "<stdin>", line 4, in Outer
  File "<stdin>", line 3, in <lambda>
NameError: x



> Workaround:  use an actual for loop.


Sad but true.



-- 
Steven


From steve at pearwood.info  Mon Jan 12 23:57:20 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 13 Jan 2015 04:57:20 GMT
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com>
 <54ABC52A.1050507@davea.name> <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <mailman.17645.1421102146.18130.python-list@python.org>
Message-ID: <54b4a5ac$0$2738$c3e8da3$76491128@news.astraweb.com>

On Tue, 13 Jan 2015 09:35:43 +1100, Chris Angelico wrote:

> Subclassing bool breaks this invariant, unless you never instantiate the
> subclass, in which case it's completely useless.

Not necessarily. A class that you never instantiate, but use as an object 
itself, is another way of implementing the singleton design pattern. 
Obviously all the methods have to be class methods, but it is doable.

But wacky exceptions like subclasses that aren't instantiated aside, 
normally if you subclass something you intend to instantiate it.

In Java terms bool is a "final" class which means it cannot be subclassed. 
Although Python is not anywhere near as restrictive as Java, and makes a 
virtue out of allowing the programmer to shot themselves in the foot, 
there are some restrictions and this is one of them.


-- 
Steven


From rosuav at gmail.com  Tue Jan 13 00:30:53 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 13 Jan 2015 16:30:53 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54b4a5ac$0$2738$c3e8da3$76491128@news.astraweb.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <mailman.17645.1421102146.18130.python-list@python.org>
 <54b4a5ac$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <CAPTjJmookyPdyhq9V60FyVnE8FSxPOkhjW7ySgYCbA2ymAWiOg@mail.gmail.com>

On Tue, Jan 13, 2015 at 3:57 PM, Steven D'Aprano <steve at pearwood.info> wrote:
> On Tue, 13 Jan 2015 09:35:43 +1100, Chris Angelico wrote:
>
>> Subclassing bool breaks this invariant, unless you never instantiate the
>> subclass, in which case it's completely useless.
>
> Not necessarily. A class that you never instantiate, but use as an object
> itself, is another way of implementing the singleton design pattern.
> Obviously all the methods have to be class methods, but it is doable.
>
> But wacky exceptions like subclasses that aren't instantiated aside,
> normally if you subclass something you intend to instantiate it.

True, I should have said "probably useless" instead of "completely
useless". :) There's always *something* you could do with it.

ChrisA


From ian.g.kelly at gmail.com  Tue Jan 13 00:31:24 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 12 Jan 2015 22:31:24 -0700
Subject: class-based class decorator
In-Reply-To: <1098350771.199383.1421070276837.JavaMail.yahoo@jws10769.mail.gq1.yahoo.com>
References: <CALwzidkvGKEJtZ2f2LyfA4atY0kpaQsGrCtBro5X2TyrBe98Hw@mail.gmail.com>
 <1098350771.199383.1421070276837.JavaMail.yahoo@jws10769.mail.gq1.yahoo.com>
Message-ID: <CALwzidkurTaxdVHWnSjzpU-ouCkPf2AdXcD9n2+oNGZHfW0b5w@mail.gmail.com>

On Jan 12, 2015 6:47 AM, "Albert-Jan Roskam" <fomcl at yahoo.com> wrote:
> Thanks for your replies. I changed it into a regular decorator (not a class decorator). It would have been even nicer if I only needed to specify it once per class, but, well, in my case this hardly matters. The code below works as intended. One problem (not specific to the code): the decorator destroys the signature: it always becomes "*args, **kwargs"). This is annoying with help(), but what worries me most is that my Sphinx documentation is also affected. The information about the defaults gets lost (the parameters are decribed in the docstring, but not the defaults). That kind of sucks. Is there a builtin way around this (in other words: I am aware of this package: https://pypi.python.org/pypi/decorator). I am hoping to get the code working on Python 2.7 and 3.3 and up.

As of (I think) 3.4 pydoc and the help() function will show you the
signature of the wrapped function as long as you use functools.wraps.
I don't know what the status is for Sphinx; all I can offer is this
stackoverflow link.

http://stackoverflow.com/questions/3687046/python-sphinx-autodoc-and-decorated-members


From steve at pearwood.info  Tue Jan 13 00:32:31 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 13 Jan 2015 05:32:31 GMT
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com>
 <54ABC52A.1050507@davea.name> <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
Message-ID: <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>

On Mon, 12 Jan 2015 17:59:42 -0800, Andrew Robinson wrote:

[...]
> What I am wanting to know is WHY did Guido think it so important to do
> that ?   Why was he so focused on a strict inability to have any
> instances of a bool subclass at all -- that he made a very arbitrary
> exception to the general rule that base types in Python can be
> subclassed ?

It's not arbitrary. All the singleton (doubleton in the case of bool) 
classes cannot be subclassed. E.g. NoneType:

py> class X(type(None)):
...     pass
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: Error when calling the metaclass bases
    type 'NoneType' is not an acceptable base type


Likewise for the NotImplemented and Ellipsis types.

The reason is the same: if a type promises that there is one and only one 
instance (two in the case of bool), then allowing subtypes will break 
that promise in the 99.99% of cases where the subtype is instantiated.

I suppose in principle Python could allow you to subclass singleton 
classes to your hearts content, and only raise an error if you try to 
instantiate them, but that would probably be harder and more error-prone 
to implement, and would *definitely* be harder to explain.


There may be others too:

py> from types import FunctionType
py> class F(FunctionType):
...     pass
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: Error when calling the metaclass bases
    type 'function' is not an acceptable base type


My guess here is that functions are so tightly coupled to the Python 
interpreter that allowing you to subclass them, and hence break required 
invariants, could crash the interpreter. Crashing the interpreter from 
pure Python code is *absolutely not allowed*, so anything which would 
allow that is forbidden.


> There's no reason in object oriented programming principles in general
> that requires a new subclass instance to be a COMPLETELY DISTINCT
> instance from an already existing superclass instance....

True. But what is the point of such a subclass? I don't think you have 
really thought this through in detail.

Suppose we allowed bool subclasses, and we implement one which *only* 
returns True and False, without adding a third instance:

class MyBool(bool):
    def __new__(cls, arg):
        if cls.condition(arg):
            return True
        else:
            return False
    @classmethod
    def condition(cls, obj):
        # decide whether obj is true-ish or false-ish.
        pass
    def spam(self):
        return self.eggs()
    def eggs(self):
        return 23


And then you do this:

flag = MyBool(something)
flag.spam()


What do you expect to happen?


Since flag can *only* be a regular bool, True or False, it won't have 
spam or eggs methods.

You might think of writing the code using unbound methods:

MyBool.spam(flag)

(assuming that methods don't enforce the type restriction that "self" 
must be an instance of their class), but that fails when the spam method 
calls "self.eggs". So you have to write your methods like this:

    def spam(self):
        return MyBool.eggs(self)

hard-coding the class name! You can't use type(self), because that's 
regular bool, not MyBool.

This is a horrible, error-prone, confusing mess of a system. If you're 
going to write code like this, you are better off making MyBool a module 
with functions instead of a class with methods.


> nor, have I
> ever seen Guido say that Python is designed intentionally to force this
> to always be the case... so I'm not sure that's its anything more than a
> non guaranteed implementation detail that Python acts the way you say it
> does....

It is a documented restriction on bool. Whether you agree with the 
decision or not, it is not an implementation detail, it is a language 
promise.

https://docs.python.org/2/library/functions.html#bool




-- 
Steven


From breamoreboy at yahoo.co.uk  Tue Jan 13 00:34:31 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Tue, 13 Jan 2015 05:34:31 +0000
Subject: Python 3 regex?
In-Reply-To: <7c648fa2-4a59-4d1a-923f-d29f4f2dc8f7@googlegroups.com>
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
 <mailman.17649.1421114112.18130.python-list@python.org>
 <7c648fa2-4a59-4d1a-923f-d29f4f2dc8f7@googlegroups.com>
Message-ID: <m92ap9$2v3$1@ger.gmane.org>

On 13/01/2015 02:53, Rick Johnson wrote:
> On Monday, January 12, 2015 at 7:55:32 PM UTC-6, Mark Lawrence wrote:
>> On 12/01/2015 23:47, Rick Johnson wrote:
>>>> 'Some people, when confronted with a problem, think "I
>>>> know, I'll use regular expressions." Now they have two
>>>> problems.' -  Jamie Zawinski.
>>>
>>
>> [snip]
>>
>> If you wish to use a hydrogen bomb instead of a tooth pick
>> feel free, I won't lose any sleep over it.  Meanwhile I'll
>> get on with writing code, and for the simple jobs that can
>> be completed with string methods I'll carry on using them.
>> When that gets too complicated I'll reach for the regex
>> manual, knowing full well that there's enough data in
>> books and online to help even a novice such as myself get
>> over all the hurdles. If that isn't good enough then maybe
>> a full blown parser, such as the pile listed here [snip]
>
> Mark, if you're going to quote me, then at least quote me in
> a manner that does not confuse the content of my post. The
> snippet you posted was not a statement of mine, rather, it
> was a quote that i was responding to, and without any
> context of my response, what is the point of quoting
> anything at all? It would be better to quote nothing and
> just say @Rick, then to quote something which does not have
> any context.

You snipped the bit that says [normal cobblers snipped].

>
> Every python programmer worth his *SALT* should master the
> following three text processing capabilities of Python, and
> he should know how and when to apply them (for they all have
> strengths and weaknesses):
>
>      (1) String methods: Simplistic API, but with limited
>          capabilities -- but never underestimate the
>          possibilities!
>
>      (2) Regexps: Great for pattern matching with a powerful
>          and concise syntax, but highly cryptic and unintuitive
>          for the neophyte (and sometimes even the guru! *wink*).
>
>      (3) Parsers: Great for extracting deeper meaning from text,
>          but if pattern matching is all you need, then why not
>          use (1) or (2) -- are you scared or uninformed?
>

String methods, regexes, parsers, isn't that what I've already said 
above?  Why repeat it?

>      "We can easily forgive a child who is afraid of the
>      dark; the real tragedy of life is when men are afraid of
>      the light. -- Plato
>
> IMHO, if you seek to only match patterns, then string
> methods should be your first choice, however, if the pattern
> is too difficult for string methods, then graduate to
> regexps. If you need to extract deeper meaning from
> text, by all means utilize a parser.
>

I feel humbled that a great such as yourself is again repeating what 
I've already said.

> But above all, don't fall for these "religious teachings"
> about how regexps are too difficult for mortals -- that's
> just hysteria. If you follow the outline i provided above,
> you should find Python's "text processing Nirvana".
>

My favourite things in programming all go along the lines of DRY and 
KISS, with "Although practicality beats purity" being the most important 
of the lot.  So called "religious teachings" never enter into my way of 
doing things.  For example I can't stand code which jumps through hoops 
to avoid using GOTO, whereas nothing is cleaner than (say) GOTO ERROR. 
You'll (plural) find loads of them in cPython.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From ethan at stoneleaf.us  Tue Jan 13 01:00:27 2015
From: ethan at stoneleaf.us (Ethan Furman)
Date: Mon, 12 Jan 2015 22:00:27 -0800
Subject: Namespace puzzle, list comprehension fails within class definition
In-Reply-To: <54b4a3dd$0$2738$c3e8da3$76491128@news.astraweb.com>
References: <af9bb2fd-f0b9-4efb-874e-78f30ac65b7e@googlegroups.com>
 <mailman.17638.1421095249.18130.python-list@python.org>
 <54b4a3dd$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <54B4B47B.4040105@stoneleaf.us>

On 01/12/2015 08:49 PM, Steven D'Aprano wrote:
> On Mon, 12 Jan 2015 12:40:13 -0800, Ethan Furman wrote:
>> 
>> [...] class name lookup skips nonlocal namespaces.
> 
> Actually, no it doesn't.
> [...] 
> The "problem" is that *functions* lookup don't include the class body in 
> their scope.

Ah, thanks for the correction!

--
~Ethan~

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From mail at timgolden.me.uk  Tue Jan 13 01:08:08 2015
From: mail at timgolden.me.uk (Tim Golden)
Date: Tue, 13 Jan 2015 06:08:08 +0000
Subject: I must be missing something obvious in installing Python 3.4.2...
In-Reply-To: <f49c0c9c-09ab-4aec-8dbc-253d78170f9f@googlegroups.com>
References: <ec7b8633-3b02-42b3-89e4-ef002ebd78e6@googlegroups.com>
 <mailman.17640.1421095928.18130.python-list@python.org>
 <4723ce7c-53ec-463b-b270-63241305f867@googlegroups.com>
 <mailman.17642.1421100022.18130.python-list@python.org>
 <6474bfec-ce53-4967-8a76-5bedda9110a8@googlegroups.com>
 <f49c0c9c-09ab-4aec-8dbc-253d78170f9f@googlegroups.com>
Message-ID: <54B4B648.2000903@timgolden.me.uk>

On 12/01/2015 23:12, Andrew Koenig wrote:
> Fixed it!
>
> The aforementioned article is correct. I downloaded the RegDelNull
> program mentioned in the article
> (http://technet.microsoft.com/en-us/sysinternals/bb897448.aspx) and
> ran it on hkcr, hkcu, hklm, hku, and hkcc (short for
> HKEY_CLASSES_ROOT, HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, HKEY_USERS,
> and HKEY_CURRENT_CONFIG), respectively. It deleted a bunch of keys.
> Rerunning the program you posted earlier revealed no keys with
> embedded nulls in their names, and ensurepip now works.
>
> I have no idea how these keys got there. For all I know they are the
> result of malware.
>
> I think it would be worthwhile changing the Python code to detect
> nulls and perhaps issue a warning that directs people to this article
> or something like it.
>

Thanks, yes. Unfortunate that no-one's actually reported this before as 
a bug -- as far as I'm aware. Would you be in a position to report this 
at bugs.python.org? If not, I'll do it when I get a chance.

TJG


From rosuav at gmail.com  Tue Jan 13 01:13:52 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 13 Jan 2015 17:13:52 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <CAPTjJmq5E+LJ8gjXQa7Sf+smc8ug59YZpofp7PH6WwjL55Gv=Q@mail.gmail.com>

On Tue, Jan 13, 2015 at 4:32 PM, Steven D'Aprano <steve at pearwood.info> wrote:
> Crashing the interpreter from
> pure Python code is *absolutely not allowed*, so anything which would
> allow that is forbidden.

Except when you willingly shoot yourself in the foot.

rosuav at sikorsky:~$ python
Python 2.7.3 (default, Mar 13 2014, 11:03:55)
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> def f(): sys.setrecursionlimit(sys.getrecursionlimit()+1) or f()
...
>>> f()
Segmentation fault
rosuav at sikorsky:~$ python3
Python 3.5.0a0 (default:1c51f1650c42+, Dec 29 2014, 02:29:06)
[GCC 4.7.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> def f(): sys.setrecursionlimit(sys.getrecursionlimit()+1) or f()
...
>>> f()
Segmentation fault

But otherwise, yes. You shouldn't be able to segfault Python with Python code.

ChrisA


From ian.g.kelly at gmail.com  Tue Jan 13 01:22:50 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 12 Jan 2015 23:22:50 -0700
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54B49C34.6050900@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <54B47C0E.208@r3dsolutions.com>
 <CAPTjJmpX-Y++Uv=pMT6xVTpPk5-dkJd6BwUD0RFqLtON4XRm=Q@mail.gmail.com>
 <54B49C34.6050900@r3dsolutions.com>
Message-ID: <CALwzidmzaHkFqNJSQB+NqgENpuwW5zDR7Fa=nYBoM8bhB4LfJQ@mail.gmail.com>

On Mon, Jan 12, 2015 at 9:16 PM, Andrew Robinson
<andrew3 at r3dsolutions.com> wrote:
> Instead of pretending what if -- let's actually REPLACE python's built in
> bool class with an emulation that ALLOWS subclassing and THEN let's TEST my
> hypothesis that the assert statement you gave me can't tell the difference
> between bools any anthing else by it's actions...  ( ooooh ... another
> back-door that Guido forgot about... or perhaps purposely left open...)
>
> class bool( int ):
>     def __new__(self,data): return super( bool, self).__new__(self,
> [0,1][data!=0] )
>     def __repr__(self): return [ 'True', 'False' ][self>0]
>
> __builtins__.bool=bool
> __builtins__.True=bool( 1==1 )
> __builtins__.False=bool( 1==0 )

Your posts are so wordy that I'm not even going to try to respond to
all of them, but this is an interesting point that bears explanation.
The reason you can reassign True and False in Python 2.x is for
backward compatibility with scripts that predated the built-in bool
type and would do things like:

True = 1
False = 0

However, this longstanding wart was fixed in Python 3 by making True
and False keywords:

>>> True = 42
  File "<stdin>", line 1
SyntaxError: can't assign to keyword
>>> __builtins__.True = 42
  File "<stdin>", line 1
    __builtins__.True = 42
                    ^
SyntaxError: invalid syntax


From steve at pearwood.info  Tue Jan 13 01:39:44 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 13 Jan 2015 06:39:44 GMT
Subject: Python 3 regex?
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
Message-ID: <54b4bdae$0$2738$c3e8da3$76491128@news.astraweb.com>

On Mon, 12 Jan 2015 15:47:08 -0800, Rick Johnson wrote:

>> 'Some people, when confronted with a problem, think "I know, I'll use
>> regular expressions." Now they have two problems.' -  Jamie Zawinski.
> 
> I wonder if Jamie's conclusions are a result of careful study, or
> merely, an attempt to resolve his own cognitive dissonance? 

Zawinski is one of the pantheon of geek demi-gods, with Linus, Larry, 
Guido, RMS, and a few others. (Just don't ask me to rank them. I'm not 
qualified.) His comment isn't based on a failure to grok regular 
expressions, but on an understanding that many people use regular 
expressions inappropriately.

Here is more on the context of the famous quote:

http://regex.info/blog/2006-09-15/247


(By the way, the quote actually wasn't original to JZ, he stole it from 
an all but identical quote about awk.)


[...]
> For instance, in the following example, i contrive a similarly ironic
> statement to showcase the effects of such propaganda, but one that
> covers a subject matter in which laymen either: already understand, or,
> can easily attain "enough knowledge" to appreciate the humor.
> 
>     ############################################################ #      
>                     Ironic Twist                       #
>     ############################################################ # Some
>     diabetics, when confronted with hunger, think "I    # # know, I'll
>     eat a box of sugar cookies." -- now they have # # two problems!'    

Not the best of analogies, since there are two forms of diabetes. Those 
with Type 2 diabetes can best manage their illness by avoiding sugar 
cookies. Those with Type 1 should keep a box of sugar cookies (well, 
perhaps glucose lollies are more appropriate) on hand for emergencies.

http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Diabetes_explained?open

In any case, most people with diabetes (or at least those who are still 
alive) are reasonably good at managing their illness and wouldn't make 
the choice you suggest. You have missed the point that people who misuse 
regexes are common in programming circles, while diabetics who eat a box 
of sugar cookies instead of a meal are rare.

To take your analogy to an extreme:

  Some people, when faced with a problem, say "I know, I'll cut 
  my arm off with a pocketknife!" Now they have two problems.

This is not insightful or useful. Except in the most specialised and 
extreme circumstances, such as being trapped in the wilderness with a 
boulder on your arm, nobody would consider this to be good advice. But 
using regexes to validate email addresses or parse HTML? The internet is 
full of people who thought that was a good idea.


[...]
> Yes, i'll admit, regexps are very cryptic, but once you grasp their
> intricacies, you appreciate the succinctness of there syntax, because,
> what makes them so powerful is not only the extents of their pattern
> matching abilities, but their conciseness.

Even Larry Wall says that regexes are too concise and cryptic:

http://perl6.org/archive/doc/design/apo/A05.html



-- 
Steve


From steve at pearwood.info  Tue Jan 13 01:59:53 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 13 Jan 2015 06:59:53 GMT
Subject: Using a ChangeLog as a canonical source of package metadata
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17488.1420762070.18130.python-list@python.org>
 <54b2be27$0$13000$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17593.1421007692.18130.python-list@python.org>
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Message-ID: <54b4c269$0$2738$c3e8da3$76491128@news.astraweb.com>

On Mon, 12 Jan 2015 05:24:00 -0800, wxjmfauth wrote:

> To tell you the truth, I'm unable to
> put your product to work.


If you follow the instructions in the README, and it still doesn't work, 
that's a bug and I will be happy to fix it.

If you insist on doing things your own way, and breaking the package, 
then I cannot help you.



-- 
Steve


From cjgohlke at gmail.com  Tue Jan 13 02:05:49 2015
From: cjgohlke at gmail.com (cjgohlke at gmail.com)
Date: Mon, 12 Jan 2015 23:05:49 -0800 (PST)
Subject: I must be missing something obvious in installing Python 3.4.2...
In-Reply-To: <mailman.17658.1421129286.18130.python-list@python.org>
References: <ec7b8633-3b02-42b3-89e4-ef002ebd78e6@googlegroups.com>
 <mailman.17640.1421095928.18130.python-list@python.org>
 <4723ce7c-53ec-463b-b270-63241305f867@googlegroups.com>
 <mailman.17642.1421100022.18130.python-list@python.org>
 <6474bfec-ce53-4967-8a76-5bedda9110a8@googlegroups.com>
 <f49c0c9c-09ab-4aec-8dbc-253d78170f9f@googlegroups.com>
 <mailman.17658.1421129286.18130.python-list@python.org>
Message-ID: <11fa246b-f488-4bab-b6cb-a813217bef8b@googlegroups.com>

On Monday, January 12, 2015 at 10:09:03 PM UTC-8, Tim Golden wrote:
> On 12/01/2015 23:12, Andrew Koenig wrote:
> > Fixed it!
> >
> > The aforementioned article is correct. I downloaded the RegDelNull
> > program mentioned in the article
> > (http://technet.microsoft.com/en-us/sysinternals/bb897448.aspx) and
> > ran it on hkcr, hkcu, hklm, hku, and hkcc (short for
> > HKEY_CLASSES_ROOT, HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, HKEY_USERS,
> > and HKEY_CURRENT_CONFIG), respectively. It deleted a bunch of keys.
> > Rerunning the program you posted earlier revealed no keys with
> > embedded nulls in their names, and ensurepip now works.
> >
> > I have no idea how these keys got there. For all I know they are the
> > result of malware.
> >
> > I think it would be worthwhile changing the Python code to detect
> > nulls and perhaps issue a warning that directs people to this article
> > or something like it.
> >
> 
> Thanks, yes. Unfortunate that no-one's actually reported this before as 
> a bug -- as far as I'm aware. Would you be in a position to report this 
> at bugs.python.org? If not, I'll do it when I get a chance.
> 
> TJG

<http://bugs.python.org/issue22028>


From ben+python at benfinney.id.au  Tue Jan 13 02:34:08 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Tue, 13 Jan 2015 18:34:08 +1100
Subject: [RELEASE] =?utf-8?Q?=E2=80=98python-daemon?= =?utf-8?B?4oCZ?=
 version 2.0.2 released
Message-ID: <20150113073408.GB24694@benfinney.id.au>

Howdy all,

I am pleased to announce the release of version 2.0.2 of the
?python-daemon? library.

The current release is always available at
<URL:https://pypi.python.org/pypi/python-daemon/>.

The project's forums and VCS are hosted at Alioth
<URL:https://alioth.debian.org/projects/python-daemon/>.


Significant changes since the previous version
==============================================

This is a bug fix release, addressing packaging bugs:

* Declare test-time dependency on recent ?unittest2?.
* Declare packaging-time dependency on ?docutils? library.

Many thanks to users who promptly reported these omissions.


What is the ?python-daemon? library?
====================================

?python-daemon? is a Python library to implement a well-behaved Unix
daemon process.

-- 
 \       ?? one of the main causes of the fall of the Roman Empire was |
  `\        that, lacking zero, they had no way to indicate successful |
_o__)                  termination of their C programs.? ?Robert Firth |
Ben Finney <ben at benfinney.id.au>
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From fabien.maussion at gmail.com  Tue Jan 13 02:51:00 2015
From: fabien.maussion at gmail.com (Fabien)
Date: Tue, 13 Jan 2015 08:51:00 +0100
Subject: What does "pip install" do?
References: <m91i6i$3ft$1@speranza.aioe.org>
 <mailman.17646.1421102814.18130.python-list@python.org>
Message-ID: <m92iqd$7ko$1@speranza.aioe.org>

On 12.01.2015 23:46, Chris Angelico wrote:
> On Tue, Jan 13, 2015 at 9:35 AM, Fabien<fabien.maussion at gmail.com>  wrote:
>> >BUT I'm still asking myself: what does "pip install"*concretely*  do on my
>> >virtual environment?
> As far as I know, it's equivalent to three steps:
>
> 1) Download the appropriate version of a package (the latest, if you
> didn't say otherwise)
> 2) Extract that package
> 3) Run 'python setup.py'.
>
> What setup.py does is up to the package, but for a pure-Python package
> it should simply create something in site-packages. It might do a lot
> more, though - compiling C or Fortran code, for instance.

Thanks Chris. I should then rephrase my question to "what does python 
setup.pt do?" ;-). My point was also that I think that this information 
(mostly: what will change on my system or my virtual env when I install 
a python package?) could/should be provided in the mentioned resources:

"Python Packaging Authority" website 
(https://pip.pypa.io/en/latest/user_guide.html),
"python-packaging-user-guide" 
(http://python-packaging-user-guide.readthedocs.org/en/latest/installing.html) 

"Installing python packages" from the python docs 
(https://docs.python.org/3/installing/)

I've found a bit more about this ("How installation works") in the 
Python 3 doc which is now considered legacy and might therefore not be 
read:
https://docs.python.org/3.4/install/index.html#installing-python-modules-legacy-version

Fabien






From rosuav at gmail.com  Tue Jan 13 02:59:12 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 13 Jan 2015 18:59:12 +1100
Subject: What does "pip install" do?
In-Reply-To: <m92iqd$7ko$1@speranza.aioe.org>
References: <m91i6i$3ft$1@speranza.aioe.org>
 <mailman.17646.1421102814.18130.python-list@python.org>
 <m92iqd$7ko$1@speranza.aioe.org>
Message-ID: <CAPTjJmr_3RzNrSrrfQrTPkk3HKH1Rm-+08BCDgVYp7mWHH-tjQ@mail.gmail.com>

On Tue, Jan 13, 2015 at 6:51 PM, Fabien <fabien.maussion at gmail.com> wrote:
> Thanks Chris. I should then rephrase my question to "what does python
> setup.pt do?" ;-). My point was also that I think that this information
> (mostly: what will change on my system or my virtual env when I install a
> python package?) could/should be provided in the mentioned resources:

You'd have to look at the individual packages' setup.py files, I guess.

ChrisA


From wxjmfauth at gmail.com  Tue Jan 13 03:09:04 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Tue, 13 Jan 2015 00:09:04 -0800 (PST)
Subject: Using a ChangeLog as a canonical source of package metadata
In-Reply-To: <54b4c269$0$2738$c3e8da3$76491128@news.astraweb.com>
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17488.1420762070.18130.python-list@python.org>
 <54b2be27$0$13000$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17593.1421007692.18130.python-list@python.org>
 <d0131022-c085-411e-a554-ec45f1ed4021@googlegroups.com>
 <54b35f33$0$2738$c3e8da3$76491128@news.astraweb.com>
 <c82ac862-9f9a-41b6-b774-a8506e0a4f88@googlegroups.com>
 <54b4c269$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <d911aa4b-c1ad-40c1-a9c6-30e18897cace@googlegroups.com>

Le mardi 13 janvier 2015 08:00:06 UTC+1, Steven D'Aprano a ?crit?:
> On Mon, 12 Jan 2015 05:24:00 -0800, wxjmfauth wrote:
> 
> > To tell you the truth, I'm unable to
> > put your product to work.
> 
> 
> If you follow the instructions in the README, and it still doesn't work, 
> that's a bug and I will be happy to fix it.
> 
> If you insist on doing things your own way, and breaking the package, 
> then I cannot help you.
> 

No, I do not claim, your package is buggy.
I just wanted to toy with it without installing
it in the XXX\pythonXX directory structure.


From mail at timgolden.me.uk  Tue Jan 13 03:18:27 2015
From: mail at timgolden.me.uk (Tim Golden)
Date: Tue, 13 Jan 2015 08:18:27 +0000
Subject: I must be missing something obvious in installing Python 3.4.2...
In-Reply-To: <11fa246b-f488-4bab-b6cb-a813217bef8b@googlegroups.com>
References: <ec7b8633-3b02-42b3-89e4-ef002ebd78e6@googlegroups.com>
 <mailman.17640.1421095928.18130.python-list@python.org>
 <4723ce7c-53ec-463b-b270-63241305f867@googlegroups.com>
 <mailman.17642.1421100022.18130.python-list@python.org>
 <6474bfec-ce53-4967-8a76-5bedda9110a8@googlegroups.com>
 <f49c0c9c-09ab-4aec-8dbc-253d78170f9f@googlegroups.com>
 <mailman.17658.1421129286.18130.python-list@python.org>
 <11fa246b-f488-4bab-b6cb-a813217bef8b@googlegroups.com>
Message-ID: <54B4D4D3.8030808@timgolden.me.uk>

On 13/01/2015 07:05, cjgohlke at gmail.com wrote:
> On Monday, January 12, 2015 at 10:09:03 PM UTC-8, Tim Golden wrote:
>> On 12/01/2015 23:12, Andrew Koenig wrote:
>>> Fixed it!
>>>
>>> The aforementioned article is correct. I downloaded the RegDelNull
>>> program mentioned in the article
>>> (http://technet.microsoft.com/en-us/sysinternals/bb897448.aspx) and
>>> ran it on hkcr, hkcu, hklm, hku, and hkcc (short for
>>> HKEY_CLASSES_ROOT, HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, HKEY_USERS,
>>> and HKEY_CURRENT_CONFIG), respectively. It deleted a bunch of keys.
>>> Rerunning the program you posted earlier revealed no keys with
>>> embedded nulls in their names, and ensurepip now works.
>>>
>>> I have no idea how these keys got there. For all I know they are the
>>> result of malware.
>>>
>>> I think it would be worthwhile changing the Python code to detect
>>> nulls and perhaps issue a warning that directs people to this article
>>> or something like it.
>>>
>>
>> Thanks, yes. Unfortunate that no-one's actually reported this before as 
>> a bug -- as far as I'm aware. Would you be in a position to report this 
>> at bugs.python.org? If not, I'll do it when I get a chance.
>>
>> TJG
> 
> <http://bugs.python.org/issue22028>
> 

(Sigh). Thanks -- and I'm even listed on the call. In my defence it was
logged while I was away over the summer and I did a bit of a bulk delete
when I came back.

Thanks

TJG


From steve at pearwood.info  Tue Jan 13 03:22:58 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 13 Jan 2015 08:22:58 GMT
Subject: Using a ChangeLog as a canonical source of package metadata
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17488.1420762070.18130.python-list@python.org>
 <54b2be27$0$13000$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17593.1421007692.18130.python-list@python.org>
 <d0131022-c085-411e-a554-ec45f1ed4021@googlegroups.com>
 <54b35f33$0$2738$c3e8da3$76491128@news.astraweb.com>
 <c82ac862-9f9a-41b6-b774-a8506e0a4f88@googlegroups.com>
 <54b4c269$0$2738$c3e8da3$76491128@news.astraweb.com>
 <d911aa4b-c1ad-40c1-a9c6-30e18897cace@googlegroups.com>
Message-ID: <54b4d5e2$0$2738$c3e8da3$76491128@news.astraweb.com>

On Tue, 13 Jan 2015 00:09:04 -0800, wxjmfauth wrote:

> Le mardi 13 janvier 2015 08:00:06 UTC+1, Steven D'Aprano a ?crit?:
>> On Mon, 12 Jan 2015 05:24:00 -0800, wxjmfauth wrote:
>> 
>> > To tell you the truth, I'm unable to
>> > put your product to work.
>> 
>> 
>> If you follow the instructions in the README, and it still doesn't
>> work, that's a bug and I will be happy to fix it.
>> 
>> If you insist on doing things your own way, and breaking the package,
>> then I cannot help you.
>> 
>> 
> No, I do not claim, your package is buggy. I just wanted to toy with it
> without installing it in the XXX\pythonXX directory structure.


It is a pure Python package. Copy the package directory out of the tar 
ball and put it where Python can see it, and it will work.

If you need to read more about packages, start here:

https://docs.python.org/2/tutorial/modules.html#packages


-- 
Steve


From fomcl at yahoo.com  Tue Jan 13 03:25:32 2015
From: fomcl at yahoo.com (Albert-Jan Roskam)
Date: Tue, 13 Jan 2015 08:25:32 +0000 (UTC)
Subject: class-based class decorator
In-Reply-To: <2047794092.9155299.1421076051020.JavaMail.root@sequans.com>
References: <2047794092.9155299.1421076051020.JavaMail.root@sequans.com>
Message-ID: <129524411.66934.1421137532472.JavaMail.yahoo@jws10725.mail.gq1.yahoo.com>





----- Original Message -----
> From: Jean-Michel Pichavant <jeanmichel at sequans.com>
> To: Albert-Jan Roskam <fomcl at yahoo.com>
> Cc: Python <python-list at python.org>
> Sent: Monday, January 12, 2015 4:20 PM
> Subject: Re: class-based class decorator
> 
> ----- Original Message -----
>>  From: "Albert-Jan Roskam" <fomcl at yahoo.com.dmarc.invalid>
> 
>>  import functools
>>  import inspect
>>  import warnings
>> 
>>  warnings.simplefilter("always")
>> 
>>  class check_deprecated_args(object):
>> 
>>      def __init__(self, deprecated_params, msg=None):
>>          self.deprecated_params = deprecated_params
>>          self.msg = msg
>> 
>>      def __call__(self, func):
>>          @functools.wraps(func)
>>          def inner(*args, **kwargs):
>>              argspec = inspect.getargspec(func)
>>              default_signature = dict(zip(argspec.args[1:],
>>              argspec.defaults))
>>              callargs = inspect.getcallargs(func, *args, **kwargs)
>>              deprecated_calls = [(p, a) for p, a in callargs.items()
>>              if
>>                                   p in self.deprecated_params and
>>                                   a != default_signature[p]]
>>              for (param, arg) in deprecated_calls:
>>                  msg = "you're using obsolete parameters in %s:
>>                  [%s:%s]"
>>                  msg = msg % (func.__name__, param, arg)
>>                  msg = msg + " " + self.msg if self.msg else msg
>>                  warnings.warn(msg, DeprecationWarning, stacklevel=2)
>>              return func(*args, **kwargs)
>>          functools.update_wrapper(inner, func)
>>          return inner
>> 
>>  if __name__ == "__main__":
>>      class Foo(object):
>> 
>>          @check_deprecated_args(["old", "older"], 
> "use 'brand_new'
>>          param instead")
>>          def __init__(self, old="old", older="ancient"):
>>              print "hello"
>> 
>>          @check_deprecated_args(deprecated_params=["old", 
> "older"])
>>          def bar(self, old="default"):
>>              print "world"
>> 
>>      f = Foo(old="old", older="dino era")
>>      f.bar("gnarly")
>> 
>>      help(f)  # now the signature is *args, **kwargs, which makes my
>>      Sphinx documentation less readable!
>> 
>>  Best wishes,
>>  Albert-Jan
> 
> I don't really understand how you successfuly manage positional parameters, 
> since the caller may not name them.
> I'm asking because if your intend to check only the keyword parameters, 
> there's a much simplier solution.
> 
> JM


Hi,

Can you give an example of where/how my code would fail? I do not intend to use *args and **kwargs, if that is what you mean. I am interested in hearing a simpler approach, especially if it would also solve the messed-up-signature problem that I mentioned.

Thank you!

Albert-Jan


From road01 at yahoo.fr  Tue Jan 13 04:03:16 2015
From: road01 at yahoo.fr (brice DORA)
Date: Tue, 13 Jan 2015 01:03:16 -0800 (PST)
Subject: How can i use a dictionnary
Message-ID: <233574bb-a552-49f2-b803-86523e2b5741@googlegroups.com>

i consume a web service that return a element whose the type is "instance". but this element seem be a dictionary but when i want to use it like a dictionary, i got some errors. so this is the element and please someone can tell me how can i use it. tkanks in advance.


(tCountryInfo){
   sISOCode = "CI"
   sName = "C??te D'Ivoire (Ivory Coast)"
   sCapitalCity = "Yamoussoukro"
   sPhoneCode = "225"
   sContinentCode = "AF"
   sCurrencyISOCode = "XOF"
   sCountryFlag = "http://www.oorsprong.org/WebSamples.CountryInfo/Images/C??te D'Ivoire.jpg"
   Languages = 
      (ArrayOftLanguage){
         tLanguage[] = 
            (tLanguage){
               sISOCode = "fr"
               sName = "French"
            },
      }
 }


From maxischmeii at gmail.com  Tue Jan 13 04:31:03 2015
From: maxischmeii at gmail.com (Maxime S)
Date: Tue, 13 Jan 2015 10:31:03 +0100
Subject: Broken IF statement
In-Reply-To: <dd384c6d-17c0-4850-ad5b-6b073c80bdb8@googlegroups.com>
References: <dd384c6d-17c0-4850-ad5b-6b073c80bdb8@googlegroups.com>
Message-ID: <CAGqiJR_QKnW=x3uaoFpdYxvv_r9jpTDGGuT6nYC9VkXKCf734Q@mail.gmail.com>

2015-01-12 22:19 GMT+01:00 <joboppsgpp at gmail.com>:
>
> https://bpaste.net/show/93be9e15634b <--- Line 19 through 22
>
> At all times, my program is assigning the object priority of 0, even if
one already exists in the database with a priority of 0 (it's supposed to
be assigning it a priority of 1 in those cases).
>
> I'm a non developer trying to fix a freelancer's code. Would anybody be
able to suggest changes to the IF logic that might be able to fix it,
assuming the statements in the code provided look flawed?
>
> Thanks...
> --
> https://mail.python.org/mailman/listinfo/python-list


This line:

obj, created = SocialAccount.objects.get_or_create(...)

suggest you are using Django. If it is the case you have to add obj.save()
after changing the priority to send the new value to the DB.

Best,

Maxime
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From fomcl at yahoo.com  Tue Jan 13 04:43:15 2015
From: fomcl at yahoo.com (Albert-Jan Roskam)
Date: Tue, 13 Jan 2015 01:43:15 -0800
Subject: class-based class decorator
Message-ID: <1421142195.60033.BPMail_high_carrier@web163805.mail.gq1.yahoo.com>


----------------------------
On Tue, Jan 13, 2015 6:31 AM CET Ian Kelly wrote:

>On Jan 12, 2015 6:47 AM, "Albert-Jan Roskam" <fomcl at yahoo.com> wrote:
>> Thanks for your replies. I changed it into a regular decorator (not a class decorator). It would have been even nicer if I only needed to specify it once per class, but, well, in my case this hardly matters. The code below works as intended. One problem (not specific to the code): the decorator destroys the signature: it always becomes "*args, **kwargs"). This is annoying with help(), but what worries me most is that my Sphinx documentation is also affected. The information about the defaults gets lost (the parameters are decribed in the docstring, but not the defaults). That kind of sucks. Is there a builtin way around this (in other words: I am aware of this package: https://pypi.python.org/pypi/decorator). I am hoping to get the code working on Python 2.7 and 3.3 and up.
>
>As of (I think) 3.4 pydoc and the help() function will show you the
>signature of the wrapped function as long as you use functools.wraps.
>I don't know what the status is for Sphinx; all I can offer is this
>stackoverflow link.
>
>http://stackoverflow.com/questions/3687046/python-sphinx-autodoc-and-decorated-members

Thank you! Luckily, decorator.py is just one file, so I could easily include it. Version 3.4 is needed, because of a bug in an older version. Now I still need to find out how to create a git submodule to a hg repo, where the decorator package is. :-)



From jacob at blindza.co.za  Tue Jan 13 04:43:24 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Tue, 13 Jan 2015 11:43:24 +0200
Subject: Python 2.7, on windows7 64 bit development machine,
 inconsistent issue on similar machines
Message-ID: <A5E269C08DCE4D69B5A82C14FD81AB07@JakesPC>

Trying to run through all steps in data conversion app, and, up to last point, it's fine, but, if I try to handle direct execution of data structure, and data insertion scripts against a mySQL database, hosted locally here on same machine, running under wamp, then after code has completely finished executing everything, the command line just stops, and then I get the windows error dialogue pop up, telling me python.exe has stopped working.

If I run the same code on my other dev machine, which might just have a slightly simpler/cleaner combination of software, etc. installed on it, then it just runs straight through, and exits python interpreter instance, with no issues, and am just not sure how to try track down actual cause of this issue.

Here's part of the error dialogue's detailed information:
Problem signature:

Problem Event Name: APPCRASH

Application Name: python.exe

Application Version: 0.0.0.0

Application Timestamp: 4c303241

Fault Module Name: StackHash_0a9e

Fault Module Version: 0.0.0.0

Fault Module Timestamp: 00000000

Exception Code: c0000005

Exception Offset: 028e1289

OS Version: 6.1.7601.2.1.0.256.1

Locale ID: 2057

Additional Information 1: 0a9e

Additional Information 2: 0a9e372d3b4ad19135b953a78882e789

Additional Information 3: 0a9e

Additional Information 4: 0a9e372d3b4ad19135b953a78882e789

#---end of error info---



If I look for something similar via google, etc., I come across some mention of 32-64 bit incompatibility, or something, but, not sure if relevant, although am working with 32 bit versions of python 2.7, and both of my dev machines are in fact 64 bit windows7 machines, but haven't had issues like this in past.



Also, if I exclude last part of code, which handles directly working with MySQL database, then all cooperates fine, but, am pretty sure am closing all relevant connections, cursors, etc. - here's the last function that am calling/executing, in case relevant - there is still some testing/manual debugging stuff in here, but anyway:

#---start code---

  def convertExport(self):
    try:
      f_mysql = open("mysql.set", "rb")
      d_mysql = pickle.load(f_mysql)
      f_mysql.close()
      cn = None
      s_host = str(d_mysql["host"])
      s_user = str(d_mysql["user"])
      s_pass = str(d_mysql["password"])
      s_db = self.s_target_value
      cn = MySQLdb.connect(s_host, s_user, s_pass, s_db)
      if cn:
        cn.autocommit = True
        cur = cn.cursor()
        i_struct = 0
        i_data = 0
        f = open(self.s_sql_struct_file, "rb")
        s = f.read()
        f.close()
        l_struct = s.split(";")
        f = open(self.s_sql_data_file, "rb")
        s = f.read()
        f.close()
        l_data = unidecode(s).split(";")
        l_struct_errors = []
        l_data_errors = []
        i_start_time = int(time.time())
        s_status = "/{0} structs".format(str(len(l_struct)))
        for I in range(len(l_struct)):
          try:
            i_struct = I
            if str(l_struct[I]).strip() != "": res = cur.execute(l_struct[I] + ";")
            print(l_struct[I])
          #except Warning as wrn:
          #  print("warning: " + str(wrn.args))
          except Exception as exc:
            l_struct_errors.append([l_struct[I], copy.copy(exc)])
          finally:
            pass
        cn.commit()
        time.sleep(2.0)
        sNada = raw_input("hit enter to continue with data")
        s_status = "/{0} data".format(str(len(l_data)))
        for I in range(len(l_data)):
          try:
            #self.SetStatusText(str(I) + s_status)
            i_data = I
            if str(l_data[I]).strip() != "": res = cur.execute(l_data[I][l_data[I].index("INSERT"):] + ";")
            print(l_data[I][l_data[I].index("INSERT"):] + ";")
          except Exception as exc:
            l_data_errors.append([l_data[I], copy.copy(exc)])
          finally:
            pass
        i_end_time = int(time.time())
        s_time_taken = sTimeDiffFormat(i_start_time, i_end_time)
        cn.commit()
        cur.close()
        cn.close()
        print("cn and cur closed")
        fPickle = open("testDataErrors.pickle", "wb")
        pickle.dump(l_struct_errors, fPickle, 2)
        pickle.dump(l_data_errors, fPickle, 2)
        fPickle.close()
        print("pickled")
        print("MySQL Results - {0} structure queries, and {1} data queries completed - total of {2}".format(str(i_struct), str(i_data), s_time_taken))
        print("MySQL Errors - {0} structure query errors, and {1} data query errors".format(str(len(l_struct_errors)), str(len(l_data_errors))))
        print("Done!")
        sys.exit()
      else:
        print("Connection issue - There was a problem connecting to MySQL server")
        sys.exit()
    except Exception as exc:
      s_exc = str(exc.args)
      #lbc.DialogShow(title="errorMessage", message=s_exc)
      print(s_exc)
      exc_type, exc_obj, tb = sys.exc_info()
      print(str(exc_obj))
      print("line number: " + str(tb.tb_lineno))
  #end of convertExport function

#---end code---



If this is operating system specific, sorry, and will maybe also try debugging code via VS.Net 2013 shortly, but, thought someone might have an off-hand thought regarding something could try use to figure out this issue in meantime...?



TIA


Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."

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From tjreedy at udel.edu  Tue Jan 13 05:49:22 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Tue, 13 Jan 2015 05:49:22 -0500
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <CAPTjJmq5E+LJ8gjXQa7Sf+smc8ug59YZpofp7PH6WwjL55Gv=Q@mail.gmail.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <CAPTjJmq5E+LJ8gjXQa7Sf+smc8ug59YZpofp7PH6WwjL55Gv=Q@mail.gmail.com>
Message-ID: <m92t7i$q7q$1@ger.gmane.org>

On 1/13/2015 1:13 AM, Chris Angelico wrote:
> On Tue, Jan 13, 2015 at 4:32 PM, Steven D'Aprano <steve at pearwood.info> wrote:
>> Crashing the interpreter from
>> pure Python code is *absolutely not allowed*, so anything which would
>> allow that is forbidden.
>
> Except when you willingly shoot yourself in the foot.
>
> rosuav at sikorsky:~$ python
> Python 2.7.3 (default, Mar 13 2014, 11:03:55)
> [GCC 4.7.2] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
>>>> import sys
>>>> def f(): sys.setrecursionlimit(sys.getrecursionlimit()+1) or f()
> ...
>>>> f()
> Segmentation fault
> rosuav at sikorsky:~$ python3
> Python 3.5.0a0 (default:1c51f1650c42+, Dec 29 2014, 02:29:06)
> [GCC 4.7.2] on linux
> Type "help", "copyright", "credits" or "license" for more information.
>>>> import sys
>>>> def f(): sys.setrecursionlimit(sys.getrecursionlimit()+1) or f()
> ...
>>>> f()
> Segmentation fault
>
> But otherwise, yes. You shouldn't be able to segfault Python with Python code.

I would have expected an out-of-memory error.  If there is not already a 
crash issue on the tracker for this, you could add one.


-- 
Terry Jan Reedy



From rosuav at gmail.com  Tue Jan 13 05:56:47 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 13 Jan 2015 21:56:47 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <m92t7i$q7q$1@ger.gmane.org>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <CAPTjJmq5E+LJ8gjXQa7Sf+smc8ug59YZpofp7PH6WwjL55Gv=Q@mail.gmail.com>
 <m92t7i$q7q$1@ger.gmane.org>
Message-ID: <CAPTjJmq6ZjDMA8Z1x7tGX=8WuvLQmbxm_m5Cy-hektJWhi888w@mail.gmail.com>

On Tue, Jan 13, 2015 at 9:49 PM, Terry Reedy <tjreedy at udel.edu> wrote:
> I would have expected an out-of-memory error.  If there is not already a
> crash issue on the tracker for this, you could add one.

It's a stack fault, and it's a documented possibility:

https://docs.python.org/2/library/sys.html#sys.setrecursionlimit
https://docs.python.org/3/library/sys.html#sys.setrecursionlimit

Tracker search brings up this as a definite hit, and some other maybes:
http://bugs.python.org/issue6356

ChrisA


From marko at pacujo.net  Tue Jan 13 06:00:14 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Tue, 13 Jan 2015 13:00:14 +0200
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <CAPTjJmq5E+LJ8gjXQa7Sf+smc8ug59YZpofp7PH6WwjL55Gv=Q@mail.gmail.com>
 <mailman.17669.1421146184.18130.python-list@python.org>
Message-ID: <87lhl7c5dt.fsf@elektro.pacujo.net>

Terry Reedy <tjreedy at udel.edu>:

> On 1/13/2015 1:13 AM, Chris Angelico wrote:
>>>>> def f(): sys.setrecursionlimit(sys.getrecursionlimit()+1) or f()
>> ...
>>>>> f()
>> Segmentation fault
>>
>> But otherwise, yes. You shouldn't be able to segfault Python with
>> Python code.
>
> I would have expected an out-of-memory error. If there is not already
> a crash issue on the tracker for this, you could add one.

Linux grants memory it doesn't have. The truth comes out as a
segmentation fault. Call it modern banking.

The code above, though, shouldn't consume memory since it is a simple
tail-recursive loop.


Marko


From rosuav at gmail.com  Tue Jan 13 06:20:06 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 13 Jan 2015 22:20:06 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <87lhl7c5dt.fsf@elektro.pacujo.net>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <CAPTjJmq5E+LJ8gjXQa7Sf+smc8ug59YZpofp7PH6WwjL55Gv=Q@mail.gmail.com>
 <mailman.17669.1421146184.18130.python-list@python.org>
 <87lhl7c5dt.fsf@elektro.pacujo.net>
Message-ID: <CAPTjJmppq_4Bova_OvXVJN8Q+jGK22rFdoxjLWtM9F5_yF4RsQ@mail.gmail.com>

On Tue, Jan 13, 2015 at 10:00 PM, Marko Rauhamaa <marko at pacujo.net> wrote:
> Terry Reedy <tjreedy at udel.edu>:
>
>> On 1/13/2015 1:13 AM, Chris Angelico wrote:
>>>>>> def f(): sys.setrecursionlimit(sys.getrecursionlimit()+1) or f()
>>> ...
>>>>>> f()
>>> Segmentation fault
>>>
>>> But otherwise, yes. You shouldn't be able to segfault Python with
>>> Python code.
>>
>> I would have expected an out-of-memory error. If there is not already
>> a crash issue on the tracker for this, you could add one.
>
> Linux grants memory it doesn't have. The truth comes out as a
> segmentation fault. Call it modern banking.

I'm not sure it's a Linux problem. The same thing happens on Windows,
only without the "Segmentation fault" line. The exact behaviour on
stack overflow would depend on the layout of memory... back when I
wrote real-mode single-segment programs in DOS, the standard layout
was PSP, then code, then data, then stack, so overusing the stack
would overwrite your static data (and then, if you're really bad, your
code as well... things got fun then). My best guess now would be that
there's an actual boundary to the stack, and trying to access beyond
that triggers an immediate error - "you're not allowed to use that
memory". Nothing to do with over-allocating memory.

> The code above, though, shouldn't consume memory since it is a simple
> tail-recursive loop.

Only if the interpreter can optimize it away. Bear in mind that it
doesn't _return_ the result of that expression, so it needs to take
whatever f() returns, discard it, and return None. But I could have
defeated that, if I'd wanted to, by coding it to reduce the recursion
limit again after the call - it can't optimize away a non-tail-call.
Point is, if you take away the recursion limit, you _can_ crash
CPython. Likewise if you fiddle around with ctypes:

$ python3
Python 3.5.0a0 (default:1c51f1650c42+, Dec 29 2014, 02:29:06)
[GCC 4.7.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import ctypes
>>> ctypes.cast(id(1), ctypes.POINTER(ctypes.c_int))[6]=2
>>> 1
Segmentation fault

Not a bug. just a gun that you can shoot yourself in the foot with.

(Code nicked from
http://www.reddit.com/r/Python/comments/2441cv/can_you_change_the_value_of_1/
- from a comment saying "changing 1 this way just destroys
everything". Yep, it does, and pretty quckly too.)

ChrisA


From PointedEars at web.de  Tue Jan 13 06:43:07 2015
From: PointedEars at web.de (Thomas 'PointedEars' Lahn)
Date: Tue, 13 Jan 2015 12:43:07 +0100
Subject: Python 3 regex woes (parsing ISC DHCPD config)
References: <mailman.17631.1421087744.18130.python-list@python.org>
Message-ID: <1533669.jpulXfXtly@PointedEars.de>

Jason Bailey wrote:

> My script first reads the DHCPD configuration file into memory -
> variable "filebody". It then utilizes the re module to find the
> configuration details for the wanted "shared network".
> 
> The config file might look something like this:
> 
> ######################################
> 
> shared-network My-Network-MOHE {
>    subnet 192.168.0.0 netmask 255.255.248.0 {
>      option routers 192.168.0.1;
>      option tftp-server-name "192.168.90.12";
>      pool {
>        deny dynamic bootp clients;
>        range 192.168.0.20 192.168.7.254;
>      }
>    }
> }
> 
> shared-network My-Network-CDCO {
>    subnet 192.168.8.0 netmask 255.255.248.0 {
>      option routers 10.101.8.1;
>      option tftp-server-name "192.168.90.12";
>      pool {
>        deny dynamic bootp clients;
>        range 192.168.8.20 192.168.15.254;
>      }
>    }
> }
> 
> shared-network My-Network-FECO {
>    subnet 192.168.16.0 netmask 255.255.248.0 {
>      option routers 192.168.16.1;
>      option tftp-server-name "192.168.90.12";
>      pool {
>        deny dynamic bootp clients;
>        range 192.168.16.20 192.168.23.254;
>      }
>    }
> }
> 
> ######################################
> 
> Suppose I'm trying to grab the shared network called "My-Network-FECO"
> from the above config file stored in the variable 'filebody'.
> 
> First I have my variable 'shared_network' which contains the string
> "My-Network-FECO".
> 
> I compile my regex:
> m = re.compile(r"^(shared\-network (" + re.escape(shared_network) + r")
> \{((\n|.|\r\n)*?)(^\}))", re.MULTILINE|re.UNICODE)

This code does not run as posted.  Applying Occam?s Razor, I think you meant 
to post

m = re.compile(r"^(shared\-network ("
  + re.escape(shared_network)
  + r") \{((\n|.|\r\n)*?)(^\}))", re.MULTILINE|re.UNICODE)

(If you post long lines, know where your automatic word wrap happens.)

> I search for regex matches in my config file:
> m.search(filebody)

I find using the identifier ?m? for the expression very strange.  Usually I 
reserve ?m? to hold the *matches* for an expression on a string.
Consider ?r? or ?rx? or something else instead of ?m? for the expression.

> Unfortunately, I get no matches. From output on the command line, I can
> see that Python is adding extra backslashes to my re.compile string. I
> have added the raw 'r' in front of the strings to prevent it, but to no
> avail.

Python is adding the extra backslashes because you used ?r?.  Note that the 
console-printed string representations of strings do not have an ?r? in 
front of them.  What you see is what you would have needed to write for 
equivalent code if you had not used ?r?.  (Different from some other 
languages, Python does not distinguish between single-quoted and double-
quoted strings with regard to parsing.  Hence the r'?' feature, the triple-
quoted string, and the .format() method.)

You get no matches because you have escaped the HYPHEN-MINUSes (?-?).  You 
never need to escape those characters, in fact you must not do that here 
because r'\-' is not an (unnecessarily) escaped HYPHEN-MINUS, it is a 
literal backslash followed by a HYPHEN-MINUS, a character sequence that does 
not occur in your string.  Outside of a character class you do not need to 
do that, and in a character class you can put it as first or last character 
instead (?[-?]? or ?[?-]?).

You have escaped the first HYPHEN-MINUS; re.escape() has escaped the other 
two for you:

| >>> re.escape('-')
| '\\-'

I presume this behavior is because of character classes, and the idea that 
the return value should work at any position in a character class.

ISTM that you cannot use re.escape() here, and you must escape special 
characters yourself (using re.sub()), should they be possible in the file.

I do not see a reason for making the entire expression a group (but for 
making the network name a group).  

You should refrain from parsing non-regular languages with a *single* 
regular expression (multiple expressions or expressions with alternation in 
a loop are usually fine; this can be used for building efficient parsers), 
even though Python?s regular expressions, which are not an exception there, 
are not exactly ?regular? in the theoretical computer science sense.  See 
the Chomsky hierarchy and Jeffrey E. F. Friedl?s insightful textbook 
?Mastering Regular Expressions?.

It is possible that there is a Python module for parsing ISC dhcpd 
configuration files already.  If so, you should use that instead.

-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.


From stephen.boulet at gmail.com  Tue Jan 13 07:23:13 2015
From: stephen.boulet at gmail.com (stephen.boulet at gmail.com)
Date: Tue, 13 Jan 2015 04:23:13 -0800 (PST)
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <b4d90fbf-9f5a-4ffa-9013-0e70fc3e4e24@googlegroups.com>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
 <2f1dd848-e075-4435-93ef-c65af9a5148b@googlegroups.com>
 <b4d90fbf-9f5a-4ffa-9013-0e70fc3e4e24@googlegroups.com>
Message-ID: <5ac77acc-c8db-40a8-812d-731ef6224c01@googlegroups.com>

I found a solution that I'm happy with.

from datetime import datetime
from easygui_qt import *

datestring = get_date()
mydate = datetime.strptime(datestring, '%b %d %Y')

On Saturday, January 10, 2015 at 1:02:30 AM UTC, Andr? Roberge wrote:
> On Friday, 9 January 2015 19:09:15 UTC-4, stephen... at gmail.com  wrote:
> > On Wednesday, December 31, 2014 at 4:24:50 PM UTC-6, Andr? Roberge wrote:
> > > EasyGUI_Qt version 0.9 has been released.  This is the first announcement about EasyGUI_Qt on this list.
> > > 
> > > Like the original EasyGUI (which used Tkinter), 
> > > EasyGUI_Qt seeks to provide simple GUI widgets
> > > that can be called in a procedural program. 
> > > 
> > > EasyGUI_Qt is NOT event-driven: all GUI interactions are invoked by simple function calls.
> > > 
> > > The archetype is get_string(message)
> > > which pops a box whose purpose is exactly the same as Python's input(prompt),
> > > that is, present the user with a question/prompt, have the user enter an
> > > answer, and return the provided answer as a string.  Thus
> > > easygui_qt.get_string() can be used as a drop-in replacement for
> > > input().
> > > 
> > > Similarly, instead of using a print() function to display a message,
> > > show_message() is used which pops a message window.
> > > 
> > > EasyGUI_Qt requires PyQt4 and is really targeted for Python 3.3+ - although it can work (possibly with some unicode problems ...) using Python 2.7.
> > > 
> > > More information can be found at 
> > > http://easygui-qt.readthedocs.org/en/latest/index.html
> > > 
> > > Feedback is most welcome, including reporting bugs to 
> > > https://github.com/aroberge/easygui_qt/issues
> > > 
> > > Happy 2015 everyone,
> > > 
> > > Andr? Roberge
> > 
> > Very nice, thanks.
> > 
> > One issue is the format returned for the calendar selection. For today, the string returned is "Fri Jan 9 2015". My script needs to convert the date to a datetime.date, and having the month returned as a string instead of an integer makes this harder.
> 
> Would today's date be represented as the string "09.01.2015" useful to you? (I found out how to do this.)  If so, I could perhaps add an argument like numeric_format = True.
> 
> Andr?


From stephen.boulet at gmail.com  Tue Jan 13 07:51:19 2015
From: stephen.boulet at gmail.com (stephen.boulet at gmail.com)
Date: Tue, 13 Jan 2015 04:51:19 -0800 (PST)
Subject: Help understanding list operatoins inside functions in python 3
Message-ID: <eb7dcc11-410d-44a9-b619-e5ae70876aa1@googlegroups.com>

I'm a bit confused why in the second case x is not [1,2,3]:

x = []

def y():
    x.append(1)

def z():
    x = [1,2,3]

y()
print(x)
z()
print(x)

Output:
[1]
[1]


From alister.nospam.ware at ntlworld.com  Tue Jan 13 08:23:24 2015
From: alister.nospam.ware at ntlworld.com (alister)
Date: Tue, 13 Jan 2015 13:23:24 GMT
Subject: Python 3 regex?
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <54b4a0d6$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <g%8tw.7$et7.1@fx45.am4>

On Tue, 13 Jan 2015 04:36:38 +0000, Steven D'Aprano wrote:

> On Mon, 12 Jan 2015 19:48:18 +0000, Ian wrote:
> 
>> My recommendation would be to write a recursive decent parser for your
>> files.
>> 
>> That way will be easier to write,
> 
> I know that writing parsers is a solved problem in computer science, and
> that doing so is allegedly one of the more trivial things computer
> scientists are supposed to be able to do, but the learning curve to
> write parsers is if anything even higher than the learning curve to
> write a regex.
> 
> I wish that Python made it as easy to use EBNF to write a parser as it
> makes to use a regex :-(
> 
> http://en.wikipedia.org/wiki/Extended_Backus?Naur_Form



I would not say that writing parsers is a solved problem.
there may be solutions for a number of specific cases but many cases 
still cause difficulty, as an example I do not think there is a 100% 
complete parser for English (even native English speakers don't always 
get it)

-- 
Keep the number of passes in a compiler to a minimum.
		-- D. Gries


From joel.goldstick at gmail.com  Tue Jan 13 08:39:46 2015
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Tue, 13 Jan 2015 08:39:46 -0500
Subject: Help understanding list operatoins inside functions in python 3
In-Reply-To: <eb7dcc11-410d-44a9-b619-e5ae70876aa1@googlegroups.com>
References: <eb7dcc11-410d-44a9-b619-e5ae70876aa1@googlegroups.com>
Message-ID: <CAPM-O+x=G7xPaPJPAVsVtK+7Nr7DtcZk9KqpxL3QxuSbTYZCrg@mail.gmail.com>

On Tue, Jan 13, 2015 at 7:51 AM, <stephen.boulet at gmail.com> wrote:

> I'm a bit confused why in the second case x is not [1,2,3]:
>
> x = []
>
> def y():
>     x.append(1)
>
> def z():
>     x = [1,2,3]
>
> y()
> print(x)
> z()
> print(x)
>
> Output:
> [1]
> [1]
>

x in the outer scope is not x in the z() scope

> --
> https://mail.python.org/mailman/listinfo/python-list
>



-- 
Joel Goldstick
http://joelgoldstick.com
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From Shambhu.Rajak at sandisk.com  Tue Jan 13 08:40:52 2015
From: Shambhu.Rajak at sandisk.com (Shambhu Rajak)
Date: Tue, 13 Jan 2015 13:40:52 +0000
Subject: what would be the regular expression for null byte present in a string
Message-ID: <39F9E8A5546B9448A82E55FBEBE3EC450BD029A5@SACMBXIP03.sdcorp.global.sandisk.com>

I have a string that I get as an output of a command as:
'\x01\x00\x00\x00\x00\x00\x00\x00\x0c\x00\x00\x0010232ae8944a\x02\x00\x00\x00\x00\x00\x00\x00\n'

I want to fetch '10232ae8944a' from the above string.

I want to find a re pattern that could replace all the \x01..\x0z to be replace by empty string '',  so that I can get the desired portion of string

Can anyone help me with a working regex for it.

Thanks,
Shambhu

________________________________

PLEASE NOTE: The information contained in this electronic mail message is intended only for the use of the designated recipient(s) named above. If the reader of this message is not the intended recipient, you are hereby notified that you have received this message in error and that any review, dissemination, distribution, or copying of this message is strictly prohibited. If you have received this communication in error, please notify the sender by telephone or e-mail (as shown above) immediately and destroy any and all copies of this message in your possession (whether hard copies or electronically stored copies).

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From laurent.pointal at laposte.net  Tue Jan 13 08:43:28 2015
From: laurent.pointal at laposte.net (Laurent Pointal)
Date: Tue, 13 Jan 2015 14:43:28 +0100
Subject: Help understanding list operatoins inside functions in python 3
References: <eb7dcc11-410d-44a9-b619-e5ae70876aa1@googlegroups.com>
Message-ID: <54b52101$0$12756$426a34cc@news.free.fr>

Hello,

stephen.boulet at gmail.com wrote:

> I'm a bit confused why in the second case x is not [1,2,3]:
> 
> x = []
> 
> def y():
>     x.append(1)
> 
> def z():
>     x = [1,2,3]

Here x is a local, so global x is not modified.
If you want to modify gobal x, write:
def z():
    global x
    x = [1,2,3]

You can read the Python FAQ about global/local rules:

https://docs.python.org/3/faq/programming.html#what-are-the-rules-for-local-and-global-variables-in-python

Or Dive Into Python

http://www.diveintopython.net/html_processing/locals_and_globals.html

(and for your problem, its the same with Python2 and Python3)

Or?

A+
Laurent.


From mortoxa at gmx.com  Tue Jan 13 08:49:06 2015
From: mortoxa at gmx.com (mortoxa)
Date: Wed, 14 Jan 2015 00:49:06 +1100
Subject: Help understanding list operatoins inside functions in python
 3
In-Reply-To: <eb7dcc11-410d-44a9-b619-e5ae70876aa1@googlegroups.com>
References: <eb7dcc11-410d-44a9-b619-e5ae70876aa1@googlegroups.com>
Message-ID: <54B52252.20707@gmx.com>


On 01/13/15 23:51, stephen.boulet at gmail.com wrote:
> I'm a bit confused why in the second case x is not [1,2,3]:
>
> x = []
>
> def y():
>      x.append(1)
>
> def z():
>      x = [1,2,3]
>
> y()
> print(x)
> z()
> print(x)
>
> Output:
> [1]
> [1]

In your y() function, as you are appending data, the list must already 
exist. So the global list x is used

In your z() function, you are creating a local list x which only exists 
as long as you are in the function.
Anything you do to that list has no effect on the global list x. That is 
why the list does not change.

If you specifically wanted to change the global list x, you could do this:

def z():
     global x
     x = [1, 2, 3]

Output:
[1]
[1, 2, 3]

Or better

def z():
     x = [1, 2, 3]
     return x

y()
print(x)
x = z()
print(x)

Output:
[1]
[1, 2, 3]
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From jpiitula at ling.helsinki.fi  Tue Jan 13 08:58:11 2015
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 13 Jan 2015 15:58:11 +0200
Subject: Python 3 regex?
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <54b4a0d6$0$2738$c3e8da3$76491128@news.astraweb.com> <g%8tw.7$et7.1@fx45.am4>
Message-ID: <qotbnm2wznw.fsf@ruuvi.it.helsinki.fi>

alister <alister.nospam.ware at ntlworld.com> writes:

> On Tue, 13 Jan 2015 04:36:38 +0000, Steven D'Aprano wrote:
> 
> > On Mon, 12 Jan 2015 19:48:18 +0000, Ian wrote:
> > 
> >> My recommendation would be to write a recursive decent parser for
> >> your files.
> >> 
> >> That way will be easier to write,
> > 
> > I know that writing parsers is a solved problem in computer
> > science, and that doing so is allegedly one of the more trivial
> > things computer scientists are supposed to be able to do, but the
> > learning curve to write parsers is if anything even higher than
> > the learning curve to write a regex.
> > 
> > I wish that Python made it as easy to use EBNF to write a parser as it
> > makes to use a regex :-(
> > 
> > http://en.wikipedia.org/wiki/Extended_Backus?Naur_Form
> 
> I would not say that writing parsers is a solved problem.  there may
> be solutions for a number of specific cases but many cases still
> cause difficulty, as an example I do not think there is a 100%
> complete parser for English (even native English speakers don't
> always get it)

There is no complete characterization of English as a set of character
strings, nor will there ever be. Linguists have a slogan for this: All
Grammars Leak. (They used to write formal grammars to characterize
"all and only the well-formed sentences" of a language, or to capture
"necessary and sufficient conditions", and those grammars turned out
to both "over-generate" and "under-generate".)

Ambiguity doesn't help. In practice, it's not enough to find a parse.
One wants a contextually appropriate parse. Sometimes this requires
genuine understanding and knowledge. Also in practice, one may not be
in the business of rejecting ill-formed sentences: one wants to make
partial sense of even those. So, no, never 100 percent complete or 100
percent correct :)

The solved problem is the unambiguous parsing of formal languages that
are defined by a formal grammar to begin with, like the configuration
file format at hand.


From joboppsgpp at gmail.com  Tue Jan 13 09:28:36 2015
From: joboppsgpp at gmail.com (joboppsgpp at gmail.com)
Date: Tue, 13 Jan 2015 06:28:36 -0800 (PST)
Subject: Broken IF statement
In-Reply-To: <ae5a458e-2914-4cd3-81f0-a3b93eab1a14@googlegroups.com>
References: <dd384c6d-17c0-4850-ad5b-6b073c80bdb8@googlegroups.com>
 <mailman.17641.1421099337.18130.python-list@python.org>
 <ae5a458e-2914-4cd3-81f0-a3b93eab1a14@googlegroups.com>
Message-ID: <8e7a3125-c8dd-4616-aebb-13eb96bc5665@googlegroups.com>

On Monday, January 12, 2015 at 4:55:43 PM UTC-5, jobop... at gmail.com wrote:
> Thanks Chris. This definitely helps. I will test it and see what happens. In terms of the previous code, what it was intended to do wasn't actually happening.

Thanks Chris. Your change worked.


From joboppsgpp at gmail.com  Tue Jan 13 09:29:11 2015
From: joboppsgpp at gmail.com (joboppsgpp at gmail.com)
Date: Tue, 13 Jan 2015 06:29:11 -0800 (PST)
Subject: Broken IF statement
In-Reply-To: <mailman.17668.1421143058.18130.python-list@python.org>
References: <dd384c6d-17c0-4850-ad5b-6b073c80bdb8@googlegroups.com>
 <mailman.17668.1421143058.18130.python-list@python.org>
Message-ID: <9a808384-6c59-4266-b5b4-32ce6bed9531@googlegroups.com>

On Tuesday, January 13, 2015 at 4:57:50 AM UTC-5, Maxime S wrote:
> 2015-01-12 22:19 GMT+01:00 <jobop... at gmail.com>:
> >
> > https://bpaste.net/show/93be9e15634b <--- Line 19 through 22
> >
> > At all times, my program is assigning the object priority of 0, even if one already exists in the database with a priority of 0 (it's supposed to be assigning it a priority of 1 in those cases).
> >
> > I'm a non developer trying to fix a freelancer's code. Would anybody be able to suggest changes to the IF logic that might be able to fix it, assuming the statements in the code provided look flawed?
> >
> > Thanks...
> > --
> > https://mail.python.org/mailman/listinfo/python-list
> 
> 
> This line:
> 
> obj, created = SocialAccount.objects.get_or_create(...)
> 
> suggest you are using Django. If it is the case you have to add obj.save() after changing the priority to send the new value to the DB.
> 
> Best,
> 
> Maxime

Thanks Maxime. I'll try that as well.


From __peter__ at web.de  Tue Jan 13 09:41:51 2015
From: __peter__ at web.de (Peter Otten)
Date: Tue, 13 Jan 2015 15:41:51 +0100
Subject: what would be the regular expression for null byte present in a
 string
References: <39F9E8A5546B9448A82E55FBEBE3EC450BD029A5@SACMBXIP03.sdcorp.global.sandisk.com>
Message-ID: <m93arg$r9h$1@ger.gmane.org>

Shambhu Rajak wrote:

> I have a string that I get as an output of a command as:
> 
'\x01\x00\x00\x00\x00\x00\x00\x00\x0c\x00\x00\x0010232ae8944a\x02\x00\x00\x00\x00\x00\x00\x00\n'
> 
> I want to fetch '10232ae8944a' from the above string.
> 
> I want to find a re pattern that could replace all the \x01..\x0z to be
> replace by empty string '',  so that I can get the desired portion of
> string
> 
> Can anyone help me with a working regex for it.

I think you want the str.tranlate() method rather than a regex. 

Assuming you are using Python 2:

>>> delenda = "".join(map(chr, range(32)))
>>> identity = "".join(map(chr, range(256)))
>>> 
'\x01\x00\x00\x00\x00\x00\x00\x00\x0c\x00\x00\x0010232ae8944a\x02\x00\x00\x00\x00\x00\x00\x00\n'.translate(identity, 
delenda)
'10232ae8944a'

With Python3:

>>> mapping = dict.fromkeys(range(32))
>>> 
'\x01\x00\x00\x00\x00\x00\x00\x00\x0c\x00\x00\x0010232ae8944a\x02\x00\x00\x00\x00\x00\x00\x00\n'.translate(mapping)
'10232ae8944a'




From gregory.j.baker at gmail.com  Tue Jan 13 09:56:11 2015
From: gregory.j.baker at gmail.com (Novocastrian_Nomad)
Date: Tue, 13 Jan 2015 06:56:11 -0800 (PST)
Subject: How can i use a dictionnary
In-Reply-To: <233574bb-a552-49f2-b803-86523e2b5741@googlegroups.com>
References: <233574bb-a552-49f2-b803-86523e2b5741@googlegroups.com>
Message-ID: <2b71cef0-fae6-466c-af9c-79c503bd1402@googlegroups.com>

On Tuesday, January 13, 2015 at 2:03:30 AM UTC-7, brice DORA wrote:
> i consume a web service that return a element whose the type is "instance". but this element seem be a dictionary but when i want to use it like a dictionary, i got some errors. so this is the element and please someone can tell me how can i use it. tkanks in advance.
> 
> 
> (tCountryInfo){
>    sISOCode = "CI"
>    sName = "C??te D'Ivoire (Ivory Coast)"
>    sCapitalCity = "Yamoussoukro"
>    sPhoneCode = "225"
>    sContinentCode = "AF"
>    sCurrencyISOCode = "XOF"
>    sCountryFlag = "http://www.oorsprong.org/WebSamples.CountryInfo/Images/C??te D'Ivoire.jpg"
>    Languages = 
>       (ArrayOftLanguage){
>          tLanguage[] = 
>             (tLanguage){
>                sISOCode = "fr"
>                sName = "French"
>             },
>       }
>  }

This data is not a Python dictionary, nor is it a JSON object.  You will probably need to code your own conversion function to make it a Python dictionary.


From random832 at fastmail.us  Tue Jan 13 11:01:05 2015
From: random832 at fastmail.us (random832 at fastmail.us)
Date: Tue, 13 Jan 2015 11:01:05 -0500
Subject: How can i use a dictionnary
In-Reply-To: <233574bb-a552-49f2-b803-86523e2b5741@googlegroups.com>
References: <233574bb-a552-49f2-b803-86523e2b5741@googlegroups.com>
Message-ID: <1421164865.3735855.213348249.357DD2BF@webmail.messagingengine.com>

On Tue, Jan 13, 2015, at 04:03, brice DORA wrote:
> i consume a web service that return a element whose the type is
> "instance". but this element seem be a dictionary but when i want to use
> it like a dictionary, i got some errors. so this is the element and
> please someone can tell me how can i use it. tkanks in advance.

Do you have any more information about this web service, so that you can
find a formal specification (or at least name) of the output format, or
maybe a way to make it return XML or JSON instead?


From rantingrickjohnson at gmail.com  Tue Jan 13 11:01:32 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Tue, 13 Jan 2015 08:01:32 -0800 (PST)
Subject: Python 3 regex?
In-Reply-To: <mailman.17656.1421127286.18130.python-list@python.org>
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
 <mailman.17649.1421114112.18130.python-list@python.org>
 <7c648fa2-4a59-4d1a-923f-d29f4f2dc8f7@googlegroups.com>
 <mailman.17656.1421127286.18130.python-list@python.org>
Message-ID: <d527c717-e743-415b-b90d-2404c2160344@googlegroups.com>

On Monday, January 12, 2015 at 11:34:57 PM UTC-6, Mark Lawrence wrote:
> You snipped the bit that says [normal cobblers snipped].

Oh my, where are my *manners* today? Tell you what, next time when
your sneaking up behind me with a knife in hand, do be a
friend and tap me on the shoulder first, so i can take the
knife and stab *myself* in the back!

Your pal, Rick.


From info at egenix.com  Tue Jan 13 11:08:10 2015
From: info at egenix.com (eGenix Team: M.-A. Lemburg)
Date: Tue, 13 Jan 2015 17:08:10 +0100
Subject: =?UTF-8?Q?ANN:_Python_Meeting_D=c3=bcsseldorf_-_20.01.2014?=
Message-ID: <54B542EA.2000902@egenix.com>

[This announcement is in German since it targets a local user group
 meeting in D?sseldorf, Germany]

________________________________________________________________________
ANK?NDIGUNG

                     Python Meeting D?sseldorf

                         http://pyddf.de/

       Ein Treffen von Python Enthusiasten und Interessierten
                    in ungezwungener Atmosph?re.

                  Dienstag, 20.01.2014, 18:00 Uhr
          Raum 1, 2.OG im B?rgerhaus Stadtteilzentrum Bilk
        D?sseldorfer Arcaden, Bachstr. 145, 40217 D?sseldorf

Diese Nachricht ist auch online verf?gbar:
http://www.egenix.com/company/news/Python-Meeting-Duesseldorf-2015-01-20

________________________________________________________________________
NEUIGKEITEN

 * Bereits angemeldete Vortr?ge:

   Dr. Klaus Bremer
       "Class-based Views in Django"
       "Evolutionssimulation mit genetischen Algorithmen"

   Detlef Lannert
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   Weitere Vortr?ge k?nnen gerne noch angemeldet werden: info at pyddf.de

 * Startzeit und Ort:

   Wir treffen uns um 18:00 Uhr im B?rgerhaus in den D?sseldorfer
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   Das B?rgerhaus teilt sich den Eingang mit dem Schwimmbad
   und befindet sich an der Seite der Tiefgarageneinfahrt der
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   ?ber dem Eingang steht ein gro?es ?Schwimm?'in Bilk?
   Logo. Hinter der T?r direkt links zu den zwei Aufz?gen,
   dann in den 2. Stock hochfahren. Der Eingang zum Raum 1
   liegt direkt links, wenn man aus dem Aufzug kommt.

   Google Street View: http://bit.ly/11sCfiw

________________________________________________________________________
EINLEITUNG

Das Python Meeting D?sseldorf ist eine regelm??ige Veranstaltung in
D?sseldorf, die sich an Python Begeisterte aus der Region wendet:

 * http://pyddf.de/

Einen guten ?berblick ?ber die Vortr?ge bietet unser YouTube-Kanal,
auf dem wir die Vortr?ge nach den Meetings ver?ffentlichen:

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Veranstaltet wird das Meeting von der eGenix.com GmbH, Langenfeld,
in Zusammenarbeit mit Clark Consulting & Research, D?sseldorf:

 * http://www.egenix.com/
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________________________________________________________________________
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Das Python Meeting D?sseldorf nutzt eine Mischung aus Open Space
und Lightning Talks, wobei die Gewitter bei uns auch schon mal
20 Minuten dauern k?nnen ;-).

Lightning Talks k?nnen vorher angemeldet werden, oder auch
spontan w?hrend des Treffens eingebracht werden. Ein Beamer mit
XGA Aufl?sung steht zur Verf?gung. Folien bitte als PDF auf USB
Stick mitbringen.

Lightning Talk Anmeldung bitte formlos per EMail an info at pyddf.de

________________________________________________________________________
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Das Python Meeting D?sseldorf wird von Python Nutzern f?r Python
Nutzer veranstaltet. Um die Kosten zumindest teilweise zu
refinanzieren, bitten wir die Teilnehmer um einen Beitrag
in H?he von EUR 10,00 inkl. 19% Mwst, Sch?ler und Studenten
zahlen EUR 5,00 inkl. 19% Mwst.

Wir m?chten alle Teilnehmer bitten, den Betrag in bar mitzubringen.

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Da wir nur f?r ca. 20 Personen Sitzpl?tze haben, m?chten wir
bitten, sich per EMail anzumelden. Damit wird keine Verpflichtung
eingegangen. Es erleichtert uns allerdings die Planung.

Meeting Anmeldung bitte formlos per EMail an info at pyddf.de

________________________________________________________________________
WEITERE INFORMATIONEN

Weitere Informationen finden Sie auf der Webseite des Meetings:

    http://pyddf.de/

Mit freundlichen Gr??en,
-- 
Marc-Andre Lemburg
eGenix.com

Professional Python Services directly from the Source  (#1, Jan 13 2015)
>>> Python Projects, Coaching and Consulting ...  http://www.egenix.com/
>>> mxODBC Plone/Zope Database Adapter ...       http://zope.egenix.com/
>>> mxODBC, mxDateTime, mxTextTools ...        http://python.egenix.com/
________________________________________________________________________

::::: Try our mxODBC.Connect Python Database Interface for free ! ::::::

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From PointedEars at web.de  Tue Jan 13 11:09:36 2015
From: PointedEars at web.de (Thomas 'PointedEars' Lahn)
Date: Tue, 13 Jan 2015 17:09:36 +0100
Subject: Python 3 regex woes (parsing ISC DHCPD config)
References: <mailman.17631.1421087744.18130.python-list@python.org>
 <1533669.jpulXfXtly@PointedEars.de>
Message-ID: <5646501.ZqAenxCB1C@PointedEars.de>

Thomas 'PointedEars' Lahn wrote:

> Jason Bailey wrote:
>> shared-network My-Network-MOHE {
>>    [?] {
>>
>> I compile my regex:
>> m = re.compile(r"^(shared\-network (" + re.escape(shared_network) + r")
>> \{((\n|.|\r\n)*?)(^\}))", re.MULTILINE|re.UNICODE)
> 
> This code does not run as posted.  Applying Occam?s Razor, I think you
> meant to post
> 
> m = re.compile(r"^(shared\-network ("
>   + re.escape(shared_network)
>   + r") \{((\n|.|\r\n)*?)(^\}))", re.MULTILINE|re.UNICODE)
> 
> [?]
> You get no matches because you have escaped the HYPHEN-MINUSes (?-?).  You
> never need to escape those characters, in fact you must not do that here
> because r'\-' is not an (unnecessarily) escaped HYPHEN-MINUS, it is a
> literal backslash followed by a HYPHEN-MINUS, a character sequence that
> does not occur in your string.  Outside of a character class you do not
> need to do that, and in a character class you can put it as first or last
> character instead (?[-?]? or ?[?-]?).
> 
> You have escaped the first HYPHEN-MINUS; re.escape() has escaped the other
> two for you:
> 
> | >>> re.escape('-')
> | '\\-'
> 
> I presume this behavior is because of character classes, and the idea that
> the return value should work at any position in a character class.

It would appear that while my answer is not entirely wrong, the first 
sentence of that section is.  You may escape the HYPHEN-MINUS there, and may 
use re.escape(); it has no effect on the expression because of what I said 
following that sentence.  One must consider that the string is first parsed 
by Python?s string parser and then by Python?s re parser.

So I have presently no specific idea why you get no matches, however

  r'\{((\n|.|\r\n)*?)(^\}'

is not a proper way to match matching braces and everything in-between.

To begin with, the proper expression to match any newline is r'(\r?\n|\r)' 
because the first matching alternative in an alternation, not the longest 
one, wins.  But if you specify re.DOTALL, you can simply use ?.? for any 
character (including any newline combination).
 
> [?]
> You should refrain from parsing non-regular languages with a *single*
> regular expression (multiple expressions or expressions with alternation
> in a loop are usually fine; this can be used for building efficient
> parsers), even though Python?s regular expressions, which are not an
> exception there,
> are not exactly ?regular? in the theoretical computer science sense.  See
> the Chomsky hierarchy and Jeffrey E. F. Friedl?s insightful textbook
> ?Mastering Regular Expressions?.

And for matching matching braces (sic!) with regular expressions, you need a 
recursive one (which is another extension of regular expressions as they are 
discussed in CS).  Or a parser in the first place.  Otherwise you match too 
much with greedy matching

  { { } } { { } }
  ^-------------^

or too little with non-greedy matching

  { { } } { { } }
  ^---^

CS regular expressions can be used to describe *regular* languages (Chomsky-
type 3).  Bracket languages are, in general, not regular (see ?pumping lemma 
for regular languages?), so for them you need an PDA?-like extension of CS 
regular expressions (the aforementioned recursive ones), or a PDA 
implementation in the first place.  Such a PDA implementation is part of a 
parser.

____
?  <https://en.wikipedia.org/wiki/Pushdown_automaton>
-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.


From robertchen117 at gmail.com  Tue Jan 13 11:17:18 2015
From: robertchen117 at gmail.com (robertchen117 at gmail.com)
Date: Tue, 13 Jan 2015 08:17:18 -0800 (PST)
Subject: how can I create a class and decode/encode as json?
Message-ID: <d6ddd0ed-c783-4e28-8a27-e17a4240ed41@googlegroups.com>

I want to send Message to rabbitmq and receive from rabbitmq, message format is below. 

how can I create a class and decode/encode as json? 

{
   "message":{
      "dateCreated": "1417713299",
      "sourceApplication": "ID",
	"destinationApplication": "Name",
      "messageUUID": "sdafdasdfas",
      "response-type":"queue",
      "response-type-details":"queue-name",
      "messageType":"request",
      "operations":[
         {
            "sequence":0,
            "operation":"add",
            "version":1,
            "data-type":"json",
            "data-schema":"a.json",
            "data-encoding":"base64",
            "data-encryption":"BLOWFISH",
            "data-encryption-keyname":"psk-name",
            "data":"<base64 data>"
         },
         {
            "sequence":1,
            "operation":"otherOperation",
            "version":2.1,
            "response-type":"topic",
            "response-type-details":"topic-name",
            "data-type":"XML",
            "data-schema":"ddd.xsd",
            "data-encoding":"string",
            "data-encryption":"NONE",
            "data":"<xml></xml>"
         }
      ]
   }
}

thanks.


From jeanmichel at sequans.com  Tue Jan 13 11:37:25 2015
From: jeanmichel at sequans.com (Jean-Michel Pichavant)
Date: Tue, 13 Jan 2015 17:37:25 +0100 (CET)
Subject: class-based class decorator
In-Reply-To: <129524411.66934.1421137532472.JavaMail.yahoo@jws10725.mail.gq1.yahoo.com>
Message-ID: <41960019.9418586.1421167045799.JavaMail.root@sequans.com>

----- Original Message -----
> From: "Albert-Jan Roskam" <fomcl at yahoo.com>
> > From: Jean-Michel Pichavant <jeanmichel at sequans.com>
> > I don't really understand how you successfuly manage positional
> > parameters,
> > since the caller may not name them.
> > I'm asking because if your intend to check only the keyword
> > parameters,
> > there's a much simplier solution.
> > 
> > JM
> 
> 
> Hi,
> 
> Can you give an example of where/how my code would fail? I do not
> intend to use *args and **kwargs, if that is what you mean. I am
> interested in hearing a simpler approach, especially if it would
> also solve the messed-up-signature problem that I mentioned.
> 
> Thank you!
> 
> Albert-Jan
> 

In the example you've given you've deprecated only keyword arguments. So I was wondering...

would the following *untested* code work ? :

def check_deprecated_args(deprecated):
  def decorator(func):
    def inner(*args, **kwargs):
      for p in deprecated:
        if p in kwargs:
          print '%s is deprecated' % p
      return func(*args, **kwargs)
    return inner
  return decorator

JM


-- IMPORTANT NOTICE: 

The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

From jbaptiste.braun at gmail.com  Tue Jan 13 12:02:17 2015
From: jbaptiste.braun at gmail.com (Jean-Baptiste Braun)
Date: Tue, 13 Jan 2015 18:02:17 +0100
Subject: Performance in exec environnements
Message-ID: <CABUUr0zB97+PnVm46WAHjzP=RFtwn8QrSFwqm_nw6ZWXk1qRVw@mail.gmail.com>

Hi,

I'm working on auto-generated python code with the exec function. I've done
some performance benches :

% python -m timeit '1 + 1'
10000000 loops, best of 3: 0.0229 usec per loop

% python -m timeit "exec('1 + 1')"
100000 loops, best of 3: 11.6 usec per loop

-> Maybe creating an exec environnement (I don't know how it works) takes
time. But :

% python -m timeit "1 + 1; 1 + 1"
10000000 loops, best of 3: 0.042 usec per loop

% python -m timeit "exec('1 + 1; 1 + 1')"
100000 loops, best of 3: 15.7 usec per loop

-> As if executing one more 1 + 1 would take 4 more seconds (100000
iterations) in an exec environnement.

Am I missing something or should I expect that result ? What does using
exec imply that causes such a difference ?

Jean-Baptiste Braun
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From israel at ravnalaska.net  Tue Jan 13 12:03:22 2015
From: israel at ravnalaska.net (Israel Brewster)
Date: Tue, 13 Jan 2015 08:03:22 -0900
Subject: Track down SIGABRT
In-Reply-To: <CANy1k1jiNGXSJVJjCAh4xEw9eiS=hdswEhhioONqsLRvxeSdTw@mail.gmail.com>
References: <B967FFA3-810A-4C9F-A353-A3C5E8C9ED6B@ravnalaska.net>
 <CANy1k1jiNGXSJVJjCAh4xEw9eiS=hdswEhhioONqsLRvxeSdTw@mail.gmail.com>
Message-ID: <901C1EAD-ED8E-495E-BEAC-76F3E702CF86@ravnalaska.net>

On Jan 12, 2015, at 5:51 PM, Jason Friedman <jsf80238 at gmail.com> wrote:

>> I have a long-running python/CherryPy Web App server process that I am
>> running on Mac OS X 10.8.5. Python 2.7.2 running in 32-bit mode (for now, I
>> have the code in place to change over to 64 bit, but need to schedule the
>> downtime to do it). On the 6th of this month, during normal operation from
>> what I can tell, and after around 33 days of trouble-free uptime, the python
>> process crashed with a SIGABRT. I restarted the process, and everything
>> looked good again until yesterday, when it again crashed with a SIGABRT.
> 
> Can you monitor disk and memory on the host?  Perhaps it is climbing
> towards an unacceptable value right before crashing.

Good thought. I'm pretty sure that the system monitor still showed a couple of gigs free memory before the last crash, but the process could still be using unacceptable amounts of resources

> 
> Do you have the option of stopping and starting your process every
> night or every week?

Yes, that's an option, and as a work-around I'll consider it. Of course, I'd much rather not have the thing crash in the first place :-)

> -- 
> https://mail.python.org/mailman/listinfo/python-list

-----------------------------------------------
Israel Brewster
Systems Analyst II
Ravn Alaska
5245 Airport Industrial Rd
Fairbanks, AK 99709
(907) 450-7293
-----------------------------------------------



From israel at ravnalaska.net  Tue Jan 13 12:05:17 2015
From: israel at ravnalaska.net (Israel Brewster)
Date: Tue, 13 Jan 2015 08:05:17 -0900
Subject: Track down SIGABRT
In-Reply-To: <7FF67692-9F7B-4EE1-AD9F-83DAC545A78A@mac.com>
References: <B967FFA3-810A-4C9F-A353-A3C5E8C9ED6B@ravnalaska.net>
 <7FF67692-9F7B-4EE1-AD9F-83DAC545A78A@mac.com>
Message-ID: <41D1FC10-000B-4DD7-8C40-12D92F62BC25@ravnalaska.net>

On Jan 13, 2015, at 6:27 AM, William Ray Wing <wrw at mac.com> wrote:

> 
>> On Jan 9, 2015, at 12:40 PM, Israel Brewster <israel at ravnalaska.net> wrote:
>> 
>> I have a long-running python/CherryPy Web App server process that I am running on Mac OS X 10.8.5. Python 2.7.2 running in 32-bit mode (for now, I have the code in place to change over to 64 bit, but need to schedule the downtime to do it). On the 6th of this month, during normal operation from what I can tell, and after around 33 days of trouble-free uptime, the python process crashed with a SIGABRT. I restarted the process, and everything looked good again until yesterday, when it again crashed with a SIGABRT. The crash dump the system gave me doesn't tell me much, other than that it looks like python is calling some C function when it crashes. I've attached the crash report, in case it can mean something more to someone else.
>> 
>> Can anyone give me some hints as to how to track down the cause of this crash? It's especially problematic since I can't mess with the live server for testing, and it is quite a while between crashes, making it difficult, if not impossible, to reproduce in testing. Thanks.
>> -----------------------------------------------
>> Israel Brewster
>> Systems Analyst II
>> Ravn Alaska
>> 5245 Airport Industrial Rd
>> Fairbanks, AK 99709
>> (907) 450-7293
>> -----------------------------------------------
> 
> 
> Can you run the application in an IDE?

Yes - I run it through Wing during development. I don't think that would be such a good option for my production machine, however. If it gets really bad I'll consider it though - that should at least tell me where it is crashing.

> 
> -Bill

-----------------------------------------------
Israel Brewster
Systems Analyst II
Ravn Alaska
5245 Airport Industrial Rd
Fairbanks, AK 99709
(907) 450-7293
-----------------------------------------------

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From rantingrickjohnson at gmail.com  Tue Jan 13 12:09:03 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Tue, 13 Jan 2015 09:09:03 -0800 (PST)
Subject: Python 3 regex?
In-Reply-To: <54b4bdae$0$2738$c3e8da3$76491128@news.astraweb.com>
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
 <54b4bdae$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <ea906715-a11e-439b-ac46-2b6d75c14967@googlegroups.com>

On Tuesday, January 13, 2015 at 12:39:55 AM UTC-6, Steven D'Aprano wrote:
> On Mon, 12 Jan 2015 15:47:08 -0800, Rick Johnson wrote:
> [...]
> > [...]
> > ############################################################
> > #                Ironic Twist (Reformatted)                #
> > ############################################################
> > # Some diabetics, when confronted with hunger, think "I    #
> > # know, I'll eat a box of sugar cookies." -- now they have #
> > # # # two problems!'                                       #
> > ############################################################
>
> Not the best of analogies, since there are two forms of
> diabetes. Those with Type 2 diabetes can best manage their
> illness by avoiding sugar cookies. Those with Type 1
> should keep a box of sugar cookies (well, perhaps glucose
> lollies are more appropriate) on hand for emergencies.

You seem to misunderstand the basic distinction between
type1 and type2 diabetes, it's not a mere dichotomy between
hyperglycemia and hypoglycemia that defines a diabetes
diagnosis, NO, Type1 can be simplified as "insulin
deficiency" and Type2 as "insulin resistance" -- with both
resulting in the inability of glucose (aka: fuel) to nourish
the cells.

YOUR ASSESSMENT OF MY ANALOGY IS JUST AS "WEAK".

Both my and Jamie's analogy present an example of the "cruel
irony". The only *DIFFERENCE* is that mine utilizes a
subject matter which requires less study to understand.

One can learn enough about diabetes to draw his own factual
conclusions of my statement from a simple Google search,
however, for regexps, a neophyte would need days, weeks, or
even months of serious study to drawn sensible conclusions
of merit.

> In any case, most people with diabetes (or at least those
> who are still alive) are reasonably good at managing their
> illness and wouldn't make the choice you suggest. You have
> missed the point that people who misuse regexes are common
> in programming circles, while diabetics who eat a box of
> sugar cookies instead of a meal are rare.

I believe you could find many diabetics who've eaten poorly
and suffered from the result -- even died! I'm not missing
the point, you are! 

    HECK, *I'M* THE ONE WHO *DEFINED* THE "POINT".

> To take your analogy to an extreme:
>
>   Some people, when faced with a problem, say "I know, I'll cut
>   my arm off with a pocketknife!" Now they have two problems.
>
> This is not insightful or useful. Except in the most
> specialized and extreme circumstances, such as being
> trapped in the wilderness with a boulder on your arm,
> nobody would consider this to be good advice.

I'm not giving *advice*, i'm merely drawing parallels. I
think your repeated failures to understand me are are a
result of your superficiality. When reading my posts, you
need to learn to: "read between the lines". Many of the
writings i author are implicit philosophical statements,
musings, and/or explorations. For me, everything has deeper
meanings, just begging to be *plundered*!

> But using regexes to validate email addresses or parse
> HTML? The internet is full of people who thought that was
> a good idea.

Again, i did not suggested that people have never done
anything stupid with regexps, on the contrary, this list has
bear witness to many of them. My only intention was to point
out the damaging (albeit interesting) effects of propaganda.

    MY WHOLE POINT IS ABOUT "PROPAGANDA"!
    
    THAT'S IT!

    DO YOU NEED ME TO DRAW YOU A PICTURE?



From denismfmcmahon at gmail.com  Tue Jan 13 12:25:11 2015
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Tue, 13 Jan 2015 17:25:11 +0000 (UTC)
Subject: what would be the regular expression for null byte present in a
 string
References: <mailman.17674.1421159068.18130.python-list@python.org>
Message-ID: <m93kdn$qlb$1@dont-email.me>

On Tue, 13 Jan 2015 13:40:52 +0000, Shambhu Rajak wrote:

> I have a string that I get as an output of a command as:
> '\x01\x00\x00\x00\x00\x00\x00\x00\x0c\x00\x00\x0010232ae8944a\x02\x00
\x00\x00\x00\x00\x00\x00\n'
> 
> I want to fetch '10232ae8944a' from the above string.
> 
> I want to find a re pattern that could replace all the \x01..\x0z to be
> replace by empty string '',  so that I can get the desired portion of
> string
> 
> Can anyone help me with a working regex for it.

What have you tried, and what was the result?

Regex isn't designed to work with byte strings.

>>> str = '\x01\x00\x00\x00\x00\x00\x00\x00\x0c\x00\x00\x0010232ae8944a
\x02\x00\x00\x00\x00\x00\x00\x00\n'

>>> str.replace('\x00','').replace('\x0c','').replace('\x01','').replace
('\x02','').replace('\n','')
'10232ae8944a'

This works for the specific example you gave, will your "string" ever 
contain unwanted characters apart from \x00, \x01, \x02, \x0c, \n, and is 
it ever possible for one of those to be in the wanted set?

>>> str[12:24]
'10232ae8944a'

This also works for the specific example you gave, is the data you want 
to extract always going to be at the same offset in the string, and of 
the same length?

>>> ''.join([str[x] for x in range(len(str)) if str[x] >= ' ' and str[x] 
<= '~'])
'10232ae8944a'

This also works for the specific example you gave, and is a way to remove 
non printing and 8bit characters from a string. Is this what you actually 
want to do?

>>> str.strip('\x00\x0c\x01\x02\n')
'10232ae8944a'

This also works for the specific example that you gave, it uses the strip 
function with a string of characters to be stripped, this will work as 
long as you can predefine all the characters to strip and none of the 
characters to strip is ever desired as part of the result.

So 4 different methods, each of which seems to do, in the case of the 
specific example you gave, exactly what you want.

However although I tried a few patterns, I don't seem to be able to 
create an re that will do the job.

eg:

>>> patt = re.compile(r'[0-9a-zA-Z]+')
>>> res = patt.match(str)
>>> res
>>> print res
None
>>> type(res)
<type 'NoneType'>

>>> patt = re.compile(r'[0-z]+')
>>> res = patt.match(str)
>>> res
>>> print res
None
>>> type(res)
<type 'NoneType'>
>>> 

>>> patt = re.compile(r'[ -~]+')
>>> res = patt.match(str)
>>> res
>>> print res
None
>>> type(res)
<type 'NoneType'>
>>> 

-- 
Denis McMahon, denismfmcmahon at gmail.com


From skip.montanaro at gmail.com  Tue Jan 13 12:26:43 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Tue, 13 Jan 2015 11:26:43 -0600
Subject: Track down SIGABRT
In-Reply-To: <41D1FC10-000B-4DD7-8C40-12D92F62BC25@ravnalaska.net>
References: <B967FFA3-810A-4C9F-A353-A3C5E8C9ED6B@ravnalaska.net>
 <7FF67692-9F7B-4EE1-AD9F-83DAC545A78A@mac.com>
 <41D1FC10-000B-4DD7-8C40-12D92F62BC25@ravnalaska.net>
Message-ID: <CANc-5Uzi-0XSJzAMQecNDwdi6RAr7cfj5-vT1-9b5PKsoJW+LQ@mail.gmail.com>

Assuming you have gdb available, you should be able to attach to the
running process, then set a breakpoint in relevant functions (like
exit() or abort()). Once there, you can pick through the C stack
manually (kind of tedious) or use the gdbinit file which comes with
Python to get a Python stack trace (much less tedious, once you've
made sure any version dependencies have been eliminated). Or, with the
latest versions of gdb (7.x I think), you get more stuff built into
gdb itself.

More details here:

https://wiki.python.org/moin/DebuggingWithGdb

Skip


From no.email at nospam.invalid  Tue Jan 13 12:31:12 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Tue, 13 Jan 2015 09:31:12 -0800
Subject: Track down SIGABRT
References: <B967FFA3-810A-4C9F-A353-A3C5E8C9ED6B@ravnalaska.net>
 <7FF67692-9F7B-4EE1-AD9F-83DAC545A78A@mac.com>
 <mailman.17686.1421168721.18130.python-list@python.org>
Message-ID: <87h9vuoae7.fsf@jester.gateway.pace.com>

Israel Brewster <israel at ravnalaska.net> writes:
>         when it again crashed with a SIGABRT. The crash dump the
>         system gave me doesn't tell me much, other than that it looks
>         like python is calling some C function when it crashes. I've
>         attached the crash report, in case it can mean something more
>         to someone else.

Somehow I missed the original post: did you get a core dump?  The
next thing to do is examine it under gdb.

>         
>         Can anyone give me some hints as to how to track down the
>         cause of this crash? 

If it's recurring, recompile python with -g to generate debugging
symbols, so you'll have an easier time examining the dump.  You can even
run the whole interpreter under gdb, though doing that for 33 days might
be uncharted territory.


From israel at ravnalaska.net  Tue Jan 13 12:34:27 2015
From: israel at ravnalaska.net (Israel Brewster)
Date: Tue, 13 Jan 2015 08:34:27 -0900
Subject: Track down SIGABRT
In-Reply-To: <CANc-5Uzi-0XSJzAMQecNDwdi6RAr7cfj5-vT1-9b5PKsoJW+LQ@mail.gmail.com>
References: <B967FFA3-810A-4C9F-A353-A3C5E8C9ED6B@ravnalaska.net>
 <7FF67692-9F7B-4EE1-AD9F-83DAC545A78A@mac.com>
 <41D1FC10-000B-4DD7-8C40-12D92F62BC25@ravnalaska.net>
 <CANc-5Uzi-0XSJzAMQecNDwdi6RAr7cfj5-vT1-9b5PKsoJW+LQ@mail.gmail.com>
Message-ID: <5D1E5CA9-E8BA-403A-BEE8-5B7DE8F2EB5B@ravnalaska.net>

On Jan 13, 2015, at 8:26 AM, Skip Montanaro <skip.montanaro at gmail.com> wrote:

> Assuming you have gdb available, you should be able to attach to the
> running process, then set a breakpoint in relevant functions (like
> exit() or abort()). Once there, you can pick through the C stack
> manually (kind of tedious) or use the gdbinit file which comes with
> Python to get a Python stack trace (much less tedious, once you've
> made sure any version dependencies have been eliminated). Or, with the
> latest versions of gdb (7.x I think), you get more stuff built into
> gdb itself.
> 
> More details here:
> 
> https://wiki.python.org/moin/DebuggingWithGdb

Thanks, I'll look into that. Hopefully running with the debugger attached won't slow things down to much. The main thing I think will be getting the python extensions installed - the instructions only talk about doing this for linux packages.

> 
> Skip



From denismfmcmahon at gmail.com  Tue Jan 13 13:02:43 2015
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Tue, 13 Jan 2015 18:02:43 +0000 (UTC)
Subject: how can I create a class and decode/encode as json?
References: <d6ddd0ed-c783-4e28-8a27-e17a4240ed41@googlegroups.com>
Message-ID: <m93mk3$qlb$2@dont-email.me>

On Tue, 13 Jan 2015 08:17:18 -0800, robertchen117 wrote:

> I want to send Message to rabbitmq and receive from rabbitmq, message
> format is below.
> 
> how can I create a class and decode/encode as json?

It may be easier to use dictionaries than classes.

>>> import json
>>> thing = {}
>>> thing["message"] = {}
>>> thing["message"]["dateCreated"] = "1417713299"
>>> thing["message"]["operations"] = []
>>> for i in range(3):
...     bit = {}
...     bit["sequence"] = i
...     bit["data"] = "blah blah blah"
...     thing["message"]["operations"].append(bit)
... 
>>> json.dumps(thing)
'{"message": {"operations": [{"data": "blah blah blah", "sequence": 0}, 
{"data": "blah blah blah", "sequence": 1}, {"data": "blah blah blah", 
"sequence": 2}], "dateCreated": "1417713299"}}'

-- 
Denis McMahon, denismfmcmahon at gmail.com


From rantingrickjohnson at gmail.com  Tue Jan 13 13:17:55 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Tue, 13 Jan 2015 10:17:55 -0800 (PST)
Subject: Python 3 regex?
In-Reply-To: <ea906715-a11e-439b-ac46-2b6d75c14967@googlegroups.com>
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
 <54b4bdae$0$2738$c3e8da3$76491128@news.astraweb.com>
 <ea906715-a11e-439b-ac46-2b6d75c14967@googlegroups.com>
Message-ID: <223d2aa6-7bd6-4b1c-98ad-3a4269d14c98@googlegroups.com>

On Tuesday, January 13, 2015 at 11:09:17 AM UTC-6, Rick Johnson wrote:
> [...]
>     DO YOU NEED ME TO DRAW YOU A PICTURE?

I don't normally do this, but in the interest of education
i feel i must bear the burdens for which all professional
educators like myself are responsible. 

  https://plus.google.com/114883720122692827712/posts/Nxo3rR7TwQS


From dan at tombstonezero.net  Tue Jan 13 13:21:27 2015
From: dan at tombstonezero.net (Dan Sommers)
Date: Tue, 13 Jan 2015 18:21:27 +0000 (UTC)
Subject: How can i use a dictionnary
References: <233574bb-a552-49f2-b803-86523e2b5741@googlegroups.com>
 <2b71cef0-fae6-466c-af9c-79c503bd1402@googlegroups.com>
Message-ID: <m93nn7$mr$1@dont-email.me>

On Tue, 13 Jan 2015 06:56:11 -0800, Novocastrian_Nomad wrote:

> On Tuesday, January 13, 2015 at 2:03:30 AM UTC-7, brice DORA wrote:

>> i consume a web service that return a element whose the type is
>> "instance". but this element seem be a dictionary but when i want to
>> use it like a dictionary, i got some errors. so this is the element
>> and please someone can tell me how can i use it. tkanks in advance.
>> 
>> (tCountryInfo){
>>    sISOCode = "CI"
>>    sName = "C??te D'Ivoire (Ivory Coast)"
>>    sCapitalCity = "Yamoussoukro"
>>    sPhoneCode = "225"
>>    sContinentCode = "AF"
>>    sCurrencyISOCode = "XOF"
>>    sCountryFlag = "http://www.oorsprong.org/WebSamples.CountryInfo/Images/C??te D'Ivoire.jpg"
>>    Languages = 
>>       (ArrayOftLanguage){
>>          tLanguage[] = 
>>             (tLanguage){
>>                sISOCode = "fr"
>>                sName = "French"
>>             },
>>       }
>>  }

> This data is not a Python dictionary, nor is it a JSON object.  You
> will probably need to code your own conversion function to make it a
> Python dictionary.

This looks like the str (or maybe it's the repr) of an object returned
by the suds library.  If so, then that object has appropriate attributes
for accessing the data; please see the documentation.  What happens when
you print object.sName (assuming that your element is named "object")?

HTH,
Dan


From jacob at blindza.co.za  Tue Jan 13 13:37:19 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Tue, 13 Jan 2015 20:37:19 +0200
Subject: Python 2.7, on windows7 64 bit development machine,
 inconsistent issue on similar machines
In-Reply-To: <np8abap11vuvfkcil3af7jps4mnhvteten@4ax.com>
References: <A5E269C08DCE4D69B5A82C14FD81AB07@JakesPC>
 <np8abap11vuvfkcil3af7jps4mnhvteten@4ax.com>
Message-ID: <8F8AAFF9D3374888AF2E332647595EB7@JakesPC>

See answers below.

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."

----- Original Message ----- 
From: "Dennis Lee Bieber" <wlfraed at ix.netcom.com>
<snip />

> The very first hit /I/ get is:
> https://social.technet.microsoft.com/Forums/windows/en-US/3932e3eb-c034-4eb7-aa06-4a0a8e6ea493/fault-module-namestackhash0a9e
>

Played around with data expraction policy changes/settings now, and didn't 
make it change behaviour.

>>
<snip />
>>      s_host = str(d_mysql["host"])
>>      s_user = str(d_mysql["user"])
>>      s_pass = str(d_mysql["password"])
>>      s_db = self.s_target_value
>
> ONE: Have you confirmed all of these are coming in correctly
>
Yes - that mysql.set pickle dump is just a way of storing some string values 
relating to mysql server connection to sort of hide it from an end-user, 
but, yes, the values work fine in that sense.

>>      cn = MySQLdb.connect(s_host, s_user, s_pass, s_db)
>>      if cn:
>>        cn.autocommit = True
>
> TWO-A: you've turned on autocommit here, yet...

Sorry - that was sort of left-over from when was trying to make sure that 
other parts were happening/working - along with trying out specific commit 
call lower down - have tried taking eitehr of them out one by one, to see if 
made a difference, but, no-go.

>
>>        cur = cn.cursor()
>>        i_struct = 0
>>        i_data = 0
>>        f = open(self.s_sql_struct_file, "rb")
>>        s = f.read()
>>        f.close()
>>        l_struct = s.split(";")
>
> THREE-A: here you split some string on semicolons, just to...
>
>>        f = open(self.s_sql_data_file, "rb")
>>        s = f.read()
>>        f.close()
>>        l_data = unidecode(s).split(";")
>>        l_struct_errors = []
>>        l_data_errors = []
>>        i_start_time = int(time.time())
>>        s_status = "/{0} structs".format(str(len(l_struct)))
>>        for I in range(len(l_struct)):
>
> Very UN-Pythonic...

I know - that was also since originally used this code in a sort of GUI 
version, and meant to use one by one counter to update status bar text at 
sort of intervals of 10 records, to let guys track progress - but, FWIW, it 
seemed to overload my screen reader with too many changes, partly since some 
of these collections of insert statements are processing over 40000 record 
insertions - not currently with test data, but, some of the other test 
database files I used were operating in that region of the number of data 
record numbers. Have taken that part out again now.

>
> for a_struct in l_struct:
> # do stuff with a_struct directly, no indexing into l_struct
>
>>          try:
>>            i_struct = I
>>            if str(l_struct[I]).strip() != "": res = 
>> cur.execute(l_struct[I] + ";")
>
> THREE-B: ... reappend the semicolon here... which probably isn't needed
> -- cur.execute() assumes, as I recall, that the provided argument is a
> complete statement; unlike a command line interface where the semicolon is
> needed to tell the CLI that the statement is complete and can be sent to
> the DBMS for processing.
>
> And very confusing names... l_struct and i_struct, where the latter is
> an index into the former (and I don't see it used anywhere).

Have taken out counter now, and, yes, cursor seems happy to execute 
statements without ; character at end.

>
>>            print(l_struct[I])
>>          #except Warning as wrn:
>>          #  print("warning: " + str(wrn.args))
>>          except Exception as exc:
>>            l_struct_errors.append([l_struct[I], copy.copy(exc)])
>>          finally:
>>            pass
>>        cn.commit()
>
> TWO-B: ... here you attempt to force a commit.

That was also during test phase when was just trying to make sure parts of 
this were being executed/committed - taken out additional commits now.

>
>>        time.sleep(2.0)
>>        sNada = raw_input("hit enter to continue with data")
>>        s_status = "/{0} data".format(str(len(l_data)))
>>        for I in range(len(l_data)):
>>          try:
>>            #self.SetStatusText(str(I) + s_status)
>>            i_data = I
>>            if str(l_data[I]).strip() != "": res = 
>> cur.execute(l_data[I][l_data[I].index("INSERT"):] + ";")
>>            print(l_data[I][l_data[I].index("INSERT"):] + ";")
>>          except Exception as exc:
>>            l_data_errors.append([l_data[I], copy.copy(exc)])
>>          finally:
>>            pass
>>        i_end_time = int(time.time())
>>        s_time_taken = sTimeDiffFormat(i_start_time, i_end_time)
>>        cn.commit()
>
> TWO-C: ... and here too.
>
>>        cur.close()
>>        cn.close()
>>        print("cn and cur closed")
>>        fPickle = open("testDataErrors.pickle", "wb")
>>        pickle.dump(l_struct_errors, fPickle, 2)
>>        pickle.dump(l_data_errors, fPickle, 2)
>>        fPickle.close()
>>        print("pickled")
>>        print("MySQL Results - {0} structure queries, and {1} data queries 
>> completed - total of {2}".format(str(i_struct), str(i_data), 
>> s_time_taken))
>>        print("MySQL Errors - {0} structure query errors, and {1} data 
>> query errors".format(str(len(l_struct_errors)), str(len(l_data_errors))))
>>        print("Done!")
>>        sys.exit()
>>      else:
>>        print("Connection issue - There was a problem connecting to MySQL 
>> server")
>>        sys.exit()
>>    except Exception as exc:
>>      s_exc = str(exc.args)
>>      #lbc.DialogShow(title="errorMessage", message=s_exc)
>>      print(s_exc)
>>      exc_type, exc_obj, tb = sys.exc_info()
>>      print(str(exc_obj))
>>      print("line number: " + str(tb.tb_lineno))
>>  #end of convertExport function
>>
>>#---end code---
>>
>
> What is this affair with pickling everything? Mistakes in a pickle
> could lead to anything happening <G>

More to do with tracking errors later on, since person executing this app, 
on site, might not be too technical, and idea would be that, aside from sql 
statements, they might be able to just copy .pickle files onto flash drive 
to bring back for later review, and it was also my form of post-execution 
debugging to let me try figure out what was causing issues with regards to 
actual statements, etc.

>
> I'm not even going to try to figure out what your attempted SQL
> operations turn into. Only that, from what I can see, there is no attempt
> at preventing SQL injection attacks -- other than the use of pickled data
> (and I still wouldn't trust that the pickle hasn't been tampered with).
>

I am pulling data out of MS access .mdb files, using pyodbc, and then 
generating the relevant text files, with all the SQL statements inside them, 
and one of the command line options indicates if the user wants to just 
generate the SQL statement files for copying, or wants to directly execute 
these statements against an instance of a mySQL database, so, yes, in 
theory, the worries of sql injection shouldn't be too much of an issue, and 
when generating the sql statements higher up, before writing them into these 
text files am reading in here, I do things like remove any ; characters, 
from inside actual data values, etc. etc. to work with forms of sql 
injection, but, this would also, in theory not be interacting with anything 
other than sort of interim instances of mysql databases that we then want to 
process the transformation of using some other code, etc. - but later's 
problem.

>>
>>
>>If this is operating system specific, sorry, and will maybe also try 
>>debugging code via VS.Net 2013 shortly, but, thought someone might have an 
>>off-hand thought regarding something could try use to figure out this 
>>issue in meantime...?
>>
> Yes, it is OS specific.
>
> Either the accounts have different privileges of the different machines
> (presuming a DEP problem, and something you are doing is executing data),
> or http://winwiki.org/stackhash_0a9e-fix/ indicates potentially corrupted
> system files.

Will have a look at that one, and another thing found mention of with 
regards to someone's wxPython code was sort of inserting different controls, 
with same names onto wx.Frame parents, which they were guessing might have 
had something to with application garbage collection at end of execution, 
and could thus also be causing issues, but, am pretty sure haven't done 
something like that here - might also try taking out taking copies of parts 
of dictionary objects, since that was also more to do with testing, and not 
wanting to mutilate/manipulate original values during test process, but 
anyway.

In terms of user privileges, both of these machines, I just run as 
administrator, and the machine that's not currently giving me these hassles 
is windows7 pro 64 bit, where machine with issues is windows7 ultimate 64 
bit, but, it's my test/play-time machine, so, yes, I do install/uninstall a 
lot more of things on/off it at times, but, I also reinstalled operating 
system from scratch roundabout a month ago, so wouldn't have thought it 
could have too many issues as of yet, but anyway.

Did also try figuring out debug process using MS visual studio.net 2013, 
community edition, but, just got pretty much same info/error message, and 
pdb is not something have ever really worked with, and not sure it would do 
too much more than what I'm already working with.

Other thing tried doing now was just taking out chunks of functionality in 
that function/method, to try see if could track down cause of issue like 
that, and, actually seems like trigger is even if I just connect to mysql 
server/database, since if I then just wait 1 second, and close the 
connection, and then just try invoke sys.exit(), same thing happens, whereas 
if I comment out db connection, then it just exits happily.

Will have to look for more specific examples of something like MySQLdb 
connections that might cause something like this.

Might also try running it against a different version/instance of MySQL 
server since have both WAMP and XAMPP on this machine, but, make sure they 
only run one at a time, or might fire up both machines, turn on public 
access to 'happy' machine, and execute code from this machine against it's 
MySQL server instance, and see if that affects it as well.

> -- 
> Wulfraed                 Dennis Lee Bieber         AF6VN

Thanks

>    wlfraed at ix.netcom.com    HTTP://wlfraed.home.netcom.com/
>
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 



From ian.g.kelly at gmail.com  Tue Jan 13 13:56:22 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Tue, 13 Jan 2015 11:56:22 -0700
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <CAPTjJmppq_4Bova_OvXVJN8Q+jGK22rFdoxjLWtM9F5_yF4RsQ@mail.gmail.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <CAPTjJmq5E+LJ8gjXQa7Sf+smc8ug59YZpofp7PH6WwjL55Gv=Q@mail.gmail.com>
 <mailman.17669.1421146184.18130.python-list@python.org>
 <87lhl7c5dt.fsf@elektro.pacujo.net>
 <CAPTjJmppq_4Bova_OvXVJN8Q+jGK22rFdoxjLWtM9F5_yF4RsQ@mail.gmail.com>
Message-ID: <CALwzid=2ezc7ziQWXYp5zOg6ZVJZzZ+g8NeRMNTF6pWQ+n31VQ@mail.gmail.com>

On Tue, Jan 13, 2015 at 4:20 AM, Chris Angelico <rosuav at gmail.com> wrote:
> On Tue, Jan 13, 2015 at 10:00 PM, Marko Rauhamaa <marko at pacujo.net> wrote:
>> The code above, though, shouldn't consume memory since it is a simple
>> tail-recursive loop.
>
> Only if the interpreter can optimize it away. Bear in mind that it
> doesn't _return_ the result of that expression, so it needs to take
> whatever f() returns, discard it, and return None.

And CPython doesn't even try to optimize tail recursion anyway.


From rosuav at gmail.com  Tue Jan 13 14:02:20 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 14 Jan 2015 06:02:20 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <CALwzid=2ezc7ziQWXYp5zOg6ZVJZzZ+g8NeRMNTF6pWQ+n31VQ@mail.gmail.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <CAPTjJmq5E+LJ8gjXQa7Sf+smc8ug59YZpofp7PH6WwjL55Gv=Q@mail.gmail.com>
 <mailman.17669.1421146184.18130.python-list@python.org>
 <87lhl7c5dt.fsf@elektro.pacujo.net>
 <CAPTjJmppq_4Bova_OvXVJN8Q+jGK22rFdoxjLWtM9F5_yF4RsQ@mail.gmail.com>
 <CALwzid=2ezc7ziQWXYp5zOg6ZVJZzZ+g8NeRMNTF6pWQ+n31VQ@mail.gmail.com>
Message-ID: <CAPTjJmpNmB3CzijxHLGxfrdWTSy+cD1B=vQ6-M1Zo+k-QB9RzA@mail.gmail.com>

On Wed, Jan 14, 2015 at 5:56 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> On Tue, Jan 13, 2015 at 4:20 AM, Chris Angelico <rosuav at gmail.com> wrote:
>> On Tue, Jan 13, 2015 at 10:00 PM, Marko Rauhamaa <marko at pacujo.net> wrote:
>>> The code above, though, shouldn't consume memory since it is a simple
>>> tail-recursive loop.
>>
>> Only if the interpreter can optimize it away. Bear in mind that it
>> doesn't _return_ the result of that expression, so it needs to take
>> whatever f() returns, discard it, and return None.
>
> And CPython doesn't even try to optimize tail recursion anyway.

I presumed that Marko's "shouldn't" was "CPython should be smarter than this".

ChrisA


From wxjmfauth at gmail.com  Tue Jan 13 14:19:47 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Tue, 13 Jan 2015 11:19:47 -0800 (PST)
Subject: Python 3 regex?
In-Reply-To: <7c648fa2-4a59-4d1a-923f-d29f4f2dc8f7@googlegroups.com>
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
 <mailman.17649.1421114112.18130.python-list@python.org>
 <7c648fa2-4a59-4d1a-923f-d29f4f2dc8f7@googlegroups.com>
Message-ID: <0fdf17d0-2dd7-4512-8f2a-104d78a27d72@googlegroups.com>

Le mardi 13 janvier 2015 03:53:43 UTC+1, Rick Johnson a ?crit?:
> 
> [...]
> you should find Python's "text processing Nirvana"
> [...]


I recommend, you write a "small" application sorting
strings composed of latin characters, a sort based on
diacritical characters (and eventually, taking into
account linguistic specific aspects).
And, why not? compare Py3.2 and Py3.3+ !

jmf



From jacob at blindza.co.za  Tue Jan 13 14:39:13 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Tue, 13 Jan 2015 21:39:13 +0200
Subject: Python 2.7, on windows7 64 bit development machine,
 inconsistent issue on similar machines
In-Reply-To: <8F8AAFF9D3374888AF2E332647595EB7@JakesPC>
References: <A5E269C08DCE4D69B5A82C14FD81AB07@JakesPC>
 <np8abap11vuvfkcil3af7jps4mnhvteten@4ax.com>
 <8F8AAFF9D3374888AF2E332647595EB7@JakesPC>
Message-ID: <CCB8AA2323234F208A95F53FCFA7DCD1@JakesPC>

Ok, and just tested MySQLdb connection to both XAMPP server instance on same 
machine, as well as slightly remote connection to other machine over wifi, 
and same error - so, seems issue is invoked/caused by MySQLdb connection 
closing - if just put process to sleep for 30 seconds, nothing happens, but, 
the moment I in fact try to then just close the connection, that's when 
error dialogue immediately pops up.

Stay well

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."

----- Original Message ----- 
From: "Jacob Kruger" <jacob at blindza.co.za>
To: "Dennis Lee Bieber" <wlfraed at ix.netcom.com>
Cc: <python-list at python.org>
Sent: Tuesday, January 13, 2015 8:37 PM
Subject: Re: Python 2.7, on windows7 64 bit development machine, 
inconsistent issue on similar machines


> See answers below.
>
> Jacob Kruger
> Blind Biker
> Skype: BlindZA
> "Roger Wilco wants to welcome you...to the space janitor's closet..."
>
> ----- Original Message ----- 
> From: "Dennis Lee Bieber" <wlfraed at ix.netcom.com>
> <snip />
>
>> The very first hit /I/ get is:
>> https://social.technet.microsoft.com/Forums/windows/en-US/3932e3eb-c034-4eb7-aa06-4a0a8e6ea493/fault-module-namestackhash0a9e
>>
>
> Played around with data expraction policy changes/settings now, and didn't 
> make it change behaviour.
>
>>>
> <snip />
>>>      s_host = str(d_mysql["host"])
>>>      s_user = str(d_mysql["user"])
>>>      s_pass = str(d_mysql["password"])
>>>      s_db = self.s_target_value
>>
>> ONE: Have you confirmed all of these are coming in correctly
>>
> Yes - that mysql.set pickle dump is just a way of storing some string 
> values relating to mysql server connection to sort of hide it from an 
> end-user, but, yes, the values work fine in that sense.
>
>>>      cn = MySQLdb.connect(s_host, s_user, s_pass, s_db)
>>>      if cn:
>>>        cn.autocommit = True
>>
>> TWO-A: you've turned on autocommit here, yet...
>
> Sorry - that was sort of left-over from when was trying to make sure that 
> other parts were happening/working - along with trying out specific commit 
> call lower down - have tried taking eitehr of them out one by one, to see 
> if made a difference, but, no-go.
>
>>
>>>        cur = cn.cursor()
>>>        i_struct = 0
>>>        i_data = 0
>>>        f = open(self.s_sql_struct_file, "rb")
>>>        s = f.read()
>>>        f.close()
>>>        l_struct = s.split(";")
>>
>> THREE-A: here you split some string on semicolons, just to...
>>
>>>        f = open(self.s_sql_data_file, "rb")
>>>        s = f.read()
>>>        f.close()
>>>        l_data = unidecode(s).split(";")
>>>        l_struct_errors = []
>>>        l_data_errors = []
>>>        i_start_time = int(time.time())
>>>        s_status = "/{0} structs".format(str(len(l_struct)))
>>>        for I in range(len(l_struct)):
>>
>> Very UN-Pythonic...
>
> I know - that was also since originally used this code in a sort of GUI 
> version, and meant to use one by one counter to update status bar text at 
> sort of intervals of 10 records, to let guys track progress - but, FWIW, 
> it seemed to overload my screen reader with too many changes, partly since 
> some of these collections of insert statements are processing over 40000 
> record insertions - not currently with test data, but, some of the other 
> test database files I used were operating in that region of the number of 
> data record numbers. Have taken that part out again now.
>
>>
>> for a_struct in l_struct:
>> # do stuff with a_struct directly, no indexing into l_struct
>>
>>>          try:
>>>            i_struct = I
>>>            if str(l_struct[I]).strip() != "": res = 
>>> cur.execute(l_struct[I] + ";")
>>
>> THREE-B: ... reappend the semicolon here... which probably isn't needed
>> -- cur.execute() assumes, as I recall, that the provided argument is a
>> complete statement; unlike a command line interface where the semicolon 
>> is
>> needed to tell the CLI that the statement is complete and can be sent to
>> the DBMS for processing.
>>
>> And very confusing names... l_struct and i_struct, where the latter is
>> an index into the former (and I don't see it used anywhere).
>
> Have taken out counter now, and, yes, cursor seems happy to execute 
> statements without ; character at end.
>
>>
>>>            print(l_struct[I])
>>>          #except Warning as wrn:
>>>          #  print("warning: " + str(wrn.args))
>>>          except Exception as exc:
>>>            l_struct_errors.append([l_struct[I], copy.copy(exc)])
>>>          finally:
>>>            pass
>>>        cn.commit()
>>
>> TWO-B: ... here you attempt to force a commit.
>
> That was also during test phase when was just trying to make sure parts of 
> this were being executed/committed - taken out additional commits now.
>
>>
>>>        time.sleep(2.0)
>>>        sNada = raw_input("hit enter to continue with data")
>>>        s_status = "/{0} data".format(str(len(l_data)))
>>>        for I in range(len(l_data)):
>>>          try:
>>>            #self.SetStatusText(str(I) + s_status)
>>>            i_data = I
>>>            if str(l_data[I]).strip() != "": res = 
>>> cur.execute(l_data[I][l_data[I].index("INSERT"):] + ";")
>>>            print(l_data[I][l_data[I].index("INSERT"):] + ";")
>>>          except Exception as exc:
>>>            l_data_errors.append([l_data[I], copy.copy(exc)])
>>>          finally:
>>>            pass
>>>        i_end_time = int(time.time())
>>>        s_time_taken = sTimeDiffFormat(i_start_time, i_end_time)
>>>        cn.commit()
>>
>> TWO-C: ... and here too.
>>
>>>        cur.close()
>>>        cn.close()
>>>        print("cn and cur closed")
>>>        fPickle = open("testDataErrors.pickle", "wb")
>>>        pickle.dump(l_struct_errors, fPickle, 2)
>>>        pickle.dump(l_data_errors, fPickle, 2)
>>>        fPickle.close()
>>>        print("pickled")
>>>        print("MySQL Results - {0} structure queries, and {1} data 
>>> queries completed - total of {2}".format(str(i_struct), str(i_data), 
>>> s_time_taken))
>>>        print("MySQL Errors - {0} structure query errors, and {1} data 
>>> query errors".format(str(len(l_struct_errors)), 
>>> str(len(l_data_errors))))
>>>        print("Done!")
>>>        sys.exit()
>>>      else:
>>>        print("Connection issue - There was a problem connecting to MySQL 
>>> server")
>>>        sys.exit()
>>>    except Exception as exc:
>>>      s_exc = str(exc.args)
>>>      #lbc.DialogShow(title="errorMessage", message=s_exc)
>>>      print(s_exc)
>>>      exc_type, exc_obj, tb = sys.exc_info()
>>>      print(str(exc_obj))
>>>      print("line number: " + str(tb.tb_lineno))
>>>  #end of convertExport function
>>>
>>>#---end code---
>>>
>>
>> What is this affair with pickling everything? Mistakes in a pickle
>> could lead to anything happening <G>
>
> More to do with tracking errors later on, since person executing this app, 
> on site, might not be too technical, and idea would be that, aside from 
> sql statements, they might be able to just copy .pickle files onto flash 
> drive to bring back for later review, and it was also my form of 
> post-execution debugging to let me try figure out what was causing issues 
> with regards to actual statements, etc.
>
>>
>> I'm not even going to try to figure out what your attempted SQL
>> operations turn into. Only that, from what I can see, there is no attempt
>> at preventing SQL injection attacks -- other than the use of pickled data
>> (and I still wouldn't trust that the pickle hasn't been tampered with).
>>
>
> I am pulling data out of MS access .mdb files, using pyodbc, and then 
> generating the relevant text files, with all the SQL statements inside 
> them, and one of the command line options indicates if the user wants to 
> just generate the SQL statement files for copying, or wants to directly 
> execute these statements against an instance of a mySQL database, so, yes, 
> in theory, the worries of sql injection shouldn't be too much of an issue, 
> and when generating the sql statements higher up, before writing them into 
> these text files am reading in here, I do things like remove any ; 
> characters, from inside actual data values, etc. etc. to work with forms 
> of sql injection, but, this would also, in theory not be interacting with 
> anything other than sort of interim instances of mysql databases that we 
> then want to process the transformation of using some other code, etc. - 
> but later's problem.
>
>>>
>>>
>>>If this is operating system specific, sorry, and will maybe also try 
>>>debugging code via VS.Net 2013 shortly, but, thought someone might have 
>>>an off-hand thought regarding something could try use to figure out this 
>>>issue in meantime...?
>>>
>> Yes, it is OS specific.
>>
>> Either the accounts have different privileges of the different machines
>> (presuming a DEP problem, and something you are doing is executing data),
>> or http://winwiki.org/stackhash_0a9e-fix/ indicates potentially corrupted
>> system files.
>
> Will have a look at that one, and another thing found mention of with 
> regards to someone's wxPython code was sort of inserting different 
> controls, with same names onto wx.Frame parents, which they were guessing 
> might have had something to with application garbage collection at end of 
> execution, and could thus also be causing issues, but, am pretty sure 
> haven't done something like that here - might also try taking out taking 
> copies of parts of dictionary objects, since that was also more to do with 
> testing, and not wanting to mutilate/manipulate original values during 
> test process, but anyway.
>
> In terms of user privileges, both of these machines, I just run as 
> administrator, and the machine that's not currently giving me these 
> hassles is windows7 pro 64 bit, where machine with issues is windows7 
> ultimate 64 bit, but, it's my test/play-time machine, so, yes, I do 
> install/uninstall a lot more of things on/off it at times, but, I also 
> reinstalled operating system from scratch roundabout a month ago, so 
> wouldn't have thought it could have too many issues as of yet, but anyway.
>
> Did also try figuring out debug process using MS visual studio.net 2013, 
> community edition, but, just got pretty much same info/error message, and 
> pdb is not something have ever really worked with, and not sure it would 
> do too much more than what I'm already working with.
>
> Other thing tried doing now was just taking out chunks of functionality in 
> that function/method, to try see if could track down cause of issue like 
> that, and, actually seems like trigger is even if I just connect to mysql 
> server/database, since if I then just wait 1 second, and close the 
> connection, and then just try invoke sys.exit(), same thing happens, 
> whereas if I comment out db connection, then it just exits happily.
>
> Will have to look for more specific examples of something like MySQLdb 
> connections that might cause something like this.
>
> Might also try running it against a different version/instance of MySQL 
> server since have both WAMP and XAMPP on this machine, but, make sure they 
> only run one at a time, or might fire up both machines, turn on public 
> access to 'happy' machine, and execute code from this machine against it's 
> MySQL server instance, and see if that affects it as well.
>
>> -- 
>> Wulfraed                 Dennis Lee Bieber         AF6VN
>
> Thanks
>
>>    wlfraed at ix.netcom.com    HTTP://wlfraed.home.netcom.com/
>>
>> -- 
>> https://mail.python.org/mailman/listinfo/python-list
>>
>
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 



From ian.g.kelly at gmail.com  Tue Jan 13 14:46:09 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Tue, 13 Jan 2015 12:46:09 -0700
Subject: Performance in exec environnements
In-Reply-To: <CABUUr0zB97+PnVm46WAHjzP=RFtwn8QrSFwqm_nw6ZWXk1qRVw@mail.gmail.com>
References: <CABUUr0zB97+PnVm46WAHjzP=RFtwn8QrSFwqm_nw6ZWXk1qRVw@mail.gmail.com>
Message-ID: <CALwzid=FKpt+f00HA9gdBSAx7zh3q_n_MUvJLvQOdBST5S1ZHg@mail.gmail.com>

On Tue, Jan 13, 2015 at 10:02 AM, Jean-Baptiste Braun
<jbaptiste.braun at gmail.com> wrote:
> Hi,
>
> I'm working on auto-generated python code with the exec function. I've done
> some performance benches :
>
> % python -m timeit '1 + 1'
> 10000000 loops, best of 3: 0.0229 usec per loop
>
> % python -m timeit "exec('1 + 1')"
> 100000 loops, best of 3: 11.6 usec per loop
>
> -> Maybe creating an exec environnement (I don't know how it works) takes
> time. But :
>
> % python -m timeit "1 + 1; 1 + 1"
> 10000000 loops, best of 3: 0.042 usec per loop
>
> % python -m timeit "exec('1 + 1; 1 + 1')"
> 100000 loops, best of 3: 15.7 usec per loop
>
> -> As if executing one more 1 + 1 would take 4 more seconds (100000
> iterations) in an exec environnement.
>
> Am I missing something or should I expect that result ? What does using exec
> imply that causes such a difference ?

Since you're execing a string, the string has to be compiled each time
exec is called. In contrast, the 1 + 1 in the timeit loop is only
compiled once.

C:\Users\Ian>python -m timeit "1 + 1"
10000000 loops, best of 3: 0.0397 usec per loop

C:\Users\Ian>python -m timeit "exec('1 + 1')"
100000 loops, best of 3: 17 usec per loop

C:\Users\Ian>python -m timeit "compile('1 + 1', '', 'exec')"
100000 loops, best of 3: 17 usec per loop

C:\Users\Ian>python -m timeit -s "c = compile('1 + 1', '', 'exec')" "exec(c)"
1000000 loops, best of 3: 0.684 usec per loop

I expect the function call probably accounts for most of the rest of
the difference.


From andre.roberge at gmail.com  Tue Jan 13 15:29:54 2015
From: andre.roberge at gmail.com (=?ISO-8859-1?Q?Andr=E9_Roberge?=)
Date: Tue, 13 Jan 2015 12:29:54 -0800 (PST)
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <5ac77acc-c8db-40a8-812d-731ef6224c01@googlegroups.com>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
 <2f1dd848-e075-4435-93ef-c65af9a5148b@googlegroups.com>
 <b4d90fbf-9f5a-4ffa-9013-0e70fc3e4e24@googlegroups.com>
 <5ac77acc-c8db-40a8-812d-731ef6224c01@googlegroups.com>
Message-ID: <725b74da-2ab6-4300-b81f-cf7f75d97582@googlegroups.com>

On Tuesday, 13 January 2015 08:23:30 UTC-4, stephen... at gmail.com  wrote:
> I found a solution that I'm happy with.
> 
> from datetime import datetime
> from easygui_qt import *
> 
> datestring = get_date()
> mydate = datetime.strptime(datestring, '%b %d %Y')

I'm thinking of having the new version return a datetime object automatically.

Andr?

> 
> On Saturday, January 10, 2015 at 1:02:30 AM UTC, Andr? Roberge wrote:
> > On Friday, 9 January 2015 19:09:15 UTC-4, stephen... at gmail.com  wrote:
> > > On Wednesday, December 31, 2014 at 4:24:50 PM UTC-6, Andr? Roberge wrote:
> > > > EasyGUI_Qt version 0.9 has been released.  This is the first announcement about EasyGUI_Qt on this list.
> > > > 
> > > > Like the original EasyGUI (which used Tkinter), 
> > > > EasyGUI_Qt seeks to provide simple GUI widgets
> > > > that can be called in a procedural program. 
> > > > 
> > > > EasyGUI_Qt is NOT event-driven: all GUI interactions are invoked by simple function calls.
> > > > 
> > > > The archetype is get_string(message)
> > > > which pops a box whose purpose is exactly the same as Python's input(prompt),
> > > > that is, present the user with a question/prompt, have the user enter an
> > > > answer, and return the provided answer as a string.  Thus
> > > > easygui_qt.get_string() can be used as a drop-in replacement for
> > > > input().
> > > > 
> > > > Similarly, instead of using a print() function to display a message,
> > > > show_message() is used which pops a message window.
> > > > 
> > > > EasyGUI_Qt requires PyQt4 and is really targeted for Python 3.3+ - although it can work (possibly with some unicode problems ...) using Python 2.7.
> > > > 
> > > > More information can be found at 
> > > > http://easygui-qt.readthedocs.org/en/latest/index.html
> > > > 
> > > > Feedback is most welcome, including reporting bugs to 
> > > > https://github.com/aroberge/easygui_qt/issues
> > > > 
> > > > Happy 2015 everyone,
> > > > 
> > > > Andr? Roberge
> > > 
> > > Very nice, thanks.
> > > 
> > > One issue is the format returned for the calendar selection. For today, the string returned is "Fri Jan 9 2015". My script needs to convert the date to a datetime.date, and having the month returned as a string instead of an integer makes this harder.
> > 
> > Would today's date be represented as the string "09.01.2015" useful to you? (I found out how to do this.)  If so, I could perhaps add an argument like numeric_format = True.
> > 
> > Andr?



From mal at python.org  Tue Jan 13 16:18:05 2015
From: mal at python.org (M.-A. Lemburg)
Date: Tue, 13 Jan 2015 22:18:05 +0100
Subject: ANN: Python Events Calendar - Please submit your 2015 events
Message-ID: <54B58B8D.3010502@python.org>

[Please help spread the word by forwarding to other relevant mailing lists,
 user groups, etc. world-wide; thanks :-)]

________________________________________________________________________
ANNOUNCING

         Python Events Calendars - Please submit your 2015 events

           maintained by the Python Software Foundation (PSF)
                    and a group of volunteers

________________________________________________________________________
INTRODUCTION

As some of you may know, the PSF has a team of volunteers who are
maintaining a set of central Python event calendars. We currently have
two calendars in place:

 * Python Events Calendar - meant for conferences and larger gatherings
   focusing on Python or a related technology (in whole or in part)

 * Python User Group Calendar - meant for user group events and other
   smaller local events

The calendars are displayed on http://pycon.org/ and also on the new
https://python.org/ website at https://www.python.org/events/python-events/
and https://www.python.org/events/python-user-group/.

You can subscribe to the calendars using iCal and RSS feeds and also
embed the calendar widgets on your sites. We have also added a
Twitter feed @PythonEvents to get immediate updates whenever a new
event is added. Please see our wiki page for details:

   https://wiki.python.org/moin/PythonEventsCalendar

The calendars are open to the world-wide Python community, so you
can have local user group events, as well as regional and
international conference events added to the calendars.

________________________________________________________________________
NEWS

Looking back on 2014, the calendars have proven to be a great tool
for the Python community to connect, with more than 60 conferences
and more than a hundred of user group events listed.

We would therefore like to encourage everyone to submit their
2015 events, so that the Python community can get a better overview
over what's happening in Python land.

________________________________________________________________________
ADDING EVENTS

Please see the instructions at https://wiki.python.org/moin/PythonEventsCalendar#Available_Calendars
for details on how to
submit an event. We've made it really easy for you: just need to send
an email to our team address using the email template we
provide for this. Thanks.

________________________________________________________________________
MORE INFORMATION

More information on the calendars, the URLs, feed links, IDs, embedding,
etc. is available on the wiki:

    https://wiki.python.org/moin/PythonEventsCalendar

Enjoy,
-- 
Marc-Andre Lemburg
Director
Python Software Foundation
http://www.python.org/psf/



From stephane at wirtel.be  Tue Jan 13 16:24:16 2015
From: stephane at wirtel.be (=?utf-8?q?St=C3=A9phane?= Wirtel)
Date: Tue, 13 Jan 2015 22:24:16 +0100
Subject: Python Events Calendar - Please submit your 2015 events
In-Reply-To: <54B58B8D.3010502@python.org>
References: <54B58B8D.3010502@python.org>
Message-ID: <FD1ACA96-2BB3-4C22-B70A-7361BDD9BAEB@wirtel.be>

Hi Marc-Andr?,

In fact, during the PythonFOSDEM 2015, there will be a presentation with 
the future events in 2015.
I will use the python-events calendar for that.

So, in this case, I propose to all the organisers of conferences to 
submit as soon as possible the calendar of their events.

Thank you for your message,

Stephane

On 13 Jan 2015, at 22:18, M.-A. Lemburg wrote:

> [Please help spread the word by forwarding to other relevant mailing 
> lists,
> user groups, etc. world-wide; thanks :-)]
>
> ________________________________________________________________________
> ANNOUNCING
>
>       Python Events Calendars - Please submit your 2015 events
>
>         maintained by the Python Software Foundation (PSF)
>                  and a group of volunteers
>
> ________________________________________________________________________
> INTRODUCTION
>
> As some of you may know, the PSF has a team of volunteers who are
> maintaining a set of central Python event calendars. We currently have
> two calendars in place:
>
> * Python Events Calendar - meant for conferences and larger gatherings
> focusing on Python or a related technology (in whole or in part)
>
> * Python User Group Calendar - meant for user group events and other
> smaller local events
>
> The calendars are displayed on http://pycon.org/ and also on the new
> https://python.org/ website at 
> https://www.python.org/events/python-events/
> and https://www.python.org/events/python-user-group/.
>
> You can subscribe to the calendars using iCal and RSS feeds and also
> embed the calendar widgets on your sites. We have also added a
> Twitter feed @PythonEvents to get immediate updates whenever a new
> event is added. Please see our wiki page for details:
>
> https://wiki.python.org/moin/PythonEventsCalendar
>
> The calendars are open to the world-wide Python community, so you
> can have local user group events, as well as regional and
> international conference events added to the calendars.
>
> ________________________________________________________________________
> NEWS
>
> Looking back on 2014, the calendars have proven to be a great tool
> for the Python community to connect, with more than 60 conferences
> and more than a hundred of user group events listed.
>
> We would therefore like to encourage everyone to submit their
> 2015 events, so that the Python community can get a better overview
> over what's happening in Python land.
>
> ________________________________________________________________________
> ADDING EVENTS
>
> Please see the instructions at 
> https://wiki.python.org/moin/PythonEventsCalendar#Available_Calendars
> for details on how to
> submit an event. We've made it really easy for you: just need to send
> an email to our team address using the email template we
> provide for this. Thanks.
>
> ________________________________________________________________________
> MORE INFORMATION
>
> More information on the calendars, the URLs, feed links, IDs, 
> embedding,
> etc. is available on the wiki:
>
>  https://wiki.python.org/moin/PythonEventsCalendar
>
> Enjoy,
> -- 
> Marc-Andre Lemburg
> Director
> Python Software Foundation
> http://www.python.org/psf/
>
> -- 
> https://mail.python.org/mailman/listinfo/python-list


--
St?phane Wirtel - http://wirtel.be - @matrixise


From mal at python.org  Tue Jan 13 16:25:52 2015
From: mal at python.org (M.-A. Lemburg)
Date: Tue, 13 Jan 2015 22:25:52 +0100
Subject: Python Events Calendar - Please submit your 2015 events
In-Reply-To: <FD1ACA96-2BB3-4C22-B70A-7361BDD9BAEB@wirtel.be>
References: <54B58B8D.3010502@python.org>
 <FD1ACA96-2BB3-4C22-B70A-7361BDD9BAEB@wirtel.be>
Message-ID: <54B58D60.8010704@python.org>

On 13.01.2015 22:24, =?utf-8?q?St=C3=A9phane?= Wirtel wrote:
> Hi Marc-Andr?,
> 
> In fact, during the PythonFOSDEM 2015, there will be a presentation with the future events in 2015.
> I will use the python-events calendar for that.
> 
> So, in this case, I propose to all the organisers of conferences to submit as soon as possible the
> calendar of their events.

That would be great ! Thanks.

> Thank you for your message,
> 
> Stephane
> 
> On 13 Jan 2015, at 22:18, M.-A. Lemburg wrote:
> 
>> [Please help spread the word by forwarding to other relevant mailing lists,
>> user groups, etc. world-wide; thanks :-)]
>>
>> ________________________________________________________________________
>> ANNOUNCING
>>
>>       Python Events Calendars - Please submit your 2015 events
>>
>>         maintained by the Python Software Foundation (PSF)
>>                  and a group of volunteers
>>
>> ________________________________________________________________________
>> INTRODUCTION
>>
>> As some of you may know, the PSF has a team of volunteers who are
>> maintaining a set of central Python event calendars. We currently have
>> two calendars in place:
>>
>> * Python Events Calendar - meant for conferences and larger gatherings
>> focusing on Python or a related technology (in whole or in part)
>>
>> * Python User Group Calendar - meant for user group events and other
>> smaller local events
>>
>> The calendars are displayed on http://pycon.org/ and also on the new
>> https://python.org/ website at https://www.python.org/events/python-events/
>> and https://www.python.org/events/python-user-group/.
>>
>> You can subscribe to the calendars using iCal and RSS feeds and also
>> embed the calendar widgets on your sites. We have also added a
>> Twitter feed @PythonEvents to get immediate updates whenever a new
>> event is added. Please see our wiki page for details:
>>
>> https://wiki.python.org/moin/PythonEventsCalendar
>>
>> The calendars are open to the world-wide Python community, so you
>> can have local user group events, as well as regional and
>> international conference events added to the calendars.
>>
>> ________________________________________________________________________
>> NEWS
>>
>> Looking back on 2014, the calendars have proven to be a great tool
>> for the Python community to connect, with more than 60 conferences
>> and more than a hundred of user group events listed.
>>
>> We would therefore like to encourage everyone to submit their
>> 2015 events, so that the Python community can get a better overview
>> over what's happening in Python land.
>>
>> ________________________________________________________________________
>> ADDING EVENTS
>>
>> Please see the instructions at https://wiki.python.org/moin/PythonEventsCalendar#Available_Calendars
>> for details on how to
>> submit an event. We've made it really easy for you: just need to send
>> an email to our team address using the email template we
>> provide for this. Thanks.
>>
>> ________________________________________________________________________
>> MORE INFORMATION
>>
>> More information on the calendars, the URLs, feed links, IDs, embedding,
>> etc. is available on the wiki:
>>
>>  https://wiki.python.org/moin/PythonEventsCalendar
>>
>> Enjoy,
>> -- 
>> Marc-Andre Lemburg
>> Director
>> Python Software Foundation
>> http://www.python.org/psf/
>>
>> -- 
>> https://mail.python.org/mailman/listinfo/python-list
> 
> 
> -- 
> St?phane Wirtel - http://wirtel.be - @matrixise

-- 
Marc-Andre Lemburg
Director
Python Software Foundation
http://www.python.org/psf/


From steve+comp.lang.python at pearwood.info  Tue Jan 13 16:48:27 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 14 Jan 2015 08:48:27 +1100
Subject: Performance in exec environnements
References: <mailman.17684.1421168544.18130.python-list@python.org>
Message-ID: <54b592ac$0$12995$c3e8da3$5496439d@news.astraweb.com>

Jean-Baptiste Braun wrote:

> Hi,
> 
> I'm working on auto-generated python code with the exec function. I've
> done some performance benches :

[snip timing results]

> Am I missing something or should I expect that result ? What does using
> exec imply that causes such a difference ?

exec'ing a string will be slower than directly executing code.

Firstly, your initial test:

    python -m timeit "1 + 1"

 is probably biased. Python has a keyhole optimizer which does constant
folding, so that is equivalent to:

    python -m timeit "2"

which does very little work. To get a more realistic timing, try this:

    python -m timeit "n = 1; n + 1"

which will defeat the peephole optimizer.

So you have been comparing:

    2

versus

    exec('1+1')


The first case just fetches a reference to a pre-existing int object, and
then deletes the reference. That's fast.

The second case:

- creates a new string '1+1'
- does a global lookup to find the built-in exec function
- passes the string to the function
- the function then parses that string and compiles it to byte-code
- runs the keyhole optimizer over it
- and finally executes the byte code for "2", same as above.

Only the last step is the same as your earlier test case.


In my experience, the difference between running a piece of code, and
running the same code as a string passed to exec, will be *at least* a
factor of 10 slowdown.

Sometimes you can speed things up by pre-compiling code with compile(), or
with little micro-optimization tricks such as:

def f():
    for x in seq:
        exec(x)  # Looks up the global exec many times.


def f():
    ex = exec  # Look up the global once.
    for x in seq:
        ex(x)  # fast local variable lookup


But that is a micro-optimization which might shave off a few microseconds
per loop, don't expect it to give big savings.

Bigger savings come from avoiding exec. Instead, try to use factory
functions, closures, etc. If you give an example of what you are trying to
generate with exec, we may be able to offer an alternative.



-- 
Steven



From irmen.NOSPAM at xs4all.nl  Tue Jan 13 18:01:14 2015
From: irmen.NOSPAM at xs4all.nl (Irmen de Jong)
Date: Wed, 14 Jan 2015 00:01:14 +0100
Subject: List of "python -m" tools
In-Reply-To: <9d6346ee-b29d-45a8-bde0-29072a9dca73@googlegroups.com>
References: <9d6346ee-b29d-45a8-bde0-29072a9dca73@googlegroups.com>
Message-ID: <54b5a3bb$0$2878$e4fe514c@news.xs4all.nl>

On 12-1-2015 5:17, Miki Tebeka wrote:
> Greetings,
> 
> I've compiled a list of "python -m" tools at pythonwise.blogspot.com/2015/01/python-m.html.
> 
> Did I miss something? What are your favorite "python -m" tools?
> 
> Thanks,
> --
> Miki
> 


python -m calendar
python -m test.pystone
python -m antigravity


Irmen



From andrew3 at r3dsolutions.com  Tue Jan 13 19:12:54 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Tue, 13 Jan 2015 16:12:54 -0800
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <54B5B486.7080406@r3dsolutions.com>


On 01/12/2015 09:32 PM, Steven D'Aprano wrote:
> On Mon, 12 Jan 2015 17:59:42 -0800, Andrew Robinson wrote:
>
> [...]
>> What I am wanting to know is WHY did Guido think it so important to do
>> that ?   Why was he so focused on a strict inability to have any
>> instances of a bool subclass at all -- that he made a very arbitrary
>> exception to the general rule that base types in Python can be
>> subclassed ?
> It's not arbitrary. All the singleton (doubleton in the case of bool)
> classes cannot be subclassed. E.g. NoneType:
>
> py> class X(type(None)):
> ...     pass
> ...
> Traceback (most recent call last):
>    File "<stdin>", line 1, in <module>
> TypeError: Error when calling the metaclass bases
>      type 'NoneType' is not an acceptable base type
>
>
> Likewise for the NotImplemented and Ellipsis types.
>
> The reason is the same: if a type promises that there is one and only one
> instance (two in the case of bool), then allowing subtypes will break
> that promise in the 99.99% of cases where the subtype is instantiated.
Ok. That's something I did not know.  So much for the just four classes 
can't be subtyped remark someone else made...

At least Guido is consistent.
But that doesn't give me any idea of why he thought it important.

> I suppose in principle Python could allow you to subclass singleton
> classes to your hearts content, and only raise an error if you try to
> instantiate them, but that would probably be harder and more error-prone
> to implement, and would *definitely* be harder to explain.
>
>
> There may be others too:
>
> py> from types import FunctionType
> py> class F(FunctionType):
> ...     pass
> ...
> Traceback (most recent call last):
>    File "<stdin>", line 1, in <module>
> TypeError: Error when calling the metaclass bases
>      type 'function' is not an acceptable base type
>
>
> My guess here is that functions are so tightly coupled to the Python
> interpreter that allowing you to subclass them, and hence break required
> invariants, could crash the interpreter. Crashing the interpreter from
> pure Python code is *absolutely not allowed*, so anything which would
> allow that is forbidden.
>
>
>> There's no reason in object oriented programming principles in general
>> that requires a new subclass instance to be a COMPLETELY DISTINCT
>> instance from an already existing superclass instance....
> True. But what is the point of such a subclass? I don't think you have
> really thought this through in detail.

I have. Such a subclass allows refining of the meaning/precision of a 
previous type while improving compatibility with existing applications 
-- and without being so easy to do that everyone will abuse it.  That's 
the standard kind of things which go into deciding that a singleton is 
appropriate...

Subclasses of singletons is a tried and true way of improving 
productivity regardless of how it is implemented.

> Suppose we allowed bool subclasses, and we implement one which *only*
> returns True and False, without adding a third instance:
>
> class MyBool(bool):
>      def __new__(cls, arg):
>          if cls.condition(arg):
>              return True
>          else:
>              return False
>      @classmethod
>      def condition(cls, obj):
>          # decide whether obj is true-ish or false-ish.
>          pass
>      def spam(self):
>          return self.eggs()
>      def eggs(self):
>          return 23
>
>
> And then you do this:
>
> flag = MyBool(something)
> flag.spam()
>
>
> What do you expect to happen?
Flag is not an instance of MyBool, so it's going to generate an exception.
>
> Since flag can *only* be a regular bool, True or False, it won't have
> spam or eggs methods.
Correct.  It would generate an exception.
> You might think of writing the code using unbound methods:
>
> MyBool.spam(flag)
>
> (assuming that methods don't enforce the type restriction that "self"
> must be an instance of their class), but that fails when the spam method
> calls "self.eggs". So you have to write your methods like this:
>
>      def spam(self):
>          return MyBool.eggs(self)
>
> hard-coding the class name! You can't use type(self), because that's
> regular bool, not MyBool.
>
> This is a horrible, error-prone, confusing mess of a system. If you're
> going to write code like this, you are better off making MyBool a module
> with functions instead of a class with methods.

Every design method has its trade offs... but how you organize you code 
will affect whether it is messy or clean.

In terms of information encoding -- both an instance of a type,  or a 
class definition held in a type variable -- eg: a class name -- are 
pretty much interchangeable when it comes to being able to tell two 
items are not the same one, or are the same one.

So -- even a cursory thought shows that the information could be encoded 
in a very few lines even without an instance of a subclass:

class CAllFalse():
     @classmethod
     def __nonzero__(Kls): return False

class CPartFalse():
     @classmethod
     def __nonzero__(Kls): return False

...

class cmp():
     lex=( CAllFalse,  CPartFalse, True )
     @staticmethod
     def __cmp__( left, right ):
         if type(left) == type(right): # advanced statistical compare
             return cmp.lex.index( right ).__cmp__( cmp.lex.index( left ) )
         else: # legacy bool compare...
            return right.__nonzero__().__cmp__( left.__nonzero__() )

 >>> CAllFalse.__nonzero__()
False
 >>> cmp.__cmp__( CPartFalse, CAllFalse )
-1
 >>> cmp.__cmp__( CPartFalse, False )
0

This is not optimal code, but I could definitely refine it until it was 
compact and clean.

I do admit that, being more used to instantated variables, I can make 
proxy wrappers far more easily and robustly than subclassed ones with no 
instances at all.  Both methods are traditionally used for making the 
equivalent of a subclass of a singleton...

And it's pretty clear that the return values of comparison operators are 
what have to be preserved in legacy operations vs. advanced ones 
regardless of how the singletons are implemented.

Essentially, any type of if statement that mixes bool with an advanced 
class must be wanting a legacy result -- so basically, I just need a 
simple way to encode and carry out a complicated compare, and always 
return a True or False final value at the appropriate time...

The most basic wrapper class is merely one that extends the idea of 
comparision to rich comparision; eg: like this one...

def _op(op,other): # Call an operation, to match data sizes...
         try: other[0]
         except: return op((other,))
         return op(other)

class ETuple(tuple):
     """
     Enhanced Tuple.
     A tuple which does rich comparisons even when the item being
     compared against is not an iterable by converting non iterables to
     tuples of length, exactly one.
     """
     def __new__(cls, data):return super(ETuple,cls).__new__(cls,data)
     def __eq__(self,other):return _op(super(ETuple,self).__eq__,other)
     def __ne__(self,other):return _op(super(ETuple,self).__ne__,other)
     def __lt__(self,other):return _op(super(ETuple,self).__lt__,other)
     def __le__(self,other):return _op(super(ETuple,self).__le__,other)
     def __gt__(self,other):return _op(super(ETuple,self).__gt__,other)
     def __ge__(self,other):return _op(super(ETuple,self).__ge__,other)
     def __cmp__(self,other):return _op(super(ETuple,self).__cmp__,other)
     def __nonzero__(self,other):return 
_op(super(ETuple,self).__cmp__,other)

 >>> PartFalse = ETuple( (False,) )
 >>> True > PartFalse
True
 >>>  PartFalse < True
True
 >>> PartFalse > False
False
 >>> False < PartFalse
False
 >>> False == PartFalse
True
 >>> False is PartFalse
False
 >>> False == True
False
 >>> print PartFalse
(False,)

It's pretty well behaved, and does everything I want.

A full implementation, that distinguishes between legacy and 
probabilistic interpretations for the math operators could be done in 
several ways;  Here's one that I think is reasonably clean.

class RBool(tuple):
     """
     Rich compare bool.
     A tuple which contains a bool, and a relative certainty value.
     Whenever a RBool is compared against a bool or single valued object 
tuple,
     it will default to legacy mode and compare only against the bool
     However, whenever compared against another RBool, or multi-element 
tuple,
     it will do a full rich comparison.
     """
     def __new__(cls, data):return super(RBool,cls).__new__(cls,data)
     def _legacy(self,other):
         'Resize local data for proper legacy compares as needed.'
         try:
             if len(other)==1: return (self[0],)  # legacy compare in 
tuples.
         except TypeError: return self[0] # non iterables are a legacy 
compare.
         return tuple(self) # A full rich non-recursive compare is 
warranted
     def __eq__(self,other):return self._legacy(other) == other
     def __ne__(self,other):return self._legacy(other) != other
     def __lt__(self,other):return self._legacy(other) <  other
     def __le__(self,other):return self._legacy(other) <= other
     def __gt__(self,other):return self._legacy(other) >  other
     def __ge__(self,other):return self._legacy(other) >= other
     # def __cmp__( #TODO:
     # def __nonzero__( #TODO:

AllTrue   = True
PartTrue  = RBool((False,3))
Uncertain = RBool((False,2))
PartFalse = RBool((False,1))
AllFalse  = RBool((False,0))

>> nor, have I
>> ever seen Guido say that Python is designed intentionally to force this
>> to always be the case... so I'm not sure that's its anything more than a
>> non guaranteed implementation detail that Python acts the way you say it
>> does....
> It is a documented restriction on bool. Whether you agree with the
> decision or not, it is not an implementation detail, it is a language
> promise.
>
> https://docs.python.org/2/library/functions.html#bool

It was documented in the link I gave too. So -- It's not like I didn't 
know that already.  It just doesn't look like he had thought it out 
carefully and might change his mind in the future.  He is great on the 
saying what will happen -- but not so good at clearly stating why, and 
he does change his mind.  I do recall reading about a time when Python 
had a bool factory function ... with a plethora of values...

And even if he doesn't change his mind --  it's still a language 
implementation detail; because Proxy objects are still possible even if 
subclassing is not.  And, it is therefore possible to get an object 
which is not bool -- to return isinstance( myvar, bool ) True -- when it 
proxies a bool (I have actually done this...)

Besides which, If you really want to get down to it -- I can redefine 
class bool from main and make it subclassable for selected libraries I 
want to import; it's hairy, but I certainly can make a replacement class 
that will allow subclassing and which is compatible with the present 
definition of bool.

So -- it's not like Guido's choices (including saying that duck-typing 
ruins the whole point of having bools) -- are carved in stone for all 
eternity.

There are always options....




From jhoulberg.90 at gmail.com  Tue Jan 13 19:36:29 2015
From: jhoulberg.90 at gmail.com (no nein)
Date: Tue, 13 Jan 2015 16:36:29 -0800 (PST)
Subject: Compiling multiple python scripts into an exe file
Message-ID: <24d5878b-8f5f-48a5-8b47-1c4fbe6e5268@googlegroups.com>

Basically, is it possible to compile multiple unrelated python scripts into a single exe file, so when execute it several python programs are run at once.
In order to use this on another machine without python installed and only by using one single file.


From pengyu.ut at gmail.com  Tue Jan 13 22:26:15 2015
From: pengyu.ut at gmail.com (Peng Yu)
Date: Tue, 13 Jan 2015 21:26:15 -0600
Subject: UnicodeEncodeError: 'ascii' codec can't encode character u'\ua000' in
 position 0: ordinal not in range(128)
Message-ID: <CABrM6w=F9PJ=KZupGqPMikGLOY_jqKteBKj6+AO4+48jkkuEjw@mail.gmail.com>

Hi,

I am trying to understand what does encode() do. What are the hex
representations of "u" in main.py? Why there is UnicodeEncodeError
when main.py is piped to xxd? Why there is no such error when it is
not piped? Thanks.

~$ cat main.py
#!/usr/bin/env python

u = unichr(40960) + u'abcd' + unichr(1972)
print u
~$ cat main_encode.py
#!/usr/bin/env python

u = unichr(40960) + u'abcd' + unichr(1972)
print u.encode('utf-8')
$ ./main.py
?abcd?
~$ cat main.sh
#!/usr/bin/env bash

set -v
./main.py | xxd
./main_encode.py | xxd

~$ ./main.sh
./main.py | xxd
Traceback (most recent call last):
  File "./main.py", line 4, in <module>
    print u
UnicodeEncodeError: 'ascii' codec can't encode character u'\ua000' in
position 0: ordinal not in range(128)
./main_encode.py | xxd
0000000: ea80 8061 6263 64de b40a                 ...abcd...

-- 
Regards,
Peng


From ben+python at benfinney.id.au  Tue Jan 13 22:35:28 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Wed, 14 Jan 2015 14:35:28 +1100
Subject: [RELEASE] =?utf-8?Q?=E2=80=98python-daemon?= =?utf-8?B?4oCZ?=
 version 2.0.3 released
Message-ID: <20150114033528.GF24694@benfinney.id.au>

Howdy all,

I am pleased to announce the release of version 2.0.3 of the
?python-daemon? library.

The current release is always available at
<URL:https://pypi.python.org/pypi/python-daemon/>.

The project's forums and VCS are hosted at Alioth
<URL:https://alioth.debian.org/projects/python-daemon/>.


Significant changes since the previous version
==============================================

This is a bug fix release, addressing packaging bugs:

* Break circular import dependency for ?setup.py?.

Many thanks to users who promptly reported this bug.


What is the ?python-daemon? library?
====================================

?python-daemon? is a Python library to implement a well-behaved Unix
daemon process.

-- 
 \        ?To me, boxing is like a ballet, except there's no music, no |
  `\       choreography, and the dancers hit each other.? ?Jack Handey |
_o__)                                                                  |
Ben Finney <ben at benfinney.id.au>


From jacob at blindza.co.za  Tue Jan 13 23:05:52 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Wed, 14 Jan 2015 06:05:52 +0200
Subject: Python 2.7, on windows7 64 bit development machine,
 inconsistent issue on similar machines
In-Reply-To: <CCB8AA2323234F208A95F53FCFA7DCD1@JakesPC>
References: <A5E269C08DCE4D69B5A82C14FD81AB07@JakesPC>
 <np8abap11vuvfkcil3af7jps4mnhvteten@4ax.com>
 <8F8AAFF9D3374888AF2E332647595EB7@JakesPC>
 <CCB8AA2323234F208A95F53FCFA7DCD1@JakesPC>
Message-ID: <CE310C7D95034015BDE9A0E9BEFC86B1@JakesPC>

> Ok, and just tested MySQLdb connection to both XAMPP server instance on 
> same machine, as well as slightly remote connection to other machine over 
> wifi, and same error - so, seems issue is invoked/caused by MySQLdb 
> connection closing - if just put process to sleep for 30 seconds, nothing 
> happens, but, the moment I in fact try to then just close the connection, 
> that's when error dialogue immediately pops up.

Sorry - should also have mentioned the connection, cursor, etc. ec. all work 
fine under normal python interpreter, but anyway.

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."




From cloverobert at gmail.com  Wed Jan 14 01:22:10 2015
From: cloverobert at gmail.com (Robert Clove)
Date: Wed, 14 Jan 2015 11:52:10 +0530
Subject: Threading in Python, Please check the script
Message-ID: <CAEMktPUaiQrEEhvK4okxfBzAynqZDM8c=a93dAo3cfJX1VcWRw@mail.gmail.com>

Hi All,

I have made a script in which i have started two thread named thread 1 and
thread 2.
In thread 1 one function will run named func1 and in thread 2 function 2
will run named func 2.
Thread 1 will execute a command and wait for 60 seconds.
Thread 2 will run only till thread 1 is running .
Again after that the same process continues in while after a break of 80
Seconds.

I am a beginner in python.
Please suggest what all i have done wrong and how to correct it.


#!/usr/bin/python

import threading
import time
import subprocess
import datetime
import os
import thread

thread.start_new_thread( print_time, (None, None))
thread.start_new_thread( print_time1, (None, None))
command= "strace -o /root/Desktop/a.txt -c ./server"
final_dir = "/root/Desktop"
exitflag = 0
# Define a function for the thread
def print_time(*args):
    os.chdir(final_dir)
    print "IN first thread"
    proc = subprocess.Popen(command,shell=True,stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
    proc.wait(70)
    exitflag=1

def print_time1(*args):
    print "In second thread"
    global exitflag
    while exitflag:
        thread.exit()
        #proc =
subprocess.Popen(command1,shell=True,stdout=subprocess.PIPE,
sterr=subprocess.PIPE)



# Create two threads as follows
try:
    while (1):
        t1=threading.Thread(target=print_time)
        t1.start()
        t2=threading.Thread(target=print_time1)
        t2=start()
        time.sleep(80)
        z = t1.isAlive()
        z1 = t2.isAlive()
        if z:
            z.exit()
        if z1:
            z1.exit()
           threading.Thread(target=print_time1).start()
           threading.Thread(target=print_time1).start()
        print "In try"
except:
   print "Error: unable to start thread"
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From dieter at handshake.de  Wed Jan 14 01:53:45 2015
From: dieter at handshake.de (dieter)
Date: Wed, 14 Jan 2015 07:53:45 +0100
Subject: Compiling multiple python scripts into an exe file
References: <24d5878b-8f5f-48a5-8b47-1c4fbe6e5268@googlegroups.com>
Message-ID: <87387dg8ee.fsf@handshake.de>

no nein <jhoulberg.90 at gmail.com> writes:

> Basically, is it possible to compile multiple unrelated python scripts into a single exe file, so when execute it several python programs are run at once.

These are two distinct problems:

  *  for doing things in paralell, look at "threading" or "multiprocessing"
  *  for generating exe files, look at "freeze".



From ian.g.kelly at gmail.com  Wed Jan 14 03:31:15 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 14 Jan 2015 01:31:15 -0700
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54B5B486.7080406@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
Message-ID: <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>

On Tue, Jan 13, 2015 at 5:12 PM, Andrew Robinson
<andrew3 at r3dsolutions.com> wrote:
> So -- even a cursory thought shows that the information could be encoded in
> a very few lines even without an instance of a subclass:
>
> class CAllFalse():
>     @classmethod
>     def __nonzero__(Kls): return False
>
> class CPartFalse():
>     @classmethod
>     def __nonzero__(Kls): return False

This doesn't actually work.

>>> class CAllFalse(object):
...   @classmethod
...   def __nonzero__(cls): return False
...
>>> bool(CAllFalse)
True

When Python evaluates the "truthiness" of an object, it looks up the
__nonzero__ method on the object's class, not on the object itself
(same goes for all the other special dunder methods). Since CAllFalse
is itself a class, its own class (or rather, metaclass) is type [1].
Thus there's no point in using @classmethod on one of these special
methods. If you really want to proceed with this, you would have to
override the metaclass and define its __nonzero__ to return False,
like so:

>>> class CAllFalseMeta(type):
...     def __nonzero__(self): return False
...
>>> class CAllFalse(object):
...     __metaclass__ = CAllFalseMeta
...
>>> bool(CAllFalse)
False

In this code CAllFalse is an instance of CAllFalseMeta, while also
being a class itself.  But I'm not sure what the point of this is,
when you could just make CAllFalse a normal class and create an
instance of it.

[1] Actually, its metaclass is only type if you inherit from object,
which you didn't do, although in Python 2.x it must be done
explicitly. If you don't inherit from object, you get what is known as
a "classic class" instead of a new-style class. There is no reason to
use the old-style classes unless you really know what you are doing.

> class cmp():
>     lex=( CAllFalse,  CPartFalse, True )
>     @staticmethod
>     def __cmp__( left, right ):
>         if type(left) == type(right): # advanced statistical compare
>             return cmp.lex.index( right ).__cmp__( cmp.lex.index( left ) )
>         else: # legacy bool compare...
>            return right.__nonzero__().__cmp__( left.__nonzero__() )

Magic methods are generally meant to be used by the interpreter, not
called directly. The Pythonic way to write that last line would have
been:

    return cmp(bool(right), bool(left))

(Assuming of course that you rename the class to something that
doesn't shadow the cmp builtin function). This also would have
revealed sooner that your __nonzero__ method isn't actually invoked by
the interpreter.

> A full implementation, that distinguishes between legacy and probabilistic
> interpretations for the math operators could be done in several ways;
> Here's one that I think is reasonably clean.
>
> class RBool(tuple):
>     """
>     Rich compare bool.
>     A tuple which contains a bool, and a relative certainty value.
>     Whenever a RBool is compared against a bool or single valued object
> tuple,
>     it will default to legacy mode and compare only against the bool
>     However, whenever compared against another RBool, or multi-element
> tuple,
>     it will do a full rich comparison.
>     """
>     def __new__(cls, data):return super(RBool,cls).__new__(cls,data)
>     def _legacy(self,other):
>         'Resize local data for proper legacy compares as needed.'
>         try:
>             if len(other)==1: return (self[0],)  # legacy compare in tuples.
>         except TypeError: return self[0] # non iterables are a legacy
> compare.
>         return tuple(self) # A full rich non-recursive compare is warranted
>     def __eq__(self,other):return self._legacy(other) == other
>     def __ne__(self,other):return self._legacy(other) != other
>     def __lt__(self,other):return self._legacy(other) <  other
>     def __le__(self,other):return self._legacy(other) <= other
>     def __gt__(self,other):return self._legacy(other) >  other
>     def __ge__(self,other):return self._legacy(other) >= other
>     # def __cmp__( #TODO:
>     # def __nonzero__( #TODO:
>
> AllTrue   = True
> PartTrue  = RBool((False,3))
> Uncertain = RBool((False,2))
> PartFalse = RBool((False,1))
> AllFalse  = RBool((False,0))

This seems fine, but I don't get why you're messing around with
subclassing tuples. Do you really want to have boolean values that are
iterable, indexable, etc. for no reason? Just create a normal class
(or maybe subclass int, to match the normal bool class) and let your
instances contain a tuple instead of being one.


From list at qtrac.plus.com  Wed Jan 14 03:42:33 2015
From: list at qtrac.plus.com (Mark Summerfield)
Date: Wed, 14 Jan 2015 00:42:33 -0800 (PST)
Subject: Is anyone doing Python 3 bindings for the IUP GUI library?
Message-ID: <eb2c3c46-69a0-4650-8de8-ebe1d67606f2@googlegroups.com>

Just wondering if anyone is doing Python 3 bindings for the IUP GUI library?
The library is pure C and GUI only (so not a giant framework), and uses native controls. It comes with Lua bindings and I believe there are third-party Ruby bindings.
http://webserver2.tecgraf.puc-rio.br/iup/


From sperelat at hanmail.net  Wed Jan 14 03:50:43 2015
From: sperelat at hanmail.net (sperelat at hanmail.net)
Date: Wed, 14 Jan 2015 00:50:43 -0800 (PST)
Subject: "cannot set color attribute.." with Mayavi
Message-ID: <4c2d888d-151c-4bca-8e9d-d8f89e3d1ec4@googlegroups.com>

Hello.
I use mayavi module to plot  some function on a spherical surface.
The code read data from files and make 3d plot.

This code  worked well when I ran it with ipython interpreter on one machine.

---------code--------------------------------------------
from numpy import *
from mayavi.mlab import *

theta=load('theta_q.npy')
phi=load('phi_q.npy')

spin_q=load("spin_qfunction.npy")





r=3


gap=9

x = r*sin(theta)*cos(phi)   
y = r*sin(theta)*sin(phi)
z = r*cos(theta) 


mesh(x, y, z,scalars=spin_q,colormap='jet')
---------------------------------------------------------

When I tried to run it on another machine, it makes error like below.

"Cannot set the undefined 'color' attribute of a 'Light' object.
<mayavi.modules.surface.Surface at 0xbc17240>

I actually don't understand what the problem is.

I just guess  that there was some installation problem.

The machine that works well with the code has Windows  XP as its OS,

and another machine has Windows 7.

PythonXY does not seem to be installed properly on this Windows 7 machine.

Does anyone have idea on  the meaning and the origin   of the error  message ?





From jbaptiste.braun at gmail.com  Wed Jan 14 04:02:36 2015
From: jbaptiste.braun at gmail.com (Jean-Baptiste Braun)
Date: Wed, 14 Jan 2015 10:02:36 +0100
Subject: Performance in exec environnements
In-Reply-To: <54b592ac$0$12995$c3e8da3$5496439d@news.astraweb.com>
References: <mailman.17684.1421168544.18130.python-list@python.org>
 <54b592ac$0$12995$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CABUUr0yYBM=EJpcZXX2mJ0pz13Tum8px3Z8y3EZcr0VEo6Bfpw@mail.gmail.com>

2015-01-13 22:48 GMT+01:00 Steven D'Aprano <
steve+comp.lang.python at pearwood.info>:

> So you have been comparing:
>
>     2
>
> versus
>
>     exec('1+1')
>
>
> The first case just fetches a reference to a pre-existing int object, and
> then deletes the reference. That's fast.
>
> The second case:
>
> - creates a new string '1+1'
> - does a global lookup to find the built-in exec function
> - passes the string to the function
> - the function then parses that string and compiles it to byte-code
> - runs the keyhole optimizer over it
> - and finally executes the byte code for "2", same as above.
>
> Only the last step is the same as your earlier test case.
>
What I don't understand is the ratio between test 2 / 4 and test 1 / 3.

Let 0.0229 sec be the execution time to read a bytecode (1st test).
Executing two times that bytecode takes 0.042 sec (test 3), which looks
coherent.

Let 11.6 sec be the execution time to call the global exec, parse, do some
stuff and read a bytecode (test 2). I'm trying to understand why does doing
the same thing and reading one more bytecode is much longer (15.7 sec) in
comparison.


> Bigger savings come from avoiding exec. Instead, try to use factory
> functions, closures, etc. If you give an example of what you are trying to
> generate with exec, we may be able to offer an alternative.
>
I think I'm going to compile before exec'ing.

What I'm trying to do is to map a transformation description in a markup
langage (XSLT) in python to improve execution time. Here is a
simplification of what it looks like :

XSLT :
<title>
 <xsl:choose>
  <xsl:when test="gender='M'">
   Mr
  </xsl:when>
  <xsl:otherwise>
   Mrs
  </xsl:otherwise>
 </xsl:choose>
</title>

Generated python :
print('<title>')
if gender == 'M':
    print('Mr')
else:
    print('Mrs')
print('</title>')
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From fomcl at yahoo.com  Wed Jan 14 04:33:51 2015
From: fomcl at yahoo.com (Albert-Jan Roskam)
Date: Wed, 14 Jan 2015 09:33:51 +0000 (UTC)
Subject: List of "python -m" tools
In-Reply-To: <54b5a3bb$0$2878$e4fe514c@news.xs4all.nl>
References: <54b5a3bb$0$2878$e4fe514c@news.xs4all.nl>
Message-ID: <1260511422.203315.1421228031817.JavaMail.yahoo@jws10779.mail.gq1.yahoo.com>






----- Original Message -----
> From: Irmen de Jong <irmen.NOSPAM at xs4all.nl>
> To: python-list at python.org
> Cc: 
> Sent: Wednesday, January 14, 2015 12:01 AM
> Subject: Re: List of "python -m" tools
> 
> On 12-1-2015 5:17, Miki Tebeka wrote:
>>  Greetings,
>> 
>>  I've compiled a list of "python -m" tools at 
> pythonwise.blogspot.com/2015/01/python-m.html.
>> 
>>  Did I miss something? What are your favorite "python -m" tools?
>> 
>>  Thanks,
>>  --
>>  Miki
>> 
> 
> 
> python -m calendar
> python -m test.pystone
> python -m antigravity
> 


cool, thanks.

You say "Python 2.7.9 and 3.x comes with an easy way to install pip. Run python -m ensurepip and pypi is at your service." . 

But here https://docs.python.org/3/library/ensurepip.html it says that "This module does not access the internet. All of the components needed to bootstrap pip are included as internal parts of the package." So pypi is not involved, right?

Albert-Jan


From davea at davea.name  Wed Jan 14 05:24:52 2015
From: davea at davea.name (Dave Angel)
Date: Wed, 14 Jan 2015 05:24:52 -0500
Subject: UnicodeEncodeError: 'ascii' codec can't encode character u'\ua000'
 in position 0: ordinal not in range(128)
In-Reply-To: <CABrM6w=F9PJ=KZupGqPMikGLOY_jqKteBKj6+AO4+48jkkuEjw@mail.gmail.com>
References: <CABrM6w=F9PJ=KZupGqPMikGLOY_jqKteBKj6+AO4+48jkkuEjw@mail.gmail.com>
Message-ID: <54B643F4.9050709@davea.name>

On 01/13/2015 10:26 PM, Peng Yu wrote:
> Hi,
>

First, you should always specify your Python version and OS version when 
asking questions here.  Even if you've  been asking questions, many of 
us cannot keep track of everyone's specifics, and need to refer to a 
standard place, the head of the current thread.

I'll assume you're using Python 2.7, on Linux or equivalent.

> I am trying to understand what does encode() do. What are the hex
> representations of "u" in main.py? Why there is UnicodeEncodeError
> when main.py is piped to xxd? Why there is no such error when it is
> not piped? Thanks.
>
> ~$ cat main.py
> #!/usr/bin/env python
>
> u = unichr(40960) + u'abcd' + unichr(1972)
> print u

The unicode characters in 'u' must be decoded to a byte stream before 
sent to the standard out device.  How they're decoded depends on the 
device, and what Python knows (or thinks it knows) about it.

> ~$ cat main_encode.py
> #!/usr/bin/env python
>
> u = unichr(40960) + u'abcd' + unichr(1972)
> print u.encode('utf-8')

Here, print is trying to send bytes to a byte-device, and doesn't try to 
second guess anything.

> $ ./main.py
> ?abcd?
> ~$ cat main.sh
> #!/usr/bin/env bash
>
> set -v
> ./main.py | xxd
> ./main_encode.py | xxd
>
> ~$ ./main.sh
> ./main.py | xxd
> Traceback (most recent call last):
>    File "./main.py", line 4, in <module>
>      print u
> UnicodeEncodeError: 'ascii' codec can't encode character u'\ua000' in
> position 0: ordinal not in range(128)
> ./main_encode.py | xxd
> 0000000: ea80 8061 6263 64de b40a                 ...abcd...
>

I'm guessing (since i already guessed you're running on Linux) that in 
the main_encode case, you're printing to a terminal window that Python 
already knows is utf-8.

But in the pipe case, it cannot tell what's on the other side.  So it 
guesses ASCII, and runs into the conversion problem.

(Everything's different in Python 3.x, though in general the problem 
still exists.  If the interpreter cannot tell what encoding is needed, 
it has to guess.)

There are ways to tell Python 2.7 what encoding a given file object 
should have, so you could tell Python to use utf-8 for sys.stdout.  I 
don't know if that's the best answer, but here's what my notes say:

     import sys, codecs
     sys.stdout = codecs.getwriter('utf8')(sys.stdout)

Once you've done that, print output will go through the specified codec 
on the way to the redirected pipe.


-- 
DaveA



From davea at davea.name  Wed Jan 14 05:40:27 2015
From: davea at davea.name (Dave Angel)
Date: Wed, 14 Jan 2015 05:40:27 -0500
Subject: Threading in Python, Please check the script
In-Reply-To: <CAEMktPUaiQrEEhvK4okxfBzAynqZDM8c=a93dAo3cfJX1VcWRw@mail.gmail.com>
References: <CAEMktPUaiQrEEhvK4okxfBzAynqZDM8c=a93dAo3cfJX1VcWRw@mail.gmail.com>
Message-ID: <54B6479B.6080607@davea.name>

On 01/14/2015 01:22 AM, Robert Clove wrote:
> Hi All,
>

In any new thread, you should specify what versions of Python and OS 
you're using.  I'll assume Python 2.7 and Linux for this message.

> I have made a script in which i have started two thread named thread 1 and
> thread 2.
> In thread 1 one function will run named func1 and in thread 2 function 2
> will run named func 2.
> Thread 1 will execute a command and wait for 60 seconds.
> Thread 2 will run only till thread 1 is running .
> Again after that the same process continues in while after a break of 80
> Seconds.
>
> I am a beginner in python.
> Please suggest what all i have done wrong and how to correct it.
>
>
> #!/usr/bin/python
>
> import threading
> import time
> import subprocess
> import datetime
> import os
> import thread
>
> thread.start_new_thread( print_time, (None, None))
> thread.start_new_thread( print_time1, (None, None))

In these two lines you're referencing a function that hasn't been 
defined yet.  This top-level code should be moved to the end of the 
file, after the if __name__ = "__main__": line

Or just drop it, since you've got a second set of code also trying to 
create new threads.

> command= "strace -o /root/Desktop/a.txt -c ./server"
> final_dir = "/root/Desktop"
> exitflag = 0
> # Define a function for the thread
> def print_time(*args):
>      os.chdir(final_dir)
>      print "IN first thread"
>      proc = subprocess.Popen(command,shell=True,stdout=subprocess.PIPE,
> stderr=subprocess.PIPE)
>      proc.wait(70)
>      exitflag=1

You just set a local variable, not the global one.  So it won't be 
visible in the other thread.  If you must rebind a top-level variable 
from a function, you need to use the 'global' declaration in your function.


>
> def print_time1(*args):
>      print "In second thread"
>      global exitflag
>      while exitflag:
>          thread.exit()
>          #proc =
> subprocess.Popen(command1,shell=True,stdout=subprocess.PIPE,
> sterr=subprocess.PIPE)
>
>
>
> # Create two threads as follows
> try:
>      while (1):
>          t1=threading.Thread(target=print_time)
>          t1.start()
>          t2=threading.Thread(target=print_time1)
>          t2=start()
>          time.sleep(80)
>          z = t1.isAlive()
>          z1 = t2.isAlive()
>          if z:
>              z.exit()
>          if z1:
>              z1.exit()
>             threading.Thread(target=print_time1).start()
>             threading.Thread(target=print_time1).start()

What are you trying to do in those two lines?  If nothing else, they'll 
give an indentation error.  But if you fix that, you'll still have the 
potential problem of creating more and more threads as you loop around.

>          print "In try"
> except:

Bare excepts are "evil."  Your user can't tell what went wrong, from a 
syntax error to the user hitting control-C.  Even if you can't handle a 
particular kind of exception, at least have the courtesy of telling the 
user what went wrong.

>     print "Error: unable to start thread"
>
>
>

I'm sure there are other things, but these popped out at me.

-- 
DaveA


From ben+python at benfinney.id.au  Wed Jan 14 05:59:45 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Wed, 14 Jan 2015 21:59:45 +1100
Subject: Using a ChangeLog as a canonical source of package metadata
References: <54ae0917$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17465.1420701187.18130.python-list@python.org>
 <54ae6715$0$12987$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17488.1420762070.18130.python-list@python.org>
 <54b2be27$0$13000$c3e8da3$5496439d@news.astraweb.com>
 <85bnm5ukze.fsf@benfinney.id.au>
Message-ID: <851tmxvd9a.fsf@benfinney.id.au>

Ben Finney <ben+python at benfinney.id.au> writes:

> The idea is to parse from the Changelog the version metadata, and
> record it in Setuptools metadata. Then the ?pkg_resources? module of
> Setuptools allows programmatic access to that metadata.

One tricky aspect is: at what specific point should the Changelog be
parsed and the version metadata recorded in Setuptools package metadata?

At first I thought it should be done immediately on starting ?setup.py?,
in order to have values to supply to the ?setup()? call. So I imported
the ?version? module which itself imports ?docutils? to have the reST
parsing available; then ?setup.py? continues by feeding the Changelog to
a function which parses it and emits values which are used to supply
parameters to ?setup()?.

As was revealed in a recent version of the code base, though, this
causes a circular dependency. Docutils is a third-party library, which
needs to be declared as a dependency and satsified before it can be
imported. But that dependency can't be declared until ?setup()? has run
to specify what the dependencies are!

So in a later release I've had to break that circle by introducing an
initial ?unknown? state for the version information, in order to allow
?setup()? to run and get the dependencies installed. Then when the
?setup.py egg_info? command is run, the Changelog is parsed and the
version info metadata file is injected into the Setuptools metadata for
the distribution.

Rather more complicated than I would like, because of the need to have
?setup()? as a top-level call in ?setup.py?. This would be more
straightforward if we could assume the commonly-deployed existence of a
*declarative* build system (such as Make); but in Python we're stuck
with ?setup.py? and its limitations for now. Fortunately, the hard work
of many people have made those much better in recent years.


I'm interested to know what people writing Python distributions think of
this approach. Again, the example I'm discussing is in ?python-daemon?'s
code base, at <URL:https://alioth.debian.org/projects/python-daemon/>.

Eventually I might propose this to the Distutils folks as a possible
improvement, but I'd like to refine it more in the face of actual usage.

-- 
 \          ?? a Microsoft Certified System Engineer is to information |
  `\     technology as a McDonalds Certified Food Specialist is to the |
_o__)                               culinary arts.? ?Michael Bacarella |
Ben Finney



From ben+python at benfinney.id.au  Wed Jan 14 06:08:56 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Wed, 14 Jan 2015 22:08:56 +1100
Subject: What does "pip install" do?
References: <m91i6i$3ft$1@speranza.aioe.org>
 <mailman.17646.1421102814.18130.python-list@python.org>
 <m92iqd$7ko$1@speranza.aioe.org>
Message-ID: <85wq4pty9j.fsf@benfinney.id.au>

Fabien <fabien.maussion at gmail.com> writes:

> On 12.01.2015 23:46, Chris Angelico wrote:
> > As far as I know, it's equivalent to three steps:
> >
> > 1) Download the appropriate version of a package (the latest, if you
> > didn't say otherwise)
> > 2) Extract that package
> > 3) Run 'python setup.py'.
> >
> > What setup.py does is up to the package, but for a pure-Python
> > package it should simply create something in site-packages. It might
> > do a lot more, though - compiling C or Fortran code, for instance.
>
> Thanks Chris. I should then rephrase my question to "what does python
> setup.pt do?" ;-).

You're re-phrasing that as a question which has already been answered,
though. What ?setup.py? actually does is up to each package. Some are
quite small and simple; others are large complex applications.

> My point was also that I think that this information (mostly: what
> will change on my system or my virtual env when I install a python
> package?) could/should be provided in the mentioned resources:
>
> "Python Packaging Authority" website
> (https://pip.pypa.io/en/latest/user_guide.html),
> "python-packaging-user-guide"
> (http://python-packaging-user-guide.readthedocs.org/en/latest/installing.html)

Why, though? The point of an end-user program is that an end-user should
not need to be bothered by what it does internally, only what the
observable behaviour is. In the case of ?pip install?, the observable
behaviour is that a package is installed and ready for use.

Your questions drive ever toward ?What is the *implementation* of this??
which is not material suitable for a user guide ? especially when the
implementation details are in much more appropriate documents
<URL:https://python-packaging-user-guide.readthedocs.org/en/latest/distributing.html>
<URL:https://python-packaging-user-guide.readthedocs.org/en/latest/additional.html>.

If you want to learn about the internals and the implementation details,
you are expressly moving beyond the scope of the user guide. There's
nothing wrong with doing that, but you need to recognise the shift and
look for the appropriate documentation.

-- 
 \      ?The most common way people give up their power is by thinking |
  `\                               they don't have any.? ?Alice Walker |
_o__)                                                                  |
Ben Finney



From rosuav at gmail.com  Wed Jan 14 06:14:56 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 14 Jan 2015 22:14:56 +1100
Subject: Performance in exec environnements
In-Reply-To: <CABUUr0yYBM=EJpcZXX2mJ0pz13Tum8px3Z8y3EZcr0VEo6Bfpw@mail.gmail.com>
References: <mailman.17684.1421168544.18130.python-list@python.org>
 <54b592ac$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <CABUUr0yYBM=EJpcZXX2mJ0pz13Tum8px3Z8y3EZcr0VEo6Bfpw@mail.gmail.com>
Message-ID: <CAPTjJmoTyMuLaY-z06Bfiw-SSratCkRMktQ1mQ2UhG=7jm6vZg@mail.gmail.com>

On Wed, Jan 14, 2015 at 8:02 PM, Jean-Baptiste Braun
<jbaptiste.braun at gmail.com> wrote:
> What I'm trying to do is to map a transformation description in a markup
> langage (XSLT) in python to improve execution time. Here is a simplification
> of what it looks like :
>
> XSLT :
> <title>
>  <xsl:choose>
>   <xsl:when test="gender='M'">
>    Mr
>   </xsl:when>
>   <xsl:otherwise>
>    Mrs
>   </xsl:otherwise>
>  </xsl:choose>
> </title>
>
> Generated python :
> print('<title>')
> if gender == 'M':
>     print('Mr')
> else:
>     print('Mrs')
> print('</title>')

Would it be possible to do a one-off transformation of the entire XSLT
file into a Python module with a single function in it, and then every
time you need that XSLT, you import that module and call the function?
That would potentially be a lot quicker than exec(), *and* would be
much clearer - there'd be an actual file on the disk with your
generated Python code, and anyone could read it and understand what
it's doing.

ChrisA


From cloverobert at gmail.com  Wed Jan 14 07:11:35 2015
From: cloverobert at gmail.com (Robert Clove)
Date: Wed, 14 Jan 2015 17:41:35 +0530
Subject: Threading in Python, Please check the script
In-Reply-To: <54B6479B.6080607@davea.name>
References: <CAEMktPUaiQrEEhvK4okxfBzAynqZDM8c=a93dAo3cfJX1VcWRw@mail.gmail.com>
 <54B6479B.6080607@davea.name>
Message-ID: <CAEMktPURDmUDsCX_4mUVkRUD8dagKEijsiGj87YGm5BGgFVaCw@mail.gmail.com>

Can u provide me the pseudo script.


On Wed, Jan 14, 2015 at 4:10 PM, Dave Angel <davea at davea.name> wrote:

> On 01/14/2015 01:22 AM, Robert Clove wrote:
>
>> Hi All,
>>
>>
> In any new thread, you should specify what versions of Python and OS
> you're using.  I'll assume Python 2.7 and Linux for this message.
>
>  I have made a script in which i have started two thread named thread 1 and
>> thread 2.
>> In thread 1 one function will run named func1 and in thread 2 function 2
>> will run named func 2.
>> Thread 1 will execute a command and wait for 60 seconds.
>> Thread 2 will run only till thread 1 is running .
>> Again after that the same process continues in while after a break of 80
>> Seconds.
>>
>> I am a beginner in python.
>> Please suggest what all i have done wrong and how to correct it.
>>
>>
>> #!/usr/bin/python
>>
>> import threading
>> import time
>> import subprocess
>> import datetime
>> import os
>> import thread
>>
>> thread.start_new_thread( print_time, (None, None))
>> thread.start_new_thread( print_time1, (None, None))
>>
>
> In these two lines you're referencing a function that hasn't been defined
> yet.  This top-level code should be moved to the end of the file, after the
> if __name__ = "__main__": line
>
> Or just drop it, since you've got a second set of code also trying to
> create new threads.
>
>  command= "strace -o /root/Desktop/a.txt -c ./server"
>> final_dir = "/root/Desktop"
>> exitflag = 0
>> # Define a function for the thread
>> def print_time(*args):
>>      os.chdir(final_dir)
>>      print "IN first thread"
>>      proc = subprocess.Popen(command,shell=True,stdout=subprocess.PIPE,
>> stderr=subprocess.PIPE)
>>      proc.wait(70)
>>      exitflag=1
>>
>
> You just set a local variable, not the global one.  So it won't be visible
> in the other thread.  If you must rebind a top-level variable from a
> function, you need to use the 'global' declaration in your function.
>
>
>
>> def print_time1(*args):
>>      print "In second thread"
>>      global exitflag
>>      while exitflag:
>>          thread.exit()
>>          #proc =
>> subprocess.Popen(command1,shell=True,stdout=subprocess.PIPE,
>> sterr=subprocess.PIPE)
>>
>>
>>
>> # Create two threads as follows
>> try:
>>      while (1):
>>          t1=threading.Thread(target=print_time)
>>          t1.start()
>>          t2=threading.Thread(target=print_time1)
>>          t2=start()
>>          time.sleep(80)
>>          z = t1.isAlive()
>>          z1 = t2.isAlive()
>>          if z:
>>              z.exit()
>>          if z1:
>>              z1.exit()
>>             threading.Thread(target=print_time1).start()
>>             threading.Thread(target=print_time1).start()
>>
>
> What are you trying to do in those two lines?  If nothing else, they'll
> give an indentation error.  But if you fix that, you'll still have the
> potential problem of creating more and more threads as you loop around.
>
>           print "In try"
>> except:
>>
>
> Bare excepts are "evil."  Your user can't tell what went wrong, from a
> syntax error to the user hitting control-C.  Even if you can't handle a
> particular kind of exception, at least have the courtesy of telling the
> user what went wrong.
>
>      print "Error: unable to start thread"
>>
>>
>>
>>
> I'm sure there are other things, but these popped out at me.
>
> --
> DaveA
> --
> https://mail.python.org/mailman/listinfo/python-list
>
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From davea at davea.name  Wed Jan 14 07:37:59 2015
From: davea at davea.name (Dave Angel)
Date: Wed, 14 Jan 2015 07:37:59 -0500
Subject: Threading in Python, Please check the script
In-Reply-To: <CAEMktPURDmUDsCX_4mUVkRUD8dagKEijsiGj87YGm5BGgFVaCw@mail.gmail.com>
References: <CAEMktPUaiQrEEhvK4okxfBzAynqZDM8c=a93dAo3cfJX1VcWRw@mail.gmail.com>	<54B6479B.6080607@davea.name>
 <CAEMktPURDmUDsCX_4mUVkRUD8dagKEijsiGj87YGm5BGgFVaCw@mail.gmail.com>
Message-ID: <54B66327.30605@davea.name>

On 01/14/2015 07:11 AM, Robert Clove wrote:
> Can u provide me the pseudo script.
>
>
You say you're a beginner.  If so, you shouldn't be trying to use 
threads, which are tricky.  I've been programming for 46 years, and I 
seldom have had to write multi-threading code.

But this looks like a school assignment.  And it looks like the code has 
little to do with the assignment.  So let's break down the assignment a bit.

Your assignment says the two threads will be called thread1 and thread2. 
  So why do you call them t1 and t2?

Your assignment says the two functions will be called func1 and func2. 
So why do you call them print_time and print_time1 ?

The assignment doesn't say anything and about running an external 
process.  Since that's also complex and error prone, perhaps you should 
keep it simple till everything else works.

Some general principles:

1) try not to do the same thing in several places.  You create threads 
in 3 places, and two of them are wrong or at least non-optimal.  Keep 
just the one where you do it right.

2) Use useful names for the various variables.  Except of course where 
the assignment specifies the name to be used.  Then use that name.

3) Learn one new concept at a time.  If you're concentrating on threads 
here, don't try to learn subprocess at the same time, unless that's what 
the assignment calls for.

4) Avoid chdir, especially in multithreaded programs.  Use an absolute 
path if you must when dealing with files.  Except for trivial programs, 
changing the working directory is likely to bite you in the foot 
somewhere else in the program.


-- 
DaveA


From PointedEars at web.de  Wed Jan 14 08:02:27 2015
From: PointedEars at web.de (Thomas 'PointedEars' Lahn)
Date: Wed, 14 Jan 2015 14:02:27 +0100
Subject: Python 3 regex?
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
 <mailman.17649.1421114112.18130.python-list@python.org>
 <7c648fa2-4a59-4d1a-923f-d29f4f2dc8f7@googlegroups.com>
 <0fdf17d0-2dd7-4512-8f2a-104d78a27d72@googlegroups.com>
Message-ID: <1879486.f98NMJPo2z@PointedEars.de>

wxjmfauth at gmail.com wrote:

> Le mardi 13 janvier 2015 03:53:43 UTC+1, Rick Johnson a ?crit :
>> [...]
>> you should find Python's "text processing Nirvana"
>> [...]
> 
> I recommend, you write a "small" application

I recommend you get a real name and do not post using the troll and spam-
infested Google Groups, but a newsreader instead.

> sorting strings composed of latin characters, a sort based on
> diacritical characters

I do not think you need regular expressions for that: you can use Unicode 
collations.

> (and eventually, taking into account linguistic specific aspects).

BTDT.  For a translator application, I used Python to sort a dictionary of 
the Latin phonetic transcription of Golic Vulcan whose alphabet is ?S T P K 
R L A Sh O U D V Kh E H G Ch I N Zh M Y F Z Th W B? [1].  re helped a lot 
with that because inversely sorting the list by character length and turning 
it into an alternation allowed me to easily find the characters in words, 
and assign numbers to the letters so that I could sort the words according 
to this alphabet.  If anyone is interested, I can post the relevant code.

> And, why not? compare Py3.2 and Py3.3+ !

What are you getting at?

[1] <http://home.comcast.net/~markg61/vlif.htm>

-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.


From ganesh1pal at gmail.com  Wed Jan 14 08:07:22 2015
From: ganesh1pal at gmail.com (Ganesh Pal)
Date: Wed, 14 Jan 2015 18:37:22 +0530
Subject: How to terminate the function that runs every n seconds
Message-ID: <CACT3xuWvN=zUs5CmuxceG9yv2gPWkmxF2dTgWOr8WqmaJxag+A@mail.gmail.com>

Iam using Linux and  Python 2.7  and playing with the threading.Timer module.

I had the below question on the same.

(a) How to I prevent the execution  the  "EXECUTED SLEEP" after 4
seconds ? , current this is running in an infinite loop

node-1# cat  file_01.py

import threading
import time
def printit():
        threading.Timer(2, printit).start()
        print "EXECUTED SLEEP"
printit()
print "hi"
time.sleep(4)
print "hi"
time.sleep(5)

Output:
node-1# python  file_01.py
EXECUTED SLEEP
hi
EXECUTED SLEEP
EXECUTED SLEEP
EXECUTED SLEEP



Regards,
Ganesh


From ganesh1pal at gmail.com  Wed Jan 14 08:09:45 2015
From: ganesh1pal at gmail.com (Ganesh Pal)
Date: Wed, 14 Jan 2015 18:39:45 +0530
Subject: How to terminate the function that runs every n seconds
In-Reply-To: <CACT3xuWvN=zUs5CmuxceG9yv2gPWkmxF2dTgWOr8WqmaJxag+A@mail.gmail.com>
References: <CACT3xuWvN=zUs5CmuxceG9yv2gPWkmxF2dTgWOr8WqmaJxag+A@mail.gmail.com>
Message-ID: <CACT3xuUr-07yW-FjiKBjPbsbn5j7r1vUfu1E0A6Myz=7sYpnzA@mail.gmail.com>

Corrected Typos .

>a) How to I prevent the execution  of   Print "EXECUTED SLEEP" after 4
> seconds ? , current this is running in an infinite loop


On Wed, Jan 14, 2015 at 6:37 PM, Ganesh Pal <ganesh1pal at gmail.com> wrote:
> Iam using Linux and  Python 2.7  and playing with the threading.Timer module.
>
> I had the below question on the same.
>
> (a) How to I prevent the execution  the  "EXECUTED SLEEP" after 4
> seconds ? , current this is running in an infinite loop
>
> node-1# cat  file_01.py
>
> import threading
> import time
> def printit():
>         threading.Timer(2, printit).start()
>         print "EXECUTED SLEEP"
> printit()
> print "hi"
> time.sleep(4)
> print "hi"
> time.sleep(5)
>
> Output:
> node-1# python  file_01.py
> EXECUTED SLEEP
> hi
> EXECUTED SLEEP
> EXECUTED SLEEP
> EXECUTED SLEEP
>
>
>
> Regards,
> Ganesh


From ganesh1pal at gmail.com  Wed Jan 14 08:24:38 2015
From: ganesh1pal at gmail.com (Ganesh Pal)
Date: Wed, 14 Jan 2015 18:54:38 +0530
Subject: How to terminate the function that runs every n seconds
In-Reply-To: <CACT3xuUr-07yW-FjiKBjPbsbn5j7r1vUfu1E0A6Myz=7sYpnzA@mail.gmail.com>
References: <CACT3xuWvN=zUs5CmuxceG9yv2gPWkmxF2dTgWOr8WqmaJxag+A@mail.gmail.com>
 <CACT3xuUr-07yW-FjiKBjPbsbn5j7r1vUfu1E0A6Myz=7sYpnzA@mail.gmail.com>
Message-ID: <CACT3xuXkE0Gpooww9Zkg5o35eO14RU=H0-eAO2OXko8y6+On4Q@mail.gmail.com>

I quick modified the code and it now looks like this ,is this ok for
termination ? I played with t.canel() it didn't work

import threading
import time
def printit():
        print "EXECUTED SLEEP"

t = threading.Timer(4, printit)
t.start()
printit()
print "hello"

output :

Throttling-1# python  file_02.py
EXECUTED SLEEP
hello
EXECUTED SLEEP



On Wed, Jan 14, 2015 at 6:39 PM, Ganesh Pal <ganesh1pal at gmail.com> wrote:
> Corrected Typos .
>
>>a) How to I prevent the execution  of   Print "EXECUTED SLEEP" after 4
>> seconds ? , current this is running in an infinite loop
>
>
> On Wed, Jan 14, 2015 at 6:37 PM, Ganesh Pal <ganesh1pal at gmail.com> wrote:
>> Iam using Linux and  Python 2.7  and playing with the threading.Timer module.
>>
>> I had the below question on the same.
>>
>> (a) How to I prevent the execution  the  "EXECUTED SLEEP" after 4
>> seconds ? , current this is running in an infinite loop
>>
>> node-1# cat  file_01.py
>>
>> import threading
>> import time
>> def printit():
>>         threading.Timer(2, printit).start()
>>         print "EXECUTED SLEEP"
>> printit()
>> print "hi"
>> time.sleep(4)
>> print "hi"
>> time.sleep(5)
>>
>> Output:
>> node-1# python  file_01.py
>> EXECUTED SLEEP
>> hi
>> EXECUTED SLEEP
>> EXECUTED SLEEP
>> EXECUTED SLEEP
>>
>>
>>
>> Regards,
>> Ganesh


From jbaptiste.braun at gmail.com  Wed Jan 14 08:38:44 2015
From: jbaptiste.braun at gmail.com (Jean-Baptiste Braun)
Date: Wed, 14 Jan 2015 14:38:44 +0100
Subject: Performance in exec environnements
In-Reply-To: <CAPTjJmoTyMuLaY-z06Bfiw-SSratCkRMktQ1mQ2UhG=7jm6vZg@mail.gmail.com>
References: <mailman.17684.1421168544.18130.python-list@python.org>
 <54b592ac$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <CABUUr0yYBM=EJpcZXX2mJ0pz13Tum8px3Z8y3EZcr0VEo6Bfpw@mail.gmail.com>
 <CAPTjJmoTyMuLaY-z06Bfiw-SSratCkRMktQ1mQ2UhG=7jm6vZg@mail.gmail.com>
Message-ID: <CABUUr0wj5-WKmwFb7RgoFzLOtMjEgQqm2nQDPtjLJGPhXiVPvQ@mail.gmail.com>

2015-01-14 12:14 GMT+01:00 Chris Angelico <rosuav at gmail.com>:

> Would it be possible to do a one-off transformation of the entire XSLT
> file into a Python module with a single function in it, and then every
> time you need that XSLT, you import that module and call the function?
> That would potentially be a lot quicker than exec(), *and* would be
> much clearer - there'd be an actual file on the disk with your
> generated Python code, and anyone could read it and understand what
> it's doing.
>
I've done some tests executing compiled generated python and it doesn't
seem to be worth over processing xslt directly. What you propose could be a
solution. In fact I'm not sure yet how it will be designed.

Thank you for feedback anyway.
-------------- next part --------------
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From PointedEars at web.de  Wed Jan 14 08:42:45 2015
From: PointedEars at web.de (Thomas 'PointedEars' Lahn)
Date: Wed, 14 Jan 2015 14:42:45 +0100
Subject: what would be the regular expression for null byte present in a
 string
References: <mailman.17674.1421159068.18130.python-list@python.org>
Message-ID: <18707534.kH9cM8qlhB@PointedEars.de>

Shambhu Rajak wrote:

> I have a string that I get as an output of a command as:
> 
'\x01\x00\x00\x00\x00\x00\x00\x00\x0c\x00\x00\x0010232ae8944a\x02\x00\x00\x00\x00\x00\x00\x00\n'
> 
> I want to fetch '10232ae8944a' from the above string.
> 
> I want to find a re pattern that could replace all the \x01..\x0z to be
> replace by empty string '',  so that I can get the desired portion of
> string

You need a character class with that range.

> Can anyone help me with a working regex for it.

Yes.

> ________________________________
> 
> PLEASE NOTE: The information contained in this electronic mail message is
> intended only for the use of the designated recipient(s) named above. [?]

Please disable this nonsense, do not post multi-part messages, or if this is 
not possible with your e-mail client or provider, use another one, 
respectively.

-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.


From rosuav at gmail.com  Wed Jan 14 08:43:48 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 15 Jan 2015 00:43:48 +1100
Subject: Performance in exec environnements
In-Reply-To: <CABUUr0wj5-WKmwFb7RgoFzLOtMjEgQqm2nQDPtjLJGPhXiVPvQ@mail.gmail.com>
References: <mailman.17684.1421168544.18130.python-list@python.org>
 <54b592ac$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <CABUUr0yYBM=EJpcZXX2mJ0pz13Tum8px3Z8y3EZcr0VEo6Bfpw@mail.gmail.com>
 <CAPTjJmoTyMuLaY-z06Bfiw-SSratCkRMktQ1mQ2UhG=7jm6vZg@mail.gmail.com>
 <CABUUr0wj5-WKmwFb7RgoFzLOtMjEgQqm2nQDPtjLJGPhXiVPvQ@mail.gmail.com>
Message-ID: <CAPTjJmrHB4t=-1QwhUbdfntWTXCjxbWse-3ZF+j2KWcY5PKTNg@mail.gmail.com>

On Thu, Jan 15, 2015 at 12:38 AM, Jean-Baptiste Braun
<jbaptiste.braun at gmail.com> wrote:
> 2015-01-14 12:14 GMT+01:00 Chris Angelico <rosuav at gmail.com>:
>>
>> Would it be possible to do a one-off transformation of the entire XSLT
>> file into a Python module with a single function in it, and then every
>> time you need that XSLT, you import that module and call the function?
>> That would potentially be a lot quicker than exec(), *and* would be
>> much clearer - there'd be an actual file on the disk with your
>> generated Python code, and anyone could read it and understand what
>> it's doing.
>
> I've done some tests executing compiled generated python and it doesn't seem
> to be worth over processing xslt directly. What you propose could be a
> solution. In fact I'm not sure yet how it will be designed.
>
> Thank you for feedback anyway.

I don't know how often you need to re-process the same XSLT file, but
if you often run the same file (eg with different input data), then
you could create a .py file and import it, and then call it. Something
like this:

# Python code generated from some_file.xslt - DO NOT MODIFY
def process(gender):
    print('<title>')
    if gender == 'M':
        print('Mr')
    else:
        print('Mrs')
    print('</title>')


And then you'd use it thus:

import some_file
some_file.process(gender='M')

Although rather than using print(), it might be better to use yield:

# Python code generated from some_file.xslt - DO NOT MODIFY
def process(gender):
    yield '<title>'
    if gender == 'M':
        yield 'Mr'
    else:
        yield 'Mrs'
    yield'</title>'

And then usage would be:

import some_file
print("\n".join(some_file.process(gender='M')))

which gives you the flexibility of sending it somewhere other than
stdout, without monkey-patching the print function to do something
else.

ChrisA


From PointedEars at web.de  Wed Jan 14 08:52:06 2015
From: PointedEars at web.de (Thomas 'PointedEars' Lahn)
Date: Wed, 14 Jan 2015 14:52:06 +0100
Subject: what would be the regular expression for null byte present in a
 string
References: <39F9E8A5546B9448A82E55FBEBE3EC450BD029A5@SACMBXIP03.sdcorp.global.sandisk.com>
 <mailman.17677.1421160126.18130.python-list@python.org>
Message-ID: <13414923.1GtqDO6yAl@PointedEars.de>

Peter Otten wrote:

> Shambhu Rajak wrote:
>> I have a string that I get as an output of a command as:
>> 
> 
'\x01\x00\x00\x00\x00\x00\x00\x00\x0c\x00\x00\x0010232ae8944a\x02\x00\x00\x00\x00\x00\x00\x00\n'
>> 
>> I want to fetch '10232ae8944a' from the above string.
>> 
>> I want to find a re pattern that could replace all the \x01..\x0z to be
>> replace by empty string '',  so that I can get the desired portion of
>> string
>> 
>> Can anyone help me with a working regex for it.
> 
> I think you want the str.tranlate() method rather than a regex.

Another possibility, but given the length of the list probably not the most 
efficient one.  Aside from re and this one, here is another (tested with 
Python 3.4.2):

  filtered = ''.join(filter(lambda ch: ord(ch) > 0x0f, s))

-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.


From PointedEars at web.de  Wed Jan 14 09:11:24 2015
From: PointedEars at web.de (Thomas 'PointedEars' Lahn)
Date: Wed, 14 Jan 2015 15:11:24 +0100
Subject: what would be the regular expression for null byte present in a
 string
References: <39F9E8A5546B9448A82E55FBEBE3EC450BD029A5@SACMBXIP03.sdcorp.global.sandisk.com>
 <mailman.17677.1421160126.18130.python-list@python.org>
 <13414923.1GtqDO6yAl@PointedEars.de>
Message-ID: <2003101.I8trXTtxXO@PointedEars.de>

Thomas 'PointedEars' Lahn wrote:

> Peter Otten wrote:
>> Shambhu Rajak wrote:
>>> I want to find a re pattern that could replace all the \x01..\x0z to be
>>> replace by empty string '',  so that I can get the desired portion of
>>> string
>>> 
>>> Can anyone help me with a working regex for it.
>> 
>> I think you want the str.tranlate() method rather than a regex.
> 
> Another possibility, but given the length of the list probably not the
> most efficient one.  Aside from re and this one, here is another (tested
> with Python 3.4.2):
> 
>   filtered = ''.join(filter(lambda ch: ord(ch) > 0x0f, s))

  filtered = ''.join(filter(lambda ch: ch > "\x0f", s))

-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.


From wolfgang.maier at biologie.uni-freiburg.de  Wed Jan 14 09:21:33 2015
From: wolfgang.maier at biologie.uni-freiburg.de (Wolfgang Maier)
Date: Wed, 14 Jan 2015 15:21:33 +0100
Subject: what would be the regular expression for null byte present in
 a string
In-Reply-To: <39F9E8A5546B9448A82E55FBEBE3EC450BD029A5@SACMBXIP03.sdcorp.global.sandisk.com>
References: <39F9E8A5546B9448A82E55FBEBE3EC450BD029A5@SACMBXIP03.sdcorp.global.sandisk.com>
Message-ID: <m95u1o$pbu$1@ger.gmane.org>

On 01/13/2015 02:40 PM, Shambhu Rajak wrote:
> I have a string that I get as an output of a command as:
>
> '\x01\x00\x00\x00\x00\x00\x00\x00\x0c\x00\x00\x0010232ae8944a\x02\x00\x00\x00\x00\x00\x00\x00\n'
>
> I want to fetch ?*10232ae8944a*? from the above string.
>
> I want to find a re pattern that could replace all the \x01..\x0z to be
> replace by empty string ??,  so that I can get the desired portion of string
>
> Can anyone help me with a working regex for it.
>

Sorry, no regex either, but depending on what exact behavior you need 
str.isprintable() or even str.isalnum() could be for you:

e.g.

s_in = 
'\x01\x00\x00\x00\x00\x00\x00\x00\x0c\x00\x00\x0010232ae8944a\x02\x00\x00\x00\x00\x00\x00\x00\n'
s_out = ''.join(c for c in s_in if c.isprintable())

Wolfgang



From wolfgang.maier at biologie.uni-freiburg.de  Wed Jan 14 09:35:40 2015
From: wolfgang.maier at biologie.uni-freiburg.de (Wolfgang Maier)
Date: Wed, 14 Jan 2015 15:35:40 +0100
Subject: what would be the regular expression for null byte present in
 a string
In-Reply-To: <39F9E8A5546B9448A82E55FBEBE3EC450BD029A5@SACMBXIP03.sdcorp.global.sandisk.com>
References: <39F9E8A5546B9448A82E55FBEBE3EC450BD029A5@SACMBXIP03.sdcorp.global.sandisk.com>
Message-ID: <m95us7$94d$1@ger.gmane.org>

On 01/13/2015 02:40 PM, Shambhu Rajak wrote:
> I have a string that I get as an output of a command as:
>
> '\x01\x00\x00\x00\x00\x00\x00\x00\x0c\x00\x00\x00*10232ae8944a*\x02\x00\x00\x00\x00\x00\x00\x00\n'
>
> I want to fetch ?*10232ae8944a*? from the above string.
>
> I want to find a re pattern that could replace all the \x01..\x0z to be
> replace by empty string ??,  so that I can get the desired portion of string
>
> Can anyone help me with a working regex for it.
>
> Thanks,
>
> Shambhu
>

If the characters you need to keep always form a contiguous stretch, you 
can also use:

exclude = ''.join(chr(n) for n in range(32))
s_in.strip(exclude)

Wolfgang



From ganesh1pal at gmail.com  Wed Jan 14 10:03:36 2015
From: ganesh1pal at gmail.com (Ganesh Pal)
Date: Wed, 14 Jan 2015 20:33:36 +0530
Subject: How to terminate the function that runs every n seconds
In-Reply-To: <CACT3xuWvN=zUs5CmuxceG9yv2gPWkmxF2dTgWOr8WqmaJxag+A@mail.gmail.com>
References: <CACT3xuWvN=zUs5CmuxceG9yv2gPWkmxF2dTgWOr8WqmaJxag+A@mail.gmail.com>
Message-ID: <CACT3xuUjmpr=GtQXm_mTuV4T5r3W76Fm8W-ic3pmKRmb43e4mw@mail.gmail.com>

This is bit urgent and I all stuck form last few hours   :(

On Wed, Jan 14, 2015 at 6:37 PM, Ganesh Pal <ganesh1pal at gmail.com> wrote:
> Iam using Linux and  Python 2.7  and playing with the threading.Timer module.
>
> I had the below question on the same.
>
> (a) How to I prevent the execution  the  "EXECUTED SLEEP" after 4
> seconds ? , current this is running in an infinite loop
>
> node-1# cat  file_01.py
>
> import threading
> import time
> def printit():
>         threading.Timer(2, printit).start()
>         print "EXECUTED SLEEP"
> printit()
> print "hi"
> time.sleep(4)
> print "hi"
> time.sleep(5)
>
> Output:
> node-1# python  file_01.py
> EXECUTED SLEEP
> hi
> EXECUTED SLEEP
> EXECUTED SLEEP
> EXECUTED SLEEP
>
>
>
> Regards,
> Ganesh


From alister.nospam.ware at ntlworld.com  Wed Jan 14 10:11:56 2015
From: alister.nospam.ware at ntlworld.com (alister)
Date: Wed, 14 Jan 2015 15:11:56 GMT
Subject: Python 3 regex?
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
 <mailman.17649.1421114112.18130.python-list@python.org>
 <7c648fa2-4a59-4d1a-923f-d29f4f2dc8f7@googlegroups.com>
 <0fdf17d0-2dd7-4512-8f2a-104d78a27d72@googlegroups.com>
 <1879486.f98NMJPo2z@PointedEars.de>
Message-ID: <0Hvtw.60541$i22.34472@fx07.am4>

On Wed, 14 Jan 2015 14:02:27 +0100, Thomas 'PointedEars' Lahn wrote:

> wxjmfauth at gmail.com wrote:
> 
>> Le mardi 13 janvier 2015 03:53:43 UTC+1, Rick Johnson a ?crit :
>>> [...]
>>> you should find Python's "text processing Nirvana"
>>> [...]
>> 
>> I recommend, you write a "small" application
> 
> I recommend you get a real name and do not post using the troll and
> spam- infested Google Groups, but a newsreader instead.
> 
>> sorting strings composed of latin characters, a sort based on
>> diacritical characters
> 
> I do not think you need regular expressions for that: you can use
> Unicode collations.
> 
>> (and eventually, taking into account linguistic specific aspects).
> 
> BTDT.  For a translator application, I used Python to sort a dictionary
> of the Latin phonetic transcription of Golic Vulcan whose alphabet is ?S
> T P K R L A Sh O U D V Kh E H G Ch I N Zh M Y F Z Th W B? [1].  re
> helped a lot with that because inversely sorting the list by character
> length and turning it into an alternation allowed me to easily find the
> characters in words, and assign numbers to the letters so that I could
> sort the words according to this alphabet.  If anyone is interested, I
> can post the relevant code.
> 
>> And, why not? compare Py3.2 and Py3.3+ !
> 
> What are you getting at?
> 
> [1] <http://home.comcast.net/~markg61/vlif.htm>

Do not wast you/our time with JMF
he is a resident troll but unlike some of our resident trolls I don't 
think he has ever contributed anything useful 



-- 
An actor's a guy who if you ain't talkin' about him, ain't listening.
		-- Marlon Brando


From breamoreboy at yahoo.co.uk  Wed Jan 14 11:18:31 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Wed, 14 Jan 2015 16:18:31 +0000
Subject: How to terminate the function that runs every n seconds
In-Reply-To: <CACT3xuUjmpr=GtQXm_mTuV4T5r3W76Fm8W-ic3pmKRmb43e4mw@mail.gmail.com>
References: <CACT3xuWvN=zUs5CmuxceG9yv2gPWkmxF2dTgWOr8WqmaJxag+A@mail.gmail.com>
 <CACT3xuUjmpr=GtQXm_mTuV4T5r3W76Fm8W-ic3pmKRmb43e4mw@mail.gmail.com>
Message-ID: <m964so$it7$1@ger.gmane.org>

On 14/01/2015 15:03, Ganesh Pal wrote:
> This is bit urgent and I all stuck form last few hours   :(
>

I'm not inclined to help a person who throws four posts at us in two 
hours and top posts, sorry.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From davea at davea.name  Wed Jan 14 11:33:31 2015
From: davea at davea.name (Dave Angel)
Date: Wed, 14 Jan 2015 11:33:31 -0500
Subject: How to terminate the function that runs every n seconds
In-Reply-To: <CACT3xuUr-07yW-FjiKBjPbsbn5j7r1vUfu1E0A6Myz=7sYpnzA@mail.gmail.com>
References: <CACT3xuWvN=zUs5CmuxceG9yv2gPWkmxF2dTgWOr8WqmaJxag+A@mail.gmail.com>
 <CACT3xuUr-07yW-FjiKBjPbsbn5j7r1vUfu1E0A6Myz=7sYpnzA@mail.gmail.com>
Message-ID: <54B69A5B.5000801@davea.name>

On 01/14/2015 08:09 AM, Ganesh Pal wrote:
> Corrected Typos .
>
>> a) How to I prevent the execution  of   Print "EXECUTED SLEEP" after 4
>> seconds ? , current this is running in an infinite loop
>
>

Please on't top-post.  If you want to comment on a message, insert your 
comments after the portion of the message you'd like to comment on.

> On Wed, Jan 14, 2015 at 6:37 PM, Ganesh Pal <ganesh1pal at gmail.com> wrote:
>> Iam using Linux and  Python 2.7  and playing with the threading.Timer module.
>>
>> I had the below question on the same.
>>
>> (a) How to I prevent the execution  the  "EXECUTED SLEEP" after 4
>> seconds ? , current this is running in an infinite loop
>>
>> node-1# cat  file_01.py
>>
>> import threading
>> import time
>> def printit():
>>          threading.Timer(2, printit).start()
>>          print "EXECUTED SLEEP"
>> printit()
>> print "hi"
>> time.sleep(4)
>> print "hi"
>> time.sleep(5)
>>
>> Output:
>> node-1# python  file_01.py
>> EXECUTED SLEEP
>> hi
>> EXECUTED SLEEP
>> EXECUTED SLEEP
>> EXECUTED SLEEP
>>

Do you want to fix the symptom, fix the problem, or finish a school 
assignment?  To do the first, make a global variable that contains the 
time you want to stop making new threads, and conditionally test it 
before calling threading.Timer

Something like
    quit_time = timer.time() + 4

If you want to fix the problem, consider that creating a new thread for 
each iteration is overkill, and consider how you might better solve it. 
  For example a single thread that loops through a range, and prints 
once each time could easily do something a fixed number of times.

if you want to get the homework done, better reread the assignment.  For 
example, if you just want to print the string a fixed number of times 
with a delay each time, you don't need threads at all.  But the 
assignment may have specified that you're stuck with using threads for 
the purpose, and it may have even required that you use Timer somewhere.

Note that neither Timer nor sleep makes any promises about how 
accurately it matches the requested time.

-- 
DaveA


From jasonsewall at gmail.com  Wed Jan 14 11:45:12 2015
From: jasonsewall at gmail.com (jason)
Date: Wed, 14 Jan 2015 08:45:12 -0800 (PST)
Subject: Calling a derived class's constructor from a parent method
Message-ID: <cb109c66-090a-4779-b00e-43d964ae7252@googlegroups.com>

If I have a class hierarchy like so:

 
class A(object):
      def __init__(self, s):
            self.s = s
      def foo(self, s):
            return A(s)

class B(A):
      def __init__(self, s):
            A.__init__(self, s)

If I make a B:

b = B(0)

I'd like b.foo(1) to return an instance of B. Is there a way to do that besides implementing a construct(self, s) for each part of the hierarchy? I.e. is there a way for the base class to look at self and find out what type to create?

I'm using Python 2.7.5, but I'm curious what the 3.x answer is too.


From breamoreboy at yahoo.co.uk  Wed Jan 14 11:54:10 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Wed, 14 Jan 2015 16:54:10 +0000
Subject: How to terminate the function that runs every n seconds
In-Reply-To: <54B69A5B.5000801@davea.name>
References: <CACT3xuWvN=zUs5CmuxceG9yv2gPWkmxF2dTgWOr8WqmaJxag+A@mail.gmail.com>
 <CACT3xuUr-07yW-FjiKBjPbsbn5j7r1vUfu1E0A6Myz=7sYpnzA@mail.gmail.com>
 <54B69A5B.5000801@davea.name>
Message-ID: <m966vk$n71$1@ger.gmane.org>

On 14/01/2015 16:33, Dave Angel wrote:
>
> Note that neither Timer nor sleep makes any promises about how
> accurately it matches the requested time.
>

Reminds me of working on Telematics S200/300/4000/5000 telecomms kit in 
the early 90s where the timers were mains based, so a one hour timer 
would go off at about one hour, 30 seconds.  Programming becomes such 
fun working around such things :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rosuav at gmail.com  Wed Jan 14 11:56:46 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 15 Jan 2015 03:56:46 +1100
Subject: Calling a derived class's constructor from a parent method
In-Reply-To: <cb109c66-090a-4779-b00e-43d964ae7252@googlegroups.com>
References: <cb109c66-090a-4779-b00e-43d964ae7252@googlegroups.com>
Message-ID: <CAPTjJmrk=zdDzgjf=8o3CX9+tXW8mm-JjHz8PDTF=9jLcwmrfg@mail.gmail.com>

On Thu, Jan 15, 2015 at 3:45 AM, jason <jasonsewall at gmail.com> wrote:
> If I have a class hierarchy like so:
>
>
> class A(object):
>       def __init__(self, s):
>             self.s = s
>       def foo(self, s):
>             return A(s)
>
> class B(A):
>       def __init__(self, s):
>             A.__init__(self, s)
>
> If I make a B:
>
> b = B(0)
>
> I'd like b.foo(1) to return an instance of B. Is there a way to do that besides implementing a construct(self, s) for each part of the hierarchy? I.e. is there a way for the base class to look at self and find out what type to create?
>
> I'm using Python 2.7.5, but I'm curious what the 3.x answer is too.

Assuming you require that every subclass be able to be constructed
with that single parameter, it's not too hard. You get a 'self'
parameter; its type is the type you want to construct.

    def foo(self, s):
        return type(self)(s)

That should work just fine on either 2.7 or 3.x.

I'm not sure what this function would do in context, but this basic
technique should work.

ChrisA


From ian.g.kelly at gmail.com  Wed Jan 14 12:00:11 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 14 Jan 2015 10:00:11 -0700
Subject: Calling a derived class's constructor from a parent method
In-Reply-To: <cb109c66-090a-4779-b00e-43d964ae7252@googlegroups.com>
References: <cb109c66-090a-4779-b00e-43d964ae7252@googlegroups.com>
Message-ID: <CALwzidkLpmbtd=AKz1MxR36N6GgvVDnry3S8gyd-STX=NVMQeA@mail.gmail.com>

On Wed, Jan 14, 2015 at 9:45 AM, jason <jasonsewall at gmail.com> wrote:
> class A(object):
>       def __init__(self, s):
>             self.s = s
>       def foo(self, s):
>             return A(s)

Instead of explicitly naming the return class here, do this:

    return self.__class__(s)

Alternatively, since you never use self elsewhere in the method, it
may be cleaner to use a classmethod here:

    @classmethod
    def foo(cls, s):
        return cls(s)

> I'm using Python 2.7.5, but I'm curious what the 3.x answer is too.

The answer is the same in 3.x.


From breamoreboy at yahoo.co.uk  Wed Jan 14 12:05:27 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Wed, 14 Jan 2015 17:05:27 +0000
Subject: Calling a derived class's constructor from a parent method
In-Reply-To: <cb109c66-090a-4779-b00e-43d964ae7252@googlegroups.com>
References: <cb109c66-090a-4779-b00e-43d964ae7252@googlegroups.com>
Message-ID: <m967kp$2tu$1@ger.gmane.org>

On 14/01/2015 16:45, jason wrote:
> If I have a class hierarchy like so:
>
>
> class A(object):
>        def __init__(self, s):
>              self.s = s
>        def foo(self, s):
>              return A(s)
>
> class B(A):
>        def __init__(self, s):
>              A.__init__(self, s)
>
> If I make a B:
>
> b = B(0)
>
> I'd like b.foo(1) to return an instance of B. Is there a way to do that besides implementing a construct(self, s) for each part of the hierarchy? I.e. is there a way for the base class to look at self and find out what type to create?
>
> I'm using Python 2.7.5, but I'm curious what the 3.x answer is too.
>

I'm confused, can you please explain what you're trying to achieve 
rather than how you're trying to achieve it and I'm sure that others 
will give better answers than I can :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From ian.g.kelly at gmail.com  Wed Jan 14 12:11:13 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 14 Jan 2015 10:11:13 -0700
Subject: Performance in exec environnements
In-Reply-To: <CABUUr0yYBM=EJpcZXX2mJ0pz13Tum8px3Z8y3EZcr0VEo6Bfpw@mail.gmail.com>
References: <mailman.17684.1421168544.18130.python-list@python.org>
 <54b592ac$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <CABUUr0yYBM=EJpcZXX2mJ0pz13Tum8px3Z8y3EZcr0VEo6Bfpw@mail.gmail.com>
Message-ID: <CALwzidmjh5N5driHAxLJKbNmJiQ2GFNo6nBRf=o-=pFtt6gTvA@mail.gmail.com>

On Wed, Jan 14, 2015 at 2:02 AM, Jean-Baptiste Braun
<jbaptiste.braun at gmail.com> wrote:
> What I don't understand is the ratio between test 2 / 4 and test 1 / 3.
>
> Let 0.0229 sec be the execution time to read a bytecode (1st test).
> Executing two times that bytecode takes 0.042 sec (test 3), which looks
> coherent.
>
> Let 11.6 sec be the execution time to call the global exec, parse, do some
> stuff and read a bytecode (test 2). I'm trying to understand why does doing
> the same thing and reading one more bytecode is much longer (15.7 sec) in
> comparison.

You've also given it twice as much code to parse and compile.

C:\Users\Ian>python -m timeit "compile('1 + 1', '', 'exec')"
100000 loops, best of 3: 16.8 usec per loop

C:\Users\Ian>python -m timeit "compile('1 + 1; 1 + 1', '', 'exec')"
10000 loops, best of 3: 22.4 usec per loop


From stephen.boulet at gmail.com  Wed Jan 14 12:12:05 2015
From: stephen.boulet at gmail.com (stephen.boulet at gmail.com)
Date: Wed, 14 Jan 2015 09:12:05 -0800 (PST)
Subject: [ANN] EasyGUI_Qt version 0.9
In-Reply-To: <725b74da-2ab6-4300-b81f-cf7f75d97582@googlegroups.com>
References: <4c3dbebe-0184-4ca7-9d7d-30462ae2a578@googlegroups.com>
 <2f1dd848-e075-4435-93ef-c65af9a5148b@googlegroups.com>
 <b4d90fbf-9f5a-4ffa-9013-0e70fc3e4e24@googlegroups.com>
 <5ac77acc-c8db-40a8-812d-731ef6224c01@googlegroups.com>
 <725b74da-2ab6-4300-b81f-cf7f75d97582@googlegroups.com>
Message-ID: <3b518dff-6c62-49ba-8955-a92cfc0563fa@googlegroups.com>

On Tuesday, January 13, 2015 at 8:30:13 PM UTC, Andr? Roberge wrote:
> On Tuesday, 13 January 2015 08:23:30 UTC-4, stephen... at gmail.com  wrote:
> > I found a solution that I'm happy with.
> > 
> > from datetime import datetime
> > from easygui_qt import *
> > 
> > datestring = get_date()
> > mydate = datetime.strptime(datestring, '%b %d %Y')
> 
> I'm thinking of having the new version return a datetime object automatically.
> 
> Andr?

That's probably a cleaner solution.

> > On Saturday, January 10, 2015 at 1:02:30 AM UTC, Andr? Roberge wrote:
> > > On Friday, 9 January 2015 19:09:15 UTC-4, stephen... at gmail.com  wrote:
> > > > On Wednesday, December 31, 2014 at 4:24:50 PM UTC-6, Andr? Roberge wrote:
> > > > > EasyGUI_Qt version 0.9 has been released.  This is the first announcement about EasyGUI_Qt on this list.
> > > > > 
> > > > > Like the original EasyGUI (which used Tkinter), 
> > > > > EasyGUI_Qt seeks to provide simple GUI widgets
> > > > > that can be called in a procedural program. 
> > > > > 
> > > > > EasyGUI_Qt is NOT event-driven: all GUI interactions are invoked by simple function calls.
> > > > > 
> > > > > The archetype is get_string(message)
> > > > > which pops a box whose purpose is exactly the same as Python's input(prompt),
> > > > > that is, present the user with a question/prompt, have the user enter an
> > > > > answer, and return the provided answer as a string.  Thus
> > > > > easygui_qt.get_string() can be used as a drop-in replacement for
> > > > > input().
> > > > > 
> > > > > Similarly, instead of using a print() function to display a message,
> > > > > show_message() is used which pops a message window.
> > > > > 
> > > > > EasyGUI_Qt requires PyQt4 and is really targeted for Python 3.3+ - although it can work (possibly with some unicode problems ...) using Python 2.7.
> > > > > 
> > > > > More information can be found at 
> > > > > http://easygui-qt.readthedocs.org/en/latest/index.html
> > > > > 
> > > > > Feedback is most welcome, including reporting bugs to 
> > > > > https://github.com/aroberge/easygui_qt/issues
> > > > > 
> > > > > Happy 2015 everyone,
> > > > > 
> > > > > Andr? Roberge
> > > > 
> > > > Very nice, thanks.
> > > > 
> > > > One issue is the format returned for the calendar selection. For today, the string returned is "Fri Jan 9 2015". My script needs to convert the date to a datetime.date, and having the month returned as a string instead of an integer makes this harder.
> > > 
> > > Would today's date be represented as the string "09.01.2015" useful to you? (I found out how to do this.)  If so, I could perhaps add an argument like numeric_format = True.
> > > 
> > > Andr?


From ganesh1pal at gmail.com  Wed Jan 14 12:26:11 2015
From: ganesh1pal at gmail.com (Ganesh Pal)
Date: Wed, 14 Jan 2015 22:56:11 +0530
Subject: How to terminate the function that runs every n seconds
In-Reply-To: <54B69A5B.5000801@davea.name>
References: <CACT3xuWvN=zUs5CmuxceG9yv2gPWkmxF2dTgWOr8WqmaJxag+A@mail.gmail.com>
 <CACT3xuUr-07yW-FjiKBjPbsbn5j7r1vUfu1E0A6Myz=7sYpnzA@mail.gmail.com>
 <54B69A5B.5000801@davea.name>
Message-ID: <CACT3xuXSuXyRu8ReXLczFw9N_LEajQzDM=eccdU3GPmj4MgYLA@mail.gmail.com>

> Do you want to fix the symptom, fix the problem, or finish a school
> assignment?  To do the first, make a global variable that contains the time
> you want to stop making new threads, and conditionally test it before
> calling threading.Timer
>

 I firstly apologise for multiple posts and thanks for the reply  . I
was actually in hurry to complete my assignment  and there was no way
to figure out what was going wrong !!

 My assignment  was to write a subroutine that run itself every n
minutes  and terminate before the main thread completes.

  I thought threading.Timer helped me achieve this  but timer.cancel()
didn't help me terminate the timer .

> Something like
>    quit_time = timer.time() + 4
>

Thanks for the above  hint, I will try this and get back to you

> Note that neither Timer nor sleep makes any promises about how accurately it
> matches the requested time.

Sure will keep this in mind

Regards ,
Ganesh


From invalid at invalid.invalid  Wed Jan 14 12:37:00 2015
From: invalid at invalid.invalid (Grant Edwards)
Date: Wed, 14 Jan 2015 17:37:00 +0000 (UTC)
Subject: How to terminate the function that runs every n seconds
References: <CACT3xuWvN=zUs5CmuxceG9yv2gPWkmxF2dTgWOr8WqmaJxag+A@mail.gmail.com>
 <CACT3xuUr-07yW-FjiKBjPbsbn5j7r1vUfu1E0A6Myz=7sYpnzA@mail.gmail.com>
 <54B69A5B.5000801@davea.name>
 <mailman.17726.1421254466.18130.python-list@python.org>
Message-ID: <m969fs$cic$1@reader1.panix.com>

On 2015-01-14, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> On 14/01/2015 16:33, Dave Angel wrote:
>
>> Note that neither Timer nor sleep makes any promises about how
>> accurately it matches the requested time.
>
> Reminds me of working on Telematics S200/300/4000/5000 telecomms kit in 
> the early 90s where the timers were mains based, so a one hour timer 
> would go off at about one hour, 30 seconds.

I don't understand.  Power line frequencies are _very_ accurate and
have been relied upon for timekeeping since the 1930s.  We're talking
a few hundred PPM over a 24 hour period.  A 30 second error over a one
hour period seems _really_ high.

-- 
Grant Edwards               grant.b.edwards        Yow! All right, you
                                  at               degenerates!  I want
                              gmail.com            this place evacuated in
                                                   20 seconds!


From breamoreboy at yahoo.co.uk  Wed Jan 14 12:54:00 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Wed, 14 Jan 2015 17:54:00 +0000
Subject: How to terminate the function that runs every n seconds
In-Reply-To: <m969fs$cic$1@reader1.panix.com>
References: <CACT3xuWvN=zUs5CmuxceG9yv2gPWkmxF2dTgWOr8WqmaJxag+A@mail.gmail.com>
 <CACT3xuUr-07yW-FjiKBjPbsbn5j7r1vUfu1E0A6Myz=7sYpnzA@mail.gmail.com>
 <54B69A5B.5000801@davea.name>
 <mailman.17726.1421254466.18130.python-list@python.org>
 <m969fs$cic$1@reader1.panix.com>
Message-ID: <m96afq$jsv$1@ger.gmane.org>

On 14/01/2015 17:37, Grant Edwards wrote:
> On 2015-01-14, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
>> On 14/01/2015 16:33, Dave Angel wrote:
>>
>>> Note that neither Timer nor sleep makes any promises about how
>>> accurately it matches the requested time.
>>
>> Reminds me of working on Telematics S200/300/4000/5000 telecomms kit in
>> the early 90s where the timers were mains based, so a one hour timer
>> would go off at about one hour, 30 seconds.
>
> I don't understand.  Power line frequencies are _very_ accurate and
> have been relied upon for timekeeping since the 1930s.  We're talking
> a few hundred PPM over a 24 hour period.  A 30 second error over a one
> hour period seems _really_ high.
>

 From 
http://www2.nationalgrid.com/uk/services/balancing-services/frequency-response/ 
"National Grid has a licence obligation to control frequency within the 
limits specified in the 'Electricity Supply Regulations', i.e. ?1% of 
nominal system frequency (50.00Hz) save in abnormal or exceptional 
circumstances.".  I wouldn't describe ?1% as very accurate and certainly 
not within a few hundred ppm.  I'm assuming that this kind of limitation 
applies around the world, so could you be getting confused with some 
other more accurate frequency control?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From invalid at invalid.invalid  Wed Jan 14 13:05:53 2015
From: invalid at invalid.invalid (Grant Edwards)
Date: Wed, 14 Jan 2015 18:05:53 +0000 (UTC)
Subject: How to terminate the function that runs every n seconds
References: <CACT3xuWvN=zUs5CmuxceG9yv2gPWkmxF2dTgWOr8WqmaJxag+A@mail.gmail.com>
 <CACT3xuUr-07yW-FjiKBjPbsbn5j7r1vUfu1E0A6Myz=7sYpnzA@mail.gmail.com>
 <54B69A5B.5000801@davea.name>
 <mailman.17726.1421254466.18130.python-list@python.org>
 <m969fs$cic$1@reader1.panix.com>
 <mailman.17732.1421258062.18130.python-list@python.org>
Message-ID: <m96b61$oek$1@reader1.panix.com>

On 2015-01-14, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> On 14/01/2015 17:37, Grant Edwards wrote:
>> On 2015-01-14, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
>>
>>> Reminds me of working on Telematics S200/300/4000/5000 telecomms kit in
>>> the early 90s where the timers were mains based, so a one hour timer
>>> would go off at about one hour, 30 seconds.
>>
>> I don't understand.  Power line frequencies are _very_ accurate and
>> have been relied upon for timekeeping since the 1930s.  We're talking
>> a few hundred PPM over a 24 hour period.  A 30 second error over a one
>> hour period seems _really_ high.
>
> http://www2.nationalgrid.com/uk/services/balancing-services/frequency-response/ 
> "National Grid has a licence obligation to control frequency within the 
> limits specified in the 'Electricity Supply Regulations', i.e. ?1% of 
> nominal system frequency (50.00Hz) save in abnormal or exceptional 
> circumstances.".  I wouldn't describe ?1% as very accurate and certainly 
> not within a few hundred ppm.

Sorry, I should have guessed from the use of the word "mains" that you
were in the UK -- which seems to have much laxer power-line frequency
regulation than the US.

> I'm assuming that this kind of limitation applies around the world,
> so could you be getting confused with some other more accurate
> frequency control?

Power line frequency control in the US is much tighter than the UK.
According to real-world data I've seen, powerline-based timings are
typically accurate to a few seconds per month.  In the US, they
implement freqency corrections every hour to keep long term,
cumulative time errors under a certain limit (the limit ranges from 2
to 10 seconds depending on region).

-- 
Grant Edwards               grant.b.edwards        Yow! I love ROCK 'N ROLL!
                                  at               I memorized the all WORDS
                              gmail.com            to "WIPE-OUT" in 1965!!


From wxjmfauth at gmail.com  Wed Jan 14 13:10:49 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Wed, 14 Jan 2015 10:10:49 -0800 (PST)
Subject: Python 3 regex?
In-Reply-To: <0Hvtw.60541$i22.34472@fx07.am4>
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
 <mailman.17649.1421114112.18130.python-list@python.org>
 <7c648fa2-4a59-4d1a-923f-d29f4f2dc8f7@googlegroups.com>
 <0fdf17d0-2dd7-4512-8f2a-104d78a27d72@googlegroups.com>
 <1879486.f98NMJPo2z@PointedEars.de> <0Hvtw.60541$i22.34472@fx07.am4>
Message-ID: <17453d9e-9168-41df-a881-4db9e7ade897@googlegroups.com>

Le mercredi 14 janvier 2015 16:12:09 UTC+1, alister a ?crit :
> On Wed, 14 Jan 2015 14:02:27 +0100, Thomas 'PointedEars' Lahn wrote:
> 
> > wxjmfauth at gmail.com wrote:
> > 
> >> Le mardi 13 janvier 2015 03:53:43 UTC+1, Rick Johnson a ?crit :
> >>> [...]
> >>> you should find Python's "text processing Nirvana"
> >>> [...]
> >> 
> >> I recommend, you write a "small" application
> > 
> > I recommend you get a real name and do not post using the troll and
> > spam- infested Google Groups, but a newsreader instead.
> > 
> >> sorting strings composed of latin characters, a sort based on
> >> diacritical characters
> > 
> > I do not think you need regular expressions for that: you can use
> > Unicode collations.
> > 
> >> (and eventually, taking into account linguistic specific aspects).
> > 
> > BTDT.  For a translator application, I used Python to sort a dictionary
> > of the Latin phonetic transcription of Golic Vulcan whose alphabet is "S
> > T P K R L A Sh O U D V Kh E H G Ch I N Zh M Y F Z Th W B" [1].  re
> > helped a lot with that because inversely sorting the list by character
> > length and turning it into an alternation allowed me to easily find the
> > characters in words, and assign numbers to the letters so that I could
> > sort the words according to this alphabet.  If anyone is interested, I
> > can post the relevant code.
> > 
> >> And, why not? compare Py3.2 and Py3.3+ !
> > 
> > What are you getting at?
> > 
> > [1] <http://home.comcast.net/~markg61/vlif.htm>
> 
> Do not wast you/our time with JMF
> he is a resident troll but unlike some of our resident trolls I don't 
> think he has ever contributed anything useful 
> 
> 
> 
> -- 
> An actor's a guy who if you ain't talkin' about him, ain't listening.
> 		-- Marlon Brando

Did you do it? I did.
That's the whole difference.

jmf


From jasonsewall at gmail.com  Wed Jan 14 13:10:57 2015
From: jasonsewall at gmail.com (jason)
Date: Wed, 14 Jan 2015 10:10:57 -0800 (PST)
Subject: Calling a derived class's constructor from a parent method
In-Reply-To: <mailman.17729.1421255143.18130.python-list@python.org>
References: <cb109c66-090a-4779-b00e-43d964ae7252@googlegroups.com>
 <mailman.17729.1421255143.18130.python-list@python.org>
Message-ID: <0fbb81a4-b37a-4428-9877-1637c5473f7f@googlegroups.com>

On Wednesday, January 14, 2015 at 12:05:55 PM UTC-5, Mark Lawrence wrote:
 
> I'm confused, can you please explain what you're trying to achieve 
> rather than how you're trying to achieve it and I'm sure that others 
> will give better answers than I can :)
> 

Good call. Coming up with a minimal example make things pretty far out of context.

The base class represents a generic function (in formal logic) with some name and a list of parameters. The derived class is some sort of specialization of that generic class (like associative functions, etc).

It is desirable to do certain things to these functions, like perform substitution or canonization, that can be implemented in the basic class but which I'd like to return as a copy rather than modify the class. Thus, the base class needs to know which derived class (if any) to create.

The burden is indeed on me to keep the signature of the init() for each of these the same. 


From alister.nospam.ware at ntlworld.com  Wed Jan 14 13:18:26 2015
From: alister.nospam.ware at ntlworld.com (alister)
Date: Wed, 14 Jan 2015 18:18:26 GMT
Subject: Calling a derived class's constructor from a parent method
References: <cb109c66-090a-4779-b00e-43d964ae7252@googlegroups.com>
 <mailman.17729.1421255143.18130.python-list@python.org>
Message-ID: <Spytw.84347$rs3.81145@fx05.am4>

On Wed, 14 Jan 2015 17:05:27 +0000, Mark Lawrence wrote:

> On 14/01/2015 16:45, jason wrote:
>> If I have a class hierarchy like so:
>>
>>
>> class A(object):
>>        def __init__(self, s):
>>              self.s = s
>>        def foo(self, s):
>>              return A(s)
>>
>> class B(A):
>>        def __init__(self, s):
>>              A.__init__(self, s)
>>
>> If I make a B:
>>
>> b = B(0)
>>
>> I'd like b.foo(1) to return an instance of B. Is there a way to do that
>> besides implementing a construct(self, s) for each part of the
>> hierarchy? I.e. is there a way for the base class to look at self and
>> find out what type to create?
>>
>> I'm using Python 2.7.5, but I'm curious what the 3.x answer is too.
>>
>>
> I'm confused, can you please explain what you're trying to achieve
> rather than how you're trying to achieve it and I'm sure that others
> will give better answers than I can :)

why not just make another b?
b2=B(1)



-- 
The computer should be doing the hard work.  That's what it's paid to do,
after all.
             -- Larry Wall in <199709012312.QAA08121 at wall.org>


From davea at davea.name  Wed Jan 14 13:41:51 2015
From: davea at davea.name (Dave Angel)
Date: Wed, 14 Jan 2015 13:41:51 -0500
Subject: Calling a derived class's constructor from a parent method
In-Reply-To: <0fbb81a4-b37a-4428-9877-1637c5473f7f@googlegroups.com>
References: <cb109c66-090a-4779-b00e-43d964ae7252@googlegroups.com>
 <mailman.17729.1421255143.18130.python-list@python.org>
 <0fbb81a4-b37a-4428-9877-1637c5473f7f@googlegroups.com>
Message-ID: <54B6B86F.4010602@davea.name>

On 01/14/2015 01:10 PM, jason wrote:
> On Wednesday, January 14, 2015 at 12:05:55 PM UTC-5, Mark Lawrence wrote:
>
>> I'm confused, can you please explain what you're trying to achieve
>> rather than how you're trying to achieve it and I'm sure that others
>> will give better answers than I can :)
>>
>
> Good call. Coming up with a minimal example make things pretty far out of context.
>
> The base class represents a generic function (in formal logic) with some name and a list of parameters. The derived class is some sort of specialization of that generic class (like associative functions, etc).
>
> It is desirable to do certain things to these functions, like perform substitution or canonization, that can be implemented in the basic class but which I'd like to return as a copy rather than modify the class. Thus, the base class needs to know which derived class (if any) to create.
>
> The burden is indeed on me to keep the signature of the init() for each of these the same.
>

If there are additional parameters possible, you might be able to use 
*args, **vargs to pass them through the call.

-- 
DaveA


From sohcahtoa82 at gmail.com  Wed Jan 14 13:55:05 2015
From: sohcahtoa82 at gmail.com (sohcahtoa82 at gmail.com)
Date: Wed, 14 Jan 2015 10:55:05 -0800 (PST)
Subject: Threading in Python, Please check the script
In-Reply-To: <mailman.17702.1421216540.18130.python-list@python.org>
References: <mailman.17702.1421216540.18130.python-list@python.org>
Message-ID: <e834a821-3f05-4a7f-a024-ab30e2e8b6d4@googlegroups.com>

On Tuesday, January 13, 2015 at 10:22:32 PM UTC-8, Robert Clove wrote:
> Hi All,
> 
> I have made a script in which i have started two thread named thread 1 and thread 2.
> In thread 1 one function will run named func1 and in thread 2 function 2 will run named func 2.
> Thread 1 will execute a command and wait for 60 seconds. 
> Thread 2 will run only till thread 1 is running .
> Again after that the same process continues in while after a break of 80 Seconds.
> 
> I am a beginner in python.
> Please suggest what all i have done wrong and how to correct it.
> 
> 
> #!/usr/bin/python
> 
> import threading
> import time
> import subprocess
> import datetime
> import os
> import thread
> 
> thread.start_new_thread( print_time, (None, None))
> thread.start_new_thread( print_time1, (None, None))
> command= "strace -o /root/Desktop/a.txt -c ./server"
> final_dir = "/root/Desktop"
> exitflag = 0
> # Define a function for the thread
> def print_time(*args):
> ??? os.chdir(final_dir)
> ??? print "IN first thread"
> ??? proc = subprocess.Popen(command,shell=True,stdout=subprocess.PIPE, stderr=subprocess.PIPE)
> ??? proc.wait(70)
> ??? exitflag=1
> ?? 
> def print_time1(*args):
> ??? print "In second thread"
> ??? global exitflag
> ??? while exitflag:
> ??? ?? ?thread.exit()
> ??????? #proc = subprocess.Popen(command1,shell=True,stdout=subprocess.PIPE, sterr=subprocess.PIPE)
> 
> 
> 
> # Create two threads as follows
> try:
> ??? while (1):
> ??? ?? ?t1=threading.Thread(target=print_time)
> ??? ?? ?t1.start()
> ??? ?? ?t2=threading.Thread(target=print_time1)
> ??? ?? ?t2=start()
> ??? ?? ?time.sleep(80)
> ??? ?? ?z = t1.isAlive()
> ??? ?? ?z1 = t2.isAlive()
> ??? ?? ?if z:
> ??? ?? ??? ?z.exit()
> ??? ?? ?if z1:
> ??? ?? ??? ?z1.exit()
> ??? ?? ??? threading.Thread(target=print_time1).start()
> ?? ?? ??? ?threading.Thread(target=print_time1).start()
> ??? ?? ?print "In try"
> except:
> ?? print "Error: unable to start thread"
> 
> ?

In addition to what others have said, it looks like you're designing your script to run as root.  This is a Very Bad Idea(tm) and has the potential to destroy your system if you make a minor mistake and end up blowing away vital system files.

If you want to be able to run the script anywhere but have the results saved in your home directory, then look into calling os.path.expanduser('~/Desktop') to write to the Desktop directory in your home directory.


From drsalists at gmail.com  Wed Jan 14 15:48:46 2015
From: drsalists at gmail.com (Dan Stromberg)
Date: Wed, 14 Jan 2015 12:48:46 -0800
Subject: Compiling multiple python scripts into an exe file
In-Reply-To: <87387dg8ee.fsf@handshake.de>
References: <24d5878b-8f5f-48a5-8b47-1c4fbe6e5268@googlegroups.com>
 <87387dg8ee.fsf@handshake.de>
Message-ID: <CAGGBd_oNg6=ZSmcwKgDTphUQZK+UL_tfMejDfSgAX9WVdZ63yg@mail.gmail.com>

On Tue, Jan 13, 2015 at 10:53 PM, dieter <dieter at handshake.de> wrote:
> no nein <jhoulberg.90 at gmail.com> writes:
>
>> Basically, is it possible to compile multiple unrelated python scripts into a single exe file, so when execute it several python programs are run at once.
>
> These are two distinct problems:
>
>   *  for doing things in paralell, look at "threading" or "multiprocessing"
Or subprocess.

>   *  for generating exe files, look at "freeze".
Or nuitka.


From jgrant at smith.edu  Wed Jan 14 16:55:03 2015
From: jgrant at smith.edu (jgrant at smith.edu)
Date: Wed, 14 Jan 2015 13:55:03 -0800 (PST)
Subject: multiprocessing queue hangs up on the Amazon cloud
Message-ID: <0b065b84-85ee-4ac0-95db-c43444d34fff@googlegroups.com>

Hello!

I searched and found posts that were similar to mine, but either I couldn't understand the answer or the problem was different enough that the answers weren't helpful - please excuse me if this seems to repeat a problem already answered.

I am trying to run a series of scripts on the Amazon cloud, multiprocessing on the 32 cores of our AWS instance.  The scripts run well, and the queuing seems to work BUT, although the processes run to completion, the script below that runs the queue never ends.  I have tried Queue and JoinableQueue and the same thing happens for both.

I've simplified the example below a bit, just having it print, but the problem is the same.  Can anyone see what I have done wrong here?

Thanks!

Jessica

----------------

#!/usr/bin/env python
import os

from multiprocessing import Lock, Process, Queue, current_process, freeze_support,JoinableQueue
from Pipeline import Pipeline
import time

def worker(done_queue,work_queue):
	try:
		for f in iter(work_queue.get, 'STOP'):
			###########################################
			# Normally I call a complicated series of scripts here but to test, just print	
			print f
			########################################### 	
			done_queue.put("%s - %s got %s." % (current_process().name, f, f))
			log("%s - %s got %s." % (current_process().name, f, f),f)
			work_queue.task_done()
	except Exception, e:
		done_queue.put("%s failed on %s with: %s" % (current_process().name, f, e.message))
		log("%s failed on %s with: %s" % (current_process().name, f, e.message),f)
		work_queue.task_done()
	done_queue.put('STOP')

	return


def log(string,f):
	outfile = open('queue_taxon_logfile' + str(f),'a')
	outfile.write(str(string) + '\n')
	outfile.close()

def main():

	workers = 32 #change if fewer processors are available
	work_queue = JoinableQueue(810) #change if more than 810 taxa
	done_queue = JoinableQueue(810)
	processes = []
	
	print "1 it  gets here"
	for f in range(64):
		work_queue.put(f)	
	work_queue.put('STOP')
	
	print "2 it  gets here"
	
	for w in xrange(workers):
		p = Process(target=worker, args=(done_queue,work_queue))
		p.start()
		processes.append(p)

	print "3  it  gets here"
	for p in processes:
		print p                     # it only prints once - <Process(Process-1, started)>
		p.join()
		
	print "it never gets here"
	for status in iter(done_queue.get, 'STOP'):
		print status


if __name__ == '__main__':
    main()
    
   


From rosuav at gmail.com  Wed Jan 14 17:16:56 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 15 Jan 2015 09:16:56 +1100
Subject: multiprocessing queue hangs up on the Amazon cloud
In-Reply-To: <0b065b84-85ee-4ac0-95db-c43444d34fff@googlegroups.com>
References: <0b065b84-85ee-4ac0-95db-c43444d34fff@googlegroups.com>
Message-ID: <CAPTjJmqH7+5euh7vGLG4bA7gWr17bUC5AuaUg13uJKAJr=WrCw@mail.gmail.com>

On Thu, Jan 15, 2015 at 8:55 AM,  <jgrant at smith.edu> wrote:
> I am trying to run a series of scripts on the Amazon cloud, multiprocessing on the 32 cores of our AWS instance.  The scripts run well, and the queuing seems to work BUT, although the processes run to completion, the script below that runs the queue never ends.  I have tried Queue and JoinableQueue and the same thing happens for both.
>

Hi! I'm not absolutely sure that this is a problem, but I'm seeing
something in the code that you might have to walk me through.

> def worker(done_queue,work_queue):
>         try:
>                 for f in iter(work_queue.get, 'STOP'):

This repeatedly asks the queue for something, until it finds the word STOP.

By the way:

>         except Exception, e:

This is an old form of exception syntax. You may want to use "except
Exception as e:" instead, assuming you don't need to support ancient
Python versions. Carrying on!

>         work_queue = JoinableQueue(810) #change if more than 810 taxa
>         work_queue.put('STOP')

There's a single work queue, with a single word STOP on it.

>         for w in xrange(workers):
>                 p = Process(target=worker, args=(done_queue,work_queue))
>                 p.start()
>                 processes.append(p)
>
>         print "3  it  gets here"
>         for p in processes:
>                 print p                     # it only prints once - <Process(Process-1, started)>
>                 p.join()

And then you seek to run multiple workers. If my reading is correct,
one of them (whichever one happens to get there first) will read the
STOP marker and finish; the others will all be blocked, waiting for
more work (which will never arrive). In theory, you could have the
first process be the one to stop, in which case you'd successfully
join() it and then go on to wait for the second, but if any other
process gets it, you'll be stuck waiting for the first. Or have I
misunderstood something in your logic?

If this is indeed what's happening, the simplest solution might be to
add as many STOPs as you have workers. Alternatively, if you can
guarantee that the work is all on the queue before the first process
starts, you could simply use the empty queue as the sentinel; which I
would recommend doing for the done_queue, as there's only one reader
for that.

But it's entirely possible I've missed some tiny fact that makes my
entire analysis wrong, in which case I apologize for the noise!

ChrisA


From ckaynor at zindagigames.com  Wed Jan 14 17:31:49 2015
From: ckaynor at zindagigames.com (Chris Kaynor)
Date: Wed, 14 Jan 2015 14:31:49 -0800
Subject: multiprocessing queue hangs up on the Amazon cloud
In-Reply-To: <CAPTjJmqH7+5euh7vGLG4bA7gWr17bUC5AuaUg13uJKAJr=WrCw@mail.gmail.com>
References: <0b065b84-85ee-4ac0-95db-c43444d34fff@googlegroups.com>
 <CAPTjJmqH7+5euh7vGLG4bA7gWr17bUC5AuaUg13uJKAJr=WrCw@mail.gmail.com>
Message-ID: <CALvWhxvvEPtMqGu=3_VNv8z2BrSXEteTCY0SMfqy+XR8=1mVDQ@mail.gmail.com>

On Wed, Jan 14, 2015 at 2:16 PM, Chris Angelico <rosuav at gmail.com> wrote:

> And then you seek to run multiple workers. If my reading is correct,
> one of them (whichever one happens to get there first) will read the
> STOP marker and finish; the others will all be blocked, waiting for
> more work (which will never arrive). In theory, you could have the
> first process be the one to stop, in which case you'd successfully
> join() it and then go on to wait for the second, but if any other
> process gets it, you'll be stuck waiting for the first. Or have I
> misunderstood something in your logic?
>
> If this is indeed what's happening, the simplest solution might be to
> add as many STOPs as you have workers. Alternatively, if you can
> guarantee that the work is all on the queue before the first process
> starts, you could simply use the empty queue as the sentinel; which I
> would recommend doing for the done_queue, as there's only one reader
> for that.
>
> But it's entirely possible I've missed some tiny fact that makes my
> entire analysis wrong, in which case I apologize for the noise!
>

My reading of the code is the same as Chris Angelico's, however I would
like to add some more:

Another solution to the STOP issue would be to have each worker re-add the
STOP to the work queue once it is complete. This is a good solution if you
cannot put all the work on the queues before starting the workers or the
number of workers is not known when creating the work queue. This can be
done by merely adding the line "work_queue.put('STOP')" to the end of the
worker function. Note that this solution will not work correctly if workers
may produce more work (but, then again, neither will the STOP entry).

I'd also like to point out a flaw in the results processing, at the end of
the worker process you have "done_queue.put('STOP')", however one thread
may run that before another has added its final work result to the
done_queue. That will cause the following two lines:
On Thu, Jan 15, 2015 at 8:55 AM,  <jgrant at smith.edu> wrote:

>         for status in iter(done_queue.get, 'STOP'):
>                 print status

to exit early, and not print the status of some of the work items.

For this, Chris A's other option is the best: due to the join loop just
above, you know all items have been entered into the done_queue, and thus,
there is no need for the STOP entry: just run until the queue has been
fully processed.

Chris
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From steve+comp.lang.python at pearwood.info  Wed Jan 14 19:33:23 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 15 Jan 2015 11:33:23 +1100
Subject: Python 3 regex?
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
 <mailman.17649.1421114112.18130.python-list@python.org>
 <7c648fa2-4a59-4d1a-923f-d29f4f2dc8f7@googlegroups.com>
 <0fdf17d0-2dd7-4512-8f2a-104d78a27d72@googlegroups.com>
 <1879486.f98NMJPo2z@PointedEars.de>
Message-ID: <54b70ad4$0$13000$c3e8da3$5496439d@news.astraweb.com>

Thomas 'PointedEars' Lahn wrote:

> wxjmfauth at gmail.com wrote:
[...]
>> And, why not? compare Py3.2 and Py3.3+ !
> 
> What are you getting at?


Don't waste your time with JMF. He is obsessed with a trivial performance
regression in Python 3.3. Unicode strings can be slightly more expensive to
create in Python 3.3 compared to earlier versions, due to a clever memory
optimization which saves up to 50% if your strings are all in the Basic
Multilingual Plane and up to 75% if they are all in Latin-1. Never mind
that for real-world code, that memory saving can often lead to applications
running faster, JMF is obsessed with an artificial benchmark of his own
devising that involves making, and throwing away, thousands of Unicode
strings as fast as possible in such a way as to exercise the worst-case of
the new Unicode model. From this unimportant performance regression, he has
convinced himself that this means that Python 3.3 and beyond is logically
and mathematically in violation of the Unicode standard.

Any time JMF mentions anything to do with Python versions or Unicode or
ASCII or French, he is in full-blown "pi equals 3 exactly" crank territory
and is best ignored.



-- 
Steven



From steve+comp.lang.python at pearwood.info  Wed Jan 14 19:40:43 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 15 Jan 2015 11:40:43 +1100
Subject: Calling a derived class's constructor from a parent method
References: <cb109c66-090a-4779-b00e-43d964ae7252@googlegroups.com>
Message-ID: <54b70c8c$0$12999$c3e8da3$5496439d@news.astraweb.com>

jason wrote:

> If I have a class hierarchy like so:
> 
>  
> class A(object):
>       def __init__(self, s):
>             self.s = s
>       def foo(self, s):
>             return A(s)

A.foo is broken, or at least rude.  Change it to this:

    def foo(self, s):
        return type(self)(s)



> class B(A):
>       def __init__(self, s):
>             A.__init__(self, s)

Unrelated:

It is better to call super than manually call the superclass. Calling A
directly means your class is no longer compatible with multiple
inheritance.

    def __init__(self, s):
        super(B, self).__init__(s)


> I'm using Python 2.7.5, but I'm curious what the 3.x answer is too.


The answer in 3.x is the same, except that super() can auto-detect the right
arguments:

        super().__init__(s)



-- 
Steven



From steve+comp.lang.python at pearwood.info  Wed Jan 14 20:26:00 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 15 Jan 2015 12:26:00 +1100
Subject: type versus __class__
Message-ID: <54b7172a$0$13007$c3e8da3$5496439d@news.astraweb.com>

There are (at least) two ways to determine the type of something in Python:


type(obj)

obj.__class__


By design, they are not guaranteed to give the same result. Is there a
definitive explanation given by the docs for the difference and which you
should use under different circumstances?


In Python 2, the type() of classic classes is always the same thing:

py> class A:  # classic class
...     def spam(self): return "from A"
...
py> class B:
...     def spam(self): return "from B"
...
py> a = A()
py> b = B()
py> a.__class__ is b.__class__
False
py> type(a) is type(b)  # a special type "instance"
True


Writing to __class__ lets you modify the behaviour of the instance:

py> a.spam()
'from A'
py> a.__class__ = B
py> a.spam()
'from B'


New-style classes are different:

py> class C(object):  # new-style class
...     def spam(self):
...             return "from C"
...
py> class D(object):
...     def spam(self):
...             return "from D"
...
py> c = C()
py> d = D()
py> c.__class__ is d.__class__
False
py> type(c) is type(d)
False

Like classic classes, you can override the __class__ attribute on instances,
and change their behaviour:

py> c.spam()
'from C'
py> c.__class__ = D
py> c.spam()
'from D'


Any other differences? 


-- 
Steven



From steve+comp.lang.python at pearwood.info  Wed Jan 14 20:51:56 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 15 Jan 2015 12:51:56 +1100
Subject: Performance in exec environnements
References: <mailman.17684.1421168544.18130.python-list@python.org>
 <54b592ac$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17707.1421226164.18130.python-list@python.org>
Message-ID: <54b71d3d$0$13001$c3e8da3$5496439d@news.astraweb.com>

Jean-Baptiste Braun wrote:

> 2015-01-13 22:48 GMT+01:00 Steven D'Aprano <
> steve+comp.lang.python at pearwood.info>:
> 
>> So you have been comparing:
>>
>>     2
>>
>> versus
>>
>>     exec('1+1')
>>
>>
>> The first case just fetches a reference to a pre-existing int object, and
>> then deletes the reference. That's fast.
>>
>> The second case:
>>
>> - creates a new string '1+1'
>> - does a global lookup to find the built-in exec function
>> - passes the string to the function
>> - the function then parses that string and compiles it to byte-code
>> - runs the keyhole optimizer over it
>> - and finally executes the byte code for "2", same as above.
>>
>> Only the last step is the same as your earlier test case.
>>
> What I don't understand is the ratio between test 2 / 4 and test 1 / 3.
> 
> Let 0.0229 sec be the execution time to read a bytecode (1st test).
> Executing two times that bytecode takes 0.042 sec (test 3), which looks
> coherent.
> 
> Let 11.6 sec be the execution time to call the global exec, parse, do some
> stuff and read a bytecode (test 2). I'm trying to understand why does
> doing the same thing and reading one more bytecode is much longer (15.7
> sec) in comparison.

I don't know. What code are you comparing? If you are comparing these:

exec('1 + 1')
exec('1 + 1; 1 + 1')

the second one has twice as much source code to parse and compile.

You can eliminate much (but not all) of the overhead of exec by pulling the
compilation step out:

[steve at ando ~]$ python -m timeit "exec('1+1')"
100000 loops, best of 3: 18.5 usec per loop
[steve at ando ~]$ python -m timeit -s \
"c = compile('1+1', '', 'exec')" "exec(c)"
1000000 loops, best of 3: 1.49 usec per loop


Obviously this only helps if you are executing the same code repeatedly.


>> Bigger savings come from avoiding exec. Instead, try to use factory
>> functions, closures, etc. If you give an example of what you are trying
>> to generate with exec, we may be able to offer an alternative.
>>
> I think I'm going to compile before exec'ing.
> 
> What I'm trying to do is to map a transformation description in a markup
> langage (XSLT) in python to improve execution time. Here is a
> simplification of what it looks like :
> 
> XSLT :
> <title>
>  <xsl:choose>
>   <xsl:when test="gender='M'">
>    Mr
>   </xsl:when>
>   <xsl:otherwise>
>    Mrs
>   </xsl:otherwise>
>  </xsl:choose>
> </title>
> 
> Generated python :
> print('<title>')
> if gender == 'M':
>     print('Mr')
> else:
>     print('Mrs')
> print('</title>')


I'm not entirely sure of the context here. If you're only executing that "if
gender ==" block once, then trying to optimize this is a waste of time. The
time you take to pre-compile will be at least as much as the time you save
from a single call. Only if you have multiple calls will it help.

Ideally, instead of exec'ing a block of code, it would be better to create a
function and call the function:

# === Don't do this! ===
while parsing XSLT:
    if tag = 'choose':
        handle_title = """print('<title>')
             if gender == 'M': print('Mr')
             else:  print('Mrs')
             print('</title>')"""

# much later...
exec(handle_title)
print "Smith"
exec(handle_title)
print "Jones"


# === This is better ===
while parsing XSLT:
    if tag = 'choose':
        def handle_title():
             print('<title>')
             if gender == 'M': print('Mr')
             else:  print('Mrs')
             print('</title>')


# much later...
handle_title()
print "Smith"
handle_title()
print "Jones"


Understand that this is just a sketch of a solution, not an actual solution.
But the important thing is that if you can build an actual function rather
than exec'ing source code, that will be much faster. If the XSLT file only
has a small number of functions such as "choose", you may be able to use
factory functions to build the functions and avoid exec.

And if not... oh well. There is nothing wrong with using exec. True, it is a
little slower, but how much data do you have to process? Engaging in
unnecessary optimization to shave the run time from 20 minutes to 19
minutes is probably a waste of effort.




-- 
Steven



From wuwei23 at gmail.com  Wed Jan 14 23:16:10 2015
From: wuwei23 at gmail.com (alex23)
Date: Thu, 15 Jan 2015 14:16:10 +1000
Subject: List of "python -m" tools
In-Reply-To: <mailman.17708.1421228350.18130.python-list@python.org>
References: <54b5a3bb$0$2878$e4fe514c@news.xs4all.nl>
 <mailman.17708.1421228350.18130.python-list@python.org>
Message-ID: <m97ete$v9f$1@dont-email.me>

On 14/01/2015 7:33 PM, Albert-Jan Roskam wrote:
> You say "Python 2.7.9 and 3.x comes with an easy way to install pip. Run python -m ensurepip and pypi is at your service." .
> But here https://docs.python.org/3/library/ensurepip.html it says that "This module does not access the internet. All of the components needed to bootstrap pip are included as internal parts of the package." So pypi is not involved, right?

The original comment doesn't mean that PyPI is involved in the 
installation, but that installing it allows for packages to be installed 
via PyPI. Obviously that isn't true if you're not net-enabled, but pip 
can still handy for installing local packages.



From breamoreboy at yahoo.co.uk  Wed Jan 14 23:44:18 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 15 Jan 2015 04:44:18 +0000
Subject: Calling a derived class's constructor from a parent method
In-Reply-To: <54b70c8c$0$12999$c3e8da3$5496439d@news.astraweb.com>
References: <cb109c66-090a-4779-b00e-43d964ae7252@googlegroups.com>
 <54b70c8c$0$12999$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <m97gj4$70f$1@ger.gmane.org>

On 15/01/2015 00:40, Steven D'Aprano wrote:
> jason wrote:
>
>> class B(A):
>>        def __init__(self, s):
>>              A.__init__(self, s)
>
> Unrelated:
>
> It is better to call super than manually call the superclass. Calling A
> directly means your class is no longer compatible with multiple
> inheritance.
>
>      def __init__(self, s):
>          super(B, self).__init__(s)
>

For the OP an excellent article on super here 
https://rhettinger.wordpress.com/2011/05/26/super-considered-super/

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rustompmody at gmail.com  Thu Jan 15 00:03:26 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Wed, 14 Jan 2015 21:03:26 -0800 (PST)
Subject: Python 3 regex?
In-Reply-To: <54b4a0d6$0$2738$c3e8da3$76491128@news.astraweb.com>
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <54b4a0d6$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <ddac1678-c1fe-4bab-b31d-fe38b88381af@googlegroups.com>

On Tuesday, January 13, 2015 at 10:06:50 AM UTC+5:30, Steven D'Aprano wrote:
> On Mon, 12 Jan 2015 19:48:18 +0000, Ian wrote:
> 
> > My recommendation would be to write a recursive decent parser for your
> > files.
> > 
> > That way will be easier to write,
> 
> I know that writing parsers is a solved problem in computer science, and 
> that doing so is allegedly one of the more trivial things computer 
> scientists are supposed to be able to do, but the learning curve to write 
> parsers is if anything even higher than the learning curve to write a 
> regex.
> 
> I wish that Python made it as easy to use EBNF to write a parser as it 
> makes to use a regex :-(
> 
> http://en.wikipedia.org/wiki/Extended_Backus-Naur_Form
> 
> 
> 
> -- 
> Steven

There appears to be at least one python package for this
https://pypi.python.org/pypi/iscconf

And for those wanting to use regexes to parse CFGs, the requried
reading is:

http://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags


From rustompmody at gmail.com  Thu Jan 15 00:08:43 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Wed, 14 Jan 2015 21:08:43 -0800 (PST)
Subject: Python 3 regex?
In-Reply-To: <54b4a0d6$0$2738$c3e8da3$76491128@news.astraweb.com>
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <54b4a0d6$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <9d34b06a-3393-4b42-8ba6-734c3b9452a6@googlegroups.com>

On Tuesday, January 13, 2015 at 10:06:50 AM UTC+5:30, Steven D'Aprano wrote:
> On Mon, 12 Jan 2015 19:48:18 +0000, Ian wrote:
> 
> > My recommendation would be to write a recursive decent parser for your
> > files.
> > 
> > That way will be easier to write,
> 
> I know that writing parsers is a solved problem in computer science, and 
> that doing so is allegedly one of the more trivial things computer 
> scientists are supposed to be able to do, 

"Solved-CS-problem" often is showing that the problem is 
unsolvable :-)

http://blog.reverberate.org/2013/08/parsing-c-is-literally-undecidable.html



From ian.g.kelly at gmail.com  Thu Jan 15 00:26:27 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 14 Jan 2015 22:26:27 -0700
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54B72D32.3090209@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
Message-ID: <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>

On Wed, Jan 14, 2015 at 8:00 PM, Andrew Robinson
<andrew3 at r3dsolutions.com> wrote:
> Hi Ian,
> On 01/14/2015 12:31 AM, Ian Kelly wrote:
>
> On Tue, Jan 13, 2015 at 5:12 PM, Andrew Robinson
> <andrew3 at r3dsolutions.com> wrote:
>
> So -- even a cursory thought shows that the information could be encoded in
> a very few lines even without an instance of a subclass:
>
> class CAllFalse():
>     @classmethod
>     def __nonzero__(Kls): return False
>
> class CPartFalse():
>     @classmethod
>     def __nonzero__(Kls): return False
>
> This doesn't actually work.
>
> class CAllFalse(object):
>
> ...   @classmethod
> ...   def __nonzero__(cls): return False
> ...
>
> bool(CAllFalse)
>
> True
>
> Yes, but I never used it that way.
> If I had not put the classmethod on there, I could not have used it with a
> class name in lieu of an instance...
>
> eg:
> class Dummy():
>     def __nonzero__(self): return False
>
> bool( Dummy.__nonzero__() )
>>>> bool( Dummy.__nonzero__() )
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> TypeError: unbound method __nonzero__() must be called with Dummy instance
> as first argument (got nothing instead)
>
> When Python evaluates the "truthiness" of an object, it looks up the
> __nonzero__ method on the object's class, not on the object itself
>
> Unless I call the __nonzero__ method using the underscores as I did...

So are you always going to call __nonzero__ then?  When you have an
uncertain boolean that you want to use in an if expression, are you
going to write:

    if value.__nonzero__():

every single time? Or is it possible that client code that isn't aware
of the extended bool might occasionally just use:

    if value:

and thus interpret CAllFalse as True? The entire point of the
__nonzero__ method is to specify for the Python *interpreter* whether
it should treat the object as truish or falsish. If you're not
interested in overriding that, then __nonzero__ is the wrong name for
the method. Dunder names are reserved for use by Python, and when you
use one, it signals that this method has a special meaning to the
interpreter. If the interpreter doesn't actually use that, then you're
just sending a confusing signal to readers of your code.  Call your
method nonzero() or bool() or is_true() or whatever you want, but
don't call it __nonzero__ because that's not what it is.

> Here's a clue:
>
> It may be easier to understand my example if you take something into
> account:  D'Aprano at the end of his email reply quoted to me a page from
> the Python online manuals and called it a "Promise", rather than telling me
> why Guido made a choice in denying subclassing of bool in the first
> place.... (which is what I asked about...)

It seems to me the answer to that has been given to you several times
already in this thread, but you don't seem to want to accept it for
some reason. You can't subclass bool because instances of the subclass
would be new instances of bool, which would break the class invariant.
Without instances all you're left with are static methods, at which
point there is no particular reason to host them on a subclass.

> So -- If you will now notice, I
> specifically  went out of my way to use __cmp__ and __nonzero__ methods in
> my limited example and they are both methods which have been discontinued in
> Python 3 in favor of more boolean friendly versions...

That would seem like all the less reason to use them, if you have any
interest in Python 3 compatibility.

> Given that Van Rosen

You mean Van Rossum?

> said that he denied subclassing of bool to prevent
> instances of bool, (eg: as a means to an end, not the end itself...)  I can
> see working up an example with no instances as a proposal that might make
> Guido happy and allow me to work around Guido's objections; but on the other
> hand -- I don't see putting a lot of effort into it until all other
> reasonable options have been exhausted... becase I can't subclass bool, he
> has effectively made the approach as defective as all others... ( eg: Threw
> the baby out with the bath water... though he may have had a good reason to
> do it... )

It would also be pointless, as I noted above. If the subclass only
exists to host static methods, then why is it important that they be
on a subclass?

> It's because Guido van Rosen said that there should never be another
> *instance* of a bool.   Now, I'm really agreeing with you -- that I would
> really like to subclass bool, and simply make an instance out of it -- even
> if a limited singleton type ; but Guido said No.  And Guido also objected to
> any kind of duck type, although he didn't specifically change the language
> to prevent them ... yet ...

When did Guido ever object to duck typing?

> And most of this thread has been nothing more than me asking "why" did Guido
> say to do that -- and people avoiding answering the question.

Wait, are you actually asking why bool is a doubleton? If nobody has
answered that, I think probably nobody understood you were asking it,
because it shouldn't need to be explained.

Boolean algebra has two values: true and false, or 1 and 0, or humpty
and dumpty, or whatever you like to call them.  The bool class
represents the values of boolean algebra. Therefore, there are two of
them. If I have an object that I know is an instance of bool, the
implication is that it is one of those two values, not something
potentially completely different.

Can you name any other language that *does* allow subclassing of
booleans or creation of new boolean values?

> [1] Actually, its metaclass is only type if you inherit from object,
> which you didn't do, although in Python 2.x it must be done
> explicitly. If you don't inherit from object, you get what is known as
> a "classic class" instead of a new-style class. There is no reason to
> use the old-style classes unless you really know what you are doing.
>
> It wastes less memory and invokes less overhead to use the old style
> classes.  Since I was making a class with a very narrow purpose, I saw no
> reason to go to the extra work of subclassing from object or type when I
> wasn't going to use the mechanisms from them anyway.

That sounds like premature optimization to me. Always subclassing
object when no more specific class is available would be a good habit
to get into. The savings you're talking about are not that great, it
will save you surprises when an old-style class doesn't do what you
expect, and it will produce code that is more compatible with and more
easily ported to Python 3.

> This seems fine, but I don't get why you're messing around with
> subclassing tuples. Do you really want to have boolean values that are
> iterable, indexable, etc. for no reason? Just create a normal class
> (or maybe subclass int, to match the normal bool class) and let your
> instances contain a tuple instead of being one.
>
> Sorting traditionally allows and uses rich compares when sorting complex
> data.  (cf. the email's name)  This point was examined  earlier in the
> thread by another poster, who suggested I wrap my values in a list to allow
> sort() functions to do a hierarchical compare.
>
> Although I couldn't implement the sort in the way that poster recommended
> for various technical reasons -- none the less, their suggestion led to a
> fruitful study of how and when sort algorithms do comparisons and what they
> expect from them.
>
> The tuple, then, is a natural object to contain an actual instance of bool
> (as opposed to a subclass) and work seamlessly with sorting algorithms
> already available in python.

Which doesn't answer my question at all: why inherit from tuple when
composition would suffice? A boolean is not a tuple, so a boolean
class should not subclass tuple. It sounds to me like you turn to
subclassing as a solution much more quickly than is wise.

As a final note, please only post plain text messages to this
newsgroup, not html. Not everybody can easily read html messages, and
as you can probably see from this post it can mess up things like
reply quoting.


From yawar.amin at gmail.com  Thu Jan 15 00:54:52 2015
From: yawar.amin at gmail.com (yawar.amin at gmail.com)
Date: Wed, 14 Jan 2015 21:54:52 -0800 (PST)
Subject: lambdak: multi-line lambda implementation in native Python
Message-ID: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>

Hi all,

First off, to each reader--if you believe that 'multi-line' lambdas are
no good and we can just use functions, decorators, &c. to accomplish
everything in Python, advance warning: this post will annoy you.

Now, the crux of my message. I have implemented what I believe is a
fairly robust, if ugly-looking, native Python module made up of
combinator functions which compose together to form function expressions
(well, callable expressions).

I've seen a lot of discussions on possibly introducing syntax support
for multi-line lambdas in some future version, but I've never seen
anyone say, here's a way you can do this in Python _today._ So I believe
lambdak fits in that niche.

    https://github.com/yawaramin/lambdak

Would anyone care to try it out? I would be happy to answer questions
whenever I can.

Regards,

Yawar


From ian.g.kelly at gmail.com  Thu Jan 15 01:03:12 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 14 Jan 2015 23:03:12 -0700
Subject: type versus __class__
In-Reply-To: <54b7172a$0$13007$c3e8da3$5496439d@news.astraweb.com>
References: <54b7172a$0$13007$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CALwzidm4Cnpov41qbRQ8eJ+MSmNOw9CTsWNVoRdP4vU1d32JVw@mail.gmail.com>

On Wed, Jan 14, 2015 at 6:26 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Any other differences?

Objects of classic builtin types don't even have the __class__ attribute.

>>> type(A)
<type 'classobj'>
>>> A.__class__
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: class A has no attribute '__class__'
>>> type(C)
<type 'type'>
>>> C.__class__
<type 'type'>


From steve at pearwood.info  Thu Jan 15 01:06:25 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 15 Jan 2015 06:06:25 GMT
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
Message-ID: <54b758e1$0$2738$c3e8da3$76491128@news.astraweb.com>

On Wed, 14 Jan 2015 21:54:52 -0800, yawar.amin wrote:

> Now, the crux of my message. I have implemented what I believe is a
> fairly robust, if ugly-looking, native Python module made up of
> combinator functions which compose together to form function expressions
> (well, callable expressions).

How about a demo?

I have a function, which I put into an expression like this:

def func(a, b=None):
    global spam
    import math
    spam = [a, b]*3
    print spam
    del spam


value = [1, "hello", int, func]
del func

How would I use lambdak to write that as an expression

value = [1, "hello", int, ??????? ]

without the intermediate def?

    
-- 
Steve


From ian.g.kelly at gmail.com  Thu Jan 15 01:39:09 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 14 Jan 2015 23:39:09 -0700
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <54b758e1$0$2738$c3e8da3$76491128@news.astraweb.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <54b758e1$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <CALwzid=N0SRKWsBy8W9qicDzAo=vj_C+LKrTVSZDA+iN5oLHHg@mail.gmail.com>

On Wed, Jan 14, 2015 at 11:06 PM, Steven D'Aprano <steve at pearwood.info> wrote:
> I have a function, which I put into an expression like this:
>
> def func(a, b=None):
>     global spam
>     import math
>     spam = [a, b]*3
>     print spam
>     del spam
>
>
> value = [1, "hello", int, func]
> del func
>
> How would I use lambdak to write that as an expression
>
> value = [1, "hello", int, ??????? ]
>
> without the intermediate def?


# Untested, but seems like this should work.

value = [1, "hello", int, given_(lambda a, b=None:
    import_("math", lambda math:
    import_("operator", lambda operator:
    do_(lambda: operator.setitem(globals(), 'spam', [a, b]*3), lambda:
    print_(globals()['spam'], lambda:
    do_(lambda: operator.delitem(globals(), 'spam')))))))]


To the OP: I note that although import_ is used in the examples, it's
not found in the list of functions in the README.


From frank at chagford.com  Thu Jan 15 01:56:10 2015
From: frank at chagford.com (Frank Millman)
Date: Thu, 15 Jan 2015 08:56:10 +0200
Subject: How to terminate the function that runs every n seconds
References: <CACT3xuWvN=zUs5CmuxceG9yv2gPWkmxF2dTgWOr8WqmaJxag+A@mail.gmail.com>
 <CACT3xuUr-07yW-FjiKBjPbsbn5j7r1vUfu1E0A6Myz=7sYpnzA@mail.gmail.com>
 <54B69A5B.5000801@davea.name>
 <CACT3xuXSuXyRu8ReXLczFw9N_LEajQzDM=eccdU3GPmj4MgYLA@mail.gmail.com>
 <1j1ebalmgkuskq0ltnv5m4sbm6d3p5f840@4ax.com>
Message-ID: <m97oa7$hou$1@ger.gmane.org>


"Dennis Lee Bieber" <wlfraed at ix.netcom.com> wrote in message 
news:1j1ebalmgkuskq0ltnv5m4sbm6d3p5f840 at 4ax.com...
>
> Pseudo (Python 2.x) code
>
> def aThread(delay=600.0): #default 10 minutes
>     while keepRunning:
>         print "thread triggered at %s" % time.time()
>         time.sleep(delay)
>     print "thread was commanded to exit"

I read a variation on this theme some years ago that uses 
event.wait(timeout=delay) to manage the delay.

>From the docs, "block until another thread calls set() to set the flag to 
true, or until the optional timeout occurs."

The benefit is that setting the flag terminates the loop straight away, as 
opposed to waiting for the sleep to finish.

I can show some sample code if anyone is interested.

Frank Millman





From wxjmfauth at gmail.com  Thu Jan 15 02:03:57 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Wed, 14 Jan 2015 23:03:57 -0800 (PST)
Subject: Python 3 regex?
In-Reply-To: <54b70ad4$0$13000$c3e8da3$5496439d@news.astraweb.com>
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
 <mailman.17649.1421114112.18130.python-list@python.org>
 <7c648fa2-4a59-4d1a-923f-d29f4f2dc8f7@googlegroups.com>
 <0fdf17d0-2dd7-4512-8f2a-104d78a27d72@googlegroups.com>
 <1879486.f98NMJPo2z@PointedEars.de>
 <54b70ad4$0$13000$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <2a918b76-ac76-411d-99ed-0ec0856a2b30@googlegroups.com>

Le jeudi 15 janvier 2015 01:33:37 UTC+1, Steven D'Aprano a ?crit?:
> Thomas 'PointedEars' Lahn wrote:
> 
> > wxjmfauth at gmail.com wrote:
> [...]
> >> And, why not? compare Py3.2 and Py3.3+ !
> > 
> > What are you getting at?
> 
> 
> Don't waste your time with JMF. He is obsessed with a trivial performance
> regression in Python 3.3. Unicode strings can be slightly more expensive to
> create in Python 3.3 compared to earlier versions, due to a clever memory
> optimization which saves up to 50% if your strings are all in the Basic
> Multilingual Plane and up to 75% if they are all in Latin-1. Never mind
> that for real-world code, that memory saving can often lead to applications
> running faster, JMF is obsessed with an artificial benchmark of his own
> devising that involves making, and throwing away, thousands of Unicode
> strings as fast as possible in such a way as to exercise the worst-case of
> the new Unicode model. From this unimportant performance regression, he has
> convinced himself that this means that Python 3.3 and beyond is logically
> and mathematically in violation of the Unicode standard.
> 
> Any time JMF mentions anything to do with Python versions or Unicode or
> ASCII or French, he is in full-blown "pi equals 3 exactly" crank territory
> and is best ignored.
> 
> 

It is not only a question of performance [*].
This kind of work is an *illustration" of a bad
design.
Unicode implementation in Python 3 is a shame,
and this brave devs are pretending to write a
serious tool? Let's be a little be serious.

What can I do against a guy who has already
invented the automatic coercion between ASCII
and Unicode. Nothing! Python3 is working in the
same spirit.

[*] on top of this, it is expectedly buggy.

For your information, I also wrote a (completely
dirty) unicode plain text editor, based on the
same widget used in TeXWorks. And I can tell
you, I'm not blind. It works very well with
Python 32  (it covers the whole unicode range).

Rembember: use a sheet of paper and a pencil
and a little bit less an editor.

jmf



From andrew3 at r3dsolutions.com  Thu Jan 15 02:23:54 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Wed, 14 Jan 2015 23:23:54 -0800
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
Message-ID: <54B76B0A.7050706@r3dsolutions.com>


>> And most of this thread has been nothing more than me asking "why" 
>> did Guido
>> say to do that -- and people avoiding answering the question.
> Wait, are you actually asking why bool is a doubleton? If nobody has
> answered that, I think probably nobody understood you were asking it,
> because it shouldn't need to be explained.
In some ways, yes I am asking that -- but in another I am not;
to be more precise -- Why did Guido refuse to allow refinement of 
meaning when in industry -- logic equations generally are not limited to 
Charles Bool's original work, but include practical enhancements of his 
theories which make them far more useful.

A subclass is generally backward compatible in any event -- as it is 
built upon a class, so that one can almost always revert to the base 
class's meaning when desired -- but subclassing allows extended meanings 
to be carried.  eg: A subclass of bool is a bool -- but it can be MORE 
than a bool in many ways.

One example: It can also be a union. So when Guido chose to cut off 
subclassing -- his decision had a wider impact than just the one he 
mentioned; eg: extra *instances* of True and False.... as if he were 
trying to save memory or something.

The reason Guido's action puzzles me is twofold -- first it has been 
standard industry practice to subclass singleton  (or n-ton) objects to 
expand their meaning in new contexts, and this practice has been 
documented for many years.  So -- why did Guido go against the general 
OOP practice unless he didn't know about it?

The mere existence of a subclass does not threaten the integrity of 
bools or security in Python in any way I can see -- as one can do a type 
check, or a base type check, on an instance to decide how to handle a 
subclass vs. base class instance. So I'm guessing he was concerned about 
something else, but I don't know what.

In general -- it's not the goal of subclassing to create more instances 
of the base types -- but rather to refine meaning in a way that can be 
automatically reverted to the base class value (when appropriate) and to 
signal to users that the type can be passed to functions that require a 
bool because of backward compatibility.

> Boolean algebra has two values: true and false, or 1 and 0, or humpty
> and dumpty, or whatever you like to call them.
You're speaking to an Electrical engineer.  I know there are 10 kinds of 
people, those who know binary and those who don't.  But you're way off 
base if you think most industrial quality code for manipulating boolean 
logic uses (or even can be restricted to use) only two values and still 
accomplish their tasks correctly and within a finite amount of time.

>    The bool class
> represents the values of boolean algebra. Therefore, there are two of
> them. If I have an object that I know is an instance of bool, the
> implication is that it is one of those two values, not something
> potentially completely different.
>
> Can you name any other language that *does* allow subclassing of
> booleans or creation of new boolean values?
Yes. Several off the top of my head -- and I have mentioned these 
before.  They generally come with the extra subclasses pre-created and 
the user doesn't get to create the classes, but only use them; none the 
less -- they have more than two values with which to do logic equations 
with.

VHDL, Verilog, HDL, Silos III, and there are IEEE variants also.
C/C++ historically allowed you to do it with instances included, 
although I am not sure it still does.

The third value is usually called "TRI-state" or "don't care". (Though 
its sometimes a misnomer which means -- don't know, but do care.)

Most of these high definition languages are used to do things like 
design micorprocessors... eg: the very intel or arm processor you 
typically run python on --- because trying to do it with boolean logic 
and theorems of the past in a pencil and paper compatible strict 
re-incarnation of what Charles Bool's did in his own time (even if done 
by computer) -- rather than including De-morgan and all the many other 
people who contributed afterward -- is about as red-neck backward as one 
can get -- and often doomed to failure (though for small applications 
you might get away with it.)

Often, only one extra ( tri state ) value is needed to do logic 
verification and testing; but in some cases, notably, where the 
exclusive 'or' function is involved, the relationship between don't care 
inputs can become important and more values are required; eg: to detect 
when in deeply nested logic, various sources of don't care inputs 
interfere with each and themselves in constructive or destructive ways 
to produce constant logic Trues or Falses.

We've discovered that we live in a quantum-mechanical universe -- yet 
people still don't grasp the pragmatic issue that basic logic can be 
indeterminate at least some of the time ?!

The name 'boolean logic' has never been re-named in honor of the many 
people who developed the advancements in computers -- including things 
like data sheets for electronic parts, or the code base used for solving 
large numbers of simultaneous logic equations with uncertainty included 
-- which have universally refined the boolean logic meanings found in 
"Truth" tables having clearly more than two values -- but don't take my 
word for it -- look in any digital electronics data book, and there they 
will be more than two states; marked with rising edges, falling edges, 
X's for don't cares, and so forth.

Even though the BASE values are 1 and 0 in all the cases I've mentioned 
-- there is more to consider.

> That sounds like premature optimization to me. Always subclassing
> object when no more specific class is available would be a good habit
> to get into. The savings you're talking about are not that great, it
> will save you surprises when an old-style class doesn't do what you
> expect, and it will produce code that is more compatible with and more
> easily ported to Python 3.
Oh I agree -- but I meant e-mail space. Not just computer memory.
I wasn't going to use any of that in the example I showed D'Aprano and 
didn't want to bother to type it up.

The example was only meant to show three things:  I -- that a class type 
can be used to replace an instance variable for a method can be called 
on a class as opposed to only an instance  II -- that types and 
instances can both be arbitrarily placed in a list to determine their 
relative lexical sorting order. III -- that both of these things can be 
done without the class being instantiated.

All three of those things were demonstrated in the example -- so it was 
good enough for my purposes.  As to all of your other objections -- hell 
-- I never intended that example to be used in a real life situation 
beyond demonstrating the basic feasability of encoding data as a type.
As I said to D'Aprano -- even a *cursory* examination (eg: as in not 
detailed) shows I could do things which he wasn't considering.

>
>> This seems fine, but I don't get why you're messing around with
>> subclassing tuples. Do you really want to have boolean values that are
>> iterable, indexable, etc. for no reason? Just create a normal class
>> (or maybe subclass int, to match the normal bool class) and let your
>> instances contain a tuple instead of being one.
>>
>> Sorting traditionally allows and uses rich compares when sorting complex
>> data.  (cf. the email's name)  This point was examined  earlier in the
>> thread by another poster, who suggested I wrap my values in a list to 
>> allow
>> sort() functions to do a hierarchical compare.
>>
>> Although I couldn't implement the sort in the way that poster 
>> recommended
>> for various technical reasons -- none the less, their suggestion led 
>> to a
>> fruitful study of how and when sort algorithms do comparisons and 
>> what they
>> expect from them.
>>
>> The tuple, then, is a natural object to contain an actual instance of 
>> bool
>> (as opposed to a subclass) and work seamlessly with sorting algorithms
>> already available in python.
> Which doesn't answer my question at all: why inherit from tuple when
> composition would suffice? A boolean is not a tuple, so a boolean
> class should not subclass tuple. It sounds to me like you turn to
> subclassing as a solution much more quickly than is wise.
>
> As a final note, please only post plain text messages to this
> newsgroup, not html. Not everybody can easily read html messages, and
> as you can probably see from this post it can mess up things like
> reply quoting.

I don't have a setting on my email to turn off html.  Sorry. Can't help.

I don't know what you mean about composition vs. sub-classing.
Would you care to show an example of how it would solve the problem and 
still allow hierarchical sorting ?

I don't see how you can get pre-existing python functions (like sort, 
max, and min) to accept a complex bool value and have that value 
automatically revert to a True or False in an intelligent manner without 
overloading the operators defined in some class -- somewhere -- to 
operate on the data the class contains.

How do you intend to achieve that with this -- composition -- thing you 
mentioned ?

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From jacob at blindza.co.za  Thu Jan 15 03:13:14 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Thu, 15 Jan 2015 10:13:14 +0200
Subject: MySQL connections
Message-ID: <DB3F78F5082B4B31A42C783C4E9BD763@JakesPC>

Development machine is windows7 64 bit machine, now working with either/both python 2.7 or 3.4 - test purposes, trying to figure out if this was something like a version incompatibility issue, and tried using both XAMPP and WAMP MySQL server version 5.0.11 instances thus far.

Now, aside from all other issues relating to character encoding, etc., now down to, hopefully, final issue.

Side note is under python 2.7, I use pyodbc to gather data from .mdb file am using to test, but under python 3.4, I use pypyodbc for same functionality.

Now, current/actual issue is something can sort of duplicate using both MySQLdb version of mysqlclient, as well as pymysql using both python 2.7 and python 3.4, but, strange thing am trying to figure out is that even if just implement a connection object in interpreter of either version, retrieve an instance of a cursor object, and do various types of statement executions, no issues, and can then close connection, or cursor, or both, and all good/fine/well.

However, if implement similar code - down to just trying to open a connection, wait a few seconds, and then close it again, inside a function called from a prior function, in the class am implementing in a file called/executed from command line, then, the moment I try to close the connection, whether or not have done anything with it, that's when I get that python.exe has stopped working/responding error message popping up, and python bombs out.

Have no idea how to try track down actual source/cause of issue, since haven't found anything obvious in system event logs, nothing appearing in MySQL server logs that makes sense/appears relevant, and no matter if I try enclosing the connection open/close code inside try except code blocks, nothing happens there except that python just stops cooperating at all, and stops working.

Now did try making sure data execution prevention was turned on/off, and that if set to second mode then told it to ignore specific applications - added both python.exe, and the compiled version of my code to it's exemption list, but, no changes there.

This still operates fine on my other dev machine, but, would like to know why it's not operating on one specific machine.

Otherwise, will just have to tell guys that, sorry, will only be able to generate SQL script text files, and they'll have to stick to the final step of then executing those via MySQL console interface, or something, but, would really prefer to at the very least, figure/find out what's causing this mis-behaviour.

Thoughts/suggestions with regards to how to find out what is happening/what I'm doing/handling wrong/incorrectly?

The two current versions of the code - which work fine under interpreter of both versions of python are basically the following:

#pymysql version
import pymysql
cn = pymysql.connect("localhost", "root", "", "import_test")
time.sleep(5)
cn.close()

#MySQLdb version
import MySQLdb
cn = MySQLdb.connect("localhost", "root", "", "import_test")
time.sleep(5)
cn.close()
#end code

Stay well (away from this machine ;) )

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."
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From wxjmfauth at gmail.com  Thu Jan 15 03:19:03 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Thu, 15 Jan 2015 00:19:03 -0800 (PST)
Subject: Python 3 regex?
In-Reply-To: <2a918b76-ac76-411d-99ed-0ec0856a2b30@googlegroups.com>
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
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Message-ID: <c93ba7ff-f08d-473c-a87a-f033529e73f2@googlegroups.com>

About parser.

>>> 9999and 0
0
>>> 

Maybe it's time for the misc. colorizing tools and other
systax analyzing tools to work coherently.



From steve at pearwood.info  Thu Jan 15 03:41:47 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 15 Jan 2015 08:41:47 GMT
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com>
 <54ABC52A.1050507@davea.name> <54ABE383.3020801@r3dsolutions.com>
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 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
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 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
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Message-ID: <54b77d4a$0$2738$c3e8da3$76491128@news.astraweb.com>

On Wed, 14 Jan 2015 23:23:54 -0800, Andrew Robinson wrote:

[...]
> A subclass is generally backward compatible in any event -- as it is
> built upon a class, so that one can almost always revert to the base
> class's meaning when desired -- but subclassing allows extended meanings
> to be carried.  eg: A subclass of bool is a bool -- but it can be MORE
> than a bool in many ways.

You don't have to explain the benefits of subclassing here.

I'm still trying to understand why you think you *need* to use a bool 
subclass. I can think of multiple alternatives:

- don't use True and False at all, create your own multi-valued 
  truth values ReallyTrue, MaybeTrue, SittingOnTheFence, ProbablyFalse,
  CertainlyFalse (or whatever names you choose to give them);

- use delegation to proxy True and False;

- write a class to handle the PossiblyTrue and PossiblyFalse cases,
  and use True and False for the True and False cases;

There may be other alternatives, but what problem are you solving that 
you think 

    class MyBool(bool): ...

is the only solution?



> One example: It can also be a union.

I don't understand what you think this means. I know what *I* think it 
means, but "subclass = union" doesn't make sense to me, so wonder what 
you think it means.

> So when Guido chose to cut off
> subclassing -- his decision had a wider impact than just the one he
> mentioned; eg: extra *instances* of True and False.... as if he were
> trying to save memory or something.

*shrug* well maybe he was.


> The reason Guido's action puzzles me is twofold -- first it has been
> standard industry practice to subclass singleton  (or n-ton) objects to
> expand their meaning in new contexts, 

I dispute that. I *strongly* dispute that.

Industry practice, in my experience, is that there is one and only one 
case where you can subclass singleton classes: when you have a factory 
which chooses at runtime which subclass to instantiate, after which you 
can no longer instantiate any of the other subclasses.

E.g. given an *abstract* class Maze, and three *concrete* subclasses 
Labyrinth, OrdinaryMaze, and EnchantedMaze, you can have a factory 
function, or method on Maze:

class Maze:
    _the_instance = None
    @classmethod
    def create(cls, variant='ordinary'):
        if cls._the_instance is None:
            # Create the Maze singleton
            if variant == 'ordinary':
                cls._the_instance = OrdinaryMaze()
            elif variant == 'labyrinth':
                cls._the_instance = Labyrinth()
            elif variant == 'enchanted':
                cls._the_instance = EnchantedMaze()
        return _the_instance


(This is just a sketch of a solution, because the caller can bypass the 
factory and just call the subclasses directly. In Java it is possible to 
write this in such a way that the caller cannot easily do so.)


Why are we limited to a single Maze? Making Maze a singleton in the first 
place was a bad idea. The singleton design pattern is *highly* over-used 
and abused. But that is another story. Let's just assume that the 
designer has good reason to insist that there be only one Maze, perhaps 
it uses some resource which truly is limited to there being one only. If 
that is the case, then allowing the caller to break that invariant by 
subclassing will just lead to horrible bugs. By using a factory and 
controlling access to the subclasses, Maze can keep the singleton 
invariant and allow subclasses.

This is not relevant to bool, since True and False are already 
instantiated.


[...]
> In general -- it's not the goal of subclassing to create more instances
> of the base types

That might not be the goal, but it is the effect. When you instantiate 
the subclass, by definition the instances are also instances of the base 
classes.

> -- but rather to refine meaning in a way that can be
> automatically reverted to the base class value (when appropriate) and to
> signal to users that the type can be passed to functions that require a
> bool because of backward compatibility.

And I am wondering what you think you can extend bools to perform that is 
completely backwards compatible to code that requires bools?

I don't think you can. I think you are engaged on a fool's errand, trying 
to do something impossible *even if subclassing bool were allowed*. But I 
could be wrong. I just don't think you can possibly write code which is 
backwards-compatible with code that expects bools while still extending 
it. People are so prone to write:

    if flag is True: ... 
    if flag is False: ...


(which is naughty of them, but what are you going to do?)




[...]
>> Can you name any other language that *does* allow subclassing of
>> booleans or creation of new boolean values?
>
> Yes. Several off the top of my head -- and I have mentioned these
> before.  They generally come with the extra subclasses pre-created and
> the user doesn't get to create the classes, but only use them; none the
> less -- they have more than two values with which to do logic equations
> with.
> 
> VHDL, Verilog, HDL, Silos III, and there are IEEE variants also. C/C++
> historically allowed you to do it with instances included, although I am
> not sure it still does.

C doesn't have instances because it doesn't have objects. I'm not 
certain, but I don't think the other languages you refer to are object-
oriented either. Verilog is a structured programming language, Silos is a 
Verilog simulator, and I think VHDL and HDL are versions of Verilog (that 
is, I've only seen them written as "Verilog-VHDL" and "Verilog-HDL").

In any case, Verilog *by design* uses four-state logic, modelling 1, 0, 
floating, undefined. It is not a bool, since *by definition* bools model 
only two states.


> The third value is usually called "TRI-state" or "don't care". (Though
> its sometimes a misnomer which means -- don't know, but do care.)

And SQL has NULL, which makes it an example of tri-state logic. (To be 
precise, SQL uses a version of Kleene K3 logic.)


[snip description of modelling hardware circuits]
All very interesting, but completely irrelevant to the question of 
subclassing bool.


> We've discovered that we live in a quantum-mechanical universe -- yet
> people still don't grasp the pragmatic issue that basic logic can be
> indeterminate at least some of the time ?!

Of course they do. My first post to you in this thread suggested that 
before you start re-inventing the wheel you look at prior art in the 
multi-value logic field.



> The name 'boolean logic' has never been re-named in honor of the many
> people who developed the advancements in computers -- including things
> like data sheets for electronic parts, 

Are you really suggesting that the name of Boolean Logic should be 
renamed away from the person who invented the field and instead named 
after the person who first wrote down a list of electronic part numbers 
and their specifications?


> or the code base used for solving
> large numbers of simultaneous logic equations with uncertainty included
> -- which have universally refined the boolean logic meanings found in
> "Truth" tables having clearly more than two values -- but don't take my
> word for it -- look in any digital electronics data book, and there they
> will be more than two states; marked with rising edges, falling edges,
> X's for don't cares, and so forth.

And those truth tables are not part of Boolean algebra.


[...]
> As I said to D'Aprano -- even a *cursory* examination (eg: as in not
> detailed) shows I could do things which he wasn't considering.

Andrew, I think you will be surprised at what I have considered. If you 
search the archives, you will find that (by memory) a decade ago I had 
considered using classes without instantiating them.

The questions I have about your strategy is not what can be done in 
Python, but how you think these things you want to do will solve the 
problem you apparently have?

To give an analogy... I have no doubt that you can build an television. 
But I question how building a television solves your problem of 
transporting a goat, a wolf and a cabbage across the river.

[...]
> I don't have a setting on my email to turn off html.  Sorry. Can't help.

You are using Thunderbird. You certainly do have such a setting.


> I don't know what you mean about composition vs. sub-classing. Would you
> care to show an example of how it would solve the problem and still
> allow hierarchical sorting ?

Composition is just another name for delegation, which is often used as 
the implementation of proxying. In an earlier message, you claimed to be 
able to write proxies. Does that help?


> I don't see how you can get pre-existing python functions (like sort,
> max, and min) to accept a complex bool value and have that value
> automatically revert to a True or False in an intelligent manner without
> overloading the operators defined in some class -- somewhere -- to
> operate on the data the class contains.


Here, let me get you started on this:


class TriStateLogic(int):
    def __new__(cls, value):
        if value in (0, 1): return bool(value)
        # Fold all other values to 2.
        obj = super(TriStateLogic, cls).__new__(cls, 2)
        return obj
    def __repr__(self):
        return "Undefined"
    def __nonzero__(self):
        return False


And an example in use:

py> Undefined = TriStateLogic(999)
py> if Undefined:
...     print "This is true"
... else:
...     print "This is false"
... 
This is false
py> sorted([True, False, Undefined, 99, 100])
[False, True, Undefined, 99, 100]
py> sorted([True, False, Undefined, 99, 100], reverse=True)
[100, 99, Undefined, True, False]




-- 
Steven


From marko at pacujo.net  Thu Jan 15 04:34:54 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 15 Jan 2015 11:34:54 +0200
Subject: How to terminate the function that runs every n seconds
References: <CACT3xuWvN=zUs5CmuxceG9yv2gPWkmxF2dTgWOr8WqmaJxag+A@mail.gmail.com>
 <CACT3xuUr-07yW-FjiKBjPbsbn5j7r1vUfu1E0A6Myz=7sYpnzA@mail.gmail.com>
 <54B69A5B.5000801@davea.name>
 <CACT3xuXSuXyRu8ReXLczFw9N_LEajQzDM=eccdU3GPmj4MgYLA@mail.gmail.com>
 <mailman.17737.1421283049.18130.python-list@python.org>
Message-ID: <87r3uwpetd.fsf@elektro.pacujo.net>

Dennis Lee Bieber <wlfraed at ix.netcom.com>:

> 	The main thing to consider is that "killing" a thread doesn't
> work well in Python. Instead the thread has to check for some signal
> telling it to quit.

Alas, a thread can't check anything because it's blocked by I/O.


Marko


From jacob at blindza.co.za  Thu Jan 15 04:59:52 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Thu, 15 Jan 2015 11:59:52 +0200
Subject: MySQL connections
In-Reply-To: <DB3F78F5082B4B31A42C783C4E9BD763@JakesPC>
References: <DB3F78F5082B4B31A42C783C4E9BD763@JakesPC>
Message-ID: <D74E2BA52B5341ADB485A4CEF0815BCA@JakesPC>

And, FWIW, if I compile the 2.7 version on the other machine where it works, in both code and compiled forms, and then copy .exe back to the main machine, same error message pops up, so must be something to do with machine's configuration, etc.

Stay well

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."

  ----- Original Message ----- 
  From: Jacob Kruger 
  To: python-list at python.org 
  Sent: Thursday, January 15, 2015 10:13 AM
  Subject: MySQL connections


  Development machine is windows7 64 bit machine, now working with either/both python 2.7 or 3.4 - test purposes, trying to figure out if this was something like a version incompatibility issue, and tried using both XAMPP and WAMP MySQL server version 5.0.11 instances thus far.

  Now, aside from all other issues relating to character encoding, etc., now down to, hopefully, final issue.

  Side note is under python 2.7, I use pyodbc to gather data from .mdb file am using to test, but under python 3.4, I use pypyodbc for same functionality.

  Now, current/actual issue is something can sort of duplicate using both MySQLdb version of mysqlclient, as well as pymysql using both python 2.7 and python 3.4, but, strange thing am trying to figure out is that even if just implement a connection object in interpreter of either version, retrieve an instance of a cursor object, and do various types of statement executions, no issues, and can then close connection, or cursor, or both, and all good/fine/well.

  However, if implement similar code - down to just trying to open a connection, wait a few seconds, and then close it again, inside a function called from a prior function, in the class am implementing in a file called/executed from command line, then, the moment I try to close the connection, whether or not have done anything with it, that's when I get that python.exe has stopped working/responding error message popping up, and python bombs out.

  Have no idea how to try track down actual source/cause of issue, since haven't found anything obvious in system event logs, nothing appearing in MySQL server logs that makes sense/appears relevant, and no matter if I try enclosing the connection open/close code inside try except code blocks, nothing happens there except that python just stops cooperating at all, and stops working.

  Now did try making sure data execution prevention was turned on/off, and that if set to second mode then told it to ignore specific applications - added both python.exe, and the compiled version of my code to it's exemption list, but, no changes there.

  This still operates fine on my other dev machine, but, would like to know why it's not operating on one specific machine.

  Otherwise, will just have to tell guys that, sorry, will only be able to generate SQL script text files, and they'll have to stick to the final step of then executing those via MySQL console interface, or something, but, would really prefer to at the very least, figure/find out what's causing this mis-behaviour.

  Thoughts/suggestions with regards to how to find out what is happening/what I'm doing/handling wrong/incorrectly?

  The two current versions of the code - which work fine under interpreter of both versions of python are basically the following:

  #pymysql version
  import pymysql
  cn = pymysql.connect("localhost", "root", "", "import_test")
  time.sleep(5)
  cn.close()

  #MySQLdb version
  import MySQLdb
  cn = MySQLdb.connect("localhost", "root", "", "import_test")
  time.sleep(5)
  cn.close()
  #end code

  Stay well (away from this machine ;) )

  Jacob Kruger
  Blind Biker
  Skype: BlindZA
  "Roger Wilco wants to welcome you...to the space janitor's closet..."



------------------------------------------------------------------------------


  -- 
  https://mail.python.org/mailman/listinfo/python-list
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From abdul.sw84 at gmail.com  Thu Jan 15 05:34:51 2015
From: abdul.sw84 at gmail.com (Abdul Abdul)
Date: Thu, 15 Jan 2015 11:34:51 +0100
Subject: Stripping in Python
Message-ID: <CAA+hu4Wzeyn7wXrVP8Sz-g8ZPO2wdup-jC7d5x-vojHyigF_JQ@mail.gmail.com>

Hello,

I have a program where I read a line input from the keyboard.

If I remove this portion of code after reading the line, I get an error:

line = line.rstrip()

Why is that? Should stripping be always be used after reading an input in
Python?

Thanks.
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From __peter__ at web.de  Thu Jan 15 05:40:37 2015
From: __peter__ at web.de (Peter Otten)
Date: Thu, 15 Jan 2015 11:40:37 +0100
Subject: [OT] Re: MySQL connections
References: <DB3F78F5082B4B31A42C783C4E9BD763@JakesPC>
Message-ID: <m985f6$t2n$1@ger.gmane.org>

Jacob Kruger wrote:

> However, if implement similar code - down to just trying to open a
> connection, wait a few seconds, and then close it again, inside a function
> called from a prior function, in the class am implementing in a file
> called/executed from command line, then, the moment I try to close the
> connection, whether or not have done anything with it, that's when I get
> that python.exe has stopped working/responding error message popping up,
> and python bombs out.

Jacob, your writing style is incredibly long-winded and hard to follow.
Try to build shorter sentences instead of this stream of consciousness, and 
focus on the actual problem.

"python bombs out"

is not a meaningful problem description. A traceback might be.

That said, I probably cannot help with your particular problem, so feel free 
to ignore me...




From __peter__ at web.de  Thu Jan 15 05:43:44 2015
From: __peter__ at web.de (Peter Otten)
Date: Thu, 15 Jan 2015 11:43:44 +0100
Subject: Stripping in Python
References: <CAA+hu4Wzeyn7wXrVP8Sz-g8ZPO2wdup-jC7d5x-vojHyigF_JQ@mail.gmail.com>
Message-ID: <m985l0$t2n$2@ger.gmane.org>

Abdul Abdul wrote:

> I have a program where I read a line input from the keyboard.
> 
> If I remove this portion of code after reading the line, I get an error:
> 
> line = line.rstrip()
> 
> Why is that? Should stripping be always be used after reading an input in
> Python?

What version of Python are you using? How do you read the line of input?
If you provide a small program that shows the behaviour you describe we can 
probably help you fix it in no time.



From abdul.sw84 at gmail.com  Thu Jan 15 06:06:37 2015
From: abdul.sw84 at gmail.com (Abdul Abdul)
Date: Thu, 15 Jan 2015 12:06:37 +0100
Subject: Opening the file in writing mode
Message-ID: <CAA+hu4Vy76UU+wj1HCHZeEErg8-gaLQR9jW-r5Wq-ToG-=wtRQ@mail.gmail.com>

Hello,

In the Python documentation, when opening the file in write mode, it
mentions the following:

*writing (truncating the file if it already exists)*
What is meant by "truncating" here? Is it simply overwriting the file
already existing?

Thanks.
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From sadzak at gmail.com  Thu Jan 15 06:13:40 2015
From: sadzak at gmail.com (Adnan Sadzak)
Date: Thu, 15 Jan 2015 12:13:40 +0100
Subject: Opening the file in writing mode
In-Reply-To: <CAA+hu4Vy76UU+wj1HCHZeEErg8-gaLQR9jW-r5Wq-ToG-=wtRQ@mail.gmail.com>
References: <CAA+hu4Vy76UU+wj1HCHZeEErg8-gaLQR9jW-r5Wq-ToG-=wtRQ@mail.gmail.com>
Message-ID: <CAG6E59VZVsni5u_yJWguBuUdiQEi=dvwM-qz7hYbMmOwunQz2A@mail.gmail.com>

Hi,

Yes, but You also can open an existing file in 'append' mode.

Cheers,
Adnan
On Jan 15, 2015 12:08 PM, "Abdul Abdul" <abdul.sw84 at gmail.com> wrote:

> Hello,
>
> In the Python documentation, when opening the file in write mode, it
> mentions the following:
>
> *writing (truncating the file if it already exists)*
> What is meant by "truncating" here? Is it simply overwriting the file
> already existing?
>
> Thanks.
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>
>
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From abdul.sw84 at gmail.com  Thu Jan 15 06:19:43 2015
From: abdul.sw84 at gmail.com (Abdul Abdul)
Date: Thu, 15 Jan 2015 12:19:43 +0100
Subject: Opening the file in writing mode
In-Reply-To: <CAG6E59VZVsni5u_yJWguBuUdiQEi=dvwM-qz7hYbMmOwunQz2A@mail.gmail.com>
References: <CAA+hu4Vy76UU+wj1HCHZeEErg8-gaLQR9jW-r5Wq-ToG-=wtRQ@mail.gmail.com>
 <CAG6E59VZVsni5u_yJWguBuUdiQEi=dvwM-qz7hYbMmOwunQz2A@mail.gmail.com>
Message-ID: <CAA+hu4UnuJUmg0tyXe0J2So4iKE3_v5LwZSOQ-0Y8O1y2DZo=Q@mail.gmail.com>

Hi,

Thanks for your reply. I just wanted to understand the 'w' mode in Python.
So, when using it, it will overwrite any existing mode, right?

Thanks.

On Thu, Jan 15, 2015 at 12:13 PM, Adnan Sadzak <sadzak at gmail.com> wrote:

> Hi,
>
> Yes, but You also can open an existing file in 'append' mode.
>
> Cheers,
> Adnan
> On Jan 15, 2015 12:08 PM, "Abdul Abdul" <abdul.sw84 at gmail.com> wrote:
>
>> Hello,
>>
>> In the Python documentation, when opening the file in write mode, it
>> mentions the following:
>>
>> *writing (truncating the file if it already exists)*
>> What is meant by "truncating" here? Is it simply overwriting the file
>> already existing?
>>
>> Thanks.
>>
>> --
>> https://mail.python.org/mailman/listinfo/python-list
>>
>>
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From rosuav at gmail.com  Thu Jan 15 06:25:57 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 15 Jan 2015 22:25:57 +1100
Subject: MySQL connections
In-Reply-To: <DB3F78F5082B4B31A42C783C4E9BD763@JakesPC>
References: <DB3F78F5082B4B31A42C783C4E9BD763@JakesPC>
Message-ID: <CAPTjJmpvaNQNVJsmvbH6YGYnQZkofNCS0F+0UFzwsy-NVqv-ug@mail.gmail.com>

On Thu, Jan 15, 2015 at 7:13 PM, Jacob Kruger <jacob at blindza.co.za> wrote:
> However, if implement similar code - down to just trying to open a
> connection, wait a few seconds, and then close it again, inside a function
> called from a prior function, in the class am implementing in a file
> called/executed from command line, then, the moment I try to close the
> connection, whether or not have done anything with it, that's when I get
> that python.exe has stopped working/responding error message popping up, and
> python bombs out.

You've posted your working versions; can you post a non-working version?

Also, I'm seeing a very small hint here that might indicate a huge
factor that you haven't mentioned. You speak of "compiling" your
Python code. Do you mean you're turning it into an exe file? If so,
with which tool? Does the code still have problems if you run the
actual Python file?

ChrisA


From steve+comp.lang.python at pearwood.info  Thu Jan 15 06:33:06 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 15 Jan 2015 22:33:06 +1100
Subject: Opening the file in writing mode
References: <mailman.17749.1421319999.18130.python-list@python.org>
Message-ID: <54b7a573$0$12999$c3e8da3$5496439d@news.astraweb.com>

Abdul Abdul wrote:

> Hello,
> 
> In the Python documentation, when opening the file in write mode, it
> mentions the following:
> 
> *writing (truncating the file if it already exists)*
> What is meant by "truncating" here? Is it simply overwriting the file
> already existing?

Not quite. It means that if the file already has content, the content is
erased immediately you open it, not just as you write over the top.

Consider this demo:


fname = 'test'  # caution, this file will be overridden
for mode in ('w', 'r+w'):
    # first write a file with known content
    with open(fname, 'w') as f:
        f.write("hello world\n")
    # confirm the file contains what we expect
    with open(fname, 'r') as f:
        assert f.read() == "hello world\n"
    # now test the mode
    with open(fname, mode) as f:
        f.write("xxxx")
    with open(fname, 'r') as f:
        print (mode, f.read())


The output of running this code will be:

('w', xxxx'')
('r+w', 'xxxxo world\n')



-- 
Steven



From sadzak at gmail.com  Thu Jan 15 06:36:47 2015
From: sadzak at gmail.com (Adnan Sadzak)
Date: Thu, 15 Jan 2015 12:36:47 +0100
Subject: Opening the file in writing mode
In-Reply-To: <CAA+hu4UnuJUmg0tyXe0J2So4iKE3_v5LwZSOQ-0Y8O1y2DZo=Q@mail.gmail.com>
References: <CAA+hu4Vy76UU+wj1HCHZeEErg8-gaLQR9jW-r5Wq-ToG-=wtRQ@mail.gmail.com>
 <CAG6E59VZVsni5u_yJWguBuUdiQEi=dvwM-qz7hYbMmOwunQz2A@mail.gmail.com>
 <CAA+hu4UnuJUmg0tyXe0J2So4iKE3_v5LwZSOQ-0Y8O1y2DZo=Q@mail.gmail.com>
Message-ID: <CAG6E59Xvs8FV=R4sK6vo0=t00ZcwQ9387EYA7ZGvq4H6Lsvz-w@mail.gmail.com>

Hi,

in 'w' mode, if file does not exist it will create new one (if You have
permissions to write in specified location).
If file exist, it will 'truncate' it or like it is specified in
documentation "*(an existing file with the same name will be erased)*".

I'm not sure what You mean by "existing mode"? Maybe to open one file twice?
If You open file for reading, then open it again for writing - yes it will
be erased or as You said 'overwrite existing mode'. Is that what You think
about?


Kind regards,
Adnan


On Thu, Jan 15, 2015 at 12:19 PM, Abdul Abdul <abdul.sw84 at gmail.com> wrote:

> Hi,
>
> Thanks for your reply. I just wanted to understand the 'w' mode in Python.
> So, when using it, it will overwrite any existing mode, right?
>
> Thanks.
>
> On Thu, Jan 15, 2015 at 12:13 PM, Adnan Sadzak <sadzak at gmail.com> wrote:
>
>> Hi,
>>
>> Yes, but You also can open an existing file in 'append' mode.
>>
>> Cheers,
>> Adnan
>> On Jan 15, 2015 12:08 PM, "Abdul Abdul" <abdul.sw84 at gmail.com> wrote:
>>
>>> Hello,
>>>
>>> In the Python documentation, when opening the file in write mode, it
>>> mentions the following:
>>>
>>> *writing (truncating the file if it already exists)*
>>> What is meant by "truncating" here? Is it simply overwriting the file
>>> already existing?
>>>
>>> Thanks.
>>>
>>> --
>>> https://mail.python.org/mailman/listinfo/python-list
>>>
>>>
>
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From jacob at blindza.co.za  Thu Jan 15 06:48:34 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Thu, 15 Jan 2015 13:48:34 +0200
Subject: [OT] Re: MySQL connections
In-Reply-To: <m985f6$t2n$1@ger.gmane.org>
References: <DB3F78F5082B4B31A42C783C4E9BD763@JakesPC>
 <m985f6$t2n$1@ger.gmane.org>
Message-ID: <9F8BC49703624E5CBBE5BDFAEA504752@JakesPC>

----- Original Message ----- 
From: "Peter Otten" <__peter__ at web.de>
To: <python-list at python.org>
Sent: Thursday, January 15, 2015 12:40 PM
Subject: [OT] Re: MySQL connections


> Jacob Kruger wrote:
>
>> However, if implement similar code - down to just trying to open a
>> connection, wait a few seconds, and then close it again, inside a 
>> function
>> called from a prior function, in the class am implementing in a file
>> called/executed from command line, then, the moment I try to close the
>> connection, whether or not have done anything with it, that's when I get
>> that python.exe has stopped working/responding error message popping up,
>> and python bombs out.
>
> Jacob, your writing style is incredibly long-winded and hard to follow.
> Try to build shorter sentences instead of this stream of consciousness, 
> and
> focus on the actual problem.
>

Was just trying to make sure included all relevant details ;)

> "python bombs out"
>
> is not a meaningful problem description. A traceback might be.
>

Agree with that, but, like said in prior e-mail, just get windows error 
message popping up, mentioning - no track trace, since it's python 
terminating:

---error details---
  Problem Event Name: BEX
  Application Name: python.exe
  Fault Module Name: StackHash_0a9e
---end error details---

That term BEX equates to buffer overflow exception, but not sure why this is 
happening - previous suggestion was to do with data execution prevention on 
windows, but, bex apparently also relates to winsock, or something, and 
tried different types of applying DEP - think so anyway.
> That said, I probably cannot help with your particular problem, so feel 
> free
> to ignore me...
>

No worries - thanks for reply.

Just found following bit of summary of possible combination of 
bex/stackhash - but, still doesn't make sense when at this test stage I'm 
literally just opening and closing connection - might make sense if was 
executing thousands of queries against database before committing them:
---quote---
Buffer overflow is a condition when some process tries to store data beyond 
the capacity of the fixed/available buffer so it tries to overwrite some 
other memory locations, too. And in Windows we have some security feature 
called Data Execution Prevention that is intended to prevent similar 
processes to prevent buffer overflow attacks (that can introduce some 
malicious codes). But in some cases DEP can prevent some legitimate software 
from executing, too. And then you can get a BEX error.
---end quote---

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."



From road01 at yahoo.fr  Thu Jan 15 06:54:02 2015
From: road01 at yahoo.fr (brice DORA)
Date: Thu, 15 Jan 2015 03:54:02 -0800 (PST)
Subject: How can i use a dictionnary
In-Reply-To: <2b71cef0-fae6-466c-af9c-79c503bd1402@googlegroups.com>
References: <233574bb-a552-49f2-b803-86523e2b5741@googlegroups.com>
 <2b71cef0-fae6-466c-af9c-79c503bd1402@googlegroups.com>
Message-ID: <b631c90f-38d9-4eff-949e-058f1ab6d653@googlegroups.com>

Le mardi 13 janvier 2015 14:56:24 UTC, Novocastrian_Nomad a ?crit?:
> On Tuesday, January 13, 2015 at 2:03:30 AM UTC-7, brice DORA wrote:
> > i consume a web service that return a element whose the type is "instance". but this element seem be a dictionary but when i want to use it like a dictionary, i got some errors. so this is the element and please someone can tell me how can i use it. tkanks in advance.
> > 
> > 
> > (tCountryInfo){
> >    sISOCode = "CI"
> >    sName = "C??te D'Ivoire (Ivory Coast)"
> >    sCapitalCity = "Yamoussoukro"
> >    sPhoneCode = "225"
> >    sContinentCode = "AF"
> >    sCurrencyISOCode = "XOF"
> >    sCountryFlag = "http://www.oorsprong.org/WebSamples.CountryInfo/Images/C??te D'Ivoire.jpg"
> >    Languages = 
> >       (ArrayOftLanguage){
> >          tLanguage[] = 
> >             (tLanguage){
> >                sISOCode = "fr"
> >                sName = "French"
> >             },
> >       }
> >  }
> 
> This data is not a Python dictionary, nor is it a JSON object.  You will probably need to code your own conversion function to make it a Python dictionary.

thanks for your help but can you give a example that's you tell about my own conversion funcion. thanks in advance


From road01 at yahoo.fr  Thu Jan 15 06:55:45 2015
From: road01 at yahoo.fr (brice DORA)
Date: Thu, 15 Jan 2015 03:55:45 -0800 (PST)
Subject: How can i use a dictionnary
In-Reply-To: <mailman.17678.1421164869.18130.python-list@python.org>
References: <233574bb-a552-49f2-b803-86523e2b5741@googlegroups.com>
 <mailman.17678.1421164869.18130.python-list@python.org>
Message-ID: <f527da80-f78c-4a09-873c-c0e5347cc3b2@googlegroups.com>

Le mardi 13 janvier 2015 16:01:22 UTC, rand... at fastmail.us a ?crit?:
> On Tue, Jan 13, 2015, at 04:03, brice DORA wrote:
> > i consume a web service that return a element whose the type is
> > "instance". but this element seem be a dictionary but when i want to use
> > it like a dictionary, i got some errors. so this is the element and
> > please someone can tell me how can i use it. tkanks in advance.
> 
> Do you have any more information about this web service, so that you can
> find a formal specification (or at least name) of the output format, or
> maybe a way to make it return XML or JSON instead?

how can i return it in XML or JSON i can say what lib can permit me to do it easier?


From jacob at blindza.co.za  Thu Jan 15 06:59:16 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Thu, 15 Jan 2015 13:59:16 +0200
Subject: MySQL connections
In-Reply-To: <CAPTjJmpvaNQNVJsmvbH6YGYnQZkofNCS0F+0UFzwsy-NVqv-ug@mail.gmail.com>
References: <DB3F78F5082B4B31A42C783C4E9BD763@JakesPC>
 <CAPTjJmpvaNQNVJsmvbH6YGYnQZkofNCS0F+0UFzwsy-NVqv-ug@mail.gmail.com>
Message-ID: <5F6F0C3BBA694C15A513F94735D89E18@JakesPC>

----- Original Message ----- 
From: "Chris Angelico" <rosuav at gmail.com>

>
> You've posted your working versions; can you post a non-working version?

Problem is that works fine in interpreter, but, not when executing it as 
part of code in file.

>
> Also, I'm seeing a very small hint here that might indicate a huge
> factor that you haven't mentioned. You speak of "compiling" your
> Python code. Do you mean you're turning it into an exe file? If so,
> with which tool? Does the code still have problems if you run the
> actual Python file?

Tried generating .exe with both cx_freeze, and pyInstaller, and the code 
itself, and both versions of executable generate errors, same as running it 
from command line - only difference is the source of the error mentioned in 
error message then varies from a2m.exe and python.exe , and even if compile 
it on machine where all works, and then copy .exe back to this primary 
machine, then get same error - think it must relate to something else on 
this machine, but can't track it down.

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."



From ronnyma at transfinite.no  Thu Jan 15 07:03:29 2015
From: ronnyma at transfinite.no (ronnyma at transfinite.no)
Date: Thu, 15 Jan 2015 04:03:29 -0800 (PST)
Subject: Stripping in Python
In-Reply-To: <mailman.17746.1421318093.18130.python-list@python.org>
References: <mailman.17746.1421318093.18130.python-list@python.org>
Message-ID: <98a6f18d-b1b6-4c41-9b39-5800100069f4@googlegroups.com>

On Thursday, January 15, 2015 at 11:35:11 AM UTC+1, Abdul Abdul wrote:
> Hello,
> 
> I have a program where I read a line input from the keyboard.
> 
> If I remove this portion of code after reading the line, I get an error:
> 
> line = line.rstrip()
> 
> Why is that? Should stripping be always be used after reading an input in Python?
> 
> Thanks.

You have a displaced apostrophe in line 8 of your code. Sorry for the joke, but like Peter Otten says, you need to include more code, Python-version and the error message to prove us with context so that we can help you.

Best regards,

Ronny Mandal


From rosuav at gmail.com  Thu Jan 15 07:33:06 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 15 Jan 2015 23:33:06 +1100
Subject: MySQL connections
In-Reply-To: <5F6F0C3BBA694C15A513F94735D89E18@JakesPC>
References: <DB3F78F5082B4B31A42C783C4E9BD763@JakesPC>
 <CAPTjJmpvaNQNVJsmvbH6YGYnQZkofNCS0F+0UFzwsy-NVqv-ug@mail.gmail.com>
 <5F6F0C3BBA694C15A513F94735D89E18@JakesPC>
Message-ID: <CAPTjJmr3nA-g2eGGW1JHK=09FW+fY4dEmPhWCSYmF6xQGvSfbg@mail.gmail.com>

On Thu, Jan 15, 2015 at 10:59 PM, Jacob Kruger <jacob at blindza.co.za> wrote:
> Tried generating .exe with both cx_freeze, and pyInstaller, and the code
> itself, and both versions of executable generate errors, same as running it
> from command line - only difference is the source of the error mentioned in
> error message then varies from a2m.exe and python.exe , and even if compile
> it on machine where all works, and then copy .exe back to this primary
> machine, then get same error - think it must relate to something else on
> this machine, but can't track it down.

Okay. Ignore the .exe versions, and just work with what happens when
you run the .py files. If it fails as part of a .py file, post the
failing file.

ChrisA


From wxjmfauth at gmail.com  Thu Jan 15 07:49:07 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Thu, 15 Jan 2015 04:49:07 -0800 (PST)
Subject: Python 3 regex?
In-Reply-To: <54b70ad4$0$13000$c3e8da3$5496439d@news.astraweb.com>
References: <54B40C85.5000806@emerytelcom.com>
 <mailman.17635.1421092112.18130.python-list@python.org>
 <4043d09b-05b2-4dc2-8a6b-bae2d53cd01f@googlegroups.com>
 <mailman.17649.1421114112.18130.python-list@python.org>
 <7c648fa2-4a59-4d1a-923f-d29f4f2dc8f7@googlegroups.com>
 <0fdf17d0-2dd7-4512-8f2a-104d78a27d72@googlegroups.com>
 <1879486.f98NMJPo2z@PointedEars.de>
 <54b70ad4$0$13000$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <b2e1a12f-7075-4932-b307-60847026548f@googlegroups.com>

Le jeudi 15 janvier 2015 01:33:37 UTC+1, Steven D'Aprano a ?crit?:
> Thomas 'PointedEars' Lahn wrote:
> 
> > wxjmfauth at gmail.com wrote:
> [...]
> >> And, why not? compare Py3.2 and Py3.3+ !
> > 
> > What are you getting at?
> 
> 
> Don't waste your time with JMF. He is obsessed with a trivial performance
> regression in Python 3.3. Unicode strings can be slightly more expensive to
> create in Python 3.3 compared to earlier versions, due to a clever memory
> optimization which saves up to 50% if your strings are all in the Basic
> Multilingual Plane and up to 75% if they are all in Latin-1. Never mind
> that for real-world code, that memory saving can often lead to applications
> running faster, JMF is obsessed with an artificial benchmark of his own
> devising that involves making, and throwing away, thousands of Unicode
> strings as fast as possible in such a way as to exercise the worst-case of
> the new Unicode model. From this unimportant performance regression, he has
> convinced himself that this means that Python 3.3 and beyond is logically
> and mathematically in violation of the Unicode standard.
> 
> Any time JMF mentions anything to do with Python versions or Unicode or
> ASCII or French, he is in full-blown "pi equals 3 exactly" crank territory
> and is best ignored.
> 
> 
> 

Out of curiosity. Did you you try the exercise I proposed?

jmf


From roy at panix.com  Thu Jan 15 08:04:19 2015
From: roy at panix.com (Roy Smith)
Date: Thu, 15 Jan 2015 08:04:19 -0500
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
Message-ID: <roy-4AAFA6.08034915012015@news.panix.com>

yawar.amin at gmail.com wrote:

> I have implemented what I believe is a
> fairly robust, if ugly-looking, native Python module 

I don't know which zen this is, but "Beauty is important".


From mal at europython.eu  Thu Jan 15 08:09:11 2015
From: mal at europython.eu (M.-A. Lemburg)
Date: Thu, 15 Jan 2015 14:09:11 +0100
Subject: EuroPython 2015: Come join us from July 20-26 in Bilbao !
Message-ID: <54B7BBF7.9030302@europython.eu>

We are happy to announce the dates for EuroPython 2015 in Bilbao, Spain,
this year:

                   Monday, July 20 - Sunday, July 26


Please mark your calendar. We?d love to meet you all in Bilbao - and hey,
it?s summer, so you might want to combine the conference with a holiday :-)

For updates, please watch our blog at http://blog.europython.eu/.

Enjoy,
?
EuroPython Society (EPS) - http://www.europython-society.org/
Asociaci?n de Ciencias de la Computaci?n Python San Sebasti?n (ACPySS)
- http://www.pyss.org/


PS: Please help spread the word and forward this email to all your local
lists, user groups, etc. Many thanks !


From rosuav at gmail.com  Thu Jan 15 08:09:14 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 16 Jan 2015 00:09:14 +1100
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <roy-4AAFA6.08034915012015@news.panix.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
Message-ID: <CAPTjJmphOdJb2xMRA9-rUpyxzYgZtQHG6SqZvGBCSd4qq0doqA@mail.gmail.com>

On Fri, Jan 16, 2015 at 12:04 AM, Roy Smith <roy at panix.com> wrote:
> I don't know which zen this is, but "Beauty is important".

How about:
Beautiful is better than ugly.
Readability counts.
If the implementation is hard to explain, it's a bad idea.

ChrisA


From skip.montanaro at gmail.com  Thu Jan 15 08:11:10 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Thu, 15 Jan 2015 07:11:10 -0600
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <roy-4AAFA6.08034915012015@news.panix.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
Message-ID: <CANc-5UxPCNo4k8NPW-EKjV4w1VvyYmTihGwEnV+BqW7Ed5xMvw@mail.gmail.com>

On Thu, Jan 15, 2015 at 7:04 AM, Roy Smith <roy at panix.com> wrote:

> I don't know which zen this is, but "Beauty is important".


Kinda near the front:

% python -m this
The Zen of Python, by Tim Peters

Beautiful is better than ugly.
Explicit is better than implicit.
Simple is better than complex.
...

:-)

Skip
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From marko at pacujo.net  Thu Jan 15 08:24:03 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 15 Jan 2015 15:24:03 +0200
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
Message-ID: <87zj9kb2j0.fsf@elektro.pacujo.net>

Skip Montanaro <skip.montanaro at gmail.com>:

> Beautiful is better than ugly.

Yes, our job is to increase the Harmony of the Universe. Useful
applications are happy side effects.

> Explicit is better than implicit.

Corollary: Constructors are usually preferable to factories.

> Simple is better than complex.

Corollary: Make sure the complete definition of every function can be
seen at once without scrolling.


Marko


From marko at pacujo.net  Thu Jan 15 09:15:37 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 15 Jan 2015 16:15:37 +0200
Subject: How to terminate the function that runs every n seconds
References: <CACT3xuWvN=zUs5CmuxceG9yv2gPWkmxF2dTgWOr8WqmaJxag+A@mail.gmail.com>
 <CACT3xuUr-07yW-FjiKBjPbsbn5j7r1vUfu1E0A6Myz=7sYpnzA@mail.gmail.com>
 <54B69A5B.5000801@davea.name>
 <CACT3xuXSuXyRu8ReXLczFw9N_LEajQzDM=eccdU3GPmj4MgYLA@mail.gmail.com>
 <mailman.17737.1421283049.18130.python-list@python.org>
 <87r3uwpetd.fsf@elektro.pacujo.net>
 <mailman.17761.1421331127.18130.python-list@python.org>
Message-ID: <87k30ob052.fsf@elektro.pacujo.net>

Dennis Lee Bieber <wlfraed at ix.netcom.com>:

> On Thu, 15 Jan 2015 11:34:54 +0200, Marko Rauhamaa <marko at pacujo.net>
>>Alas, a thread can't check anything because it's blocked by I/O.
>
> 	My response to that then is: design the thread's I/O so that it
> is not blocking... On Linux, maybe a timed select(); Windows? short
> sleeps around a non-blocking check for available data... (if console
> I/O, msvcrt.kbhit(); otherwise may need some other library function to
> put a time-out on the I/O)

Ah, polling, the fig leaf that covers embarrassing design constraints
all over the world.


Marko


From steve+comp.lang.python at pearwood.info  Thu Jan 15 09:24:31 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 16 Jan 2015 01:24:31 +1100
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
Message-ID: <54b7cd9f$0$13011$c3e8da3$5496439d@news.astraweb.com>

Marko Rauhamaa wrote:

> Corollary: Make sure the complete definition of every function can be
> seen at once without scrolling.

Problem: I like to view code on a smartphone with a 4x4 pixel screen, and
the scroll bars obscure the text.

Solution: Change the editor to a 1pt font.



-- 
Steven



From steve+comp.lang.python at pearwood.info  Thu Jan 15 09:29:22 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 16 Jan 2015 01:29:22 +1100
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <54b758e1$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17741.1421303993.18130.python-list@python.org>
Message-ID: <54b7cec3$0$13007$c3e8da3$5496439d@news.astraweb.com>

Ian Kelly wrote:

> On Wed, Jan 14, 2015 at 11:06 PM, Steven D'Aprano <steve at pearwood.info>
> wrote:
>> I have a function, which I put into an expression like this:
>>
>> def func(a, b=None):
>>     global spam
>>     import math
>>     spam = [a, b]*3
>>     print spam
>>     del spam
>>
>>
>> value = [1, "hello", int, func]
>> del func
>>
>> How would I use lambdak to write that as an expression
>>
>> value = [1, "hello", int, ??????? ]
>>
>> without the intermediate def?
> 
> 
> # Untested, but seems like this should work.
> 
> value = [1, "hello", int, given_(lambda a, b=None:
>     import_("math", lambda math:
>     import_("operator", lambda operator:
>     do_(lambda: operator.setitem(globals(), 'spam', [a, b]*3), lambda:
>     print_(globals()['spam'], lambda:
>     do_(lambda: operator.delitem(globals(), 'spam')))))))]

Thank you for showing me that.

Now I shall try very hard to forget I ever saw it. 

*shudders at the thought of maintaining such a beast*



-- 
Steven



From skip.montanaro at gmail.com  Thu Jan 15 09:38:52 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Thu, 15 Jan 2015 08:38:52 -0600
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <54b7cec3$0$13007$c3e8da3$5496439d@news.astraweb.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <54b758e1$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17741.1421303993.18130.python-list@python.org>
 <54b7cec3$0$13007$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CANc-5Uxga5F9bvzf9FtW-DJ9+L9DQMjgMU0vu=H_zvznKiXgaA@mail.gmail.com>

On Thu, Jan 15, 2015 at 8:29 AM, Steven D'Aprano <
steve+comp.lang.python at pearwood.info> wrote:

> Now I shall try very hard to forget I ever saw it.


There are some things, no matter how hard you try, which cannot be
"unseen". :-)

Skip
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From rosuav at gmail.com  Thu Jan 15 09:50:00 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 16 Jan 2015 01:50:00 +1100
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <54b7cd9f$0$13011$c3e8da3$5496439d@news.astraweb.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <54b7cd9f$0$13011$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmpxdXXCVRyg5cu60TJU4gkc9qmc-opm51d4AkdmNhiZmw@mail.gmail.com>

On Fri, Jan 16, 2015 at 1:24 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Marko Rauhamaa wrote:
>
>> Corollary: Make sure the complete definition of every function can be
>> seen at once without scrolling.
>
> Problem: I like to view code on a smartphone with a 4x4 pixel screen, and
> the scroll bars obscure the text.
>
> Solution: Change the editor to a 1pt font.

Problem: You have a smartphone with a 4x4 pixel screen.

Solution: Utilize hammer, then get a laptop.

ChrisA


From marko at pacujo.net  Thu Jan 15 10:29:43 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 15 Jan 2015 17:29:43 +0200
Subject: How to terminate the function that runs every n seconds
References: <CACT3xuWvN=zUs5CmuxceG9yv2gPWkmxF2dTgWOr8WqmaJxag+A@mail.gmail.com>
 <CACT3xuUr-07yW-FjiKBjPbsbn5j7r1vUfu1E0A6Myz=7sYpnzA@mail.gmail.com>
 <54B69A5B.5000801@davea.name>
 <CACT3xuXSuXyRu8ReXLczFw9N_LEajQzDM=eccdU3GPmj4MgYLA@mail.gmail.com>
 <mailman.17737.1421283049.18130.python-list@python.org>
 <87r3uwpetd.fsf@elektro.pacujo.net>
 <mailman.17761.1421331127.18130.python-list@python.org>
 <87k30ob052.fsf@elektro.pacujo.net>
Message-ID: <878uh4awpk.fsf@elektro.pacujo.net>

Marko Rauhamaa <marko at pacujo.net>:
> Dennis Lee Bieber <wlfraed at ix.netcom.com>:
>> 	My response to that then is: design the thread's I/O so that it
>> is not blocking... On Linux, maybe a timed select(); Windows? short
>> sleeps around a non-blocking check for available data... (if console
>> I/O, msvcrt.kbhit(); otherwise may need some other library function to
>> put a time-out on the I/O)
>
> Ah, polling, the fig leaf that covers embarrassing design constraints
> all over the world.

And to provide something constructive, I should add:

Polling is occasionally the right way forward (consider the Linux
kernel's NAPI, for example). However, it is usually bad because:

 * it consumes resources when there is no need: the CPU wakes up from
   the power-saving mode, the hard disk spins unnecessarily; the battery
   that should be good for several years, dies in the middle of the
   winter

 * it is not reactive enough as you must wait patiently for the polling
   interval to expire.


Since you brought up select(), a better choice is right under your nose:
multiplexing. Have your program block and be prepared for any possible
stimulus. However, once you do that, you realize you lose the naive
simplicity of threads. Thus we arrive at the conclusion: asynchronous
programming and processes are usually a better design choice than
threads.


Marko


From jacob at blindza.co.za  Thu Jan 15 11:40:31 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Thu, 15 Jan 2015 18:40:31 +0200
Subject: MySQL connections
In-Reply-To: <CAPTjJmr3nA-g2eGGW1JHK=09FW+fY4dEmPhWCSYmF6xQGvSfbg@mail.gmail.com>
References: <DB3F78F5082B4B31A42C783C4E9BD763@JakesPC>
 <CAPTjJmpvaNQNVJsmvbH6YGYnQZkofNCS0F+0UFzwsy-NVqv-ug@mail.gmail.com>
 <5F6F0C3BBA694C15A513F94735D89E18@JakesPC>
 <CAPTjJmr3nA-g2eGGW1JHK=09FW+fY4dEmPhWCSYmF6xQGvSfbg@mail.gmail.com>
Message-ID: <F2BABA3F0B844089BBCAC9950B9C2456@JakesPC>

----- Original Message ----- 
From: "Chris Angelico" <rosuav at gmail.com>
Cc: <python-list at python.org>
Sent: Thursday, January 15, 2015 2:33 PM
Subject: Re: MySQL connections


> On Thu, Jan 15, 2015 at 10:59 PM, Jacob Kruger <jacob at blindza.co.za> 
> wrote:
>> Tried generating .exe with both cx_freeze, and pyInstaller, and the code
>> itself, and both versions of executable generate errors, same as running 
>> it
>> from command line - only difference is the source of the error mentioned 
>> in
>> error message then varies from a2m.exe and python.exe , and even if 
>> compile
>> it on machine where all works, and then copy .exe back to this primary
>> machine, then get same error - think it must relate to something else on
>> this machine, but can't track it down.
>
> Okay. Ignore the .exe versions, and just work with what happens when
> you run the .py files. If it fails as part of a .py file, post the
> failing file.

If you want to check it out, have attached the full code file - might be a 
bit messy/large - but, effectively, right at bottom, launch an instance of 
the class a2m, passing through arguments, and then from within __init__ call 
convertProcess function, which then initiates process, harvesting sort of 
rendition/version of structure out of MS access database file, makes call to 
convertSQL to generate structural SQL script, and save it to a file, which 
then calls convertData function to generate insert statements to populate 
database, and then that makes a call to convertExport, if you passed a 
command line argument in requesting mysql, and that's the current issue 
function - have stripped most of actual functionality out of it, since am 
just testing, so the first 16 lines of that function are what's relevant at 
moment - think shouldn't rely on any other self. objects/attributes as such 
either, unless step-through process is an issue.

And, tried cleaning it up a bit - replaced tab indentation character with 
double spaces, but, code might not look perfect/be perfectly clean as of 
yet.

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..." 
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From jacob at blindza.co.za  Thu Jan 15 11:44:20 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Thu, 15 Jan 2015 18:44:20 +0200
Subject: [OT] Re: MySQL connections
In-Reply-To: <qvifba9hcpggbqi26pc2u2arj35bjvomcm@4ax.com>
References: <DB3F78F5082B4B31A42C783C4E9BD763@JakesPC>
 <m985f6$t2n$1@ger.gmane.org> <9F8BC49703624E5CBBE5BDFAEA504752@JakesPC>
 <qvifba9hcpggbqi26pc2u2arj35bjvomcm@4ax.com>
Message-ID: <E6F4FFE868BC44D1AC9445CBCC503C6A@JakesPC>

----- Original Message -----
 > Does
> SFC /scannow
> show any problems on either machine. (should be some command that does
> version checking too which might be of interest to compare)
from sfc /scannow:
Windows Resource Protection found corrupt files but was unable to fix some 
of th
em.
Details are included in the CBS.Log

Have attached cbs.log resulting from sfc/scannow, but, not sure what it all 
means in there - couple of what they refer to as integrity errors, but 
anyway

Not sure about version verification - only, literally did install of python 
3.4 this morning, from scratch, using pip, etc. to install all required 
packages/modules, etc.

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."
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From jacob at blindza.co.za  Thu Jan 15 11:50:02 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Thu, 15 Jan 2015 18:50:02 +0200
Subject: [OT] Re: MySQL connections
In-Reply-To: <qvifba9hcpggbqi26pc2u2arj35bjvomcm@4ax.com>
References: <DB3F78F5082B4B31A42C783C4E9BD763@JakesPC>
 <m985f6$t2n$1@ger.gmane.org> <9F8BC49703624E5CBBE5BDFAEA504752@JakesPC>
 <qvifba9hcpggbqi26pc2u2arj35bjvomcm@4ax.com>
Message-ID: <3C149C4D60B84272A0BF48254F843030@JakesPC>

----- Original Message ----- 
From: "Dennis Lee Bieber" <wlfraed at ix.netcom.com>
To: <python-list at python.org>
Sent: Thursday, January 15, 2015 4:22 PM
Subject: Re: [OT] Re: MySQL connections


> On Thu, 15 Jan 2015 13:48:34 +0200, "Jacob Kruger" <jacob at blindza.co.za>
> declaimed the following:
>
>>Agree with that, but, like said in prior e-mail, just get windows error
>>message popping up, mentioning - no track trace, since it's python
>>terminating:
>>
> Python is fairly good about dumping a stack trace when the error is
> something detectable by Python.
>
Issue is it just kills python, so no error message from python being 
rendered/displayed.

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."



From ian.g.kelly at gmail.com  Thu Jan 15 12:05:55 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 15 Jan 2015 10:05:55 -0700
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54B76B0A.7050706@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
Message-ID: <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>

On Thu, Jan 15, 2015 at 12:23 AM, Andrew Robinson
<andrew3 at r3dsolutions.com> wrote:
> Can you name any other language that *does* allow subclassing of
> booleans or creation of new boolean values?
>
> Yes. Several off the top of my head -- and I have mentioned these before.
> They generally come with the extra subclasses pre-created and the user
> doesn't get to create the classes, but only use them; none the less -- they
> have more than two values with which to do logic equations with.
>
> VHDL, Verilog, HDL, Silos III, and there are IEEE variants also.
> C/C++ historically allowed you to do it with instances included, although I
> am not sure it still does.

Sorry, let me rehprase my question. Of course there will be
special-purpose languages that allow you to do interesting things with
the logic values and operators. Can you name any other
*general-purpose* language that allows subclassing of booleans or
creation of new boolean values? If not, it seems rather unfair to
single out Python and marvel that this isn't allowed when it's
actually quite normal to disallow it. Unless you care to provide an
example, I am fairly sure your claim of C/C++ is wrong. The bool type
in C++ is a primitive type, none of which can be inherited from. C
doesn't even have a bool type; at most you have macros for true and
false to 1 and 0, so the "booleans" there are just ordinary integers.


From breamoreboy at yahoo.co.uk  Thu Jan 15 12:16:56 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 15 Jan 2015 17:16:56 +0000
Subject: Opening the file in writing mode
In-Reply-To: <CAG6E59Xvs8FV=R4sK6vo0=t00ZcwQ9387EYA7ZGvq4H6Lsvz-w@mail.gmail.com>
References: <CAA+hu4Vy76UU+wj1HCHZeEErg8-gaLQR9jW-r5Wq-ToG-=wtRQ@mail.gmail.com>
 <CAG6E59VZVsni5u_yJWguBuUdiQEi=dvwM-qz7hYbMmOwunQz2A@mail.gmail.com>
 <CAA+hu4UnuJUmg0tyXe0J2So4iKE3_v5LwZSOQ-0Y8O1y2DZo=Q@mail.gmail.com>
 <CAG6E59Xvs8FV=R4sK6vo0=t00ZcwQ9387EYA7ZGvq4H6Lsvz-w@mail.gmail.com>
Message-ID: <m98sma$8g7$1@ger.gmane.org>

On 15/01/2015 11:36, Adnan Sadzak wrote:
>
> On Thu, Jan 15, 2015 at 12:19 PM, Abdul Abdul <abdul.sw84 at gmail.com

Would the two of you please stop top posting, thank you.  Either 
intersperse your answers, snipping stuff that you're not replying to, or 
post at the bottom, in order to make your replies readable.  Thanks in 
anticipation.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rustompmody at gmail.com  Thu Jan 15 12:19:18 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Thu, 15 Jan 2015 09:19:18 -0800 (PST)
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
Message-ID: <1193cd8d-cd55-4e7a-adda-5416b5933183@googlegroups.com>

On Thursday, January 15, 2015 at 11:25:11 AM UTC+5:30, Yawar Amin wrote:
> Hi all,
> 
> First off, to each reader--if you believe that 'multi-line' lambdas are
> no good and we can just use functions, decorators, &c. to accomplish
> everything in Python, advance warning: this post will annoy you.
> 
> Now, the crux of my message. I have implemented what I believe is a
> fairly robust, if ugly-looking, native Python module made up of
> combinator functions which compose together to form function expressions
> (well, callable expressions).
> 
> I've seen a lot of discussions on possibly introducing syntax support
> for multi-line lambdas in some future version, but I've never seen
> anyone say, here's a way you can do this in Python _today._ So I believe
> lambdak fits in that niche.
> 
>     https://github.com/yawaramin/lambdak
> 
> Would anyone care to try it out? I would be happy to answer questions
> whenever I can.

Looked at your suggestions...
And then got distracted by your other project
https://github.com/yawaramin/vim-cute-python

Reminded me of what I had written some months ago along similar lines
http://blog.languager.org/2014/04/unicoded-python.html

At that time this was not suggested quite seriously.
Now I see that this can be realized at least partially
and on a personal level.


From breamoreboy at yahoo.co.uk  Thu Jan 15 12:22:16 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 15 Jan 2015 17:22:16 +0000
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <CALwzid=N0SRKWsBy8W9qicDzAo=vj_C+LKrTVSZDA+iN5oLHHg@mail.gmail.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <54b758e1$0$2738$c3e8da3$76491128@news.astraweb.com>
 <CALwzid=N0SRKWsBy8W9qicDzAo=vj_C+LKrTVSZDA+iN5oLHHg@mail.gmail.com>
Message-ID: <m98t0a$ds9$1@ger.gmane.org>

On 15/01/2015 06:39, Ian Kelly wrote:
> On Wed, Jan 14, 2015 at 11:06 PM, Steven D'Aprano <steve at pearwood.info> wrote:
>> I have a function, which I put into an expression like this:
>>
>> def func(a, b=None):
>>      global spam
>>      import math
>>      spam = [a, b]*3
>>      print spam
>>      del spam
>>
>>
>> value = [1, "hello", int, func]
>> del func
>>
>> How would I use lambdak to write that as an expression
>>
>> value = [1, "hello", int, ??????? ]
>>
>> without the intermediate def?
>
>
> # Untested, but seems like this should work.
>
> value = [1, "hello", int, given_(lambda a, b=None:
>      import_("math", lambda math:
>      import_("operator", lambda operator:
>      do_(lambda: operator.setitem(globals(), 'spam', [a, b]*3), lambda:
>      print_(globals()['spam'], lambda:
>      do_(lambda: operator.delitem(globals(), 'spam')))))))]
>
>
> To the OP: I note that although import_ is used in the examples, it's
> not found in the list of functions in the README.
>

Just what I've been looking for, highly readable, higly maintainable 
Python code.  Please put this up as an Activestate recipe so it's 
preserved for prosperity, so that the entire world can see its 
asthetically pleasing properties.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rgaddi at technologyhighland.invalid  Thu Jan 15 12:54:52 2015
From: rgaddi at technologyhighland.invalid (Rob Gaddi)
Date: Thu, 15 Jan 2015 09:54:52 -0800
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <mailman.17743.1421306724.18130.python-list@python.org>
Message-ID: <20150115095452.072d5763@rg.highlandtechnology.com>

On Wed, 14 Jan 2015 23:23:54 -0800
Andrew Robinson <andrew3 at r3dsolutions.com> wrote:

> 
> > Boolean algebra has two values: true and false, or 1 and 0, or humpty
> > and dumpty, or whatever you like to call them.
> You're speaking to an Electrical engineer.  I know there are 10 kinds of 
> people, those who know binary and those who don't.  But you're way off 
> base if you think most industrial quality code for manipulating boolean 
> logic uses (or even can be restricted to use) only two values and still 
> accomplish their tasks correctly and within a finite amount of time.
> 

[snip]

Absolutely it does and can.  You store anything that's non-boolean in a
non-boolean value, and keep it as fuzzy as you like.  But at the end of
the day, an if statement has no "kinda".  You do, or you don't.  1 or
0.  And so you must ultimately resolve to a Boolean decision.

> >
> > Can you name any other language that *does* allow subclassing of
> > booleans or creation of new boolean values?
> Yes. Several off the top of my head -- and I have mentioned these 
> before.  They generally come with the extra subclasses pre-created and 
> the user doesn't get to create the classes, but only use them; none the 
> less -- they have more than two values with which to do logic equations 
> with.
> 
> VHDL, Verilog, HDL, Silos III, and there are IEEE variants also.
> C/C++ historically allowed you to do it with instances included, 
> although I am not sure it still does.
> 

Incorrect, at least in VHDL.  If I've got "signal x : boolean;", then x
is defined on the range (true, false).  I can ask VHDL "if x then; ...;
end if;"

What you're talking about is not at all a subclass of boolean, it's a
std_logic.  It's a separate enumerated type, with a set of resolution
rules defined in a function the source of which is available in
std_logic_1164.vhd.  And according to the strict rules of VHDL (up
until VHDL2008 decided to forfeit some purity for simplicity's), you
can't simply have:

	signal x: std_logic
	...
	if x then

You have to ask

	if x = '1'
or
	if (x = '1') or (x = 'H')

Because you are comparing one value of an enumerated type against
others, the result of that '=' operation being, in fact, a boolean,
defined again on the range (true, false).

> [snip]
> 
> We've discovered that we live in a quantum-mechanical universe -- yet 
> people still don't grasp the pragmatic issue that basic logic can be 
> indeterminate at least some of the time ?!
> 

But actions can't be. You're not asking the software about it's
feelings, you're telling it to follow a defined sequence of
instructions.  Do this, or don't do this.

> I don't know what you mean about composition vs. sub-classing.
> Would you care to show an example of how it would solve the problem and 
> still allow hierarchical sorting ?
> 
> I don't see how you can get pre-existing python functions (like sort, 
> max, and min) to accept a complex bool value and have that value 
> automatically revert to a True or False in an intelligent manner without 
> overloading the operators defined in some class -- somewhere -- to 
> operate on the data the class contains.
> 
> How do you intend to achieve that with this -- composition -- thing you 
> mentioned ?
> 
> 

You'd do it something like this.

class _clogic(object):
	"""Represents 'continuous' logic.  For any given instance,
there is a threshold value between 0 and 1 that delineates True from
False, with 0 being entirely False and 1 being entirely True.
	"""
	
	def __init__(self, value, threshold=0.5):
		self.value = value
		self.threshold = threshold
		
	def __bool__(self):
		return value > threshold
	__nonzero__ = __bool__
	
	def __eq__(self, other):
		if other in (True, False):
			return bool(self) == other
			
		try:
			return self.value == other.value
		except AttributeError:
			return self.value == other
		
	def __and__(self, other):
		return self.__class__(
			min(self.value, other.value),
			self.threshold)

	def __or__(self, other):
		return self.__class__(
			max(self.value, other.value),
			self.threshold)

No need to subclass bool, you just use the __bool__ (or __nonzero__)
methods to say "Alright, well when you do finally have to make a
decision on this thing, here's how you make it.  And obviously, you can
add on as many additional data members to carry additional information
as your heart desires.

-- 
Rob Gaddi, Highland Technology -- www.highlandtechnology.com
Email address domain is currently out of order.  See above to fix.


From fomcl at yahoo.com  Thu Jan 15 16:07:09 2015
From: fomcl at yahoo.com (Albert-Jan Roskam)
Date: Thu, 15 Jan 2015 21:07:09 +0000 (UTC)
Subject: class-based class decorator
In-Reply-To: <41960019.9418586.1421167045799.JavaMail.root@sequans.com>
References: <41960019.9418586.1421167045799.JavaMail.root@sequans.com>
Message-ID: <1255947379.417961.1421356029358.JavaMail.yahoo@jws10740.mail.gq1.yahoo.com>



----- Original Message -----

> From: Jean-Michel Pichavant <jeanmichel at sequans.com>
> To: Albert-Jan Roskam <fomcl at yahoo.com>
> Cc: Python <python-list at python.org>
> Sent: Tuesday, January 13, 2015 5:37 PM
> Subject: Re: class-based class decorator
> 
> ----- Original Message -----
>>  From: "Albert-Jan Roskam" <fomcl at yahoo.com>
>>  > From: Jean-Michel Pichavant <jeanmichel at sequans.com>
>>  > I don't really understand how you successfuly manage positional
>>  > parameters,
>>  > since the caller may not name them.
>>  > I'm asking because if your intend to check only the keyword
>>  > parameters,
>>  > there's a much simplier solution.
>>  > 
>>  > JM
>> 
>> 
>>  Hi,
>> 
>>  Can you give an example of where/how my code would fail? I do not
>>  intend to use *args and **kwargs, if that is what you mean. I am
>>  interested in hearing a simpler approach, especially if it would
>>  also solve the messed-up-signature problem that I mentioned.
>> 
>>  Thank you!
>> 
>>  Albert-Jan
>> 
> 
> In the example you've given you've deprecated only keyword arguments. So 
> I was wondering...
> 
> would the following *untested* code work ? :
> 
> def check_deprecated_args(deprecated):
>   def decorator(func):
>     def inner(*args, **kwargs):
>       for p in deprecated:
>         if p in kwargs:
>           print '%s is deprecated' % p
>       return func(*args, **kwargs)
>     return inner
>   return decorator
> 


This is indeed a lot simpler than a class-based version, merci bien! And now I can also make it work with the signature-preserving decorator package. Meanwhile I also found a Python 2 backport for inspect.signature, so positional args can also be used. 


Thanks again!

Albert-Jan


From roy at panix.com  Thu Jan 15 20:34:10 2015
From: roy at panix.com (Roy Smith)
Date: Thu, 15 Jan 2015 20:34:10 -0500
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
Message-ID: <roy-A43F6D.20334015012015@news.panix.com>

In article <87zj9kb2j0.fsf at elektro.pacujo.net>,
 Marko Rauhamaa <marko at pacujo.net> wrote:

> Skip Montanaro <skip.montanaro at gmail.com>:
> 
> > Beautiful is better than ugly.
> 
> Yes, our job is to increase the Harmony of the Universe. Useful
> applications are happy side effects.
> 
> > Explicit is better than implicit.
> 
> Corollary: Constructors are usually preferable to factories.

The ebb and flow of technology has recently brought me someplace I never 
thought I'd be.  Java-land.  And what I've discovered is that factories 
are so last year.  Apparently builders are the new thing.

> Corollary: Make sure the complete definition of every function can be
> seen at once without scrolling.

The problem with that, is I have a 30 inch monitor now.


From torriem at gmail.com  Thu Jan 15 20:44:24 2015
From: torriem at gmail.com (Michael Torrie)
Date: Thu, 15 Jan 2015 18:44:24 -0700
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <roy-A43F6D.20334015012015@news.panix.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com>
Message-ID: <54B86CF8.7040602@gmail.com>

On 01/15/2015 06:34 PM, Roy Smith wrote:
> The ebb and flow of technology has recently brought me someplace I never 
> thought I'd be.  Java-land.  And what I've discovered is that factories 
> are so last year.  Apparently builders are the new thing.

It's never clear to me whether all these fancy design patterns are to
make up for a deficient language, or whether some people just get their
kicks from layer upon layer of abstraction.  Certainly it's this sort of
thing that turns me right off of Java.



From andrew3 at r3dsolutions.com  Thu Jan 15 20:45:22 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Thu, 15 Jan 2015 17:45:22 -0800
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54b77d4a$0$2738$c3e8da3$76491128@news.astraweb.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <mailman.17743.1421306724.18130.python-list@python.org>
 <54b77d4a$0$2738$c3e8da3$76491128@news.astraweb.com>
Message-ID: <54B86D32.8010207@r3dsolutions.com>


On 01/15/2015 12:41 AM, Steven D'Aprano wrote:
> On Wed, 14 Jan 2015 23:23:54 -0800, Andrew Robinson wrote:
>
> [...]
>> A subclass is generally backward compatible in any event -- as it is
>> built upon a class, so that one can almost always revert to the base
>> class's meaning when desired -- but subclassing allows extended meanings
>> to be carried.  eg: A subclass of bool is a bool -- but it can be MORE
>> than a bool in many ways.
> You don't have to explain the benefits of subclassing here.
>
> I'm still trying to understand why you think you *need* to use a bool
> subclass. I can think of multiple alternatives:
>
> - don't use True and False at all, create your own multi-valued
>    truth values ReallyTrue, MaybeTrue, SittingOnTheFence, ProbablyFalse,
>    CertainlyFalse (or whatever names you choose to give them);
>
> - use delegation to proxy True and False;
>
> - write a class to handle the PossiblyTrue and PossiblyFalse cases,
>    and use True and False for the True and False cases;
>
> There may be other alternatives, but what problem are you solving that
> you think
>
>      class MyBool(bool): ...
>
> is the only solution?
That's a unfair question that has multiple overlapping answers.
Especially since I never said subclassing bool is the 'only' solution; I 
have indicated it's a far better solution than many.

So -- I'll just walk you through my thought processes and you will see 
what I consider problems:

Start with the concept that as an engineer, I have spent well over 
twenty years on and off dealing with boolean values that are very often 
mixed indistinguishably with 'don't care' or 'tri-state' or 'metastable 
states'.   A metastable state *is* going to be True or False once the 
metastability resolves by some condition of measurement/timing/etc.; but 
that value can not be known in advance.   eg: similar to the idea that 
there is early and late binding in programming.... Sometimes there is a 
very good reason to delay making a final decision until the last 
possible moment; and it is good to have a default value defined if no 
decision is made at all.

So -- From my perspective, Guido making Python go from an open ended and 
permissive use of anything goes as a return value that can handle 
metastable states -- into to a historical version of 'logic' being 
having *only* two values in a very puritanical sense, is rather -- well 
-- disappointing.  It makes me wonder -- what hit the fan?!  Is it 
lemmings syndrome ? a fight ? no idea....  and is there any hope of 
recovery or a work around ?

eg: To me -- (as an engineer) undefined *IS* equivalent in useage to an 
acutal logic value, just as infinity is a floating point value that is 
returned as a 'float'.  You COULD/CAN separate the two values from each 
other -- but always with penalties.  They generally share an OOP 'is' 
relationship with respect to how and when they are used. (inf) 'IS' a 
float value and -- uncertain -- 'IS' a logic value.

That is why I automatically thought before I ever started writing on 
this list (and you are challenging me to change...) -- that 'uncertain' 
should share the same type (or at least subtype) as Bool.  
Mathematicians can argue all they want that 'infinity' is not a float 
value, and uncertain is not a True or False.  And they are/will be 
technically right -- But as a practical matter -- I think programmers 
have demonstrated over the years that good code can handle 'infinity' 
most efficiently by considering it a value rather than an exception.  
And I think the same kind of considerations very very likely apply to 
Truth values returned from comparisons found in statistics, quantum 
mechanics, computer logic design, and several other fields that I am 
less familiar with.

So -- let's look at the examples you gave:

> - don't use True and False at all, create your own multi-valued
>    truth values ReallyTrue, MaybeTrue, SittingOnTheFence, ProbablyFalse,
>    CertainlyFalse (or whatever names you choose to give them);
>
OK.  So -- what do I think about when I see your suggestion:

First I need to note where my booleans come from -- although I've never 
called it multi-valued logic... so jargon drift is an issue... though 
you're not wrong, please note the idea of muti-value is mildly misleading.

The return values I'm concerned about come from a decimal value after a 
comparison with another decimal value.
eg:

a = magicFloat( '2.15623423423(1)' )
b = magicFloat('3()')

myTruthObject = a>b

Then I look at python development historically and look at the built in 
class's return values for compares; and I notice; they have over time 
become more and more tied to the 'type' bool.  I expect sometime in the 
future that python may implement an actual type check on all comparison 
operators so they can not be used to return anything but a bool.  (eg:  
I already noticed a type check on the return value of len() so that I 
can't return infinity, even when a method clearly is returning an 
infinitely long iterator -- such as a method computing PI dynamically.  
That suggests to me that there is significant risk in python of having 
type checking on all __xx__ methods in the future. )  This inspection is 
what points me foremost to saying that very likely, I am going to want a 
bool or subtye of it (if possible) as a return type as self defense 
against future changes in Python -- although at present, I can still get 
away with returning other types if bool turns out to be impossible.

Next, I notice that for compatibility it *is* very desirable that I use 
the existing '>' operator,  because programmers generally want to be 
able to use '>' when they are testing greater than -- and in legacy code 
I expect people have exclusively done so -- and I know from past 
experience that programmers in general will not be happy with typing 
'a.greaterThan(b)' religiously. ( Extend my reasoning to all other 
comparison operators.)

It would be worse to use '>' and have it trigger an exception when a 
non-bool is encountered to force the programmer to attend to special 
metastable states differently; because then the programmer has to write 
a compete set of secondary handling routines or a 'try' statement around 
a very large number of lines of code and that makes for legacy code 
rewriting rather than minor upgrading...

It would also be bad to have my code have modal settings because I don't 
want to bother with thread information or have programmers consider 
thread issues unless it's a last resort; although that's the approach 
used by the Decimal class and other examples I have seen.

So:  In general, the most desirable return type is determined by what 
python actually returns for normal comparison operations; eg: apparently 
a bool -- but with some way of signaling (if the user cares) that more 
precise information is available as to why a value is False if it is False.

Unfortunately, the '>', '<', '==', and other operators have no way of 
returning additional information on their own; so again, a second 
(undesirable) function/method would need to be invoked to overcome the 
limitation if only a strict bool is allowed as a return type; and that 
means con-concomitant issues of storage and wasted re-computation and 
threads.

So, your first alternative is the most at risk of future problems due to 
constraints likely to be placed on comparison return types ; and as I 
don't want to do much maintenance on my library in the future -- I don't 
think that is a very good choice for making my library with.

> - use delegation to proxy True and False;
That sounds like a far more likely to succeed alternative, and is one of 
a handful of alternatives I have been exploring on my own.

Proxies allow detection of an actual deterministic False vs. a default 
False.  So a proxy's id() can signal to a user when it is possible to 
upgrade a False to True should they care.   Therefore -- If Guido would 
see fit to permanently allow proxied True and False values to be 
returned in lieu OF an actual True and False value, then this would be a 
near ideal alternative.  But Python does not implement a general purpose 
proxy that I know of ...

I have gotten single instance of a class acting as a proxy to mostly 
work; and I have gotten isinstance( myTruthValue, bool ) to return True 
for the proxy object -- which is not a bool itself.  However, when I 
attempt multiple instances of the proxy -- it becomes more difficult.  I 
think a pure python implementation might be possible -- and I'll 
continue to try for a while -- but python may not be able to do it 
totally from the python side because there is a difference in how Python 
handles type() checks and isinstance() checks.


> - write a class to handle the PossiblyTrue and PossiblyFalse cases,
>    and use True and False for the True and False cases;
I very much would want to do as you state here because it would preserve 
both True and False unaltered --- which would ALWAYS work in legacy 
code; but I don't know how to do it safely.

Although I can use True for absolute Truth -- I can not use False as 
absolute False without inviting confusion as to when to allow advanced 
compares.

When I do a comparison on any False < False, in legacy code -- it needs 
to return False.

But, when looking at uncertainty values, if totally False 'is' the same 
as base type False -- then the issue arises that a comparison False < 
AnyOtherPartTrueFalse   needs to be False for legacy compares but True 
for advanced compares;

It's inconsistent and I have no way of detecting where the False I am 
comparing with to make a proper decision.

So:  The only solution I see is to assume that whenever a uncertainty is 
compared against a legacy bool -- that the legacy style of comparison is 
absolutely required for safety; and a second version of False must be 
defined to detect when the compare needs to take uncertainty into account.

All of these issues are handled correctly in the example tuple class I 
already showed.  So the tuple class I showed is presently the best 
solution with the most compatability that I have found so far.
>
>
>> One example: It can also be a union.
> I don't understand what you think this means. I know what *I* think it
> means, but "subclass = union" doesn't make sense to me, so wonder what
> you think it means.

It's a fringe use-case in Python that I don't think many people use/know 
about.  I was just being thorough in listing it.

I haven't seen it used in actual python code myself -- but I know from 
the literature I've read on Python that it is occasionally used in a 
manner analogous to that of C/C++.

In C/C++ unions are a datatype that allow two (or more) different types 
of data to be defined as held by one object, but only one of them is 
allowed to be initialized at a time because their location in computer 
memory which overlaps.  C places no restrictions on the compatibility of 
the datatypes -- which is different than Python, but Python has a 
similar ability.

In Python, when multiple inheritance is invoked -- it does some kind of 
check on the base types for compatibility; but still appears to be able 
/ or simply does overlap the allocated memory for the different base 
types; eg: according to several sources I have read (at least on 
C-python internals).

So one can semantically instantiate a subclass of one subtype without 
semantically instantiating the other.

ALl I know about it is what I have seen it in Python literature -- and I 
tested the examples I was shown to see if they still work, and they do 
-- and noted that at least at one time Guido apparently thought it was a 
good idea ; but I haven't pursued it beyond that.

>> So when Guido chose to cut off
>> subclassing -- his decision had a wider impact than just the one he
>> mentioned; eg: extra *instances* of True and False.... as if he were
>> trying to save memory or something.
> *shrug* well maybe he was.
:) LOL.  I don't have any real idea.... but it would be useful to know 
for sure.

>
>> The reason Guido's action puzzles me is twofold -- first it has been
>> standard industry practice to subclass singleton  (or n-ton) objects to
>> expand their meaning in new contexts,
> I dispute that. I *strongly* dispute that.
>
> Industry practice, in my experience, is that there is one and only one
> case where you can subclass singleton classes: when you have a factory
> which chooses at runtime which subclass to instantiate, after which you
> can no longer instantiate any of the other subclasses.
OK.
Well, I'll just say that I believe you -- and I'm not really sure what 
you're objecting to in what I said -- but if a singleton subclass / 
factory existed for my purpose -- I would be happy to choose it at 
runtime just like your maze guys do...!  If Guido would do that... he 
would give me a subtype of bool and that would be very nice indeed.

But dreams aside -- I still note your admission shows that industry does 
allow subclassing of singletons even if it requires the owner of the 
singleton (Guido) to allow the subtypes.

Cf: Design Patters, Elements of Reusable Object Oriented Software ( 
Erich Gamma, Richard Helm, Ralph Johnson, John Vlissides ) pp. 127 
"Chapter, Singleton -- Object Creational"
--------------------------------------------------------

-- Applicability:
Use the singleton pattern when:
-- There must be exactly one instance of a class, and it must be 
accessible to clients from a well known access point.
-- When the sole instance should be extensible by subclassing, and 
clients should be able to use an extended instance without modifying 
their code.

...

Consequences:
The singleton pattern has several benefits:
...
4. Permits a variable number of instances.   The pattern makes it easy 
to change your mind and allow more than one instance of the Singleton 
Class.  Moreover, you can use the same approach to control the number of 
instances that the application uses.  Only the operation that grants 
access to the singleton instance needs change.

...

Implementation:
2. Subclassing the Singleton Class:  The main issue is not so much 
defining the subclass but installing it's unique instance so that 
clients will be able to use it.
...
A more flexible approach uses a registry of singletons.  Instead of 
having Instance define the set of possible Singleton Classes, The 
Singleton classes can register their singleton instance by name in a 
well known registry.
...
Of course, the constructor won't get called unless someone instantiates 
the class, which echoes the problem the Singleton is trying to solve.
---------------------------------------------------------

> Why are we limited to a single Maze? Making Maze a singleton in the first
> place was a bad idea. The singleton design pattern is *highly* over-used
> and abused. But that is another story. Let's just assume that the
> designer has good reason to insist that there be only one Maze, perhaps
> it uses some resource which truly is limited to there being one only. If
> that is the case, then allowing the caller to break that invariant by
> subclassing will just lead to horrible bugs.
Right -- when a user does not know the reason for a singleton ; breaking 
it is just ASKING for bugs.  I agree.  That's why I have been asking 
about why Guido did it...  there are times to avoid breaking the rules, 
and times to crush them.

>   By using a factory and
> controlling access to the subclasses, Maze can keep the singleton
> invariant and allow subclasses.
>
> This is not relevant to bool, since True and False are already
> instantiated.

There's nothing stopping Guido from making it relevant...
>
> [...]
>> In general -- it's not the goal of subclassing to create more instances
>> of the base types
> That might not be the goal, but it is the effect. When you instantiate
> the subclass, by definition the instances are also instances of the base
> classes.
All right -- I can agree to that and will concede that point -- as I 
don't see much purpose in pursuing it further as I suspect (without 
proof) that Guido might not like that extra instances of class 
definitions that I might use as a work-around... although I don't really 
know why it's so important to him.
>> -- but rather to refine meaning in a way that can be
>> automatically reverted to the base class value (when appropriate) and to
>> signal to users that the type can be passed to functions that require a
>> bool because of backward compatibility.
> And I am wondering what you think you can extend bools to perform that is
> completely backwards compatible to code that requires bools?
I've never said 'completely compatible', and have been very careful not 
to make extremest remarks.
I want to get as close as I can to fully backward compatible -- and am 
willing to put some time into it rather than taking the first solution 
that vaguely works...

> I don't think you can. I think you are engaged on a fool's errand, trying
> to do something impossible *even if subclassing bool were allowed*. But I
> could be wrong. I just don't think you can possibly write code which is
> backwards-compatible with code that expects bools while still extending
> it. People are so prone to write:
>
>      if flag is True: ...
>      if flag is False: ...
D'Aprano -- I think your making what is known as a straw man argument.

Refer back to your earlier suggestion of re-using True and False to 
represent themselves, and some other type to represent the intermediate 
metastates;  From your remark here, I surmise that you must have already 
figured out that the alternative you gave me was never meant to work -- 
otherwise it would solve the very problem you now present me with for 
any case where my numbers are identical in meaning with legacy numbers 
-- eg: it *would* work perfectly for any truly legacy application.  The 
failures -- would show up with new applications or non legacy data which 
could erroneously trigger a legacy compare when it ought not do so 
because you can not get the new types returned unless non-legacy data 
has been encountered.
> (which is naughty of them, but what are you going to do?)
>
Nothing, except hope that the people who wrote Python itself didn't do 
anything naughty in sort() min() and max() and friends.  So far my tests 
show that they didn't.  But -- you're right -- Non core language 
implementation programmers, are going to have occasional bugs that 
either they or I will have to hunt down, depending on who it is that 
needs their software to work with my library.
> C doesn't have instances because it doesn't have objects. I'm not
> certain, but I don't think the other languages you refer to are object-
> oriented either. Verilog is a structured programming language, Silos is a
> Verilog simulator, and I think VHDL and HDL are versions of Verilog (that
> is, I've only seen them written as "Verilog-VHDL" and "Verilog-HDL").
OOP programming in C is not done using formal class keywords, etc, but 
it is done by defining structs and compiler modules and pointers to 
functions;   So -- C -- doesn't have the security measures that a C++ 
compiler implements for OOP ( 'private' ,'protected' ); but OOP can 
still be done in C including inheritance.  'C' most certainly does have 
instances and singletons.  Several packages available under GPL, such as 
the GTK widget set, are implemented in strict C (not C++) and as full 
object oriented packages, then another optional package can be compiled 
if C++ bindings to the objects are desired.

Verilog is the originator of the language family I mentioned, yes; and 
they are all variations on a theme -- but there are versions of HDL's by 
other companies, and the US government;  Most are based on C syntax, 
some are based on ADA, and other languages that engineers happen to like 
for various applications; etc.  I mentioned only the most used versions.

> In any case, Verilog *by design* uses four-state logic, modelling 1, 0,
> floating, undefined. It is not a bool, since *by definition* bools model
> only two states.

Not quite, verilog is meant to handle two state logic. AKA: Binary bit 
or Boolean, and to also work with  metastable data; eg: In electronics, 
floating or unknown or oscillating or frozen between states for a period 
of time while settling are traditionally called metastable.  I am not 
sure if this is a mathematican's definition, or if it's because these 
quasi-states were defined with/after (meta) the two stable ones.  It's 
something I will have to check. But I remember from my early college 
courses that it is technically wrong to call them all states, even 
though 'don't care' is often referred to as the tri-state.

In any event -- Your comment about verilog still just demonstrates that 
Guido has downgraded python's return types into a more more primitive 
system than is warranted by the history of the creation of the 
computer.  Verilog (1984) existed before Python (1989) so *even* 
verilog's conventions predate python's.  And I don't even remember when 
HiLo used to be around but I'm sure it's older than verilog. So -- from 
the very beginning of Python, design logic for boolean systems has 
*always* included meta-state information with boolean values.

>> The third value is usually called "TRI-state" or "don't care". (Though
>> its sometimes a misnomer which means -- don't know, but do care.)
> And SQL has NULL, which makes it an example of tri-state logic. (To be
> precise, SQL uses a version of Kleene K3 logic.)
OK.  I agree -- it does.
>
> [snip description of modelling hardware circuits]
> All very interesting, but completely irrelevant to the question of
> subclassing bool.

No, not really -- but I'll respect your difference of opinion.
I'm getting the message that the reason Guido though this was important 
was because the historical meaning of bool is more important than the 
idea that metastability is an issue to be dealt with at the same time as 
the data value -- like electrical engineers do regularly.

>
>> We've discovered that we live in a quantum-mechanical universe -- yet
>> people still don't grasp the pragmatic issue that basic logic can be
>> indeterminate at least some of the time ?!
> Of course they do. My first post to you in this thread suggested that
> before you start re-inventing the wheel you look at prior art in the
> multi-value logic field.
Did you ? -- Did I reply to that e-mail?  I'm not sure I read it...
But the word is different from what I am used to -- eg: meta-stable 
logic 'states' ... ?

Now that I'm looking up words -- I see that wikipedia is calling the 
indeterminate states 'multi-value'; I'm getting old... I am used to the 
term metastable; not multi-value.  Weird.  Jargon problems...

Even so -- I seriously don't think of Quantum mechanics as multi-value ; 
it's uncertain and 'collapses' to a definite value when measured.  I can 
understand your intention now... I'll have to go back and search for the 
old email. My apology.

>
>
>> The name 'boolean logic' has never been re-named in honor of the many
>> people who developed the advancements in computers -- including things
>> like data sheets for electronic parts,
> Are you really suggesting that the name of Boolean Logic should be
> renamed away from the person who invented the field and instead named
> after the person who first wrote down a list of electronic part numbers
> and their specifications?
Nope.
Though I DO want to point out that Charles Bool did not invent the 
computer, build the microprocessor, or any of the things which would 
give a logical reason why his more archaic *usage* is given preference 
over the useage preferred by the very people who DID invent the 
microprocessor, computer, and programming languages.

Name recognition is great for honoring a man -- but makes for a poor 
reason to choose a strict implementation of bool.

>
>> or the code base used for solving
>> large numbers of simultaneous logic equations with uncertainty included
>> -- which have universally refined the boolean logic meanings found in
>> "Truth" tables having clearly more than two values -- but don't take my
>> word for it -- look in any digital electronics data book, and there they
>> will be more than two states; marked with rising edges, falling edges,
>> X's for don't cares, and so forth.
> And those truth tables are not part of Boolean algebra.
Oh wow!!!! I never expected to hear that --  But I guess you were never 
trained to do boolean algebra, formally ? Or did you mean something else ?

http://en.wikipedia.org/wiki/Truth_table

The truth tables on data sheets are VERY VERY much intended to be 
related to boolean logic.
Electronic engineers routinely put the words "Truth table" on datasheets 
where the boolean information is recorded (and I'm sure even on relay 
logic prior to the vaccum tube) but still add  x's because *as 
inventors* they knew Bool's usage wasn't enough to convey ideas 
efficiently and fully.

It's pragmatism over rigid formalism left over from an age where the 
computer as we have it was not even conceived.

http://www.eleccircuit.com/cd4027b_datasheet-of-dual-j-k-flip-flop/

> [...]
>> As I said to D'Aprano -- even a *cursory* examination (eg: as in not
>> detailed) shows I could do things which he wasn't considering.
> Andrew, I think you will be surprised at what I have considered. If you
> search the archives, you will find that (by memory) a decade ago I had
> considered using classes without instantiating them.
No surprise.  I know from reading your work that you have been doing 
programming a long time, and have fairly well substantiated / reasonable 
opinions even if I disagree with some of them as trying to overemphasize 
to a fault a definition which has never been honored in the past by 
those who used it most.

> The questions I have about your strategy is not what can be done in
> Python, but how you think these things you want to do will solve the
> problem you apparently have?
>
> To give an analogy... I have no doubt that you can build an television.
> But I question how building a television solves your problem of
> transporting a goat, a wolf and a cabbage across the river.
Ask away.  I already have one solution that works reasonably well, the 
tuple rich compare;
So it's not like I don't have a solution -- it's just that I'm not sure 
that I can't do better.

If Python had never added the bool definition to the language, I 
wouldn't even have to bother with any of this supposed 'fools' errand 
nuisance in the first place... but I'll make the best of it.

> [...]
>> I don't have a setting on my email to turn off html.  Sorry. Can't help.
> You are using Thunderbird. You certainly do have such a setting.
It's nice to know that you read and believe what you see in an email header.
Note: Headers are sometimes modified by sysadmins who actually care 
about security.

PPS: If there is a way to turn off HTML in this email program -- it is 
not obvious -- and I have looked.
I've done my best not to push any HTML enhancement buttons...



From yawar.amin at gmail.com  Thu Jan 15 21:07:43 2015
From: yawar.amin at gmail.com (Yawar Amin)
Date: Thu, 15 Jan 2015 18:07:43 -0800 (PST)
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <mailman.17741.1421303993.18130.python-list@python.org>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <54b758e1$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17741.1421303993.18130.python-list@python.org>
Message-ID: <93a78914-9c7b-4b6e-83e3-4e3af616b838@googlegroups.com>

On Thursday, January 15, 2015 at 1:40:09 AM UTC-5, Ian wrote:
> On Wed, Jan 14, 2015 at 11:06 PM, Steven D'Aprano
> <steve at ...> wrote:
> [...]
> > def func(a, b=None):
> >     global spam
> >     import math
> >     spam = [a, b]*3
> >     print spam
> >     del spam
> >
> > value = [1, "hello", int, func]
> > del func
> [...]
> # Untested, but seems like this should work.
> [...]
> To the OP: I note that although import_ is used in the examples, it's
> not found in the list of functions in the README.

Thanks Ian. I'll update the readme soon. It's still a little behind the
actual code.

Steve, here is your example translated, about as simple as I can make
it:

    from lambdak import *

    value = [
      1,
      "hello",
      int,
      given_(lambda a, b = None:
        import_("math", lambda math:
        given_(lambda globs = globals(), spam = "spam":

        assign_(spam, [a, b] * 3, globs, lambda:
        print_(get_(spam, globs), lambda:
        del_(spam, globs))))))
    ]

    value[3](1)
    del value[3]

The problem with globals is that a Python module can't easily manipulate
the globals of its caller modules. Here you can see I had to work around
the issue by just creating a few functions[1] which generically work
with dicts and then explicitly passing in the globals dict on each call.
I don't see any other reasonable way to do it. I would welcome being
proven wrong here.

To the responders in the 'beauty of the code' subthread: yes, I realise
that lambdak is not Pythonic, and it will make angels cry, and all that.
My view is you should actually be _happy_ that it looks like this. If
anyone ever asks about multi-line lambdas again, you can point to
lambdak and say, 'See! This is what happens if you try to go against
Pythonic style.' And then you can shrug your head in disgust if they
continue to use it anyway.

Regards,

Yawar

[1] `assign_`, `get_`, `del_`. I haven't pushed these to the project
repo yet. Will do so after writing up the tests and docs.


From breamoreboy at yahoo.co.uk  Thu Jan 15 21:14:57 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Fri, 16 Jan 2015 02:14:57 +0000
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <54B86CF8.7040602@gmail.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
Message-ID: <m99s74$q2n$1@ger.gmane.org>

On 16/01/2015 01:44, Michael Torrie wrote:
> On 01/15/2015 06:34 PM, Roy Smith wrote:
>> The ebb and flow of technology has recently brought me someplace I never
>> thought I'd be.  Java-land.  And what I've discovered is that factories
>> are so last year.  Apparently builders are the new thing.
>
> It's never clear to me whether all these fancy design patterns are to
> make up for a deficient language, or whether some people just get their
> kicks from layer upon layer of abstraction.  Certainly it's this sort of
> thing that turns me right off of Java.
>

If you're interested in patterns in the Python world take a look at Alex 
Martelli's writings on the subject, e.g. http://www.aleax.it/gdd_pydp.pdf

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From yawar.amin at gmail.com  Thu Jan 15 21:18:09 2015
From: yawar.amin at gmail.com (Yawar Amin)
Date: Thu, 15 Jan 2015 18:18:09 -0800 (PST)
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <1193cd8d-cd55-4e7a-adda-5416b5933183@googlegroups.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <1193cd8d-cd55-4e7a-adda-5416b5933183@googlegroups.com>
Message-ID: <7da673f1-54a3-45ec-a6c8-e606ed7a58fb@googlegroups.com>

Hi,

On Thursday, January 15, 2015 at 12:19:31 PM UTC-5, Rustom Mody wrote:
> [...]
> Looked at your suggestions...
> And then got distracted by your other project
> https://github.com/yawaramin/vim-cute-python
> 
> Reminded me of what I had written some months ago along similar lines
> http://blog.languager.org/2014/04/unicoded-python.html
> 
> At that time this was not suggested quite seriously.
> Now I see that this can be realized at least partially
> and on a personal level.

Glad it was useful. Although let me clarify that I just forked the repo
from the original on GitHub, to publish my custom version. I have more
conservative tastes than the original, so I chose to keep the `in`, `not
in`, `and`, `or`, `not` keywords as is instead of using the symbols. I
did go through your blog post and got a previously-unused symbol out of
it: '?' to represent '/'.

Regards,

Yawar


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From breamoreboy at yahoo.co.uk  Thu Jan 15 21:27:21 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Fri, 16 Jan 2015 02:27:21 +0000
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54B86D32.8010207@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
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 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <mailman.17743.1421306724.18130.python-list@python.org>
 <54b77d4a$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B86D32.8010207@r3dsolutions.com>
Message-ID: <m99suc$4kh$1@ger.gmane.org>

On 16/01/2015 01:45, Andrew Robinson wrote:
>

[snipped as far too long to bother anybody with]

I hereby congratulate you on having made it to my Dream Team for having 
written the longest pile of drivel I've read in the 12 ish years I've 
been hanging around here.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rustompmody at gmail.com  Thu Jan 15 21:48:01 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Thu, 15 Jan 2015 18:48:01 -0800 (PST)
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <7da673f1-54a3-45ec-a6c8-e606ed7a58fb@googlegroups.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <1193cd8d-cd55-4e7a-adda-5416b5933183@googlegroups.com>
 <7da673f1-54a3-45ec-a6c8-e606ed7a58fb@googlegroups.com>
Message-ID: <3624979f-761b-4d4e-97d2-92fe1edaff64@googlegroups.com>

On Friday, January 16, 2015 at 7:48:20 AM UTC+5:30, Yawar Amin wrote:
> Hi,
> 
> On Thursday, January 15, 2015 at 12:19:31 PM UTC-5, Rustom Mody wrote:
> > [...]
> > Looked at your suggestions...
> > And then got distracted by your other project
> > https://github.com/yawaramin/vim-cute-python
> > 
> > Reminded me of what I had written some months ago along similar lines
> > http://blog.languager.org/2014/04/unicoded-python.html
> > 
> > At that time this was not suggested quite seriously.
> > Now I see that this can be realized at least partially
> > and on a personal level.
> 
> Glad it was useful. Although let me clarify that I just forked the repo
> from the original on GitHub, to publish my custom version. I have more
> conservative tastes than the original, so I chose to keep the `in`, `not
> in`, `and`, `or`, `not` keywords as is instead of using the symbols. I
> did go through your blog post and got a previously-unused symbol out of
> it: '?' to represent '/'.

The more forks the merrier!

Let there be a hundred different versions, then people will 
begin to clamor against the non-necessity of the penury-of-ASCII:

http://blog.languager.org/2015/01/unicode-and-universe.html


From breamoreboy at yahoo.co.uk  Thu Jan 15 22:02:48 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Fri, 16 Jan 2015 03:02:48 +0000
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <3624979f-761b-4d4e-97d2-92fe1edaff64@googlegroups.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <1193cd8d-cd55-4e7a-adda-5416b5933183@googlegroups.com>
 <7da673f1-54a3-45ec-a6c8-e606ed7a58fb@googlegroups.com>
 <3624979f-761b-4d4e-97d2-92fe1edaff64@googlegroups.com>
Message-ID: <m99v0r$r0$1@ger.gmane.org>

On 16/01/2015 02:48, Rustom Mody wrote:
>
> The more forks the merrier!
>

When counting them, or more specifically handles, thou shalt not stop 
counting at three, but thou shalt continue to four, and thou shalt not 
continue on to five https://www.youtube.com/watch?v=Cz2-ukrd2VQ

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rantingrickjohnson at gmail.com  Thu Jan 15 22:06:21 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 15 Jan 2015 19:06:21 -0800 (PST)
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
Message-ID: <20afdff6-1391-4bcf-a412-1c579ca15b6b@googlegroups.com>

On Wednesday, January 14, 2015 at 11:55:11 PM UTC-6, Yawar Amin wrote:
> First off, to each reader--if you believe that 'multi-
> line' lambdas are no good and we can just use functions,
> decorators, &c. to accomplish everything in Python,
> advance warning: this post will annoy you.

Well i'm not religious in that way, but i can tell you that
you'd be hard pressed to find a subject that did *NOT*
annoy someone in this group. Heck, it might even be
something like finding a "holy grail" if we all agreed!

> Now, the crux of my message. I have implemented what I
> believe is a fairly robust, if ugly-looking, native Python
> module made up of combinator functions which compose
> together to form function expressions (well, callable
> expressions).

Oh my, that's atrocious! (but kudos for trying!). If you
have not already done so, i would suggest you play around
with the Ruby language -- for which anonymous blocks are
quite prevalent.

I myself have lamented the limited power and expressiveness
of Python's anonymous functions. It's almost as though
Python lambda's are barely worth having since they are so
crippled.

Of course the majority will say "that is because people
would use them for stupid things"... well, i've seen Python
used for stupid things -- how are they going to reconcile
that?. These types of excuses are based purely on religious
or fascist thinking, and nothing more. :-(




From breamoreboy at yahoo.co.uk  Thu Jan 15 22:13:48 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Fri, 16 Jan 2015 03:13:48 +0000
Subject: MySQL connections
In-Reply-To: <F2BABA3F0B844089BBCAC9950B9C2456@JakesPC>
References: <DB3F78F5082B4B31A42C783C4E9BD763@JakesPC>
 <CAPTjJmpvaNQNVJsmvbH6YGYnQZkofNCS0F+0UFzwsy-NVqv-ug@mail.gmail.com>
 <5F6F0C3BBA694C15A513F94735D89E18@JakesPC>
 <CAPTjJmr3nA-g2eGGW1JHK=09FW+fY4dEmPhWCSYmF6xQGvSfbg@mail.gmail.com>
 <F2BABA3F0B844089BBCAC9950B9C2456@JakesPC>
Message-ID: <m99vlf$cun$1@ger.gmane.org>

On 15/01/2015 16:40, Jacob Kruger wrote:
>
> If you want to check it out, have attached the full code file - might be
> a bit messy/large - but, effectively, right at bottom, launch an
> instance of the class a2m, passing through arguments, and then from
> within __init__ call convertProcess function, which then initiates
> process, harvesting sort of rendition/version of structure out of MS
> access database file, makes call to convertSQL to generate structural
> SQL script, and save it to a file, which then calls convertData function
> to generate insert statements to populate database, and then that makes
> a call to convertExport, if you passed a command line argument in
> requesting mysql, and that's the current issue function - have stripped
> most of actual functionality out of it, since am just testing, so the
> first 16 lines of that function are what's relevant at moment - think
> shouldn't rely on any other self. objects/attributes as such either,
> unless step-through process is an issue.
>

Can you please provide us with a piece of code based on these guidelines 
http://sscce.org/ as I doubt that too many people are going to wade 
through the now deceased attachment.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rustompmody at gmail.com  Thu Jan 15 22:14:18 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Thu, 15 Jan 2015 19:14:18 -0800 (PST)
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <mailman.17781.1421377383.18130.python-list@python.org>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <1193cd8d-cd55-4e7a-adda-5416b5933183@googlegroups.com>
 <7da673f1-54a3-45ec-a6c8-e606ed7a58fb@googlegroups.com>
 <3624979f-761b-4d4e-97d2-92fe1edaff64@googlegroups.com>
 <mailman.17781.1421377383.18130.python-list@python.org>
Message-ID: <04138079-7092-4978-9702-27c71de7ebc2@googlegroups.com>

On Friday, January 16, 2015 at 8:33:14 AM UTC+5:30, Mark Lawrence wrote:
> On 16/01/2015 02:48, Rustom Mody wrote:
> >
> > The more forks the merrier!
> >
> 
> When counting them, or more specifically handles, thou shalt not stop 
> counting at three, but thou shalt continue to four, and thou shalt not 
> continue on to five https://www.youtube.com/watch?v=Cz2-ukrd2VQ

Ha Ha -- Thanks


From yawar.amin at gmail.com  Thu Jan 15 22:20:02 2015
From: yawar.amin at gmail.com (Yawar Amin)
Date: Thu, 15 Jan 2015 19:20:02 -0800 (PST)
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <20afdff6-1391-4bcf-a412-1c579ca15b6b@googlegroups.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <20afdff6-1391-4bcf-a412-1c579ca15b6b@googlegroups.com>
Message-ID: <b2418438-2314-45ab-8a31-4711f24ebb2a@googlegroups.com>

On Thursday, January 15, 2015 at 10:06:34 PM UTC-5, Rick Johnson wrote:
> [...]
> Well i'm not religious in that way, but i can tell you that
> you'd be hard pressed to find a subject that did *NOT*
> annoy someone in this group. Heck, it might even be
> something like finding a "holy grail" if we all agreed!

Ha! Indeed. And here I was thinking that Python's Holy Grail would be
finding a good multi-line lambda :-)

> Oh my, that's atrocious! (but kudos for trying!). If you
> have not already done so, i would suggest you play around
> with the Ruby language -- for which anonymous blocks are
> quite prevalent.

Yes, I've been very impressed by Ruby's ?sthetics. Matz did something
with Ruby that few other people were willing to do: he followed
expression semantics to its logical conclusion. People (including
myself) have asked if we could have that in Python, but as I understand
it Python has some strict newline and indent requirements that prevent
it.

> I myself have lamented the limited power and expressiveness
> of Python's anonymous functions. It's almost as though
> Python lambda's are barely worth having since they are so
> crippled.

I guess they are crippled from the perspective of a functional
programmer. But they work pretty well for their intended uses. And as I
mentioned, if your editor masks the keyword and displays the symbol,
they almost look natural in the code.

Regards,

Yawar


From rosuav at gmail.com  Thu Jan 15 23:00:12 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 16 Jan 2015 15:00:12 +1100
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <54B86CF8.7040602@gmail.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com>
 <54B86CF8.7040602@gmail.com>
Message-ID: <CAPTjJmqLq0S1+cGWp8evb_k9QaXVHQ91Hj=bdQnzSAzKLUmneQ@mail.gmail.com>

On Fri, Jan 16, 2015 at 12:44 PM, Michael Torrie <torriem at gmail.com> wrote:
> On 01/15/2015 06:34 PM, Roy Smith wrote:
>> The ebb and flow of technology has recently brought me someplace I never
>> thought I'd be.  Java-land.  And what I've discovered is that factories
>> are so last year.  Apparently builders are the new thing.
>
> It's never clear to me whether all these fancy design patterns are to
> make up for a deficient language, or whether some people just get their
> kicks from layer upon layer of abstraction.  Certainly it's this sort of
> thing that turns me right off of Java.

My first response was going to be "Well, you can always add another
layer of indirection to try to solve your problem", but then I went
and looked up builders on Wikipedia. Now I'm confused. What can you do
with a builder that you can't do with a constructor? Is this to get
around style guides that reject this kind of model:

x = Foo(
    opt1=True,
    opt2=True,
    color=Yellow,
)

so you instead do this?

x = Foo.Builder()
x.opt1 = True
x.opt2 = True
x.color = Yellow
x = x.get()

How is that an improvement?

In Python, of course, keyword arguments do this job brilliantly, but
I'm aware that not all languages support them. Okay. But if you can
pass a mapping object to the constructor, you can do the same job that
way, and even if you can't do that, you could pass an array of
item,value,item,value,item,value or something. Surely there must be
some way that would work.

ChrisA


From steve+comp.lang.python at pearwood.info  Thu Jan 15 23:16:16 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 16 Jan 2015 15:16:16 +1100
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <1193cd8d-cd55-4e7a-adda-5416b5933183@googlegroups.com>
 <7da673f1-54a3-45ec-a6c8-e606ed7a58fb@googlegroups.com>
 <3624979f-761b-4d4e-97d2-92fe1edaff64@googlegroups.com>
Message-ID: <54b89091$0$13004$c3e8da3$5496439d@news.astraweb.com>

Rustom Mody wrote:

> Let there be a hundred different versions, then people will
> begin to clamor against the non-necessity of the penury-of-ASCII:
> 
> http://blog.languager.org/2015/01/unicode-and-universe.html

Almost 30 years ago, Apple's Hypertalk language allowed, and encouraged, the
use of certain non-ASCII symbols. You could use ? ? and ? for
less-or-equal, greater-or-equal, and not-equal comparisons; you could use ?
for division; and you could define a square root function using ? as the
name. You could even define ? = 'INF' and do floating point operations on
it.

Apple could get away with this back in the 80s because they controlled the
platform including keyboard mappings, and they could guarantee that key
combinations such as Option-/ would generate the ? character and that any
reasonable font would include a glyph for it.

Alas and alack, 30 years on and we have to live with the down-side of
multicultural computers. Any modern Linux system is almost sure to be fully
Unicode compatible with a UTF-8 filesystem -- *almost* sure. But we have to
interoperate with Windows machines still stuck in the Dark Ages of "code
pages"; Java that insists that Unicode == UTF-16 (and support for the
supplementary multilingual planes is weak); there is a plethora of fonts
but Unicode support is extremely variable; many of us are using US
keyboards and there's no well-known or standard input method for Unicode
characters; and while Apple only had to support somewhat fewer than 256
characters, Unicode has tens of thousands.

Before Unicode can take off for programming syntax, we need to solve at
least four problems:

- we need a good selection of decent programmer's fonts with 
  extensive support for Unicode especially mathematical symbols;

- we need a platform-independent input method that will allow 
  programmers to enter these symbols without moving their hands 
  off the keyboard;

- and some way to make the existence of these symbols easily 
  discoverable, e.g. for most of us, ~ is easily discoverable 
  because we can see it on the keyboard, but the same doesn't
  apply for ?

- we have to be confident that moving source code from one 
  machine to another (Windows -> Linux or visa versa) won't
  corrupt the file. That means UTF-8 everywhere.

I live in hope, but I am not confident that these issues will be solved in
my lifetime. One of the ten most popular programming languages, PHP,
doesn't even support Unicode even as a data type. What hope do we have?



-- 
Steven



From steve+comp.lang.python at pearwood.info  Thu Jan 15 23:17:03 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 16 Jan 2015 15:17:03 +1100
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <54b758e1$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17741.1421303993.18130.python-list@python.org>
 <93a78914-9c7b-4b6e-83e3-4e3af616b838@googlegroups.com>
Message-ID: <54b890c0$0$13004$c3e8da3$5496439d@news.astraweb.com>

Yawar Amin wrote:

> To the responders in the 'beauty of the code' subthread: yes, I realise
> that lambdak is not Pythonic, and it will make angels cry, and all that.
> My view is you should actually be happy that it looks like this. If
> anyone ever asks about multi-line lambdas again, you can point to
> lambdak and say, 'See! This is what happens if you try to go against
> Pythonic style.' And then you can shrug your head in disgust if they
> continue to use it anyway.


:-)


-- 
Steven



From jacob at blindza.co.za  Thu Jan 15 23:28:03 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Fri, 16 Jan 2015 06:28:03 +0200
Subject: [OT] Re: MySQL connections
In-Reply-To: <08rgbadhtjdk62b46u9kifd9hqfnd5v1oh@4ax.com>
References: <DB3F78F5082B4B31A42C783C4E9BD763@JakesPC>
 <m985f6$t2n$1@ger.gmane.org> <9F8BC49703624E5CBBE5BDFAEA504752@JakesPC>
 <qvifba9hcpggbqi26pc2u2arj35bjvomcm@4ax.com>
 <E6F4FFE868BC44D1AC9445CBCC503C6A@JakesPC>
 <08rgbadhtjdk62b46u9kifd9hqfnd5v1oh@4ax.com>
Message-ID: <2CDF16B74C624361B3B1C0319E05F7CA@JakesPC>

----- Original Message ----- > functions. When was the last time those 
systems had Windows Update and
> reboots performed?

Daily basis.

Think, in line with your other message, will just try rewrite code - and, 
issue relating to structure etc. is left over from when pulled it out of 
wxPython implementation - you're right that should have just redone that 
part of it ;)

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."



From rustompmody at gmail.com  Thu Jan 15 23:58:39 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Thu, 15 Jan 2015 20:58:39 -0800 (PST)
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <54b89091$0$13004$c3e8da3$5496439d@news.astraweb.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <1193cd8d-cd55-4e7a-adda-5416b5933183@googlegroups.com>
 <7da673f1-54a3-45ec-a6c8-e606ed7a58fb@googlegroups.com>
 <3624979f-761b-4d4e-97d2-92fe1edaff64@googlegroups.com>
 <54b89091$0$13004$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <9dc2afda-4264-4ecb-a0ba-d523e186dc58@googlegroups.com>

On Friday, January 16, 2015 at 9:46:30 AM UTC+5:30, Steven D'Aprano wrote:
> Rustom Mody wrote:
> 
> > Let there be a hundred different versions, then people will
> > begin to clamor against the non-necessity of the penury-of-ASCII:
> > 
> > http://blog.languager.org/2015/01/unicode-and-universe.html
> 
> Almost 30 years ago, Apple's Hypertalk language allowed, and encouraged, the
> use of certain non-ASCII symbols. You could use ? ? and ? for
> less-or-equal, greater-or-equal, and not-equal comparisons; you could use ?
> for division; and you could define a square root function using ? as the
> name. You could even define ? = 'INF' and do floating point operations on
> it.

Good stuff!

> 
> Apple could get away with this back in the 80s because they controlled the
> platform including keyboard mappings, and they could guarantee that key
> combinations such as Option-/ would generate the ? character and that any
> reasonable font would include a glyph for it.

APL went much further, 60 years ago.  And IBM could get away with it
for similar monopolistic reasons

> 
> Alas and alack, 30 years on and we have to live with the down-side of
> multicultural computers. Any modern Linux system is almost sure to be fully
> Unicode compatible with a UTF-8 filesystem -- *almost* sure. But we have to
> interoperate with Windows machines still stuck in the Dark Ages of "code
> pages"; Java that insists that Unicode == UTF-16 (and support for the
> supplementary multilingual planes is weak); there is a plethora of fonts
> but Unicode support is extremely variable; many of us are using US
> keyboards and there's no well-known or standard input method for Unicode
> characters; and while Apple only had to support somewhat fewer than 256
> characters, Unicode has tens of thousands.

No direct experience but my impression is that windows is almost as
unicode-compliant as linux:

http://msdn.microsoft.com/en-us/library/windows/desktop/dd317752%28v=vs.85%29.aspx

http://msdn.microsoft.com/en-us/library/windows/desktop/dd374081%28v=vs.85%29.aspx

Yeah SMP support may be problematic. Anyways...
1. BMP alone is a 256-fold expansion over ASCII
2. SMP support all round is spotty. MySQL?? Blogger is messing my posts etc
3. For almost all the cases we're talking of BMP is enough and to spare

> 
> Before Unicode can take off for programming syntax, we need to solve at
> least four problems:
> 
> - we have to be confident that moving source code from one 
>   machine to another (Windows -> Linux or visa versa) won't
>   corrupt the file. That means UTF-8 everywhere.

Ok

> - we need a good selection of decent programmer's fonts with 
>   extensive support for Unicode especially mathematical symbols;

I guess so

> 
> - we need a platform-independent input method that will allow 
>   programmers to enter these symbols without moving their hands 
>   off the keyboard;

I dont see why.  I use laptops and desktops having different layouts.
Fumble a bit but not too much.
Others probably use much more way out devices eg android phones.

Likewise I dont see why input-methods need to match/be platform independent. As long as they work.

eg Some cars have European controls ? wiper on left, lights on right.
Or American ? the other way round.
When changing I fumble a bit but not so much its an issue

> 
> - and some way to make the existence of these symbols easily 
>   discoverable, e.g. for most of us, ~ is easily discoverable 
>   because we can see it on the keyboard, but the same doesn't
>   apply for ?

I believe this is the nub of the matter.

Discoverability of 1 million characters is a very different matter from
discoverability of a few hundred.

eg 

1. Beginning programmers do search-and-peck typing ? they need to
discover the US-104 (or whatever) keyboard
2. Beginning vi-users need to find the controls of the dragon with two modes
? one in which it beeps and one in which it corrupts the file
3. Beginning python programmers need to discover the difference
between typing at the command-prompt at the REPL and into a file? and
a dozen other things before python begins to look barely friendly

In the same way typing a ? ? ? on a stock keyboard may require some
learning/acclimatization/setup.

- Using a suitable editor mode it needs to be exactly the same as the ASCII
"<=", ">=", "!=" 
- With compose key setup its just a character more ? the above preceded
by the compose key [right-win, ALtGr, Menu, whatever]

> 
> 
> I live in hope, but I am not confident that these issues will be solved in
> my lifetime. One of the ten most popular programming languages, PHP,
> doesn't even support Unicode even as a data type. What hope do we have?

Using, canvassing, clamoring, bugging (with bug-reports) is our toolset :-)


From ian.g.kelly at gmail.com  Fri Jan 16 00:01:56 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 15 Jan 2015 22:01:56 -0700
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54B86D32.8010207@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <mailman.17743.1421306724.18130.python-list@python.org>
 <54b77d4a$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B86D32.8010207@r3dsolutions.com>
Message-ID: <CALwzidnGruqnbFv9n_4k2VWMv0Tq8Dsc-ezK6mKHm-0nvrTavA@mail.gmail.com>

On Thu, Jan 15, 2015 at 6:45 PM, Andrew Robinson
<andrew3 at r3dsolutions.com> wrote:
> Then I look at python development historically and look at the built in
> class's return values for compares; and I notice; they have over time become
> more and more tied to the 'type' bool.  I expect sometime in the future that
> python may implement an actual type check on all comparison operators so
> they can not be used to return anything but a bool.

Let's see what the documentation says about this:

"""
A rich comparison method may return the singleton NotImplemented if it
does not implement the operation for a given pair of arguments. By
convention, False and True are returned for a successful comparison.
However, these methods can return any value, so if the comparison
operator is used in a Boolean context (e.g., in the condition of an if
statement), Python will call bool() on the value to determine if the
result is true or false.
"""

https://docs.python.org/3/reference/datamodel.html#object.__lt__

So the docs explicitly promise that comparison methods can return any
value. Changing this would break backward compatibility (in particular
it would break a lot of DSLs), so it's not going to happen any time
soon, and you have nothing to worry about here.

> (eg:  I already noticed
> a type check on the return value of len() so that I can't return infinity,
> even when a method clearly is returning an infinitely long iterator -- such
> as a method computing PI dynamically.  That suggests to me that there is
> significant risk in python of having type checking on all __xx__ methods in
> the future. )  This inspection is what points me foremost to saying that
> very likely, I am going to want a bool or subtye of it (if possible) as a
> return type as self defense against future changes in Python -- although at
> present, I can still get away with returning other types if bool turns out
> to be impossible.

I suspect the reason __len__ must return an int is largely historical.
Back before __iter__ existed, the way Python did iteration was by
calling __len__ and then calling __getitem__ for each index between 0
and the result. Obviously for this to work, the result had to be an
int, and infinite iterators didn't exist in this era either.

Nowadays, that sort of iteration is non-standard, but Python will
still fall back on it if __iter__ isn't defined.

> So, your first alternative is the most at risk of future problems due to
> constraints likely to be placed on comparison return types ; and as I don't
> want to do much maintenance on my library in the future -- I don't think
> that is a very good choice for making my library with.

Except that the risk you describe is fictitious.

>>> One example: It can also be a union.
>>
>> I don't understand what you think this means. I know what *I* think it
>> means, but "subclass = union" doesn't make sense to me, so wonder what
>> you think it means.
>
>
> It's a fringe use-case in Python that I don't think many people use/know
> about.  I was just being thorough in listing it.
>
> I haven't seen it used in actual python code myself -- but I know from the
> literature I've read on Python that it is occasionally used in a manner
> analogous to that of C/C++.
>
> In C/C++ unions are a datatype that allow two (or more) different types of
> data to be defined as held by one object, but only one of them is allowed to
> be initialized at a time because their location in computer memory which
> overlaps.  C places no restrictions on the compatibility of the datatypes --
> which is different than Python, but Python has a similar ability.
>
> In Python, when multiple inheritance is invoked -- it does some kind of
> check on the base types for compatibility; but still appears to be able / or
> simply does overlap the allocated memory for the different base types; eg:
> according to several sources I have read (at least on C-python internals).
>
> So one can semantically instantiate a subclass of one subtype without
> semantically instantiating the other.
>
> ALl I know about it is what I have seen it in Python literature -- and I
> tested the examples I was shown to see if they still work, and they do --
> and noted that at least at one time Guido apparently thought it was a good
> idea ; but I haven't pursued it beyond that.

Do you have a link? I have no idea what you're referring to, and I
suspect that you're confused. You can't do multiple inheritance from
types that would internally have overlapping memory.  For example:

>>> class Foo(list, dict): pass
...
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: multiple bases have instance lay-out conflict

> I'm getting the message that the reason Guido though this was important was
> because the historical meaning of bool is more important than the idea that
> metastability is an issue to be dealt with at the same time as the data
> value -- like electrical engineers do regularly.

Maybe because Python wasn't written for electrical engineers. It's a
general purpose boolean algebra for a general purpose programming
language.


From steve+comp.lang.python at pearwood.info  Fri Jan 16 00:08:22 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 16 Jan 2015 16:08:22 +1100
Subject: Factories and Builders [was Re: lambdak...]
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com>
Message-ID: <54b89cc7$0$12975$c3e8da3$5496439d@news.astraweb.com>

Roy Smith wrote:

> The ebb and flow of technology has recently brought me someplace I never
> thought I'd be. ?Java-land. ?And what I've discovered is that factories
> are so last year. ?Apparently builders are the new thing.


I've never really understand why "abstract factory", "factory method"
and "builder" are considered different design patterns. They're variants on
the same idea.

class Spam:
    def create(self, a, b, c, d):
        if a == "fast":
            theclass = FastClass
        elif a == "steady":
            theclass = SteadyClass
        obj = theclass(b, c, d)
        # obj.extra_stuff = self.get_stuff()
        return obj


As I understand it, if FastClass and SteadyClass are subclasses of Spam,
then this is the Factory Method design pattern, but if they are independent
classes unrelated to Spam, then it is the Abstract Factory design pattern.
But if I uncomment out the "obj.extra_stuff" line, it becomes a Builder.



-- 
Steven



From ian.g.kelly at gmail.com  Fri Jan 16 00:29:21 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 15 Jan 2015 22:29:21 -0700
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <CAPTjJmqLq0S1+cGWp8evb_k9QaXVHQ91Hj=bdQnzSAzKLUmneQ@mail.gmail.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net> <roy-A43F6D.20334015012015@news.panix.com>
 <54B86CF8.7040602@gmail.com>
 <CAPTjJmqLq0S1+cGWp8evb_k9QaXVHQ91Hj=bdQnzSAzKLUmneQ@mail.gmail.com>
Message-ID: <CALwzidmr=rtSk_f_tX8gwQDhUtHyUCV0LKRWSRq6CafBpB0Vxw@mail.gmail.com>

On Thu, Jan 15, 2015 at 9:00 PM, Chris Angelico <rosuav at gmail.com> wrote:
> My first response was going to be "Well, you can always add another
> layer of indirection to try to solve your problem", but then I went
> and looked up builders on Wikipedia. Now I'm confused. What can you do
> with a builder that you can't do with a constructor?

In Java you have to write a separate constructor for every conceivable
combination of arguments. If there are a lot of optional arguments,
that's an exponentially large number of constructors. The builder
pattern provides a solution to that problem.

In Python you just have one initializer with defaults for the optional
arguments, so it's not an issue.


From ethan at stoneleaf.us  Fri Jan 16 00:42:41 2015
From: ethan at stoneleaf.us (Ethan Furman)
Date: Thu, 15 Jan 2015 21:42:41 -0800
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <CALwzidmr=rtSk_f_tX8gwQDhUtHyUCV0LKRWSRq6CafBpB0Vxw@mail.gmail.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <CAPTjJmqLq0S1+cGWp8evb_k9QaXVHQ91Hj=bdQnzSAzKLUmneQ@mail.gmail.com>
 <CALwzidmr=rtSk_f_tX8gwQDhUtHyUCV0LKRWSRq6CafBpB0Vxw@mail.gmail.com>
Message-ID: <54B8A4D1.7090005@stoneleaf.us>

On 01/15/2015 09:29 PM, Ian Kelly wrote:
> 
> In Python you just have one initializer with defaults for the optional
> arguments, so it's not an issue.

What, Python makes it easy?  That must be a mistake somewhere!  ;)

--
~Ethan~

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From rosuav at gmail.com  Fri Jan 16 01:58:05 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 16 Jan 2015 17:58:05 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54B86D32.8010207@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <mailman.17743.1421306724.18130.python-list@python.org>
 <54b77d4a$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B86D32.8010207@r3dsolutions.com>
Message-ID: <CAPTjJmrJOxyu_UoqdSx72uRVv89iEmB=ZrmYdh8h-zYDg=YCmw@mail.gmail.com>

On Fri, Jan 16, 2015 at 12:45 PM, Andrew Robinson
<andrew3 at r3dsolutions.com> wrote:
>>> I don't have a setting on my email to turn off html.  Sorry. Can't help.
>>
>> You are using Thunderbird. You certainly do have such a setting.
>
> It's nice to know that you read and believe what you see in an email header.
> Note: Headers are sometimes modified by sysadmins who actually care about
> security.
>
> PPS: If there is a way to turn off HTML in this email program -- it is not
> obvious -- and I have looked.
> I've done my best not to push any HTML enhancement buttons...

You do have another option: Change email programs. Or lean on whoever
is in charge of this one, saying that it's failing in a significant
way.

Also, what security do your sysadmins gain by lying about mail
clients? Stripping the header would gain just as much. Lying just
makes your network uncooperative at best, and possibly will be seen as
malicious. If you're using a mail client with known vulnerabilities,
*FIX THAT*, don't try to hide behind a fallacious header. Otherwise
it's not security, it's laziness.

ChrisA


From steve+comp.lang.python at pearwood.info  Fri Jan 16 02:33:49 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 16 Jan 2015 18:33:49 +1100
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <mailman.17743.1421306724.18130.python-list@python.org>
 <54b77d4a$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17777.1421372716.18130.python-list@python.org>
Message-ID: <54b8bedf$0$12986$c3e8da3$5496439d@news.astraweb.com>

Andrew Robinson wrote:

[...much about bools...]

I'll get back to that shortly, but for now I just want to make a couple of
comments about your HTML email.

>> [...]
>>> I don't have a setting on my email to turn off html.  Sorry. Can't help.
>> You are using Thunderbird. You certainly do have such a setting.
>
> It's nice to know that you read and believe what you see in an email
> header. Note: Headers are sometimes modified by sysadmins who actually
> care about security.

No they're not. They're modified by sysadmins who like to give the false
impression that they care about security. Also who don't care about your
privacy. (I wouldn't trust a sys admin who modified the headers my mail
program set. I would wonder what else he is modifying behind my back.)

Faking the Useragent header is as useful for security as removing the badge
off a Toyota and replacing it with a Ford badge. Even if you can come up
with some conceivable set of circumstances where you are more secure ("what
if a terrorist with a grudge against Toyota sees your car and is
sufficiently enraged to blow it up???"), it's just security theatre.

To quote Whitfield Diffie: 

"The secret to strong security: less reliance on secrets."

If the security of your email program depends on people being misinformed
about which email program you have, then you have no little or no security.


> PPS: If there is a way to turn off HTML in this email program -- it is
> not obvious -- and I have looked.
> I've done my best not to push any HTML enhancement buttons...

Despite your belief that you are unable to disable HTML in your email, I can
tell you that out of the twelve posts I have received from you so far,
eight have no HTML (including this one of yours which I am replying to). So
you can disable it -- the only trick is to work out what you are doing, or
not doing, to avoid triggering it.

(If you are using Thunderbird, it gives you extensive control over when HTML
mail is set. Apart from being able to disable it completely, you can set
certain domains to only receive plain text emails. Look under Preferences
or Settings or whatever it's called now -- you're an engineer. I'm sure
you'll work it out.)



-- 
Steven



From greg.ewing at canterbury.ac.nz  Fri Jan 16 04:23:35 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Fri, 16 Jan 2015 22:23:35 +1300
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <mailman.17739.1421299637.18130.python-list@python.org>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <mailman.17739.1421299637.18130.python-list@python.org>
Message-ID: <chs3kpFgp3aU1@mid.individual.net>

Ian Kelly wrote:
> Wait, are you actually asking why bool is a doubleton? If nobody has
> answered that, I think probably nobody understood you were asking it,
> because it shouldn't need to be explained.

What does perhaps need explaining is why Python goes
out of its way to *enforce* the doubleton-ness of bool.

I don't know all of Guido's reasoning on this, but part
of it is probably to do with implementation efficiencies.
There are several places in the CPython source where it's
assumed that, if an object is known to be of type bool,
then its truth or falseness can be determined with a
pointer comparison.

-- 
Greg


From miki.tebeka at gmail.com  Fri Jan 16 04:57:32 2015
From: miki.tebeka at gmail.com (Miki Tebeka)
Date: Fri, 16 Jan 2015 01:57:32 -0800 (PST)
Subject: List of "python -m" tools
In-Reply-To: <m97ete$v9f$1@dont-email.me>
References: <54b5a3bb$0$2878$e4fe514c@news.xs4all.nl>
 <mailman.17708.1421228350.18130.python-list@python.org>
 <m97ete$v9f$1@dont-email.me>
Message-ID: <ff44aee0-cb27-40fe-8652-260f7dc91cda@googlegroups.com>

Thanks for all the answers!


From mal at europython.eu  Fri Jan 16 05:56:44 2015
From: mal at europython.eu (M.-A. Lemburg)
Date: Fri, 16 Jan 2015 11:56:44 +0100
Subject: EuroPython 2015: Your chance to sign up as a launch sponsor
Message-ID: <54B8EE6C.5010206@europython.eu>

Companies who would like to sign up as a EuroPython 2015 launch sponsor
are encouraged to contact the sponsor work group at:

                        sponsoring at europython.eu

Launch sponsors will get the additional benefit of being listed on the
website when we launch - for free. You just need to be quick, since the
launch is planned for early in February.

More Booths and more Sponsor Slots
----------------------------------

The Euskalduna Conference Center and Concert Hall (ECC) venue in Bilbao
was chosen as conference venue for EuroPython 2015:

    http://www.euskalduna.net/Index.asp?idioma=en

It offers plenty of room for sponsor booths, so we will try to make
EuroPython 2015 as effective as possible for you as sponsors by offering
more booth space and sponsor slots than ever before:

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This is your chance to reach out to more than a thousand enthusiastic
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Please email us at sponsoring at europython.eu and we?ll send you the
sponsor brochure.

Thanks,
?
EuroPython Society (EPS)
http://www.europython-society.org/

PS: Please help spread the word and forward this email to companies
you know, your local lists, user groups, etc. Many thanks !


From greg.ewing at canterbury.ac.nz  Fri Jan 16 06:07:37 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sat, 17 Jan 2015 00:07:37 +1300
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <mailman.17777.1421372716.18130.python-list@python.org>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <mailman.17743.1421306724.18130.python-list@python.org>
 <54b77d4a$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17777.1421372716.18130.python-list@python.org>
Message-ID: <chs9nsFi9ogU1@mid.individual.net>

Andrew Robinson wrote:
> 
> I never said subclassing bool is the 'only' solution; I 
> have indicated it's a far better solution than many.

An assertion with which we very much disagree.

> I have spent well over 
> twenty years on and off dealing with boolean values that are very often 
> mixed indistinguishably with 'don't care' or 'tri-state' or 'metastable 
> states'.

I think you're overestimating how useful it will be to
pass one of your "extended boolean" values to existing
code expecting a plain boolean.

The purpose of the bool type in Python and other languages
is for making control-flow decisions. When you hit

    if x:
       do_something()
    else:
       do_something_else()

and x is Undefined or TriState or "47% true", what is
supposed to happen? The right thing to do will depend on
the circumstances, so you're going to need custom code
for dealing with those values.

I'm not even sure it's right to single out two of the
extended values as corresponding to True and False in
all cases. It may seem obvious that the "high" state
of a digital logic signal should be True and the "low"
state should be False, but -- what about active-low
signals? They use the opposite convention!

> Then I look at python development historically and look at the built in 
> class's return values for compares; and I notice; they have over time 
> become more and more tied to the 'type' bool.

Actually, it's the opposite. Originally, all the comparison
operators got funneled through a single special method __cmp__,
which was required to return a negative, zero or positive
integer; hard-coded logic in the interpreter then derived a
boolean from that.

When rich comparisons were introduced (i.e. the ability to
override all the comparison operators individually), that
restriction was lifted.

> I expect sometime in the 
> future that python may implement an actual type check on all comparison 
> operators so they can not be used to return anything but a bool.

That's not going to happen. If nothing else, it would
break NumPy, which compares arrays element-by-element and
returns an array of booleans.

> I already noticed a type check on the return value of len() so that I 
> can't return infinity, even when a method clearly is returning an 
> infinitely long iterator

That's acknowledged as being less than desirable, but
fixing it would have performance implications, as well as
breaking the C extension API.

It's not really much of a limitation, anyway. Iterators
don't actually have a __len__; they can optionally have a
__length_hint__ method, but infinite iterators can just
leave that undefined.

> That suggests to me that there is significant risk in python of having 
> type checking on all __xx__ methods in the future.

You need have no fear of that. The trend has actually
been towards *less* restrictions on return types, and
I can't imagine that changing.

>> - use delegation to proxy True and False;
> 
> That sounds like a far more likely to succeed alternative, and is one of 
> a handful of alternatives I have been exploring on my own.

A proxy is still a different type. Whether you use a
proxy or a completely new type for this is entirely a
matter of implementation convenience. You won't magically
gain any capabilities that you couldn't have implemented
otherwise.

> python may not be able to do it 
> totally from the python side because there is a difference in how Python 
> handles type() checks and isinstance() checks.

There's no way I know of to make type() lie about the
true type of an object, proxy or not. But that would only
be a problem for code relying on type(x) is bool, which
I expect to be extremely rare if it exists at all.

> Though I DO want to point out that Charles Bool did not invent the 
> computer,

That's correct, because he didn't exist. :-) Boolean algebra
is named after George Boole. You're probably thinking of
Charles Babbage, who design (although never fully implemented)
what could be regarded as the first general purpose programmable
computer.

> Name recognition is great for honoring a man -- but makes for a poor 
> reason to choose a strict implementation of bool.

This is utter nonsense. The "strict" implementation of
bool you speak of isn't chosen to honour George Boole.

It's chosen because it's perfectly suited for its intended
application of flow-control in programming -- which is the
vast majority of the use of logic *above* the hardware
level. And since it happens to be a true Boolean algebra,
the name is entirely appropriate.

>> And those truth tables are not part of Boolean algebra.
> 
> Oh wow!!!! I never expected to hear that --  But I guess you were never 
> trained to do boolean algebra, formally ?

A Boolean algebra is a mathematical structure with a precise
definition. There exist Boolean algebras with more than two
values, but the don't-care states found in data sheets don't
fit into any of them. The data sheets call them "truth tables",
not "Boolean algebra tables". :-)

> The truth tables on data sheets are VERY VERY much intended to be 
> related to boolean logic.

Related, yes. Boolean algebra is a part of those truth tables,
not the other way around. What Steven said is correct.

-- 
Greg


From greg.ewing at canterbury.ac.nz  Fri Jan 16 06:21:43 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sat, 17 Jan 2015 00:21:43 +1300
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <mailman.17774.1421369276.18130.python-list@python.org>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <54b7cd9f$0$13011$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmpxdXXCVRyg5cu60TJU4gkc9qmc-opm51d4AkdmNhiZmw@mail.gmail.com>
 <mailman.17774.1421369276.18130.python-list@python.org>
Message-ID: <chsai9Fih3gU1@mid.individual.net>

Dennis Lee Bieber wrote:
> On Fri, 16 Jan 2015 01:50:00 +1100, Chris Angelico <rosuav at gmail.com>
> declaimed the following:
 >
>>Problem: You have a smartphone with a 4x4 pixel screen.
>
> 	BIG problem, considering that a late 70s DECWriter needed 5x7 pixels
> for glyphs in an 8x10 pixel character cell {as I recall...}

If those are 24-bit RGB pixels, you could encode
3 characters in each pixel.

You'd need eyes with rather good colour perception
to read it, though.

-- 
Greg


From rustompmody at gmail.com  Fri Jan 16 06:22:22 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 16 Jan 2015 03:22:22 -0800 (PST)
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <mailman.17777.1421372716.18130.python-list@python.org>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <mailman.17743.1421306724.18130.python-list@python.org>
 <54b77d4a$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17777.1421372716.18130.python-list@python.org>
Message-ID: <3d5ed0d2-d27d-4282-9581-64e1a33610bd@googlegroups.com>

On Friday, January 16, 2015 at 7:20:13 AM UTC+5:30, Andrew Robinson wrote:
<snipped 542 lines>

Disclaimers 
1. Ive not really read the above 542 lines and earlier
2. I am not a fan of OOP

Still some thoughts...

Electrical engineering (EE) and computer science (CS) may seem related
but are quite different disciplines. In fact there is some amount of
'client-supplier' in this relation - you folks make the machines we use.

Now one of the basic things that needs to be effected to make this transition
is the so-called digital abstraction

To start with we say (say) that 0V is 0-logic, 3.3V is 1-logic.
But that's hardly enough, we need margins, forbidden regions, Postel's law
etc.  This mapping is hardly straightforward. And that is still the
'static-discipline'.

When time comes in we need to deal with the fact that when a gate
switches it will willy-nilly go through the forbidden region.  From here
we have to go through/into clock disciplines, delay insensitie circuits etc.

Should CS-ists deal with all this??
If you say yes then what are you EE-guys doing?
If no then you are agreeing with all the others here.

In some more detail:
You seem to want a multi-valued logic. How many values?
There are quite a few answers:

- 4 -- {0,1,Z,X} - http://en.wikipedia.org/wiki/Four-valued_logic
- 9 -- above + weak drives http://en.wikipedia.org/wiki/IEEE_1164

And probably half a dozen others.

You say you REALLY NEED these in your work.
Yes, many people need many things, eg.

1. Mars orbiter was lost due to a mismatch of MKS and FPS systems
http://edition.cnn.com/TECH/space/9909/30/mars.metric.02/

Does that make a case for building in units into programming languages?

2. C.A.R Hoare said the invention of the null-pointer was a billion-dollar
mistake. Do C programmers agree with him?

3. He also considered exception handling as a terrible disaster since it
confuses flow of control.  Are python (or most modern language) users likely
to agree?

All these are instances of a basic principle that Niklaus Wirth enunciated:
The most important decision of a language designer are what to leave out
of the language.

Finally in python 3.4 onwards there are enums. You can do this

>>> from enum import IntEnum

>>> class Bool4(IntEnum):
...   F=0
...   T=1
...   Z=2
...   X=3


From marko at pacujo.net  Fri Jan 16 07:06:59 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Fri, 16 Jan 2015 14:06:59 +0200
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <54b7cd9f$0$13011$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmpxdXXCVRyg5cu60TJU4gkc9qmc-opm51d4AkdmNhiZmw@mail.gmail.com>
 <mailman.17774.1421369276.18130.python-list@python.org>
 <chsai9Fih3gU1@mid.individual.net>
Message-ID: <87lhl39bfg.fsf@elektro.pacujo.net>

Gregory Ewing <greg.ewing at canterbury.ac.nz>:

> Dennis Lee Bieber wrote:
>> On Fri, 16 Jan 2015 01:50:00 +1100, Chris Angelico <rosuav at gmail.com>
>> declaimed the following:
>>
>>>Problem: You have a smartphone with a 4x4 pixel screen.
>>
>> 	BIG problem, considering that a late 70s DECWriter needed 5x7
>> pixels for glyphs in an 8x10 pixel character cell {as I recall...}
>
> If those are 24-bit RGB pixels, you could encode
> 3 characters in each pixel.

Not since Python3. Characters are Unicode now so you'll need to dedicate
a pixel for each character.


Marko


From rosuav at gmail.com  Fri Jan 16 10:03:57 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 17 Jan 2015 02:03:57 +1100
Subject: How to "wow" someone new to Python
Message-ID: <CAPTjJmpTbbj=Dqc6PN-ec4n6-WdFjpSAzwawObSd3Dvwbkpi=A@mail.gmail.com>

Scenario: You're introducing someone to Python for the first time.
S/he may have some previous programming experience, or may be new to
the whole idea of giving a computer instructions. You have a couple of
minutes to show off how awesome Python is. What do you do?

I was thinking along the lines of a simple demo in the REPL, showing
off some of Python's coolest features. But then I got stuck on the
specifics. What are Python's best coolnesses? What makes for a good
demo?

Ideally, this should be something that can be demo'd quickly and
easily, and it should be impressive without going into great details
of "and see, this is how it works on the inside". So, how would you
brag about this language?

ChrisA


From skip.montanaro at gmail.com  Fri Jan 16 10:15:16 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Fri, 16 Jan 2015 09:15:16 -0600
Subject: How to "wow" someone new to Python
In-Reply-To: <CAPTjJmpTbbj=Dqc6PN-ec4n6-WdFjpSAzwawObSd3Dvwbkpi=A@mail.gmail.com>
References: <CAPTjJmpTbbj=Dqc6PN-ec4n6-WdFjpSAzwawObSd3Dvwbkpi=A@mail.gmail.com>
Message-ID: <CANc-5UzWFiFROjAE0-H=qKK1PApYXhUbLz==B0w_PV1vL5rBZw@mail.gmail.com>

If you want to show off the REPL, I'd got for iPython and show them some
simple matplotlib examples (plotting sin waves, maybe dig up a CSV file on
the net with some data your friend is familiar with, etc)

Skip


On Fri, Jan 16, 2015 at 9:03 AM, Chris Angelico <rosuav at gmail.com> wrote:

> Scenario: You're introducing someone to Python for the first time.
> S/he may have some previous programming experience, or may be new to
> the whole idea of giving a computer instructions. You have a couple of
> minutes to show off how awesome Python is. What do you do?
>
> I was thinking along the lines of a simple demo in the REPL, showing
> off some of Python's coolest features. But then I got stuck on the
> specifics. What are Python's best coolnesses? What makes for a good
> demo?
>
> Ideally, this should be something that can be demo'd quickly and
> easily, and it should be impressive without going into great details
> of "and see, this is how it works on the inside". So, how would you
> brag about this language?
>
> ChrisA
> --
> https://mail.python.org/mailman/listinfo/python-list
>
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From marko at pacujo.net  Fri Jan 16 10:20:14 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Fri, 16 Jan 2015 17:20:14 +0200
Subject: How to "wow" someone new to Python
References: <mailman.17792.1421420646.18130.python-list@python.org>
Message-ID: <87fvbaah1t.fsf@elektro.pacujo.net>

Chris Angelico <rosuav at gmail.com>:

> Scenario: You're introducing someone to Python for the first time.
> S/he may have some previous programming experience, or may be new to
> the whole idea of giving a computer instructions. You have a couple of
> minutes to show off how awesome Python is. What do you do?

My experience is that if you have your "customer" try their hand on
programming and complete a simple challenge, they'll be extremely
impressed. "Did I manage that?"

On the other hand, if you want to demo your greatest achievements at the
screen, they will be left unmoved. "Even my favorite Zynga game looks
cooler than that."

> I was thinking along the lines of a simple demo in the REPL, showing
> off some of Python's coolest features. But then I got stuck on the
> specifics. What are Python's best coolnesses? What makes for a good
> demo?

I would advise steering clear of the REPL and go directly to writing a
program and executing it. Maybe the classic ASCII graphics presentation
of the sine wave:

========================================================================
#!/usr/bin/env python3

import time
import math

def main():
    for angle in range(0, 100000, 5):
        print(int((1 + math.sin(math.radians(angle))) * 35) * "*")
        time.sleep(0.1)

if __name__ == "__main__":
    main()
========================================================================

> Ideally, this should be something that can be demo'd quickly and
> easily, and it should be impressive without going into great details
> of "and see, this is how it works on the inside". So, how would you
> brag about this language?

I'd recommend not skipping the traditional boilerplate (see my example).
Be professional from the start.


Marko


From aberg010 at my.hennepintech.edu  Fri Jan 16 10:24:07 2015
From: aberg010 at my.hennepintech.edu (Andrew Berg)
Date: Fri, 16 Jan 2015 09:24:07 -0600
Subject: How to "wow" someone new to Python
In-Reply-To: <CAPTjJmpTbbj=Dqc6PN-ec4n6-WdFjpSAzwawObSd3Dvwbkpi=A@mail.gmail.com>
References: <CAPTjJmpTbbj=Dqc6PN-ec4n6-WdFjpSAzwawObSd3Dvwbkpi=A@mail.gmail.com>
Message-ID: <54B92D17.6090007@my.hennepintech.edu>

On 2015.01.16 09:03, Chris Angelico wrote:
> Scenario: You're introducing someone to Python for the first time.
> S/he may have some previous programming experience, or may be new to
> the whole idea of giving a computer instructions. You have a couple of
> minutes to show off how awesome Python is. What do you do?
> 
> I was thinking along the lines of a simple demo in the REPL, showing
> off some of Python's coolest features. But then I got stuck on the
> specifics. What are Python's best coolnesses? What makes for a good
> demo?
> 
> Ideally, this should be something that can be demo'd quickly and
> easily, and it should be impressive without going into great details
> of "and see, this is how it works on the inside". So, how would you
> brag about this language?
If the person is already familiar with programming, you could show off how
Python doesn't do a best effort guess at what to do when you make a mistake
(explicit is better than implicit). Many other languages will, for example,
make an undefined variable into a variable defined as an empty string or allow
silly things like 5 + "cheese", whereas Python will let you know that you made
a mistake somewhere instead of letting garbage propagate. This behavior can be
frustrating for newbies to Python, but with someone there to explain why it
works that way, they can learn to appreciate it instead of giving up in anger
after Python keeps throwing exceptions at them.

If the person is not familiar with programming, show them how easy it is to get
something useful written quickly, even with only the stdlib. Low-level details
are handled so that you can focus on what you want the program to do, and there
is a ton of stuff in the stdlib so that it's likely you don't need to go
searching for a bunch of different libraries so that again, you can focus what
you want the program to do. For this, chances are, that person has some things
in mind already that are not difficult to get started with using Python. Also,
using the REPL for this makes it an even better demo. You can probably have the
basic functionality of whatever cool thing they want right there in the REPL.


From marco.buttu at gmail.com  Fri Jan 16 10:46:42 2015
From: marco.buttu at gmail.com (Marco Buttu)
Date: Fri, 16 Jan 2015 16:46:42 +0100
Subject: How to "wow" someone new to Python
In-Reply-To: <CAPTjJmpTbbj=Dqc6PN-ec4n6-WdFjpSAzwawObSd3Dvwbkpi=A@mail.gmail.com>
References: <CAPTjJmpTbbj=Dqc6PN-ec4n6-WdFjpSAzwawObSd3Dvwbkpi=A@mail.gmail.com>
Message-ID: <54B93262.7000802@oa-cagliari.inaf.it>

On 16/01/2015 16:03, Chris Angelico wrote:
> Scenario: You're introducing someone to Python for the first time.
> S/he may have some previous programming experience, or may be new to
> the whole idea of giving a computer instructions. You have a couple of
> minutes to show off how awesome Python is. What do you do?

The batteries included: some useful and simple examples with only core 
data type objects, built-in functions and standard library

-- 
Marco Buttu

INAF-Osservatorio Astronomico di Cagliari
Via della Scienza n. 5, 09047 Selargius (CA)
Phone: 070 711 80 217
Email: mbuttu at oa-cagliari.inaf.it



From torriem at gmail.com  Fri Jan 16 11:23:11 2015
From: torriem at gmail.com (Michael Torrie)
Date: Fri, 16 Jan 2015 09:23:11 -0700
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <CALwzidmr=rtSk_f_tX8gwQDhUtHyUCV0LKRWSRq6CafBpB0Vxw@mail.gmail.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <CAPTjJmqLq0S1+cGWp8evb_k9QaXVHQ91Hj=bdQnzSAzKLUmneQ@mail.gmail.com>
 <CALwzidmr=rtSk_f_tX8gwQDhUtHyUCV0LKRWSRq6CafBpB0Vxw@mail.gmail.com>
Message-ID: <54B93AEF.4080207@gmail.com>

On 01/15/2015 10:29 PM, Ian Kelly wrote:
> On Thu, Jan 15, 2015 at 9:00 PM, Chris Angelico <rosuav at gmail.com> wrote:
>> My first response was going to be "Well, you can always add another
>> layer of indirection to try to solve your problem", but then I went
>> and looked up builders on Wikipedia. Now I'm confused. What can you do
>> with a builder that you can't do with a constructor?
> 
> In Java you have to write a separate constructor for every conceivable
> combination of arguments. If there are a lot of optional arguments,
> that's an exponentially large number of constructors. The builder
> pattern provides a solution to that problem.
> 
> In Python you just have one initializer with defaults for the optional
> arguments, so it's not an issue.

Which seems to confirm my understanding that these patterns are in large
part a response to limitations in the language, which certainly doesn't
engender a fondness for the Java.



From python.list at tim.thechases.com  Fri Jan 16 11:39:28 2015
From: python.list at tim.thechases.com (Tim Chase)
Date: Fri, 16 Jan 2015 10:39:28 -0600
Subject: How to "wow" someone new to Python
In-Reply-To: <CAPTjJmpTbbj=Dqc6PN-ec4n6-WdFjpSAzwawObSd3Dvwbkpi=A@mail.gmail.com>
References: <CAPTjJmpTbbj=Dqc6PN-ec4n6-WdFjpSAzwawObSd3Dvwbkpi=A@mail.gmail.com>
Message-ID: <20150116103928.33d779b8@bigbox.christie.dr>

On 2015-01-17 02:03, Chris Angelico wrote:
> Ideally, this should be something that can be demo'd quickly and
> easily, and it should be impressive without going into great details
> of "and see, this is how it works on the inside". So, how would you
> brag about this language?

First, I agree with Andrew Berg's suggestion about the breadth of the
stdlib.  This always irks me when I have to return to the C/C++
world where there's no standard library for things like networking
(and thus no stock libraries for IMAP, SMTP, HTTP, FTP, etc or
email-message handling), CSV processing, regular expressions,
zip/tar/zlib files, SHA1/MD5, command-line option processing,
threading, and no available-everywhere GUI.  In the Java world, it
feels like much of this is available, but that the glommed-on
standards have multiple ways to do them (the old way(s) and the
new/improved way).  In PHP, well...that's just PHP (difficult-to-grok
equality testing, inconsistent naming conventions and parameter
ordering, lack of namespacing, easy-to-screw-up string interpolation,
hacky OOP, etc).

My fast-introduction go-to items are dir() and help() within the REPL
interface.  Nothing speeds up my development like being able to
drop to a PDB prompt and inspect an object, ask what properties it
supports, dump them, get help on them, etc.

There's also the bigint stuff that means I don't have to worry about
over/underflow errors.

I'm sure there are more great ideas, but how you market might depend
on your audience's background in programming (what language did they
use and what pain-points did they experience).

-tkc




From miragewebstudio12 at gmail.com  Fri Jan 16 12:01:13 2015
From: miragewebstudio12 at gmail.com (Mirage Web Studio)
Date: Fri, 16 Jan 2015 22:31:13 +0530
Subject: How to "wow" someone new to Python
In-Reply-To: <CAPTjJmpTbbj=Dqc6PN-ec4n6-WdFjpSAzwawObSd3Dvwbkpi=A@mail.gmail.com>
References: <CAPTjJmpTbbj=Dqc6PN-ec4n6-WdFjpSAzwawObSd3Dvwbkpi=A@mail.gmail.com>
Message-ID: <54B943D9.6020803@gmail.com>


On 01/16/2015 08:33 PM, Chris Angelico wrote:
> Scenario: You're introducing someone to Python for the first time.
> S/he may have some previous programming experience, or may be new to
> the whole idea of giving a computer instructions. You have a couple of
> minutes to show off how awesome Python is. What do you do?
>
> I was thinking along the lines of a simple demo in the REPL, showing
> off some of Python's coolest features. But then I got stuck on the
> specifics. What are Python's best coolnesses? What makes for a good
> demo?
>
> Ideally, this should be something that can be demo'd quickly and
> easily, and it should be impressive without going into great details
> of "and see, this is how it works on the inside". So, how would you
> brag about this language?
>
> ChrisA

hello,

I am a newbie to python, I have dwelled in c,qt none in java. php a lot,
though I don't make money with any of those.

The best thing I find is python is very easy, the best part maybe
because of my inexperience with other languages are the List and Dict
data types that just solved problems I had in real life made solvable
with python very easily. when I had to worry about memory and pointers
to memory in those other languages, python just made me focus on the
solution I want. also the way I can read python program just like they
are written in plain eglish :)

a personal problem I tried to solve is that how many characters  exist
in  a sequence statistically (with 2 or more characters in len)  in any
given file and then their count.  For a 100kb file I used practially all
programming knowledge in from the other languages but failed miserably
as the computation were taking more time with each bigger chunck of
file. I would have to do a lot of memery management with python using
those style like deleting list and dict before adding another. but when
I tried to solve the problem natively with python it just took a blink
of an eye for them to solve upto 50kb file. but for larger files
although instant it is just memory consuming since I was limit with 2 gb
I ddin't poke further.

this was my exp and I find programming fun in python like ironman
talking to jarvis

keep computing!!!

GCM


From rustompmody at gmail.com  Fri Jan 16 12:16:11 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 16 Jan 2015 09:16:11 -0800 (PST)
Subject: How to "wow" someone new to Python
In-Reply-To: <mailman.17792.1421420646.18130.python-list@python.org>
References: <mailman.17792.1421420646.18130.python-list@python.org>
Message-ID: <f45114df-4032-4ad2-b178-1eca33247529@googlegroups.com>

On Friday, January 16, 2015 at 8:34:20 PM UTC+5:30, Chris Angelico wrote:
> Scenario: You're introducing someone to Python for the first time.
> S/he may have some previous programming experience, or may be new to
> the whole idea of giving a computer instructions. You have a couple of
> minutes to show off how awesome Python is. What do you do?

There is this story -- maybe apocryphal -- that the tendency to vote
democratic or republican runs so deep it can be detected from 
genetic markers.

Similar things apply to programming:
Some people are drawn to a mathematical style; some are not
Some people love cute little scripts; some are left cold
Some love graphics; some dislike
etc etc
All corollary to:
Some people can think like programmers; most cant
[Who does the last quote? Steve Jobs?]

So to start with, you need to 'fingerprint' (is that the word?)
your subject.

> 
> I was thinking along the lines of a simple demo in the REPL, showing
> off some of Python's coolest features. But then I got stuck on the
> specifics. What are Python's best coolnesses? What makes for a good
> demo?

The reason I find the REPL particularly cool for such demos
[I am surprised that Marko doesn't]
is that at least to some extent you can straddle some of the
divides above.

How about a little web-scrape with beautiful-soup?
Followed by maybe a "throw the results into a csv-file
and open in the local spreadsheet"?



From rustompmody at gmail.com  Fri Jan 16 12:31:33 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 16 Jan 2015 09:31:33 -0800 (PST)
Subject: How to "wow" someone new to Python
In-Reply-To: <mailman.17797.1421428857.18130.python-list@python.org>
References: <CAPTjJmpTbbj=Dqc6PN-ec4n6-WdFjpSAzwawObSd3Dvwbkpi=A@mail.gmail.com>
 <mailman.17797.1421428857.18130.python-list@python.org>
Message-ID: <c2eb4253-e70d-487c-9cd2-701373925a8e@googlegroups.com>

On Friday, January 16, 2015 at 10:51:52 PM UTC+5:30, Mirage Web Studio wrote:
> On 01/16/2015 08:33 PM, Chris Angelico wrote:
> > Scenario: You're introducing someone to Python for the first time.
> > S/he may have some previous programming experience, or may be new to
> > the whole idea of giving a computer instructions. You have a couple of
> > minutes to show off how awesome Python is. What do you do?
> >
> > I was thinking along the lines of a simple demo in the REPL, showing
> > off some of Python's coolest features. But then I got stuck on the
> > specifics. What are Python's best coolnesses? What makes for a good
> > demo?
> >
> > Ideally, this should be something that can be demo'd quickly and
> > easily, and it should be impressive without going into great details
> > of "and see, this is how it works on the inside". So, how would you
> > brag about this language?
> >
> > ChrisA
> 
> hello,
> 
> I am a newbie to python, I have dwelled in c,qt none in java. php a lot,
> though I don't make money with any of those.
> 
> The best thing I find is python is very easy, the best part maybe
> because of my inexperience with other languages are the List and Dict
> data types that just solved problems I had in real life made solvable
> with python very easily. when I had to worry about memory and pointers
> to memory in those other languages, python just made me focus on the
> solution I want. 

Nice point!
First class concrete data structures is a blessing especially for
a C programmer.

Here is an old Guido workout of dicts
https://www.python.org/doc/essays/graphs/

Probably can be improved to use comprehensions


From fomcl at yahoo.com  Fri Jan 16 12:33:31 2015
From: fomcl at yahoo.com (Albert-Jan Roskam)
Date: Fri, 16 Jan 2015 09:33:31 -0800
Subject: How to "wow" someone new to Python
Message-ID: <1421429611.45989.BPMail_high_carrier@web163802.mail.gq1.yahoo.com>


----------------------------
On Fri, Jan 16, 2015 4:24 PM CET Andrew Berg wrote:

>On 2015.01.16 09:03, Chris Angelico wrote:
>> Scenario: You're introducing someone to Python for the first time.
>> S/he may have some previous programming experience, or may be new to
>> the whole idea of giving a computer instructions. You have a couple of
>> minutes to show off how awesome Python is. What do you do?
>> 
>> I was thinking along the lines of a simple demo in the REPL, showing
>> off some of Python's coolest features. But then I got stuck on the
>> specifics. What are Python's best coolnesses? What makes for a good
>> demo?
>> 
>> Ideally, this should be something that can be demo'd quickly and
>> easily, and it should be impressive without going into great details
>> of "and see, this is how it works on the inside". So, how would you
>> brag about this language?
>If the person is already familiar with programming, you could show off how
>Python doesn't do a best effort guess at what to do when you make a mistake
>(explicit is better than implicit). Many other languages will, for example,
>make an undefined variable into a variable defined as an empty string or allow
>silly things like 5 + "cheese", whereas Python will let you know that you made
>a mistake somewhere instead of letting garbage propagate. This behavior can be
>frustrating for newbies to Python, but with someone there to explain why it
>works that way, they can learn to appreciate it instead of giving up in anger
>after Python keeps throwing exceptions at them.
>
>If the person is not familiar with programming, show them how easy it is to get
>something useful written quickly, even with only the stdlib

Completely agree! Find out that person's itch and make a scratch.py that shows how problem-oriented the language is, with code that somewhat reads like regular English. REPL will also work, if you prepare it well enough. Ipython Notebook!


>Low-level details
>are handled so that you can focus on what you want the program to do, and there
>is a ton of stuff in the stdlib so that it's likely you don't need to go
>searching for a bunch of different libraries so that again, you can focus what
>you want the program to do. For this, chances are, that person has some things
>in mind already that are not difficult to get started with using Python. Also,
>using the REPL for this makes it an even better demo. You can probably have the
>basic functionality of whatever cool thing they want right there in the REPL.
>-- 
>https://mail.python.org/mailman/listinfo/python-list



From rosuav at gmail.com  Fri Jan 16 12:44:22 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 17 Jan 2015 04:44:22 +1100
Subject: How to "wow" someone new to Python
In-Reply-To: <c2eb4253-e70d-487c-9cd2-701373925a8e@googlegroups.com>
References: <CAPTjJmpTbbj=Dqc6PN-ec4n6-WdFjpSAzwawObSd3Dvwbkpi=A@mail.gmail.com>
 <mailman.17797.1421428857.18130.python-list@python.org>
 <c2eb4253-e70d-487c-9cd2-701373925a8e@googlegroups.com>
Message-ID: <CAPTjJmqPXHT8XELj62hkJjHUj60-Ttkf2Y=ut1HQQd_KA48zdA@mail.gmail.com>

On Sat, Jan 17, 2015 at 4:31 AM, Rustom Mody <rustompmody at gmail.com> wrote:
> Nice point!
> First class concrete data structures is a blessing especially for
> a C programmer.

Definitely! Worth noting.

There've been some nice concepts mentioned; concrete suggestions would
be good too. Some specific feature or exact line of code that would
show off Python's awesomeness.

ChrisA


From jtim.arnold at gmail.com  Fri Jan 16 12:49:18 2015
From: jtim.arnold at gmail.com (Tim)
Date: Fri, 16 Jan 2015 09:49:18 -0800 (PST)
Subject: recursive function: use a global or pass a parameter?
Message-ID: <5e4ccec6-7a00-467d-8cf6-258ab0421c90@googlegroups.com>

I have this type of situation and wonder if I should use a global variable outside the recursive function instead of passing the updated parameter through. 

I want to get a union of all the values that any 'things' key may have, even in a nested dictionary (and I do not know beforehand how deep the nesting might go):

d = {'things':1, 'two':{'things':2}}

def walk(obj, res):
    if not hasattr(obj, 'keys'):
        return set(), set()
    
    if 'things' in obj:
        res.add(obj['things'])
        
    for k in obj:
        walk(obj[k], res)
        
    return res

walk(d, set()) # returns {1, 2}

Is it better to use a global to keep track of the values or does it even matter?

thanks,
--Tim


From rosuav at gmail.com  Fri Jan 16 12:56:08 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 17 Jan 2015 04:56:08 +1100
Subject: recursive function: use a global or pass a parameter?
In-Reply-To: <5e4ccec6-7a00-467d-8cf6-258ab0421c90@googlegroups.com>
References: <5e4ccec6-7a00-467d-8cf6-258ab0421c90@googlegroups.com>
Message-ID: <CAPTjJmqrXSNZBUsCzVAB8Uc0YHx-=gP3fJ1nC+npcfHJ_JP8HA@mail.gmail.com>

On Sat, Jan 17, 2015 at 4:49 AM, Tim <jtim.arnold at gmail.com> wrote:
> I want to get a union of all the values that any 'things' key may have, even in a nested dictionary (and I do not know beforehand how deep the nesting might go):
>
> d = {'things':1, 'two':{'things':2}}
>
> def walk(obj, res):
>     if not hasattr(obj, 'keys'):
>         return set(), set()
>
>     if 'things' in obj:
>         res.add(obj['things'])
>
>     for k in obj:
>         walk(obj[k], res)
>
>     return res
>
> walk(d, set()) # returns {1, 2}
>
> Is it better to use a global to keep track of the values or does it even matter?

I would use a parameter rather than a global, but I'd make the
parameter optional:

def all_keys(obj, accum=None):
    if accum is None: accum=set()
    if 'things' in obj:
        res.add(obj['things'])
    for val in obj.values():
        all_keys(val, accum)
    return all_keys

ChrisA


From emile at fenx.com  Fri Jan 16 12:57:29 2015
From: emile at fenx.com (Emile van Sebille)
Date: Fri, 16 Jan 2015 09:57:29 -0800
Subject: How to "wow" someone new to Python
In-Reply-To: <CAPTjJmqPXHT8XELj62hkJjHUj60-Ttkf2Y=ut1HQQd_KA48zdA@mail.gmail.com>
References: <CAPTjJmpTbbj=Dqc6PN-ec4n6-WdFjpSAzwawObSd3Dvwbkpi=A@mail.gmail.com>
 <mailman.17797.1421428857.18130.python-list@python.org>
 <c2eb4253-e70d-487c-9cd2-701373925a8e@googlegroups.com>
 <CAPTjJmqPXHT8XELj62hkJjHUj60-Ttkf2Y=ut1HQQd_KA48zdA@mail.gmail.com>
Message-ID: <m9bjec$db4$1@ger.gmane.org>

On 1/16/2015 9:44 AM, Chris Angelico wrote:
<snip>
 > exact line of code that would
> show off Python's awesomeness.


a,b = b,a


Emile




From chaselton at gmail.com  Fri Jan 16 13:06:01 2015
From: chaselton at gmail.com (Cyd Haselton)
Date: Fri, 16 Jan 2015 12:06:01 -0600
Subject: Android Native Build Help: python build_ext
Message-ID: <CAHu5PrYnF45=awns1HL9yaZuZC+Vfbwj2emVjiqcMNP-EUTjvQ@mail.gmail.com>

I'm building python on my Android tablet and, while the executable and
library builds successfully, I run into a problem when the newly built
python runs build_ext; it builds the _struct module and then
immediately afterwards my build environment throws an 'undefined
reference to dlopen' error.

To figure out what is missing dlopen, I need to somehow figure out
what build_ext is trying to do.  I've tried running the command
manually with the --verbose option with no results.

Does build_ext build modules in a certain order?  If so, what is that order?


From rustompmody at gmail.com  Fri Jan 16 13:22:09 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 16 Jan 2015 10:22:09 -0800 (PST)
Subject: recursive function: use a global or pass a parameter?
In-Reply-To: <mailman.17800.1421430971.18130.python-list@python.org>
References: <5e4ccec6-7a00-467d-8cf6-258ab0421c90@googlegroups.com>
 <mailman.17800.1421430971.18130.python-list@python.org>
Message-ID: <1d553d12-a79d-4917-9494-577bd8391d41@googlegroups.com>

On Friday, January 16, 2015 at 11:26:46 PM UTC+5:30, Chris Angelico wrote:
> On Sat, Jan 17, 2015 at 4:49 AM, Tim  wrote:
> > I want to get a union of all the values that any 'things' key may have, even in a nested dictionary (and I do not know beforehand how deep the nesting might go):
> >
> > d = {'things':1, 'two':{'things':2}}
> >
> > def walk(obj, res):
> >     if not hasattr(obj, 'keys'):
> >         return set(), set()
> >
> >     if 'things' in obj:
> >         res.add(obj['things'])
> >
> >     for k in obj:
> >         walk(obj[k], res)
> >
> >     return res
> >
> > walk(d, set()) # returns {1, 2}
> >
> > Is it better to use a global to keep track of the values or does it even matter?
> 
> I would use a parameter rather than a global, but I'd make the
> parameter optional:
> 
> def all_keys(obj, accum=None):
>     if accum is None: accum=set()
>     if 'things' in obj:
>         res.add(obj['things'])
>     for val in obj.values():
>         all_keys(val, accum)
>     return all_keys
> 
> ChrisA

I dont like the hardwired this. However keeping that...

def all_keys(obj):
    if   not isinstance(obj, type({})): return set()

    return ((set([obj['things']]) if 'things' in obj else set())   |
               set(v for s in obj.values() for v in all_keys(s)))


From __peter__ at web.de  Fri Jan 16 13:34:23 2015
From: __peter__ at web.de (Peter Otten)
Date: Fri, 16 Jan 2015 19:34:23 +0100
Subject: recursive function: use a global or pass a parameter?
References: <5e4ccec6-7a00-467d-8cf6-258ab0421c90@googlegroups.com>
Message-ID: <m9bljj$i9f$1@ger.gmane.org>

Tim wrote:

> I have this type of situation and wonder if I should use a global variable
> outside the recursive function instead of passing the updated parameter
> through.
> 
> I want to get a union of all the values that any 'things' key may have,
> even in a nested dictionary (and I do not know beforehand how deep the
> nesting might go):
> 
> d = {'things':1, 'two':{'things':2}}
> 
> def walk(obj, res):
>     if not hasattr(obj, 'keys'):
>         return set(), set()
>     
>     if 'things' in obj:
>         res.add(obj['things'])
>         
>     for k in obj:
>         walk(obj[k], res)
>         
>     return res
> 
> walk(d, set()) # returns {1, 2}
> 
> Is it better to use a global to keep track of the values or does it even
> matter?

Globals are generally bad as they make code non-reentrant; when two calls of 
the function run simultaneously the data will be messed up.

I recommend that you use a generator:

>>> def walk(obj):
...     if not hasattr(obj, "keys"):
...         return
...     if "things" in obj:
...         yield obj["things"]
...     for v in obj.values():
...         yield from walk(v)
... 
>>> d = {'things':1, 'two':{'things':2}}
>>> set(walk(d))
{1, 2}

In Python before 3.3 you have to replace

yield from walk(v)

with a loop:

for t in walk(v):
    yield t



From jtim.arnold at gmail.com  Fri Jan 16 13:48:41 2015
From: jtim.arnold at gmail.com (Tim)
Date: Fri, 16 Jan 2015 10:48:41 -0800 (PST)
Subject: recursive function: use a global or pass a parameter?
In-Reply-To: <mailman.17804.1421433277.18130.python-list@python.org>
References: <5e4ccec6-7a00-467d-8cf6-258ab0421c90@googlegroups.com>
 <mailman.17804.1421433277.18130.python-list@python.org>
Message-ID: <50dd6ef1-b52b-4516-ad15-9b866ca25fd7@googlegroups.com>

On Friday, January 16, 2015 at 1:34:51 PM UTC-5, Peter Otten wrote:
>> Tim wrote:
>> 
> Globals are generally bad as they make code non-reentrant; when two calls of 
> the function run simultaneously the data will be messed up.
> 
> I recommend that you use a generator:
> 
> >>> def walk(obj):
> ...     if not hasattr(obj, "keys"):
> ...         return
> ...     if "things" in obj:
> ...         yield obj["things"]
> ...     for v in obj.values():
> ...         yield from walk(v)
> ... 
> >>> d = {'things':1, 'two':{'things':2}}
> >>> set(walk(d))
> {1, 2}
> 
> In Python before 3.3 you have to replace
> 
> yield from walk(v)
> 
> with a loop:
> 
> for t in walk(v):
>     yield t

Ah, a generator, I wouldn't have seen the problem in this way, but with your example, it looks so natural.

thanks,
--Tim


From pcmanticore at gmail.com  Fri Jan 16 15:22:42 2015
From: pcmanticore at gmail.com (Claudiu Popa)
Date: Fri, 16 Jan 2015 22:22:42 +0200
Subject: [ANN] Pylint 1.4.1 / Astroid 1.3.3 released
Message-ID: <CAMy=CLpPNxJMgGmJ011PLq36Jn+B6MGwHRoDpx9FNX++mhcsnw@mail.gmail.com>

Hello,


It's my pleasure to announce the release of both Pylint 1.4.1 and
Astroid 1.3.3 respectively.

The following bug fixes and features made their way into Astroid 1.3.3:

    * Restore file_stream to a property, but deprecate it in favour of
      the newly added method Module.stream.

    * Add inference tips for 'tuple', 'list', 'dict' and 'set' builtins.

    * Add brain definition for most string and unicode methods

    * Add a new method to Class nodes, 'mro', for obtaining the
      the method resolution order of the class.

    * Add brain tips for six.moves. Closes issue #63.

    * .slots() can contain unicode strings on Python 2.

    * Add inference tips for nose.tools.

The complete list of changes can be seen here:
https://bitbucket.org/logilab/astroid/src/15cff6016b793bb64c92d04acc4da001a2c98683/ChangeLog?at=default#cl-4


For Pylint, we have the following fixes and features:

    * Add a new JSON reporter, usable through -f flag.

    * Add a new warning, 'redundant-unittest-assert', emitted when using
      unittest's methods assertTrue and assertFalse with constant value
      as argument.

    * Check the return of properties when checking for not-callable.
      Closes issue #406.

    * Warn about using the input() or round() built-ins for Python 3.
      Closes issue #411.

    * Use a mro traversal for finding abstract methods. Closes issue #415.

    * Fix a false positive on Python 2 for raising-bad-type, when
      raising tuples in the form 'raise (ZeroDivisionError, None)'.

    * Fix a false positive with invalid-slots-objects, where the slot entry
      was an unicode string on Python 2. Closes issue #421.

The complete list of changes can be found here:
https://bitbucket.org/logilab/pylint/src/02eabae6b72569876e7104db7724ad26a7de0af3/ChangeLog?at=default#cl-4


If you find any bugs, don't hesitate to open a new issue on our issue
tracker (https://bitbucket.org/logilab/pylint/)


Enjoy!


From greg.ewing at canterbury.ac.nz  Fri Jan 16 16:24:33 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sat, 17 Jan 2015 10:24:33 +1300
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <87lhl39bfg.fsf@elektro.pacujo.net>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>	<roy-4AAFA6.08034915012015@news.panix.com>	<mailman.17759.1421327478.18130.python-list@python.org>	<87zj9kb2j0.fsf@elektro.pacujo.net>	<54b7cd9f$0$13011$c3e8da3$5496439d@news.astraweb.com>	<CAPTjJmpxdXXCVRyg5cu60TJU4gkc9qmc-opm51d4AkdmNhiZmw@mail.gmail.com>	<mailman.17774.1421369276.18130.python-list@python.org>	<chsai9Fih3gU1@mid.individual.net>
 <87lhl39bfg.fsf@elektro.pacujo.net>
Message-ID: <chtdshF3h6cU1@mid.individual.net>

Marko Rauhamaa wrote:
> Gregory Ewing <greg.ewing at canterbury.ac.nz>:
> 
>>If those are 24-bit RGB pixels, you could encode
>>3 characters in each pixel.
> 
> Not since Python3. Characters are Unicode now so you'll need to dedicate
> a pixel for each character.

Depends on which characters you want. With the
Flexible Chromatic Representation, it could be
anything from 1 to 3.

-- 
Greg


From greg.ewing at canterbury.ac.nz  Fri Jan 16 16:25:37 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sat, 17 Jan 2015 10:25:37 +1300
Subject: Factories and Builders [was Re: lambdak...]
In-Reply-To: <54b89cc7$0$12975$c3e8da3$5496439d@news.astraweb.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com>
 <54b89cc7$0$12975$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <chtduhF3h6cU2@mid.individual.net>

Steven D'Aprano wrote:
> I've never really understand why "abstract factory", "factory method"
> and "builder" are considered different design patterns. They're variants on
> the same idea.

I think it's because they address different problems. Factories
are for hiding the details of how an object is constructed.
Builders are for working around the fact that there are no
keyword arguments in your language.

Builders are sometimes also used for algorithmic reasons;
e.g. Java's StringBuilder exists to save you from O(n**2)
behaviour when creating a string from many small parts.

Factories of various kinds can be useful in Python;
builders, not so much.

-- 
Greg


From greg.ewing at canterbury.ac.nz  Fri Jan 16 16:29:47 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sat, 17 Jan 2015 10:29:47 +1300
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <mailman.17783.1421380815.18130.python-list@python.org>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
Message-ID: <chte6eF3ke9U1@mid.individual.net>

Chris Angelico wrote:
> Is this to get
> around style guides that reject this kind of model:
> 
> x = Foo(
>     opt1=True,
>     opt2=True,
>     color=Yellow,
> )

It's to get around the fact that you *can't* do that in
Java, because it doesn't have keyword arguments.

This is a source of a lot of the complexity and boilerplate
found in Java code -- the need to work around deficencies
in the language.

> But if you can
> pass a mapping object to the constructor, you can do the same job that
> way,

Yes, but constructing the mapping object is just as
tedious. :-(

> you could pass an array of
> item,value,item,value,item,value or something.

That's certainly possible, but then you have to write
tedious code in the constructor to parse the arguments,
you lose compile-time type safety, incur runtime
overhead, etc.

We're really quite spoiled in Python-land. It's easy
to forget just *how* spoiled we are until you go back
and try to do something in one of the more primitive
languages...

-- 
Greg


From greg.ewing at canterbury.ac.nz  Fri Jan 16 17:20:57 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sat, 17 Jan 2015 11:20:57 +1300
Subject: recursive function: use a global or pass a parameter?
In-Reply-To: <5e4ccec6-7a00-467d-8cf6-258ab0421c90@googlegroups.com>
References: <5e4ccec6-7a00-467d-8cf6-258ab0421c90@googlegroups.com>
Message-ID: <chth6bF4cv1U1@mid.individual.net>

Tim wrote:
> I have this type of situation and wonder if I should use a global variable
> outside the recursive function instead of passing the updated parameter
> through.

No! Globals are evil, at least for that sort of thing.
The way you're doing it is fine.

The only thing I would change is to wrap it all up
in a top-level function that takes care of creating
the result set and returning it.

def walk(obj):
   res = set()
   _walk(obj, res)
   return res

def _walk(obj, res):
   ...

-- 
Greg


From rosuav at gmail.com  Fri Jan 16 18:49:41 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 17 Jan 2015 10:49:41 +1100
Subject: recursive function: use a global or pass a parameter?
In-Reply-To: <chth6bF4cv1U1@mid.individual.net>
References: <5e4ccec6-7a00-467d-8cf6-258ab0421c90@googlegroups.com>
 <chth6bF4cv1U1@mid.individual.net>
Message-ID: <CAPTjJmqJEuuQCf6txjvw4s_W6SztUJev+DUKyAswzTM0UCfzLg@mail.gmail.com>

On Sat, Jan 17, 2015 at 9:20 AM, Gregory Ewing
<greg.ewing at canterbury.ac.nz> wrote:
> The only thing I would change is to wrap it all up
> in a top-level function that takes care of creating
> the result set and returning it.
>
> def walk(obj):
>   res = set()
>   _walk(obj, res)
>   return res
>
> def _walk(obj, res):
>   ...

Point of style: I like to put these kinds of helpers _above_ the
corresponding public functions, to maintain a general policy of
Define-Before-Use. Tends to make code easier to read; the first
reference to a function name is its definition, then all usage comes
after that. It's not always possible, of course (eg mutual recursion),
but in simple cases like this, it's easy enough.

ChrisA


From yawar.amin at gmail.com  Fri Jan 16 21:23:53 2015
From: yawar.amin at gmail.com (Yawar Amin)
Date: Fri, 16 Jan 2015 18:23:53 -0800 (PST)
Subject: recursive function: use a global or pass a parameter?
In-Reply-To: <mailman.17804.1421433277.18130.python-list@python.org>
References: <5e4ccec6-7a00-467d-8cf6-258ab0421c90@googlegroups.com>
 <mailman.17804.1421433277.18130.python-list@python.org>
Message-ID: <e8cf4ecf-90f0-430d-843c-d6f3ec3b3aef@googlegroups.com>

On Friday, January 16, 2015 at 1:34:51 PM UTC-5, Peter Otten wrote:
> [...]
> I recommend that you use a generator:
> 
> >>> def walk(obj):
> ...     if not hasattr(obj, "keys"):
> ...         return
> ...     if "things" in obj:
> ...         yield obj["things"]
> ...     for v in obj.values():
> ...         yield from walk(v)

Cool ... but it looks like this can still potentially hit the max
recursion limit? Perhaps better to convert to an iterative style:

    def walk(obj):
      """
      Yield any value(s) contained within `obj` that is (are) indexed by
      the key 'things'. `obj` must be dict-like.
      """
      from collections import deque
      vals = deque()
      vals.append(obj)
    
      while True:
        try: curr_obj = vals.popleft()
        except IndexError: return
        if not hasattr(curr_obj, "keys"): continue
    
        if "things" in curr_obj: yield curr_obj["things"]
        vals.extend(curr_obj.values())
    
    # Examples

    d1 = list(walk({ "things": 1, "two": { "things": 2 } }))
    
    d2 = list(walk({
      "things": 1,
      "two": { "things": 2 },
      "three":
        { "four": 4,
          "things":
            { "five": 5,
              "six": 6,
              "things":
                { "seven": 7,
                  "things": 8 } } } }))

So this effectively 'flattens' a dictionary at each level into a queue
made up of the dictionary's values, and meanwhile yields the values one
by one if they are indexed by the key 'things'.

The output for `d1` should be the same as Peter Otten's example, except
I'm using a list instead of a set because I think the yielded objects
could themselves be dictionaries or other non-hashable values.

When you're looking at the output for `d2`, remember that `walk` here
will yield _any_ object that's indexed by the key, and as I mentioned,
that could be an entire dictionary object contained within the main one.

Regards,

Yawar


From nigritudeflogger at gmail.com  Fri Jan 16 22:35:37 2015
From: nigritudeflogger at gmail.com (Hektor black)
Date: Fri, 16 Jan 2015 19:35:37 -0800 (PST)
Subject: pyqtdeploy on windows
Message-ID: <c4bee587-5648-461f-b042-9934470a4e7a@googlegroups.com>


hi
i have a code with pyqt4 and i want run in android with this tutorial
http://pyqt.sourceforge.net/Docs/pyqtdeploy/command_line.html
my project include of : m.py m.pyw m.ui
when run pyqtdeploy myproject.pdy in cmd get error
installing py 3.4.2 pyqt5 for pyqtdeploy
any one know good tutorial for this module

tnx


From yawar.amin at gmail.com  Sat Jan 17 00:29:21 2015
From: yawar.amin at gmail.com (Yawar Amin)
Date: Fri, 16 Jan 2015 21:29:21 -0800 (PST)
Subject: recursive function: use a global or pass a parameter?
In-Reply-To: <e8cf4ecf-90f0-430d-843c-d6f3ec3b3aef@googlegroups.com>
References: <5e4ccec6-7a00-467d-8cf6-258ab0421c90@googlegroups.com>
 <mailman.17804.1421433277.18130.python-list@python.org>
 <e8cf4ecf-90f0-430d-843c-d6f3ec3b3aef@googlegroups.com>
Message-ID: <36e4ce9f-348a-44a3-99c0-e3efd903bd74@googlegroups.com>

On Friday, January 16, 2015 at 9:24:15 PM UTC-5, Yawar Amin wrote:
> [...]
>         vals.extend(curr_obj.values())

Ah, I should mention that the above will do a breadth-first search. If
we want to do a depth-first search we simply replace the above line
with:

    vals.extendleft(curr_obj.values())

Regards,

Yawar


From steve+comp.lang.python at pearwood.info  Sat Jan 17 05:15:47 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 17 Jan 2015 21:15:47 +1100
Subject: recursive function: use a global or pass a parameter?
References: <5e4ccec6-7a00-467d-8cf6-258ab0421c90@googlegroups.com>
Message-ID: <54ba3654$0$13008$c3e8da3$5496439d@news.astraweb.com>

Tim wrote:

> I have this type of situation and wonder if I should use a global variable
> outside the recursive function instead of passing the updated parameter
> through.

To a first approximation, the answer to:

"I have a X, should I use a global variable or a parameter?"

is *always* "use a parameter", no matter what X is.

To a second and third approximation, the answer is still "use a parameter".

Good reasons for using global variables are few and far between. Just about
the only good reason for using global variables that I can think of is if
you have one or more settings/preference that get set once at the start of
the program and then apply to the entire program.

Actually, there is one other reason... if your program is a simple script
written in imperative style:

name = "steve"
print "Hello", name
do_this()
do_that()
do_something_else()
print "Good bye", name


sort of thing.



-- 
Steven



From steve+comp.lang.python at pearwood.info  Sat Jan 17 05:30:55 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 17 Jan 2015 21:30:55 +1100
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
Message-ID: <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>

Gregory Ewing wrote:

> We're really quite spoiled in Python-land. It's easy
> to forget just how spoiled we are until you go back
> and try to do something in one of the more primitive
> languages...

Every time I think I would like to learn a new language, I quite quickly run
into some obvious feature that Python has but the newer language lacks, and
I think "bugger this for a game of soldiers" and abandon it. E.g. Ruby and
the lack of keyword arguments. Oh, I see Ruby 2.0 added them to the
language! Perhaps it's time for me to give Ruby a go again?

Ah, wait, I forgot Ruby's brilliant "feature" that whitespace *between*
expressions is significant:

[steve at ando ~]$ cat ~/coding/ruby/ws-example.rb
#!/usr/bin/ruby

def a(x=4)
    x+2
end

b = 1
print "a + b => ", (a + b), "\n"
print "a+b   => ", (a+b), "\n"
print "a+ b  => ", (a+ b), "\n"
print "a +b  => ", (a +b), "\n"

[steve at ando ~]$ ruby ~/coding/ruby/ws-example.rb
a + b => 7
a+b   => 7
a+ b  => 7
a +b  => 3


A shiny new penny for any non-Ruby coder who can explain that!



-- 
Steven



From steve+comp.lang.python at pearwood.info  Sat Jan 17 05:33:19 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 17 Jan 2015 21:33:19 +1100
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>	<roy-4AAFA6.08034915012015@news.panix.com>	<mailman.17759.1421327478.18130.python-list@python.org>	<87zj9kb2j0.fsf@elektro.pacujo.net>	<54b7cd9f$0$13011$c3e8da3$5496439d@news.astraweb.com>	<CAPTjJmpxdXXCVRyg5cu60TJU4gkc9qmc-opm51d4AkdmNhiZmw@mail.gmail.com>	<mailman.17774.1421369276.18130.python-list@python.org>	<chsai9Fih3gU1@mid.individual.net>
 <87lhl39bfg.fsf@elektro.pacujo.net> <chtdshF3h6cU1@mid.individual.net>
Message-ID: <54ba3a70$0$13008$c3e8da3$5496439d@news.astraweb.com>

Gregory Ewing wrote:

> Marko Rauhamaa wrote:
>> Gregory Ewing <greg.ewing at canterbury.ac.nz>:
>> 
>>>If those are 24-bit RGB pixels, you could encode
>>>3 characters in each pixel.
>> 
>> Not since Python3. Characters are Unicode now so you'll need to dedicate
>> a pixel for each character.
> 
> Depends on which characters you want. With the
> Flexible Chromatic Representation, it could be
> anything from 1 to 3.

Subpixel rendering is 5% slower than full pixel rendering, so it is provably
mathematically impossible to print Unicode characters.


-- 
Steven



From jpiitula at ling.helsinki.fi  Sat Jan 17 05:49:50 2015
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 17 Jan 2015 12:49:50 +0200
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi>

Steven D'Aprano writes:

> Ah, wait, I forgot Ruby's brilliant "feature" that whitespace
> *between* expressions is significant:
> 
> [steve at ando ~]$ cat ~/coding/ruby/ws-example.rb
> #!/usr/bin/ruby
> 
> def a(x=4)
>     x+2
> end
> 
> b = 1
> print "a + b => ", (a + b), "\n"
> print "a+b   => ", (a+b), "\n"
> print "a+ b  => ", (a+ b), "\n"
> print "a +b  => ", (a +b), "\n"
> 
> [steve at ando ~]$ ruby ~/coding/ruby/ws-example.rb
> a + b => 7
> a+b   => 7
> a+ b  => 7
> a +b  => 3
> 
> 
> A shiny new penny for any non-Ruby coder who can explain that!

I've only seen small amounts of Ruby code on the net. The only way I
can make some sense of that is if it gets analyzed as follows, using
parentheses for calls:

 a + b => 7  # a() + b => a(4) + b => 4 + 2 + 1
 a+b   => 7  # a() + b
 a+ b  => 7  # a() + b
 a +b  => 3  # a(+b)   => a(b) => a(1) = 1 + 2

I'm not quite fond of such surprise in programming language syntax.


From marko at pacujo.net  Sat Jan 17 06:07:45 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sat, 17 Jan 2015 13:07:45 +0200
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com>
 <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi>
Message-ID: <87a91hoebi.fsf@elektro.pacujo.net>

Jussi Piitulainen <jpiitula at ling.helsinki.fi>:

>  a+ b  => 7  # a() + b
>  a +b  => 3  # a(+b)   => a(b) => a(1) = 1 + 2
>
> I'm not quite fond of such surprise in programming language syntax.

Yes, whoever came up with the idea of whitespace having syntactic
significance!


Marko


From mal at europython.eu  Sat Jan 17 06:21:57 2015
From: mal at europython.eu (M.-A. Lemburg)
Date: Sat, 17 Jan 2015 12:21:57 +0100
Subject: EuroPython 2015: Landing in Bilbao
Message-ID: <54BA45D5.6090904@europython.eu>

After a creative and inspiring Friday afternoon, we are pleased to
announce our EuroPython 2015 landing page:

                      http://ep2015.europython.eu/

This will be the URL for EuroPython 2015 - definitely worth a
bookmark, we think :-)

Enjoy,
-?
EuroPython Society (EPS)
http://www.europython-society.org/


From jpiitula at ling.helsinki.fi  Sat Jan 17 06:59:33 2015
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 17 Jan 2015 13:59:33 +0200
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi> <87a91hoebi.fsf@elektro.pacujo.net>
Message-ID: <qotppad39ei.fsf@ruuvi.it.helsinki.fi>

Marko Rauhamaa writes:
> Jussi Piitulainen:
> 
> >  a+ b  => 7  # a() + b
> >  a +b  => 3  # a(+b)   => a(b) => a(1) = 1 + 2
> >
> > I'm not quite fond of such surprise in programming language
> > syntax.
> 
> Yes, whoever came up with the idea of whitespace having syntactic
> significance!

How far do you want to go? Is "a  b + c" the same as "a(b) + c" or the
same as "a(b + c)"?

There's meant to be two spaces between "a" and "b" but I lost one of
them, twice, to my M-q reflex when writing the above paragraph. They
may or may not be there as I send this.

And I don't really want to know which it is. I prefer parentheses.
They are not nearly as fragile.


From marko at pacujo.net  Sat Jan 17 07:15:28 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sat, 17 Jan 2015 14:15:28 +0200
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com>
 <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi>
 <87a91hoebi.fsf@elektro.pacujo.net>
 <qotppad39ei.fsf@ruuvi.it.helsinki.fi>
Message-ID: <87twzpmwm7.fsf@elektro.pacujo.net>

Jussi Piitulainen <jpiitula at ling.helsinki.fi>:

> Marko Rauhamaa writes:
>> Yes, whoever came up with the idea of whitespace having syntactic
>> significance!
>
> How far do you want to go? [...]
>
> I prefer parentheses. They are not nearly as fragile.

*cough* braces *cough*

Seriously, though, I hate the optional semicolon rules of JavaScript and
Go. I dread the day when GvR gets it in his head to allow this syntax in
Python:

   average_drop_rate = cumulative_drop_count /
       observation_period

(although, it could be defined Pythonesquely thus: "a spurious
indentation means line continuation" ? no more backslashes).


Marko


From skip.montanaro at gmail.com  Sat Jan 17 07:19:36 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Sat, 17 Jan 2015 06:19:36 -0600
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <qotppad39ei.fsf@ruuvi.it.helsinki.fi>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com>
 <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi>
 <87a91hoebi.fsf@elektro.pacujo.net>
 <qotppad39ei.fsf@ruuvi.it.helsinki.fi>
Message-ID: <CANc-5UzFgKOc11y+uHNMdBjSPdNoHWUTZPdAc88u4skkxqz8uQ@mail.gmail.com>

On Sat, Jan 17, 2015 at 5:59 AM, Jussi Piitulainen
<jpiitula at ling.helsinki.fi> wrote:
> How far do you want to go? Is "a  b + c" the same as "a(b) + c" or the
> same as "a(b + c)"?

I think there is only one practical interpretation, the one that all
shells I'm familiar with have adopted:

    a(b, +, c)

> And I don't really want to know which it is. I prefer parentheses.
> They are not nearly as fragile.

Agreed. Without parens, splitting the command line arguments on white
space is the only non-fragile way to do things.

Skip


From steve+comp.lang.python at pearwood.info  Sat Jan 17 07:27:20 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 17 Jan 2015 23:27:20 +1100
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <mailman.17743.1421306724.18130.python-list@python.org>
 <54b77d4a$0$2738$c3e8da3$76491128@news.astraweb.com>
 <mailman.17777.1421372716.18130.python-list@python.org>
Message-ID: <54ba552a$0$13007$c3e8da3$5496439d@news.astraweb.com>

Andrew, sorry for the delay in responding. Your response has been extremely
long, so for the interest of brevity I've tried to trim things down to the
most pertinent points.

Andrew Robinson wrote:

[...]
> So -- From my perspective, Guido making Python go from an open ended and
> permissive use of anything goes as a return value that can handle
> metastable states

That absolutely has not changed. You seem to be mixing the concept of
*subclassing* with the concept of being able to handle multi-state
(metastable) logic. You can certainly write multi-state logic in Python.
 

> -- into to a historical version of 'logic' being 
> having *only* two values in a very puritanical sense, is rather -- well
> -- disappointing.  It makes me wonder -- what hit the fan?!  Is it
> lemmings syndrome ? a fight ? no idea....  and is there any hope of
> recovery or a work around ?

Do you have much programming experience outside of the niche of modelling
electronic hardware?

I can tell you that it is standard for general purpose programming languages
to be restricted to two-state (Boolean) comparisons. The basic decision
construct is "if...else", which is based on two states.

The only exception that I know of is the very early, and long deprecated,
Fortran "Arithmetic IF" statement:

    IF (e) label1, label2, label3

which did a three-way jump depending on whether e was less than zero, equal
to zero, or greater than zero. Some assemblers also included three-way
jumps.

All forms of N-valued logic can be reduced to Boolean logic with appropriate
comparisons. Instead of trying to come up with syntax for a three-way
branch:

if flag: print True
else: print False
otherwise: print Indeterminate

and four-way branches, a five-way branches, ... ad infinitum, it is easier
to leave it up to the programmer to build N-way logic on top of 2-way
True/False comparisons:

# equality here returns True or False
if flag == True: print True
else:
    if flag == False: print False
    else: print Indeterminate


Some programming languages add syntax to make this more friendly:

if flag == True: print True
elif flag == False: print False
else: print Indeterminate

or even:

case flag of:
    True: ...
    False: ...
    Indeterminate: ...
    Maybe: ...
    Uncertain: ...
    Could_Be: ...

(for languages with a case or switch statement).

Not only can all N-way logics be mathematically generated from Boolean
algebra, but I'll go further and say that *almost certainly* the hardware
simulation languages you are used to with 3-way or 4-way logic use 2-way
Boolean logic under the hood.

The point of this is that you need not think of Guido "taking away"
anything. It is normal for programming languages to use Boolean
comparisons.

But in fact Python is *less* restrictive than many other languages. In
Pascal, for instance, comparisons like <= or > etc. can only return true or
false, while Python allows them to return anything.


> eg: To me -- (as an engineer) undefined *IS* equivalent in useage to an
> acutal logic value, just as infinity is a floating point value that is
> returned as a 'float'.  You COULD/CAN separate the two values from each
> other -- but always with penalties.  They generally share an OOP 'is'
> relationship with respect to how and when they are used. (inf) 'IS' a
> float value and -- uncertain -- 'IS' a logic value.

That's fine, we have no dispute with the need for multi-state logics. But
*which* multi-state logic? There are *at least* three useful ternary
logics: Kleene logic, ?ukasiewicz logic, Bochvar logic. And then there is
Belnap's four-valued relevance logic (True, False, Both True and False,
Neither True nor False), and an infinite number of other possible logics.
Which should the programming language support?

In a sense, any Turing Complete programming language supports *all of them*.
All you need to do is program the details yourself. But in the sense of
which multi-state logic should the language itself include, I think that
the answer is ... none of them. Most programming languages have no need to
include this complexity, just as most languages don't include tensors as a
language primitive.

I guess this is just a long-winded way of me saying that HDLs are
effectively a "Domain Specific Language" for hardware, and can *and should*
contain specialist semantics needed by hardware designers, e.g. 4-way
logic. But Python is a general purpose language, and while you *can*
program your own domain specific features, you have to do so within the
constraints of the needs of a general-purpose language. In Python's case,
those constraints are actually remarkably loose (not as loose as languages
like Lisp or Forth, where you can literally redesign the interpreter on the
fly!) but they do exist.

[...]
> So -- let's look at the examples you gave:
> 
>> - don't use True and False at all, create your own multi-valued
>>    truth values ReallyTrue, MaybeTrue, SittingOnTheFence, ProbablyFalse,
>>    CertainlyFalse (or whatever names you choose to give them);
>>
> OK.  So -- what do I think about when I see your suggestion:
> 
> First I need to note where my booleans come from -- although I've never
> called it multi-valued logic... so jargon drift is an issue... though
> you're not wrong, please note the idea of muti-value is mildly misleading.

I accept that jargon is an issue, but I believe that "N-way logic"
and "multi-value logic" is, if not standard, at least something that we can
agree to use. The use of "boolean" to describe anything with more than two
states is just weird.

I don't understand what you mean by "note where my booleans come from".



> The return values I'm concerned about come from a decimal value after a
> comparison with another decimal value.
> eg:
> 
> a = magicFloat( '2.15623423423(1)' )
> b = magicFloat('3()')
> 
> myTruthObject = a>b
> 
> Then I look at python development historically and look at the built in
> class's return values for compares; and I notice; they have over time
> become more and more tied to the 'type' bool.  I expect sometime in the
> future that python may implement an actual type check on all comparison
> operators so they can not be used to return anything but a bool.

That will never happen. Comparison operators are explicitly documented as
being allowed to return anything that you wish. Changing that will break so
much code, including important, high-profile libraries like numpy, that it
is never going to occur even if somebody wanted it to.


> (eg: 
> I already noticed a type check on the return value of len() so that I
> can't return infinity, even when a method clearly is returning an
> infinitely long iterator

Yes, that's a known issue, and you're not the first to notice it. That's
partly due to history, and partly to disagreements about API design.


> Next, I notice that for compatibility it *is* very desirable that I use
> the existing '>' operator,  because programmers generally want to be
> able to use '>' when they are testing greater than -- and in legacy code
> I expect people have exclusively done so -- and I know from past
> experience that programmers in general will not be happy with typing
> 'a.greaterThan(b)' religiously. ( Extend my reasoning to all other
> comparison operators.)

Don't worry, customising comparison operators for your own classes is fully
supported.


[...]
> So:  In general, the most desirable return type is determined by what
> python actually returns for normal comparison operations; eg: apparently
> a bool -- but with some way of signaling (if the user cares) that more
> precise information is available as to why a value is False if it is
> False.

Forget the "apparently a bool" part. Comparison operators can return
anything you like. If you have a good reason to return a bool, feel free,
but you are not required too.

You could, should you so choose, implement a complete fuzzy logic system:

py> class C(object):
...     def __eq__(self, other):
...             return 0.5
...
py> c = C()
py> c == 23
0.5

Although you cannot attach extra information to built-in floats like 0.5,
you can certainly create your own classes and attach extra information to
their instances.



> Unfortunately, the '>', '<', '==', and other operators have no way of
> returning additional information on their own; 

They can return any value you like. Perhaps the biggest, most important
third-party library in the Python ecosystem uses this extensively:


py> import numpy
py> a = numpy.array([1, 2, 3, 4, 5, 6])
py> b = numpy.array([2, 1, 3, 6, 5, 4])
py> a < b
array([ True, False, False,  True, False, False], dtype=bool)
py> a == b
array([False, False,  True, False,  True, False], dtype=bool)

If numpy can return an array, you can return a MaybeTrue or ProbablyFalse
object, with whatever diagnostic information you require.

(You will also note that numpy arrays don't inherit from bool.)


> So, your first alternative is the most at risk of future problems due to
> constraints likely to be placed on comparison return types ; 

"Most at risk" in this case equals zero risk. Comparison operators will not
be restricted to only returning bools. That will never happen.


>> - write a class to handle the PossiblyTrue and PossiblyFalse cases,
>>    and use True and False for the True and False cases;
>
> I very much would want to do as you state here because it would preserve
> both True and False unaltered --- which would ALWAYS work in legacy
> code; but I don't know how to do it safely.
> 
> Although I can use True for absolute Truth -- I can not use False as
> absolute False without inviting confusion as to when to allow advanced
> compares.
>  
> When I do a comparison on any False < False, in legacy code -- it needs
> to return False.

That's trivial. Give your Maybe objects __lt__ methods that return False
when compared to False. Here is a stub to get you started:


    def __lt__(self, other):
        if other is False:
            return False
        elif other == ... 



> But, when looking at uncertainty values, if totally False 'is' the same
> as base type False -- then the issue arises that a comparison False <
> AnyOtherPartTrueFalse   needs to be False for legacy compares but True
> for advanced compares;

What's a "legacy compare"? What's "advanced compares"? It seems to me that
you are inventing difficulties with Python that don't exist, and then
creating complex solutions to work around the non-existent problem.

I'm going to take a guess here... 

You have "fuzzy decimals", and when you compare two fuzzy decimals, you want
to return something like "equal", "completely less than", "partially less
than" and so on. For simplicity, I'm only going to discuss the less than
operator, but the same could apply to any comparison operator:

a < b can return:

True -- means that a certainly is less than b

False -- means that a certainly is not less than b

MostlyTrue -- means that a is probably less than b

MostlyFalse -- means that a is probably not less than b


So *fuzzy decimals* have to compare by returning four (or three, or five, or
however many you choose) tetra-logic (tri-logic, quin-logic...) values. To
implement this, you define a __lt__ method on the fuzzy decimal class,
together with the other comparison operators.

But the tetra-logic values themselves shouldn't compare fuzzily with each
other. You should define a fixed order for them, most likely:

False < MostlyFalse < MostlyTrue < True


and have comparison operators on the tetra-logic values themselves return
True or False:

False < True --> returns True
MostlyFalse < True --> returns True


However, should you disregard my advice and decide that MostlyFalse is only
*mostly* larger than False, but is also *slightly* equal to False, you can
certainly have the tetra-logic objects return *themselves* when compared. I
advise against it, not because it is hard to do in Python, but because I
think it will be hard for people to understand. But it can certainly be
done, by defining a __lt__ method on the tetra-logic class itself.


The only thing you can't do in Python is to override the boolean operators
`or` and `and` to implement three-value or four-value logic, e.g. you
cannot have this:

    MostlyFalse and True --> MostlyTrue  # or whatever rule you prefer

There have been proposals to allow overriding `and` and `or`, but so far
they have all run into difficulties with semantics, backwards
compatibility, efficiency, or all three.

I can only suggest that you accept that the `and` and `or` operators will
implicitly coerce their arguments into boolean True/False, and if you want
fuzzy operators, define some functions which do what you want:

def and_(a, b): ...
def or_(a, b): ...

A small inconvenience.


> It's inconsistent and I have no way of detecting where the False I am
> comparing with to make a proper decision.

I don't understand why you think you need to detect where False is. Where in
what sense? Objects in Python don't have a spacial location.


> So:  The only solution I see is to assume that whenever a uncertainty is
> compared against a legacy bool -- that the legacy style of comparison is
> absolutely required for safety; and a second version of False must be
> defined to detect when the compare needs to take uncertainty into account.

I don't understand this.


[...]
>> Industry practice, in my experience, is that there is one and only one
>> case where you can subclass singleton classes: when you have a factory
>> which chooses at runtime which subclass to instantiate, after which you
>> can no longer instantiate any of the other subclasses.
>
> OK.
> Well, I'll just say that I believe you -- and I'm not really sure what
> you're objecting to in what I said -- but if a singleton subclass /
> factory existed for my purpose -- I would be happy to choose it at
> runtime just like your maze guys do...!  If Guido would do that... he
> would give me a subtype of bool and that would be very nice indeed.

You cannot choose True and False at runtime because they are required by the
language. You cannot say "I don't wish to use True and False as my bools, I
wish to instantiate this alternate class instead and use CouldBe and
BuckleysChance as the two bools." That cannot work because long before your
code gets to run and create the subclass, Python has already instantiated
and used True and False. Functions are documented to return True or False,
not "some arbitrary bool subclass instances". The interpreter *cannot work*
without two known values for True and False, so replacing them at runtime
is impossible.

Could Python have been designed differently? Well yes, of course it could
have. If it were designed to be like PHP or Smalltalk or C++ then it would
have been just like PHP or Smalltalk or C++, but it wasn't. Python has the
design it has now, and some changes (like allowing the user to select which
two bools are used at runtime) are simply too extensive a change to be
practical. A bit like changing a three-story house built on a concrete slab
into a two story house on wooden foundations with a deep cellar, without
tearing the house down and starting again from scratch.



> But dreams aside -- I still note your admission shows that industry does
> allow subclassing of singletons even if it requires the owner of the
> singleton (Guido) to allow the subtypes.

And you are free to allow subclassing of your own singletons. Feel free to
allow an million instances of your singleton class, Python won't stop you
from shooting yourself in the foot if it is your own class.


[...]
>> I don't think you can. I think you are engaged on a fool's errand, trying
>> to do something impossible *even if subclassing bool were allowed*. But I
>> could be wrong. I just don't think you can possibly write code which is
>> backwards-compatible with code that expects bools while still extending
>> it. People are so prone to write:
>>
>>      if flag is True: ...
>>      if flag is False: ...
>
> D'Aprano -- I think your making what is known as a straw man argument.

I am sorry if I have misunderstood your position, but believe me, I am
responding to what I understand your position to be as accurately and
fairly as I can. But honestly Andrew, I believe that either your design is
confused and confusing, or you have failed to explain it well enough for me
to see that it is not confused.


> Refer back to your earlier suggestion of re-using True and False to
> represent themselves, and some other type to represent the intermediate
> metastates;  From your remark here, I surmise that you must have already
> figured out that the alternative you gave me was never meant to work --
> otherwise it would solve the very problem you now present me with for
> any case where my numbers are identical in meaning with legacy numbers

This is exactly the sort of confusion I'm talking about.

Logically, your numbers (I presume you are talking about the fuzzy decimals
you mentioned earlier, with some sort of uncertainty or error-bars
attached) cannot possibly be identical in meaning to legacy numbers (i.e.
regular decimals).

There is no logical sense that "number plus or minus uncertainty" can be
*identical* to "number alone", even if the uncertainty is zero. Because the
fuzzy decimals will have an uncertainty but the regular decimals will not.
If you have methods for dealing with that uncertainty, regular decimals
won't have those methods. If they have an "uncertainty" attribute, regular
decimals won't have one. If they print in such a way to show that
uncertainty, regular decimals will not.

If they have *identical* behaviour to regular decimals, then they merely
*are* regular decimals with a different (and likely slower or buggy)
implementation.

None of this is to say that you cannot have fuzzy decimals interoperate with
regular decimals, according to some rules which define how they should
combine. E.g. by treating regular numbers as exact, or giving them some
default uncertainty.


[...]
>>> or the code base used for solving
>>> large numbers of simultaneous logic equations with uncertainty included
>>> -- which have universally refined the boolean logic meanings found in
>>> "Truth" tables having clearly more than two values -- but don't take my
>>> word for it -- look in any digital electronics data book, and there they
>>> will be more than two states; marked with rising edges, falling edges,
>>> X's for don't cares, and so forth.
>>
>> And those truth tables are not part of Boolean algebra.
>
> Oh wow!!!! I never expected to hear that --  But I guess you were never
> trained to do boolean algebra, formally ? Or did you mean something else ?
> 
> http://en.wikipedia.org/wiki/Truth_table
> 
> The truth tables on data sheets are VERY VERY much intended to be
> related to boolean logic.

*Related to* boolean logic, but not *of* boolean logic. It is a
generalisation of boolean logic to more than two states, in a similar way
that complex numbers (3+2j where j = sqrt -1) are extended from the real
numbers. As an electrical engineer, I expect you are familiar with complex
numbers, and I hope that you would also understand that complex numbers are
not part of the Reals.

In any case, while the use of 3- and 4-valued logic is all very interesting
and important to electrical engineering, it is very much domain-specific
and is not so useful for a general purpose programming language. People
have difficulty enough dealing with SQL NULLs and floating point NANs.

You can write your own multi-valued logic in Python, just don't expect
Python to support it natively. Python is not a HDL.



-- 
Steven



From steve+comp.lang.python at pearwood.info  Sat Jan 17 07:48:35 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 17 Jan 2015 23:48:35 +1100
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi> <87a91hoebi.fsf@elektro.pacujo.net>
Message-ID: <54ba5a25$0$12991$c3e8da3$5496439d@news.astraweb.com>

Marko Rauhamaa wrote:

> Jussi Piitulainen <jpiitula at ling.helsinki.fi>:
> 
>>  a+ b  => 7  # a() + b
>>  a +b  => 3  # a(+b)   => a(b) => a(1) = 1 + 2
>>
>> I'm not quite fond of such surprise in programming language syntax.
> 
> Yes, whoever came up with the idea of whitespace having syntactic
> significance!

Yes, we should go back to the rules of ancient FORTRAN, where:

DO100X=1.10,2

and

DO 100 X = 1. 10, 2

mean exactly the same thing.

Not.


Whitespace is significant in nearly all programming languages, and so it
should be. Whitespace separates tokens, and lines, and is a natural way of
writing (at least for people using Western languages).

*Indentation* is significant to Python, while most languages enable tedious
and never-ending style wars over the correct placement of braces vis a vis
indentation, because their language is too simple-minded to infer block
structure from indentation. Python does derive block structure from
indentation, as god intended (otherwise he wouldn't have put tab keys on
typewriters) and so Python doesn't suffer from the interminable arguments
about formatting that most other languages do.



-- 
Steven



From steve+comp.lang.python at pearwood.info  Sat Jan 17 07:49:24 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 17 Jan 2015 23:49:24 +1100
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi>
Message-ID: <54ba5a55$0$12991$c3e8da3$5496439d@news.astraweb.com>

Jussi Piitulainen wrote:

> I've only seen small amounts of Ruby code on the net. The only way I
> can make some sense of that is if it gets analyzed as follows, using
> parentheses for calls:
> 
>  a + b => 7  # a() + b => a(4) + b => 4 + 2 + 1
>  a+b   => 7  # a() + b
>  a+ b  => 7  # a() + b
>  a +b  => 3  # a(+b)   => a(b) => a(1) = 1 + 2
> 
> I'm not quite fond of such surprise in programming language syntax.

Full marks!



-- 
Steven



From jpiitula at ling.helsinki.fi  Sat Jan 17 07:54:43 2015
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 17 Jan 2015 14:54:43 +0200
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi> <87a91hoebi.fsf@elektro.pacujo.net>
 <qotppad39ei.fsf@ruuvi.it.helsinki.fi> <87twzpmwm7.fsf@elektro.pacujo.net>
Message-ID: <qotzj9hzhws.fsf@ruuvi.it.helsinki.fi>

Marko Rauhamaa writes:

> Seriously, though, I hate the optional semicolon rules of JavaScript
> and Go. I dread the day when GvR gets it in his head to allow this
> syntax in Python:
> 
>    average_drop_rate = cumulative_drop_count /
>        observation_period
> 
> (although, it could be defined Pythonesquely thus: "a spurious
> indentation means line continuation" ? no more backslashes).

I do that:

   average_drop_rate = ( cumulative_drop_count /
                         observation_period )


From jpiitula at ling.helsinki.fi  Sat Jan 17 08:19:00 2015
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 17 Jan 2015 15:19:00 +0200
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi> <87a91hoebi.fsf@elektro.pacujo.net>
 <qotppad39ei.fsf@ruuvi.it.helsinki.fi>
 <mailman.17811.1421497179.18130.python-list@python.org>
Message-ID: <qotvbk5zgsb.fsf@ruuvi.it.helsinki.fi>

Skip Montanaro writes:
> On Sat, Jan 17, 2015 at 5:59 AM, Jussi Piitulainen wrote:
> > How far do you want to go? Is "a  b + c" the same as "a(b) + c" or
> > the same as "a(b + c)"?
> 
> I think there is only one practical interpretation, the one that all
> shells I'm familiar with have adopted:
> 
>     a(b, +, c)

Sorry, what? Oh, shells, and "a" called with three parameters. Ok.

But I think the "+" here should be the usual arithmetical operators.
It was supposed to be Ruby syntax and the question was about the
significance of different amounts of white space.

Hm. What about "b  + c"? Or "3 +1", is that calling 3 with 1? No,
I don't really want to know.


From marongiuguerrino at outlook.com  Sat Jan 17 08:19:15 2015
From: marongiuguerrino at outlook.com (MEGLIO MORTO CHE BERLUSCONICCHIO)
Date: Sat, 17 Jan 2015 05:19:15 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
References: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
Message-ID: <0120263f-500e-4c18-880d-95e9c739da34@googlegroups.com>

-- redacted --


From rosuav at gmail.com  Sat Jan 17 08:33:52 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 18 Jan 2015 00:33:52 +1100
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com>
 <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi>
Message-ID: <CAPTjJmqMiFfwZbwhMuy_AoRWKBE4xfPDSXH1KDHrJbO7nmDYSw@mail.gmail.com>

On Sat, Jan 17, 2015 at 9:49 PM, Jussi Piitulainen
<jpiitula at ling.helsinki.fi> wrote:
> I've only seen small amounts of Ruby code on the net. The only way I
> can make some sense of that is if it gets analyzed as follows, using
> parentheses for calls:
>
>  a + b => 7  # a() + b => a(4) + b => 4 + 2 + 1
>  a+b   => 7  # a() + b
>  a+ b  => 7  # a() + b
>  a +b  => 3  # a(+b)   => a(b) => a(1) = 1 + 2
>
> I'm not quite fond of such surprise in programming language syntax.

Every once in a while, someone looks at Py2's print statement and
Py3's print function and says, "why not allow function calls without
parentheses". This right here is why not. Wow. That is one nasty
surprise.

ChrisA


From daniloco at acm.org  Sat Jan 17 09:20:30 2015
From: daniloco at acm.org (Danilo Coccia)
Date: Sat, 17 Jan 2015 15:20:30 +0100
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <87a91hoebi.fsf@elektro.pacujo.net>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>	<roy-4AAFA6.08034915012015@news.panix.com>	<mailman.17759.1421327478.18130.python-list@python.org>	<87zj9kb2j0.fsf@elektro.pacujo.net>	<roy-A43F6D.20334015012015@news.panix.com>	<54B86CF8.7040602@gmail.com>	<mailman.17783.1421380815.18130.python-list@python.org>	<chte6eF3ke9U1@mid.individual.net>	<54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>	<qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi>
 <87a91hoebi.fsf@elektro.pacujo.net>
Message-ID: <m9dr2f$rt0$1@dont-email.me>

Il 17/01/2015 12.07, Marko Rauhamaa ha scritto:
> Jussi Piitulainen <jpiitula at ling.helsinki.fi>:
> 
>>  a+ b  => 7  # a() + b
>>  a +b  => 3  # a(+b)   => a(b) => a(1) = 1 + 2
>>
>> I'm not quite fond of such surprise in programming language syntax.
> 
> Yes, whoever came up with the idea of whitespace having syntactic
> significance!
> 
> 
> Marko
> 

Maybe you already knew this "esoteric" language:
  http://compsoc.dur.ac.uk/whitespace/
  https://en.wikipedia.org/wiki/Whitespace_%28programming_language%29

And, just for completeness :) http://www.stroustrup.com/whitespace98.pdf


From steve+comp.lang.python at pearwood.info  Sat Jan 17 09:26:26 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 18 Jan 2015 01:26:26 +1100
Subject: numpy.allclose()
Message-ID: <54ba7113$0$12985$c3e8da3$5496439d@news.astraweb.com>

Can anyone explain the rationale for numpy's allclose() semantics?

help(allclose) says:


allclose(a, b, rtol=1e-05, atol=1e-08)
    Returns True if two arrays are element-wise equal within a tolerance.

    The tolerance values are positive, typically very small numbers.  The
    relative difference (`rtol` * abs(`b`)) and the absolute difference
    `atol` are added together to compare against the absolute difference
    between `a` and `b`.

    [...]

    If the following equation is element-wise True, then allclose returns
    True.

    absolute(`a` - `b`) <= (`atol` + `rtol` * absolute(`b`))



I don't understand why they add the error tolerances together. I can
understand taking the minimum, or the maximum: 

* taking the maximum is equivalent to the rule "numbers are close if they
  differ by no more than EITHER the absolute tolerance OR the relative
  tolerance";

* taking the minimum is equivalent to the rule "numbers are close if they
  differ by no more than BOTH the absolute tolerance AND the relative
  tolerance".


But adding them together doesn't make any sense to me. That leads to the
situation where two values are deemed "close" if you give two tolerances
even though it fails each test individually:

py> numpy.allclose([1.2], [1.0], 0.0, 0.1)  # Fails absolute error test.
False
py> numpy.allclose([1.2], [1.0], 0.1, 0.0)  # Fails relative error test.
False
py> numpy.allclose([1.2], [1.0], 0.1, 0.1)  # Passes!
True




-- 
Steven



From albert at spenarnc.xs4all.nl  Sat Jan 17 09:51:12 2015
From: albert at spenarnc.xs4all.nl (Albert van der Horst)
Date: 17 Jan 2015 14:51:12 GMT
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
Message-ID: <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>

In article <mailman.17471.1420721626.18130.python-list at python.org>,
Chris Angelico  <rosuav at gmail.com> wrote:
<SNIP>
>
>But sure. If you want to cut out complication, dispense with user
>accounts altogether and run everything as root. That's WAY simpler!

I didn't except this strawman argument from you.
Of course you need a distinction between doing system things as
root, and working as a normal user. You just don't need sudo.

>
>ChrisA
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert at spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst



From rosuav at gmail.com  Sat Jan 17 09:57:14 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 18 Jan 2015 01:57:14 +1100
Subject: Hello World
In-Reply-To: <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
Message-ID: <CAPTjJmrG+aY89sM7sdiGJanVfZ=3Ag6ZHtcwuAYr9Z=3Kj_C9g@mail.gmail.com>

On Sun, Jan 18, 2015 at 1:51 AM, Albert van der Horst
<albert at spenarnc.xs4all.nl> wrote:
> In article <mailman.17471.1420721626.18130.python-list at python.org>,
> Chris Angelico  <rosuav at gmail.com> wrote:
> <SNIP>
>>
>>But sure. If you want to cut out complication, dispense with user
>>accounts altogether and run everything as root. That's WAY simpler!
>
> I didn't except this strawman argument from you.
> Of course you need a distinction between doing system things as
> root, and working as a normal user. You just don't need sudo.

So you have to have a password on the root account. My systems are
more secure, as they do not have a password that someone could learn.

ChrisA


From albert at spenarnc.xs4all.nl  Sat Jan 17 10:10:41 2015
From: albert at spenarnc.xs4all.nl (Albert van der Horst)
Date: 17 Jan 2015 15:10:41 GMT
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mtdtaalemtguc30127u5ifnbblrgndnrd3@4ax.com>
 <mailman.17481.1420737102.18130.python-list@python.org>
Message-ID: <54ba7b71$0$15929$e4fe514c@dreader35.news.xs4all.nl>

In article <mailman.17481.1420737102.18130.python-list at python.org>,
Chris Angelico  <rosuav at gmail.com> wrote:
>On Fri, Jan 9, 2015 at 4:02 AM, Steve Hayes <hayesstw at telkomsa.net> wrote:
>> On 08 Jan 2015 12:43:33 GMT, albert at spenarnc.xs4all.nl (Albert van der Horst)
>> wrote:
>>
>>>I don't trust sudo because it is too complicated.
>>>(To the point that I removed it from my machine.)
>>>I do
>>
>> How do you do that?
>>
>> I avoided Ubuntu because it had sudo, and then discovered that Fedora had it
>> as well.
>
>Uhh, 'apt-get remove sudo'? That ought to work on any Debian-based

That works. That is exactly what I did.

>system. With Debian itself, you get the option during installation of
>setting a root password, in which case it won't install sudo by
>default.
>
>ChrisA
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert at spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst



From cl at isbd.net  Sat Jan 17 10:18:01 2015
From: cl at isbd.net (cl at isbd.net)
Date: Sat, 17 Jan 2015 15:18:01 +0000
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17813.1421506643.18130.python-list@python.org>
Message-ID: <92bqob-aj2.ln1@esprimo.zbmc.eu>

Chris Angelico <rosuav at gmail.com> wrote:
> On Sun, Jan 18, 2015 at 1:51 AM, Albert van der Horst
> <albert at spenarnc.xs4all.nl> wrote:
> > In article <mailman.17471.1420721626.18130.python-list at python.org>,
> > Chris Angelico  <rosuav at gmail.com> wrote:
> > <SNIP>
> >>
> >>But sure. If you want to cut out complication, dispense with user
> >>accounts altogether and run everything as root. That's WAY simpler!
> >
> > I didn't except this strawman argument from you.
> > Of course you need a distinction between doing system things as
> > root, and working as a normal user. You just don't need sudo.
> 
> So you have to have a password on the root account. My systems are
> more secure, as they do not have a password that someone could learn.
> 
Yes, they do (if you use sudo) it's *your* password and IMHO it's less
secure as you only need to know one password to get root access.

-- 
Chris Green
?


From roy at panix.com  Sat Jan 17 10:20:03 2015
From: roy at panix.com (Roy Smith)
Date: Sat, 17 Jan 2015 10:20:03 -0500
Subject: recursive function: use a global or pass a parameter?
References: <5e4ccec6-7a00-467d-8cf6-258ab0421c90@googlegroups.com>
 <54ba3654$0$13008$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <roy-F5161B.10193317012015@news.panix.com>

In article <54ba3654$0$13008$c3e8da3$5496439d at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> Good reasons for using global variables are few and far between. Just about
> the only good reason for using global variables that I can think of is if
> you have one or more settings/preference that get set once at the start of
> the program and then apply to the entire program.

I will commonly put something like:

import logging
logger = logging.getLogger("logger-name-for-my-module")

in every source file in a big project.  Now I've got a global logger I 
can use anywhere in the module (even in static functions).  But, maybe 
that's just a subset of your "setting that gets set once at the start of 
the program" example.


From torriem at gmail.com  Sat Jan 17 11:29:23 2015
From: torriem at gmail.com (Michael Torrie)
Date: Sat, 17 Jan 2015 09:29:23 -0700
Subject: Hello World
In-Reply-To: <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
Message-ID: <54BA8DE3.4030706@gmail.com>

On 01/17/2015 07:51 AM, Albert van der Horst wrote:
> In article <mailman.17471.1420721626.18130.python-list at python.org>,
> Chris Angelico  <rosuav at gmail.com> wrote:
> <SNIP>
>>
>> But sure. If you want to cut out complication, dispense with user
>> accounts altogether and run everything as root. That's WAY simpler!
> 
> I didn't except this strawman argument from you.
> Of course you need a distinction between doing system things as
> root, and working as a normal user. You just don't need sudo.

I just don't see the distinction.  What's the difference between having
to type in a root password and having to type in your own administrative
user password?  Guess we're all just struggling to understand your logic
here.

On my laptop sudo has a huge advantage over su, and that is I can use my
fingerprint reader to access root. Now I could set up root to accept a
fingerprint as well which would work with su, but the sudo solution is
much quicker to configure.


From albert at spenarnc.xs4all.nl  Sat Jan 17 11:39:29 2015
From: albert at spenarnc.xs4all.nl (Albert van der Horst)
Date: 17 Jan 2015 16:39:29 GMT
Subject: Why do the URLs of posts here change?
References: <54afb3ed$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17520.1420805082.18130.python-list@python.org>
 <chbk5cF7dv9U1@mid.individual.net>
 <mailman.17551.1420862015.18130.python-list@python.org>
Message-ID: <54ba9041$0$6961$e4fe514c@dreader36.news.xs4all.nl>

In article <mailman.17551.1420862015.18130.python-list at python.org>,
Chris Angelico  <rosuav at gmail.com> wrote:
>On Sat, Jan 10, 2015 at 2:21 PM, Gregory Ewing
><greg.ewing at canterbury.ac.nz> wrote:
>> Skip Montanaro wrote:
>>>
>>> The way this is done, is
>>> that the message is removed from the underlying mbox file, and the
>>> archive regenerated. That changes the counter for every message after
>>> that point
>>
>>
>> Would it help to replace the message with a stub
>> instead of deleting it altogether?
>
>I had the same thought, but apparently not, according to the page
>Peter Otten linked to:
>
>http://wiki.list.org/display/DEV/Stable+URLs

Knowing that the source is an mbox file, I don't need to follow
that link to conclude that one is not very inventive.
It suffices to replace the content of the message by
a repetition of 'xxxx\n'. Maybe also the sender and the subject.

>
>ChrisA
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert at spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst



From cl at isbd.net  Sat Jan 17 11:47:13 2015
From: cl at isbd.net (cl at isbd.net)
Date: Sat, 17 Jan 2015 16:47:13 +0000
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
Message-ID: <h9gqob-c3e.ln1@esprimo.zbmc.eu>

Michael Torrie <torriem at gmail.com> wrote:
> On 01/17/2015 07:51 AM, Albert van der Horst wrote:
> > In article <mailman.17471.1420721626.18130.python-list at python.org>,
> > Chris Angelico  <rosuav at gmail.com> wrote:
> > <SNIP>
> >>
> >> But sure. If you want to cut out complication, dispense with user
> >> accounts altogether and run everything as root. That's WAY simpler!
> > 
> > I didn't except this strawman argument from you.
> > Of course you need a distinction between doing system things as
> > root, and working as a normal user. You just don't need sudo.
> 
> I just don't see the distinction.  What's the difference between having
> to type in a root password and having to type in your own administrative
> user password?  Guess we're all just struggling to understand your logic
> here.
> 
One big distinction is that you need to know two passwords to get root
access if there's a real root account as opposed to using sudo.  This
only applies of course if direct root login isn't allowed (via ssh or
whatever).

-- 
Chris Green
?


From roy at panix.com  Sat Jan 17 11:56:48 2015
From: roy at panix.com (Roy Smith)
Date: Sat, 17 Jan 2015 11:56:48 -0500
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <roy-FD3C53.11561817012015@news.panix.com>

In article <54ba39e0$0$13008$c3e8da3$5496439d at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> Every time I think I would like to learn a new language, I quite quickly run
> into some obvious feature that Python has but the newer language lacks, and
> I think "bugger this for a game of soldiers" and abandon it.

Wow.  Another wonderful English phrase to add to my vocabulary.  That's 
up there with Bob's your uncle :-)

> Ah, wait, I forgot Ruby's brilliant "feature" that whitespace *between*
> expressions is significant:
> 
> [steve at ando ~]$ cat ~/coding/ruby/ws-example.rb
> #!/usr/bin/ruby
> 
> def a(x=4)
>     x+2
> end
> 
> b = 1
> print "a + b => ", (a + b), "\n"
> print "a+b   => ", (a+b), "\n"
> print "a+ b  => ", (a+ b), "\n"
> print "a +b  => ", (a +b), "\n"
> 
> [steve at ando ~]$ ruby ~/coding/ruby/ws-example.rb
> a + b => 7
> a+b   => 7
> a+ b  => 7
> a +b  => 3
> 
> 
> A shiny new penny for any non-Ruby coder who can explain that!

The last time I looked at Ruby was when it was brand new.  I bought the 
original pickaxe book and read it on a plane trip.  It looked pretty 
cool at the time, but I never really got into it.  So I think I qualify.

Anyway, I'm going to guess from the above examples, that uttering a name 
means, "If the referent is callable, call it, if not, get its value".  
This is the same, for example, as django's template language.  Or, kind 
of like Python's properties.  So

(a + b)

means "Call a(), and add the value of b to that".  I'm going to further 
guess that

def a(x=4)

means a() takes an optional argument, with a default value of 4, just 
like in Python.  So

a

returns 6, i.e. 4 + 2.  I'm going to further guess that

(a +b)

is parsed as "call a, passing +b as an argument", and the "+" is taken 
as a unary prefix.

I want my penny.

This is not the only example of significant whitespace in programming 
languages.

Old-style C/C++ allowed either += or =+ for the increment operator.  
This led to parsing ambiguity for things like a=+b, where (IIRC), "a = 
+b" was parsed as an assignment and unary +, and "a =+ b" was parsed as 
an increment.  Eventually, the syntax was changed to make += the only 
legal way to write increment.

There was also the problem with nested template operators in C++, where 
"Foo<T1<T2>>" was mis-parsed, and you had to write it as "Foo <T1 <T2> 
>" (or something like that) to get it to parse right.


From roy at panix.com  Sat Jan 17 12:20:35 2015
From: roy at panix.com (Roy Smith)
Date: Sat, 17 Jan 2015 12:20:35 -0500
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi> <87a91hoebi.fsf@elektro.pacujo.net>
 <54ba5a25$0$12991$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <roy-0DF8EA.12200517012015@news.panix.com>

In article <54ba5a25$0$12991$c3e8da3$5496439d at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> Whitespace is significant in nearly all programming languages, and so it
> should be. Whitespace separates tokens, and lines, and is a natural way of
> writing (at least for people using Western languages).

>>> """x""" == " " "x" " "
False

> *Indentation* is significant to Python, while most languages enable tedious
> and never-ending style wars over the correct placement of braces vis a vis
> indentation, because their language is too simple-minded to infer block
> structure from indentation. Python does derive block structure from
> indentation, as god intended (otherwise he wouldn't have put tab keys on
> typewriters) and so Python doesn't suffer from the interminable arguments
> about formatting that most other languages do.

Well, we do get to argue about

x = [1,
     2,
     3]

vs.

x = [1,
     2,
     3,
    ]

vs. a few other variations based on how you group the first element with 
the opening bracket, or the last element with the closing bracket, and, 
of course, whether you use the last trailing comma or not.


From roy at panix.com  Sat Jan 17 12:24:00 2015
From: roy at panix.com (Roy Smith)
Date: Sat, 17 Jan 2015 12:24:00 -0500
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi> <87a91hoebi.fsf@elektro.pacujo.net>
 <qotppad39ei.fsf@ruuvi.it.helsinki.fi>
 <mailman.17811.1421497179.18130.python-list@python.org>
Message-ID: <roy-4123DE.12233017012015@news.panix.com>

In article <mailman.17811.1421497179.18130.python-list at python.org>,
 Skip Montanaro <skip.montanaro at gmail.com> wrote:

> On Sat, Jan 17, 2015 at 5:59 AM, Jussi Piitulainen
> <jpiitula at ling.helsinki.fi> wrote:
> > How far do you want to go? Is "a  b + c" the same as "a(b) + c" or the
> > same as "a(b + c)"?
> 
> I think there is only one practical interpretation, the one that all
> shells I'm familiar with have adopted:
> 
>     a(b, +, c)
> 
> > And I don't really want to know which it is. I prefer parentheses.
> > They are not nearly as fragile.
> 
> Agreed. Without parens, splitting the command line arguments on white
> space is the only non-fragile way to do things.
> 
> Skip

I once worked with a language (with vaguely C-like syntax) in which:

if(x == 4)

and

y = f (x)

were both syntax errors.  If statements *required* a space before the 
paren, and function calls *forbid* it.


From albert at spenarnc.xs4all.nl  Sat Jan 17 12:30:04 2015
From: albert at spenarnc.xs4all.nl (Albert van der Horst)
Date: 17 Jan 2015 17:30:04 GMT
Subject: recursive function: use a global or pass a parameter?
References: <5e4ccec6-7a00-467d-8cf6-258ab0421c90@googlegroups.com>
Message-ID: <54ba9c1c$0$15938$e4fe514c@dreader35.news.xs4all.nl>

In article <5e4ccec6-7a00-467d-8cf6-258ab0421c90 at googlegroups.com>,
Tim  <jtim.arnold at gmail.com> wrote:
>I have this type of situation and wonder if I should use a global
>variable outside the recursive function instead of passing the updated
>parameter through.
>
>I want to get a union of all the values that any 'things' key may have,
>even in a nested dictionary (and I do not know beforehand how deep the
>nesting might go):
>
>d = {'things':1, 'two':{'things':2}}
>
>def walk(obj, res):
>    if not hasattr(obj, 'keys'):
>        return set(), set()
>
>    if 'things' in obj:
>        res.add(obj['things'])
>
>    for k in obj:
>        walk(obj[k], res)
>
>    return res
>
>walk(d, set()) # returns {1, 2}
>
>Is it better to use a global to keep track of the values or does it even matter?

Neither. You shouldn't pass superfluous parameters, and you shouldn't
abuse globals.

The proper technique is make the global local to the normal subroutine,
then make the subroutine with those parameters you don't want to see
also local to that subroutine.
E.g.

def fib(n):
    ' return the n-th Fibonacci number '
    a,b = 0,1
    def fib1(ap,bp):
       ' for f_n,f_n+1, return f_n+1,f_n+2 '
       return bp,ap+b
    for i in xrange(n):
       a,b = fib1(a,b)
    return a

>
>thanks,
>--Tim

Groetjes Albert
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert at spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst



From albert at spenarnc.xs4all.nl  Sat Jan 17 13:06:41 2015
From: albert at spenarnc.xs4all.nl (Albert van der Horst)
Date: 17 Jan 2015 18:06:41 GMT
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
Message-ID: <54baa4b1$0$15857$e4fe514c@dreader35.news.xs4all.nl>

In article <h9gqob-c3e.ln1 at esprimo.zbmc.eu>,  <cl at isbd.net> wrote:
>Michael Torrie <torriem at gmail.com> wrote:
>> On 01/17/2015 07:51 AM, Albert van der Horst wrote:
>> > In article <mailman.17471.1420721626.18130.python-list at python.org>,
>> > Chris Angelico  <rosuav at gmail.com> wrote:
>> > <SNIP>
>> >>
>> >> But sure. If you want to cut out complication, dispense with user
>> >> accounts altogether and run everything as root. That's WAY simpler!
>> >
>> > I didn't except this strawman argument from you.
>> > Of course you need a distinction between doing system things as
>> > root, and working as a normal user. You just don't need sudo.
>>
>> I just don't see the distinction.  What's the difference between having
>> to type in a root password and having to type in your own administrative
>> user password?  Guess we're all just struggling to understand your logic
>> here.
>>
>One big distinction is that you need to know two passwords to get root
>access if there's a real root account as opposed to using sudo.  This
>only applies of course if direct root login isn't allowed (via ssh or
>whatever).

The other is that if a dozen users have sudo possibility, one compromised
password compromises the whole system. The same administrators that like
sudo will force the users into a "safe" password of at least 8 characters
a special sign a number and a capital, instead of educating them to
use a strong password like the_horse_eats_yellow_stones. 1]
Chances are that one of the users has a password like
! (first special sign) 1 (first number) Q (first capital)
followed by a weak 5 letter word (or even a guessable one).

Compare that to
"Dear administrator, I've to do this. Can I have the root password."
"Sure here it is" Looks over users shoulder. "Are you ready?"
Make sure he's logged out. Uses random generator for a new password.

If there is something, anything, change the root password and check
the disk for suid-root files.

There is no such thing as automatic security.
Security requires one thing: attention. And effort. So two things:
attention and effort. And simplicity. So three things: attention,
effort and simplicity.

sudo makes administrators careless, lazy and it is not simple at all.

>--
>Chris Green

Groetjes Albert

1] I don't claim this is *very* strong, just strong.
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert at spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst



From alister.nospam.ware at ntlworld.com  Sat Jan 17 13:30:12 2015
From: alister.nospam.ware at ntlworld.com (alister)
Date: Sat, 17 Jan 2015 18:30:12 GMT
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <54b7cd9f$0$13011$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmpxdXXCVRyg5cu60TJU4gkc9qmc-opm51d4AkdmNhiZmw@mail.gmail.com>
 <mailman.17774.1421369276.18130.python-list@python.org>
 <chsai9Fih3gU1@mid.individual.net> <87lhl39bfg.fsf@elektro.pacujo.net>
 <chtdshF3h6cU1@mid.individual.net>
 <54ba3a70$0$13008$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <USxuw.111314$551.12070@fx43.am4>

On Sat, 17 Jan 2015 21:33:19 +1100, Steven D'Aprano wrote:

> Gregory Ewing wrote:
> 
>> Marko Rauhamaa wrote:
>>> Gregory Ewing <greg.ewing at canterbury.ac.nz>:
>>> 
>>>>If those are 24-bit RGB pixels, you could encode 3 characters in each
>>>>pixel.
>>> 
>>> Not since Python3. Characters are Unicode now so you'll need to
>>> dedicate a pixel for each character.
>> 
>> Depends on which characters you want. With the Flexible Chromatic
>> Representation, it could be anything from 1 to 3.
> 
> Subpixel rendering is 5% slower than full pixel rendering, so it is
> provably mathematically impossible to print Unicode characters.

:-)



-- 
It's union rules. There's nothing we can do about it. Sorry.


From breamoreboy at yahoo.co.uk  Sat Jan 17 13:31:47 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 17 Jan 2015 18:31:47 +0000
Subject: Hello World
In-Reply-To: <h9gqob-c3e.ln1@esprimo.zbmc.eu>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
Message-ID: <m9e9qn$joj$1@ger.gmane.org>

On 17/01/2015 16:47, cl at isbd.net wrote:
> Michael Torrie <torriem at gmail.com> wrote:
>> On 01/17/2015 07:51 AM, Albert van der Horst wrote:
>>> In article <mailman.17471.1420721626.18130.python-list at python.org>,
>>> Chris Angelico  <rosuav at gmail.com> wrote:
>>> <SNIP>
>>>>
>>>> But sure. If you want to cut out complication, dispense with user
>>>> accounts altogether and run everything as root. That's WAY simpler!
>>>
>>> I didn't except this strawman argument from you.
>>> Of course you need a distinction between doing system things as
>>> root, and working as a normal user. You just don't need sudo.
>>
>> I just don't see the distinction.  What's the difference between having
>> to type in a root password and having to type in your own administrative
>> user password?  Guess we're all just struggling to understand your logic
>> here.
>>
> One big distinction is that you need to know two passwords to get root
> access if there's a real root account as opposed to using sudo.  This
> only applies of course if direct root login isn't allowed (via ssh or
> whatever).
>

Bah humbug, this has reminded me of doing secure work whereby each 
individual had two passwords, both of which had to be changed every 
thirty days, and rules were enforced so you couldn't just increment the 
number at the end of a word or similar.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From ian.g.kelly at gmail.com  Sat Jan 17 13:42:35 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Sat, 17 Jan 2015 11:42:35 -0700
Subject: numpy.allclose()
In-Reply-To: <54ba7113$0$12985$c3e8da3$5496439d@news.astraweb.com>
References: <54ba7113$0$12985$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CALwzidkxeRoSFV5o8kwFwn__WFW74PSDvftKF3rdXV03QkORgQ@mail.gmail.com>

On Sat, Jan 17, 2015 at 7:26 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> I don't understand why they add the error tolerances together. I can
> understand taking the minimum, or the maximum:

The usual idea is that the tolerance is calculated as a relative
value, but an absolute tolerance is used instead when the values get
close to zero, so under normal circumstances the relative tolerance
will dominate and the absolute tolerance will be very small in
comparison. So why add them instead of taking the maximum? I'm not
sure, but I would guess it's probably for efficiency. Determining the
maximum requires the CPU to perform a conditional branch that a simple
addition does not. In any case, this is not unique to numpy.  See
e.g.:

https://books.google.com/books?id=CbH0AwAAQBAJ&pg=PA164
(equation 8.26)

or:

https://books.google.com/books?id=j0rY3D9fx-0C&pg=PA71
(equation 7.437)

On the other hand, Matlab evidently uses the maximum:
http://www.mathworks.com/help/simbio/ref/absolutetolerance.html

> * taking the minimum is equivalent to the rule "numbers are close if they
>   differ by no more than BOTH the absolute tolerance AND the relative
>   tolerance".

This is generally not the desired semantic, and it's not unheard of to
pass 0 for one of the tolerances, in which case the minimum would
clearly be incorrect.


From invalid at invalid.invalid  Sat Jan 17 13:44:42 2015
From: invalid at invalid.invalid (Grant Edwards)
Date: Sat, 17 Jan 2015 18:44:42 +0000 (UTC)
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
Message-ID: <m9eaiq$o7v$1@reader1.panix.com>

On 2015-01-16, Gregory Ewing <greg.ewing at canterbury.ac.nz> wrote:

> We're really quite spoiled in Python-land. It's easy
> to forget just *how* spoiled we are until you go back
> and try to do something in one of the more primitive
> languages...

I had to do some work in PHP yesterday -- fixing up some code that was
written by somebody who only knows how to write C++ [though he can do
it in several different languages].

There was lot's of quiet swearing.

--
Grant




From michael at stroeder.com  Sat Jan 17 13:47:38 2015
From: michael at stroeder.com (=?UTF-8?Q?Michael_Str=c3=b6der?=)
Date: Sat, 17 Jan 2015 19:47:38 +0100
Subject: Hello World
In-Reply-To: <54baa4b1$0$15857$e4fe514c@dreader35.news.xs4all.nl>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <54baa4b1$0$15857$e4fe514c@dreader35.news.xs4all.nl>
Message-ID: <m9eane$qfm$1@dont-email.me>

albert at spenarnc.xs4all.nl (Albert van der Horst) wrote:
> In article <h9gqob-c3e.ln1 at esprimo.zbmc.eu>,  <cl at isbd.net> wrote:
>> Michael Torrie <torriem at gmail.com> wrote:
>>> On 01/17/2015 07:51 AM, Albert van der Horst wrote:
>>>> In article <mailman.17471.1420721626.18130.python-list at python.org>,
>>>> Chris Angelico  <rosuav at gmail.com> wrote:
>>>> <SNIP>
>>>>>
>>>>> But sure. If you want to cut out complication, dispense with user
>>>>> accounts altogether and run everything as root. That's WAY simpler!
>>>>
>>>> I didn't except this strawman argument from you.
>>>> Of course you need a distinction between doing system things as
>>>> root, and working as a normal user. You just don't need sudo.
>>>
>>> I just don't see the distinction.  What's the difference between having
>>> to type in a root password and having to type in your own administrative
>>> user password?  Guess we're all just struggling to understand your logic
>>> here.
>>>
>> One big distinction is that you need to know two passwords to get root
>> access if there's a real root account as opposed to using sudo.  This
>> only applies of course if direct root login isn't allowed (via ssh or
>> whatever).
> 
> The other is that if a dozen users have sudo possibility, one compromised
> password compromises the whole system.

Hmm, but it's much worse if a dozen users have to know the root password. With
this they can circumvent sudo completely (e.g. going over IPMI console).

> Compare that to
> "Dear administrator, I've to do this. Can I have the root password."
> "Sure here it is" Looks over users shoulder. "Are you ready?"
> Make sure he's logged out. Uses random generator for a new password.

This process does not work for dozens of admins maintaining thousands of
machines. Especially when something goes wrong in the night shift and has to
be fixed quickly.

> If there is something, anything, change the root password and check
> the disk for suid-root files.

Better require public key authc for SSH access and the user's own (one-time)
password for sudo. If your security requirements are really high mandate going
through a SSH gateway / jumphost.

> Security requires one thing: attention. And effort. So two things:
> attention and effort. And simplicity. So three things: attention,
> effort and simplicity.

Yes.

> sudo makes administrators careless, lazy and it is not simple at all.

Admins must have separate accounts with separate credentials for
administrative work and must be careful when using an administrative account.

Ciao, Michael.



From invalid at invalid.invalid  Sat Jan 17 13:51:21 2015
From: invalid at invalid.invalid (Grant Edwards)
Date: Sat, 17 Jan 2015 18:51:21 +0000 (UTC)
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <roy-FD3C53.11561817012015@news.panix.com>
Message-ID: <m9eav9$o7v$2@reader1.panix.com>

On 2015-01-17, Roy Smith <roy at panix.com> wrote:
> In article <54ba39e0$0$13008$c3e8da3$5496439d at news.astraweb.com>,
>  Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
>
>> Every time I think I would like to learn a new language, I quite quickly run
>> into some obvious feature that Python has but the newer language lacks, and
>> I think "bugger this for a game of soldiers" and abandon it.
>
> Wow.  Another wonderful English phrase to add to my vocabulary.  That's 
> up there with Bob's your uncle :-)

Yup, that one's brilliant.  While it's pretty much obvious what
phrases like that mean when one stumbles across them for the first
time, I find I sometimes don't have a very good grasp of where they
fall on the offensive<->polite scale...

--
Grant



From dan at tombstonezero.net  Sat Jan 17 14:08:21 2015
From: dan at tombstonezero.net (Dan Sommers)
Date: Sat, 17 Jan 2015 19:08:21 +0000 (UTC)
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net> <m9eaiq$o7v$1@reader1.panix.com>
Message-ID: <m9ebv5$ovq$1@dont-email.me>

On Sat, 17 Jan 2015 18:44:42 +0000, Grant Edwards wrote:

> ... somebody who only knows how to write C++ [though he can do it in
> several different languages].

+1 QOTW (brilliant phrases in other threads are off topic and are
disqualified)

I have also suffered through such maintenance, but I have never described
it quite so succinctly.

> There was lot's of quiet swearing.

"Quiet" is *not* one of my strong points.

-- 
Dan


From rosuav at gmail.com  Sat Jan 17 14:27:22 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 18 Jan 2015 06:27:22 +1100
Subject: recursive function: use a global or pass a parameter?
In-Reply-To: <54ba9c1c$0$15938$e4fe514c@dreader35.news.xs4all.nl>
References: <5e4ccec6-7a00-467d-8cf6-258ab0421c90@googlegroups.com>
 <54ba9c1c$0$15938$e4fe514c@dreader35.news.xs4all.nl>
Message-ID: <CAPTjJmpg=UUXoBkh0Bk4MYOhv6swWK9y1RByeOFEkyW9Zp_gnw@mail.gmail.com>

On Sun, Jan 18, 2015 at 4:30 AM, Albert van der Horst
<albert at spenarnc.xs4all.nl> wrote:
> The proper technique is make the global local to the normal subroutine,
> then make the subroutine with those parameters you don't want to see
> also local to that subroutine.
> E.g.
>
> def fib(n):
>     ' return the n-th Fibonacci number '
>     a,b = 0,1
>     def fib1(ap,bp):
>        ' for f_n,f_n+1, return f_n+1,f_n+2 '
>        return bp,ap+b
>     for i in xrange(n):
>        a,b = fib1(a,b)
>     return a

That's a fairly useless use of a nested function... you could in-line
it without any effort at all:

def fib(n):
    a,b = 0,1
    for i in xrange(n):
        a,b = b,a+b
    return a

Even in the OP's example, where the inner function needs to call
itself recursively, it doesn't need to be a closure; a simple
out-of-line helper function does work (and has already been suggested;
Gregory was, I think, first). In my opinion, it's not materially
different from having an argument with a default.

ChrisA


From alister.nospam.ware at ntlworld.com  Sat Jan 17 15:22:48 2015
From: alister.nospam.ware at ntlworld.com (alister)
Date: Sat, 17 Jan 2015 20:22:48 GMT
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net> <m9eaiq$o7v$1@reader1.panix.com>
 <m9ebv5$ovq$1@dont-email.me>
Message-ID: <swzuw.150781$e84.53768@fx29.am4>

On Sat, 17 Jan 2015 19:08:21 +0000, Dan Sommers wrote:

> On Sat, 17 Jan 2015 18:44:42 +0000, Grant Edwards wrote:
> 
>> ... somebody who only knows how to write C++ [though he can do it in
>> several different languages].
> 
> +1 QOTW (brilliant phrases in other threads are off topic and are
> disqualified)
> 
> I have also suffered through such maintenance, but I have never
> described it quite so succinctly.
> 
>> There was lot's of quiet swearing.
> 
> "Quiet" is *not* one of my strong points.

How about "Some programmes have 20 years of experience, some have 1 year 
of experience 20 times"

it covers pretty much the same poor coding practices.

-- 
Ditat Deus.
	[God enriches]


From pinoparuzzeddu at gmx.com  Sat Jan 17 15:35:46 2015
From: pinoparuzzeddu at gmx.com (GIANNI)
Date: Sat, 17 Jan 2015 12:35:46 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
References: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
Message-ID: <79e49ab7-761f-4c00-b2b9-f78bf4530428@googlegroups.com>

-- redacted --


From greg.ewing at canterbury.ac.nz  Sat Jan 17 16:07:40 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sun, 18 Jan 2015 10:07:40 +1300
Subject: recursive function: use a global or pass a parameter?
In-Reply-To: <roy-F5161B.10193317012015@news.panix.com>
References: <5e4ccec6-7a00-467d-8cf6-258ab0421c90@googlegroups.com>
 <54ba3654$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <roy-F5161B.10193317012015@news.panix.com>
Message-ID: <ci018uFo04jU1@mid.individual.net>

Roy Smith wrote:
> I will commonly put something like:
> 
> import logging
> logger = logging.getLogger("logger-name-for-my-module")

But that's not really a global variable, it's a
global constant. There's nothing wrong with those,
we use them all the time -- classes, functions, etc.

If you were to rebind logger to a different one from
time to time in your code, *then* it would be a global
variable, subject to the usual cautions.

-- 
Greg


From greg.ewing at canterbury.ac.nz  Sat Jan 17 16:25:42 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sun, 18 Jan 2015 10:25:42 +1300
Subject: recursive function: use a global or pass a parameter?
In-Reply-To: <e8cf4ecf-90f0-430d-843c-d6f3ec3b3aef@googlegroups.com>
References: <5e4ccec6-7a00-467d-8cf6-258ab0421c90@googlegroups.com>
 <mailman.17804.1421433277.18130.python-list@python.org>
 <e8cf4ecf-90f0-430d-843c-d6f3ec3b3aef@googlegroups.com>
Message-ID: <ci02aoFo8tkU1@mid.individual.net>

Yawar Amin wrote:

> Cool ... but it looks like this can still potentially hit the max
> recursion limit?

It depends on the nature of your data. If the data is
a tree, it's very unlikely you'll reach the recursion
limit unless the tree is massively unbalanced.

If there's a chance of that, or if the data structure
is really a graph that could contain long linear
chains, then a non-recursive solution is safer.

Incidentally, Python's pickle suffers from this
problem -- it's possible to create a structure that
can't be pickled due to excessive recursion depth:

 >>> x = []
 >>> for i in range(5000):
...  x = [x]
...
 >>> import pickle
 >>> s = pickle.dumps(x)
Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
RuntimeError: maximum recursion depth exceeded while pickling an object

Fortunately, the kinds of structures that cause this
tend not to be used in Python, e.g. we normally use
Python list objects instead of linked lists. So most
of the time, pickle gets away with using recursion.

-- 
Greg


From greg.ewing at canterbury.ac.nz  Sat Jan 17 16:48:18 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sun, 18 Jan 2015 10:48:18 +1300
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <ci03l2Fohi7U1@mid.individual.net>

Steven D'Aprano wrote:

> def a(x=4)
>     x+2
> end
> 
> a + b => 7
> a+b   => 7
> a+ b  => 7
> a +b  => 3
> 
> A shiny new penny for any non-Ruby coder who can explain that!

Seems pretty obvious to me: the Ruby interpreter is
infested with demons.

DWIM = Demonic Whim Infers Meaning

-- 
Greg


From greg.ewing at canterbury.ac.nz  Sat Jan 17 16:56:07 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sun, 18 Jan 2015 10:56:07 +1300
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <mailman.17812.1421501640.18130.python-list@python.org>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi>
 <mailman.17812.1421501640.18130.python-list@python.org>
Message-ID: <ci043pFoo3pU1@mid.individual.net>

Chris Angelico wrote:
> Every once in a while, someone looks at Py2's print statement and
> Py3's print function and says, "why not allow function calls without
> parentheses". This right here is why not.

There's also the fact that the parens are needed to
distinguish between calling a function and using the
function itself as a value.

Ruby doesn't have that problem because it doesn't
have functions, only methods, and the only thing you
can do with a method in Ruby is call it.

-- 
Greg


From rosuav at gmail.com  Sat Jan 17 17:04:25 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 18 Jan 2015 09:04:25 +1100
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <ci043pFoo3pU1@mid.individual.net>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com>
 <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi>
 <mailman.17812.1421501640.18130.python-list@python.org>
 <ci043pFoo3pU1@mid.individual.net>
Message-ID: <CAPTjJmoAsbUe8aJAcYyNjT=QSCi7hGzkQgtN1XL13nD-cQzcvg@mail.gmail.com>

On Sun, Jan 18, 2015 at 8:56 AM, Gregory Ewing
<greg.ewing at canterbury.ac.nz> wrote:
> Ruby doesn't have that problem because it doesn't
> have functions, only methods, and the only thing you
> can do with a method in Ruby is call it.

So functions aren't first-class objects in Ruby? Bleh. I've become
quite accustomed to passing them around casually, in several
languages. Even C lets you pass function pointers around.

ChrisA


From greg.ewing at canterbury.ac.nz  Sat Jan 17 17:31:28 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sun, 18 Jan 2015 11:31:28 +1300
Subject: Why do the URLs of posts here change?
In-Reply-To: <54ba9041$0$6961$e4fe514c@dreader36.news.xs4all.nl>
References: <54afb3ed$0$12995$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17520.1420805082.18130.python-list@python.org>
 <chbk5cF7dv9U1@mid.individual.net>
 <mailman.17551.1420862015.18130.python-list@python.org>
 <54ba9041$0$6961$e4fe514c@dreader36.news.xs4all.nl>
Message-ID: <ci0662Fp9a3U1@mid.individual.net>

Albert van der Horst wrote:
> Knowing that the source is an mbox file, I don't need to follow
> that link to conclude that one is not very inventive.
> It suffices to replace the content of the message by
> a repetition of 'xxxx\n'.

Editing the mbox file isn't the problem. From what I
gather, telling mailman to regenerate the web pages
from the mbox file causes all the messages to be given
new ID numbers, even if they remain in the same places
in the mbox.

So the web pages as well as the mbox would have to
be edited by hand, instead of using the auto regen
process.

-- 
Greg


From greg.ewing at canterbury.ac.nz  Sat Jan 17 17:41:42 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sun, 18 Jan 2015 11:41:42 +1300
Subject: lambdak: multi-line lambda implementation in native Python
In-Reply-To: <qotppad39ei.fsf@ruuvi.it.helsinki.fi>
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi> <87a91hoebi.fsf@elektro.pacujo.net>
 <qotppad39ei.fsf@ruuvi.it.helsinki.fi>
Message-ID: <ci06p8Fpe2mU1@mid.individual.net>

Jussi Piitulainen wrote:
> I prefer parentheses.
> They are not nearly as fragile.

So do I, but the other day I had occasion to write a
small piece of VBScript, and I discovered that it
actually *forbids* parens around the arguments to
procedure calls (but not function calls).

Fortunately, it requires (or at least allows, not
sure which) commas between the args, so things aren't
as bad as they *could* be.

Also fortunately, the error message was, by the
usual standard of Microsoft error messages,
remarkably helpful.

-- 
Greg


From steve+comp.lang.python at pearwood.info  Sat Jan 17 18:46:10 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 18 Jan 2015 10:46:10 +1100
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <mailman.17815.1421519526.18130.python-list@python.org>
Message-ID: <54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>

Mark Lawrence wrote:

> Bah humbug, this has reminded me of doing secure work whereby each
> individual had two passwords, both of which had to be changed every
> thirty days, and rules were enforced so you couldn't just increment the
> number at the end of a word or similar.

I hate and despise systems that force you to arbitrarily change a good
strong password after N days for no good reason.

The utterly bad reason often given by people who don't understand
probability is that if hackers try to guess your password by brute-force,
changing the password regularly will make it harder for them. That's simply
wrong, and is based on a misunderstanding of probability.

The merely poor reason given by the more thoughtful sys admins is, if the
password hashes get stolen, the hacker has a maximum of N days (and
possibly less) to crack the hashes and recover the passwords before they
get changed. That's okay as far as it goes, but it's the wrong solution for
the problem. The right solution is to salt the passwords, and to secure the
hashes from theft. Users should only be forced to change their password if
the hashes are stolen, not at arbitrary intervals.

The problem with regular password changes is that it makes it significantly
harder remember passwords, especially one that you might only use rarely.
It encourages users to pick weak, trivial passwords that can be trivially
incremented each time the computer insists they change it, "blahblah-JAN"
or "blahblahblah1", or to simply write the password down or a Post-it note
on their computer. In isolation, regular password changes seems like a good
idea, but in practice they are not.

Password management is hard enough without having to throw away perfectly
good, strong, memorable passwords every N days "just in case".



-- 
Steven



From rosuav at gmail.com  Sat Jan 17 19:04:57 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 18 Jan 2015 11:04:57 +1100
Subject: Hello World
In-Reply-To: <54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <mailman.17815.1421519526.18130.python-list@python.org>
 <54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmps7zjqqde_nKe2=g18xoL4QG+_n1SctANojWYeyCGxTw@mail.gmail.com>

On Sun, Jan 18, 2015 at 10:46 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> The merely poor reason given by the more thoughtful sys admins is, if the
> password hashes get stolen, the hacker has a maximum of N days (and
> possibly less) to crack the hashes and recover the passwords before they
> get changed. That's okay as far as it goes, but it's the wrong solution for
> the problem.

Related to that is another reason I've heard: if your password is
figured out by some means other than hash theft [1], there's a maximum
of N days to make use of it. But let's face it, if someone gets hold
of one of your accounts, it won't take long to do serious damage. Even
if it's not a high-profile target like email or banking, a service
with your password known by someone else is a problem *now*, not
"after a month of research" or something.

Password maximum age is the wrong solution to a few problems, and is
itself a problem. Don't do it.

ChrisA

[1] eg http://xkcd.com/792/


From jeanpierreda at gmail.com  Sat Jan 17 19:06:06 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Sat, 17 Jan 2015 16:06:06 -0800
Subject: Hello World
In-Reply-To: <CAPTjJmr0Y1ismpL+p=Kv4GAxvSf13px9nS45HKCqxFQRZuNrQw@mail.gmail.com>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <b157ffcf-aead-463d-b152-6abbd4994d56@googlegroups.com>
 <CAPTjJmpVK4L-1kBVywd4o=mXFN=iWhjJzWZbxZDgw3nfK8WbSQ@mail.gmail.com>
 <m75pfm$2ah$1@ger.gmane.org>
 <CAPTjJmr0Y1ismpL+p=Kv4GAxvSf13px9nS45HKCqxFQRZuNrQw@mail.gmail.com>
Message-ID: <CABicbJJToJu42vHA7OXSCmXLMcaSVsbHni+oqO5GZN3t_yPf4g@mail.gmail.com>

Sorry for necro.

On Sat, Dec 20, 2014 at 10:44 PM, Chris Angelico <rosuav at gmail.com> wrote:
> On Sun, Dec 21, 2014 at 5:31 PM, Terry Reedy <tjreedy at udel.edu> wrote:
>> Just to be clear, writing to sys.stdout works fine in Idle.
>>>>> import sys; sys.stdout.write('hello ')
>> hello  #2.7
>>
>> In 3.4, the number of chars? bytes? is returned and written also.
>>
>> Whether you mean something different by 'stdout' or not, I am not sure.  The
>> error is from writing to a non-existent file descriptor.
>
> That's because sys.stdout is replaced. But stdout itself, file
> descriptor 1, is not available:

It surprises me that IDLE, and most other shells, don't dup2
stdout/err/in so that those FDs talk to IDLE.

-- Devin


From jsf80238 at gmail.com  Sat Jan 17 20:19:10 2015
From: jsf80238 at gmail.com (Jason Friedman)
Date: Sat, 17 Jan 2015 18:19:10 -0700
Subject: Hello World
In-Reply-To: <CAPTjJmps7zjqqde_nKe2=g18xoL4QG+_n1SctANojWYeyCGxTw@mail.gmail.com>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <mailman.17815.1421519526.18130.python-list@python.org>
 <54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmps7zjqqde_nKe2=g18xoL4QG+_n1SctANojWYeyCGxTw@mail.gmail.com>
Message-ID: <CANy1k1jopS7gLwLFziKrStfOJK+witYraGPdFAPtQYuP648_mQ@mail.gmail.com>

>
>
> Password maximum age is the wrong solution to a few problems, and is
> itself a problem. Don't do it.
>
> Bruce Schneier (mostly) agrees with you:
https://www.schneier.com/blog/archives/2010/11/changing_passwo.html.
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From torriem at gmail.com  Sat Jan 17 21:09:16 2015
From: torriem at gmail.com (Michael Torrie)
Date: Sat, 17 Jan 2015 19:09:16 -0700
Subject: Hello World
In-Reply-To: <m9eane$qfm$1@dont-email.me>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <54baa4b1$0$15857$e4fe514c@dreader35.news.xs4all.nl>
 <m9eane$qfm$1@dont-email.me>
Message-ID: <54BB15CC.7020302@gmail.com>

On 01/17/2015 11:47 AM, Michael Str?der wrote:
>> sudo makes administrators careless, lazy and it is not simple at all.
> 
> Admins must have separate accounts with separate credentials for
> administrative work and must be careful when using an administrative account.

Right.  This is not a bad idea in a large organization.

In any case, Sudo is more auditable than su in my opinion, but more
importantly, it's much easier to revoke.  With su, if I fire an admin, I
have to change root passwords on every machine, and redistribute the new
password to every admin that needs it.  With sudo, I might still change
the root password, but I'll lock the root password up in a safe box
somewhere, and life goes on for everyone else.  In fact with root
disabled entirely, the whole root password needing to be changed when a
person leaves the company is completely eliminated.  sudo allows us
(especially with the idea about separate admin credentials) to have
multiple, controllable, auditable, root passwords in effect.  Surely the
benefit of this can be seen.

Another good alternative to sudo is ksu, which is a kerberized su.  This
also provides an excellent audit trail, and is easy to revoke.  This may
be more to Mr. van der Horst's liking, as normally ksu is configured to
accept only principals with a /admin suffix (arbitrarily chosen). So
admins would have their normal principal, and their admin principal.
It's a pretty slick system if you have Kerberos up and running.



From torriem at gmail.com  Sat Jan 17 21:13:56 2015
From: torriem at gmail.com (Michael Torrie)
Date: Sat, 17 Jan 2015 19:13:56 -0700
Subject: Hello World
In-Reply-To: <CAPTjJmps7zjqqde_nKe2=g18xoL4QG+_n1SctANojWYeyCGxTw@mail.gmail.com>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <mailman.17815.1421519526.18130.python-list@python.org>
 <54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmps7zjqqde_nKe2=g18xoL4QG+_n1SctANojWYeyCGxTw@mail.gmail.com>
Message-ID: <54BB16E4.90704@gmail.com>

On 01/17/2015 05:04 PM, Chris Angelico wrote:
> Related to that is another reason I've heard: if your password is
> figured out by some means other than hash theft [1], there's a maximum
> of N days to make use of it. But let's face it, if someone gets hold
> of one of your accounts, it won't take long to do serious damage. Even
> if it's not a high-profile target like email or banking, a service
> with your password known by someone else is a problem *now*, not
> "after a month of research" or something.
> 
> Password maximum age is the wrong solution to a few problems, and is
> itself a problem. Don't do it.

Most password policies are the wrong solution.  They don't seem to
increase the time to guess the password given the hash, and they
certainly don't physically secure anything, as passwords that have to be
changed often and to bizarre notions of upper case, lower case, digits,
non-alphanumeric characters, are guaranteed to be written down and
pasted to the monitor.

Like many of you I use a password manager these days.  It's pretty
slick.  But really it shows the absurdity of the situation.  Instead of
passwords we should all just use private/public keypairs and store the
private keys in a digital wallet.  Forget this password garbage with
it's 50-70 bits of entropy.  Let's go for 2048-bit keys and be done with
it, if we're going to require the use of password managers.



From steve+comp.lang.python at pearwood.info  Sat Jan 17 21:37:54 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 18 Jan 2015 13:37:54 +1100
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <54baa4b1$0$15857$e4fe514c@dreader35.news.xs4all.nl>
Message-ID: <54bb1c83$0$12979$c3e8da3$5496439d@news.astraweb.com>

Albert van der Horst wrote:

> In article <h9gqob-c3e.ln1 at esprimo.zbmc.eu>,  <cl at isbd.net> wrote:
>>Michael Torrie <torriem at gmail.com> wrote:
>>> On 01/17/2015 07:51 AM, Albert van der Horst wrote:
>>> > In article <mailman.17471.1420721626.18130.python-list at python.org>,
>>> > Chris Angelico  <rosuav at gmail.com> wrote:
>>> > <SNIP>
>>> >>
>>> >> But sure. If you want to cut out complication, dispense with user
>>> >> accounts altogether and run everything as root. That's WAY simpler!
>>> >
>>> > I didn't except this strawman argument from you.
>>> > Of course you need a distinction between doing system things as
>>> > root, and working as a normal user. You just don't need sudo.
>>>
>>> I just don't see the distinction.  What's the difference between having
>>> to type in a root password and having to type in your own administrative
>>> user password?  Guess we're all just struggling to understand your logic
>>> here.
>>>
>>One big distinction is that you need to know two passwords to get root
>>access if there's a real root account as opposed to using sudo.  This
>>only applies of course if direct root login isn't allowed (via ssh or
>>whatever).
> 
> The other is that if a dozen users have sudo possibility, one compromised
> password compromises the whole system. The same administrators that like
> sudo will force the users into a "safe" password of at least 8 characters
> a special sign a number and a capital, instead of educating them to
> use a strong password like the_horse_eats_yellow_stones. 1]

Sigh. I like XKCD, I really do, but anyone who thinks that brute force
attacks cannot simply replace words for characters is deluding themselves.

Consider a password like "mg93H$8s". Each character is taken from an
alphabet of lowercase and uppercase letters plus digits, plus 32
punctuation characters and other symbols available on a US keyboard. There
are 26+26+10+32 = 94 different "letters" in this alphabet. If your password
is ten characters long, there is a potential pool of 94**10 available
passwords. Let's say we strip out 90% of them for being "too easy to guess"
(say, eight "A"s in a row, or it happens to contain your username). That
still leaves us with:

94**10//10 = 5386151140948997017

potential passwords.

Now consider the XKCD scheme. You pick four words from a dictionary and
concatenate them. On my system, /usr/share/dict/words has a little less
than 500,000 words. The problem is, most of them are not really memorable,
and many of them are very low entropy. Here's a selection from the first
few starting with A:

A  A.  a  a'  a-  a.  A-1  A1  a1  A4  A5  AA  aa
A.A.A.  AAA  aaa  AAAA

So in practice people are going to choose words from a much, much smaller
selection. I estimate that most people are going to choose words from a
pool of about 10,000 words or so, but let's imagine that you have four
times the vocabulary (or imagination) of the average person and pick from a
pool of 40,000 words, specially crafted to avoid low-entropy selections
such as "AAA A4 aa a". That gives:

40000**4 = 2560000000000000000

potential passwords, half that of the conventional scheme. And if people
have biases in the words they pick -- and you better believe they will --
that will be reduced even further. Password crackers will take advantage of
the fact that most XKCD-style passwords will include at least one of the
most common thousand or so words, reducing the search space significantly.

I believe that the state of the art of password cracking is such now that
people cannot realistically expect to remember sufficiently strong
passwords for all the things they need passwords for. I believe that the
only good solution is to have one strong passphrase that you use to protect
a password manager, which in turn uses long (12 character or more),
completely random passwords.

Even that doesn't protect you, because your security is controlled by
websites and banks etc. with stupid security policies. E.g. I am forced to
deal with one bank that uses a cryptographic key to sign in to their bank,
but your passphrase is limited to exactly eight characters. Another bank I
use limits you to SIX characters, taken from case-insensitive(!) letters,
digits, and a small set of punctuation.

At least they do enforce rate limiting on account logins: three wrong login
attempts and they lock your account and force you to go to a branch in
person to recover it. (Can you say "Denial Of Service Attack"? I can.)



> Compare that to
> "Dear administrator, I've to do this. Can I have the root password."
> "Sure here it is" Looks over users shoulder. "Are you ready?"
> Make sure he's logged out. Uses random generator for a new password.

That is a ridiculously impractical system for anything other than a home
system.

Problems include:

- You have a single point of failure, the one administrator who controls
access to the root password. The day he stays home with his phone switched
off to play WOW is the day the mail server dies and you need root to fix
it. The "Bus Factor" (what do you do when the administrator gets hit by a
bus?) is critical.

- You might be changing the root password dozens of times a day; if you have
to restore your system from backup, chances are nobody will know what the
root password was this time two days ago.

- Lack of accountability: somebody used the root account to delete files
they're not supposed to. Who was it? No idea, it was somebody with root,
which could mean anyone who could have come up with a sufficiently
plausible excuse to convince the trusted admin to give them root access
that day. With sudo, all commands are logged, and even if the sudoer
runs "bash" to defeat the logging, it is obvious that they have done so and
can be asked to explain why they shouldn't be fired for breaching company
policy.

- Completely impractical for big sites. Imagine Google, with tens of
thousands of machines, and thousands of administrators across multiple
timezones, if they all had to go through a single admin to request the root
password.



 

-- 
Steven



From steve+comp.lang.python at pearwood.info  Sat Jan 17 21:45:04 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 18 Jan 2015 13:45:04 +1100
Subject: lambdak: multi-line lambda implementation in native Python
References: <3d8068b3-7b63-43c0-bbf2-6111b2c73aa4@googlegroups.com>
 <roy-4AAFA6.08034915012015@news.panix.com>
 <mailman.17759.1421327478.18130.python-list@python.org>
 <87zj9kb2j0.fsf@elektro.pacujo.net>
 <roy-A43F6D.20334015012015@news.panix.com> <54B86CF8.7040602@gmail.com>
 <mailman.17783.1421380815.18130.python-list@python.org>
 <chte6eF3ke9U1@mid.individual.net>
 <54ba39e0$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <qotmw5hbs1d.fsf@ruuvi.it.helsinki.fi> <87a91hoebi.fsf@elektro.pacujo.net>
 <54ba5a25$0$12991$c3e8da3$5496439d@news.astraweb.com>
 <roy-0DF8EA.12200517012015@news.panix.com>
Message-ID: <54bb1e31$0$12977$c3e8da3$5496439d@news.astraweb.com>

Roy Smith wrote:

> In article <54ba5a25$0$12991$c3e8da3$5496439d at news.astraweb.com>,
>  Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
> 
>> Whitespace is significant in nearly all programming languages, and so it
>> should be. Whitespace separates tokens, and lines, and is a natural way
>> of writing (at least for people using Western languages).
> 
>>>> """x""" == " " "x" " "
> False

I'm not sure what you are trying to say there. The left hand side is the
string "x", the right hand side is the string " x ". I can tell you why
they're different, I just can't tell you the definitive component in the
Python interpreter which causes that difference (parser, lexer, keyhole
optimizer, compiler...). I suspect the answer is implementation-dependent.

""" is not the same as " " ", just as 123 and 1 2 3 are not the same.



>> *Indentation* is significant to Python, while most languages enable
>> tedious and never-ending style wars over the correct placement of braces
>> vis a vis indentation, because their language is too simple-minded to
>> infer block structure from indentation. Python does derive block
>> structure from indentation, as god intended (otherwise he wouldn't have
>> put tab keys on typewriters) and so Python doesn't suffer from the
>> interminable arguments about formatting that most other languages do.
> 
> Well, we do get to argue about
> 
> x = [1,
>      2,
>      3]
> 
> vs.
> 
> x = [1,
>      2,
>      3,
>     ]
> 
> vs. a few other variations based on how you group the first element with
> the opening bracket, or the last element with the closing bracket, and,
> of course, whether you use the last trailing comma or not.

True, but nowhere near the Holy Wars about the One True Brace Style in
languages like C.




-- 
Steven



From steve+comp.lang.python at pearwood.info  Sat Jan 17 22:09:58 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 18 Jan 2015 14:09:58 +1100
Subject: numpy.allclose()
References: <54ba7113$0$12985$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17816.1421520205.18130.python-list@python.org>
Message-ID: <54bb2407$0$13002$c3e8da3$5496439d@news.astraweb.com>

Ian Kelly wrote:

> On Sat, Jan 17, 2015 at 7:26 AM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> I don't understand why they add the error tolerances together. I can
>> understand taking the minimum, or the maximum:
> 
> The usual idea is that the tolerance is calculated as a relative
> value, but an absolute tolerance is used instead when the values get
> close to zero, so under normal circumstances the relative tolerance
> will dominate and the absolute tolerance will be very small in
> comparison. 

That suggests that approx_equal() should return True if the actual error is
smaller than *either* the absolute or relative error, that is, using the
maximum.


> So why add them instead of taking the maximum? I'm not 
> sure, but I would guess it's probably for efficiency. Determining the
> maximum requires the CPU to perform a conditional branch that a simple
> addition does not.

That's... horrible. 

"Tell me whether these two numbers differ by at most X or Y%."

"Oh, that would take a nanosecond longer than I think is reasonable, so I'm
instead going to tell you whether they differ by some arbitrary Z instead."

I'm guessing that can only have come from the mindset of C/C++ programmers,
where this sort of thing is considered acceptable:

http://blogs.msdn.com/b/oldnewthing/archive/2014/06/27/10537746.aspx

:-)


> In any case, this is not unique to numpy.  See 
> e.g.:
> 
> https://books.google.com/books?id=CbH0AwAAQBAJ&pg=PA164
> (equation 8.26)

Ah, well as soon as you start using GPUs for numerical computation, you're
already living in a state of sin. GPU's attitude to numerical correctness
is best described as "meh, close enough".

Seriously, anyone familiar with the horrible state of numeric computing
prior to IEEE-756 surely cannot look at GPU numerics without having
flashbacks to the bad old days where:

    if x != 0:
        y = 1/x

could crash with a divide by zero!


[...]
>> * taking the minimum is equivalent to the rule "numbers are close if they
>>   differ by no more than BOTH the absolute tolerance AND the relative
>>   tolerance".
> 
> This is generally not the desired semantic, and it's not unheard of to
> pass 0 for one of the tolerances, in which case the minimum would
> clearly be incorrect.

True. In that case, you would have to treat 0 as a special case, which
starts getting messy.




-- 
Steven



From roy at panix.com  Sat Jan 17 22:18:51 2015
From: roy at panix.com (Roy Smith)
Date: Sat, 17 Jan 2015 22:18:51 -0500
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <54baa4b1$0$15857$e4fe514c@dreader35.news.xs4all.nl>
 <54bb1c83$0$12979$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <roy-6A98A2.22182117012015@news.panix.com>

In article <54bb1c83$0$12979$c3e8da3$5496439d at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> Even that doesn't protect you, because your security is controlled by
> websites and banks etc. with stupid security policies. E.g. I am forced to
> deal with one bank that uses a cryptographic key to sign in to their bank,
> but your passphrase is limited to exactly eight characters. Another bank I
> use limits you to SIX characters, taken from case-insensitive(!) letters,
> digits, and a small set of punctuation.

Tell me about it.  I have an E-Trade ATM card.  When I first got it, I 
set it up with a 6 digit PIN.  I was shocked to discover some time later 
that it actually only looks at the first 4 digits.  And, no, I'm not 
talking *characters*, I'm talking *digits*.  There are 10**4 possible 
PINs.  The mind boggles.

On the other hand, E-Trade gave me an RSA key fob so I use two-factor 
authentication on their web site.


From steve+comp.lang.python at pearwood.info  Sat Jan 17 22:45:34 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 18 Jan 2015 14:45:34 +1100
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <54baa4b1$0$15857$e4fe514c@dreader35.news.xs4all.nl>
 <54bb1c83$0$12979$c3e8da3$5496439d@news.astraweb.com>
 <roy-6A98A2.22182117012015@news.panix.com>
Message-ID: <54bb2c5f$0$12977$c3e8da3$5496439d@news.astraweb.com>

Roy Smith wrote:

> In article <54bb1c83$0$12979$c3e8da3$5496439d at news.astraweb.com>,
>  Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
> 
>> Even that doesn't protect you, because your security is controlled by
>> websites and banks etc. with stupid security policies. E.g. I am forced
>> to deal with one bank that uses a cryptographic key to sign in to their
>> bank, but your passphrase is limited to exactly eight characters. Another
>> bank I use limits you to SIX characters, taken from case-insensitive(!)
>> letters, digits, and a small set of punctuation.
> 
> Tell me about it.  I have an E-Trade ATM card.  When I first got it, I
> set it up with a 6 digit PIN.  I was shocked to discover some time later
> that it actually only looks at the first 4 digits.  And, no, I'm not
> talking *characters*, I'm talking *digits*.  There are 10**4 possible
> PINs.  The mind boggles.
> 
> On the other hand, E-Trade gave me an RSA key fob so I use two-factor
> authentication on their web site.

You know that two-factor authentication doesn't offer any real security
against Man In The Middle attacks? Scenario:

* You log in to the bank, and transfer $1 to me.
* Evil haxor intercepts the transfer between your PC and the Internet,
  changing it to a request to transfer ONE MILLION DOLLARS to evil 
  haxor's account.
* Bank receives the request and sends you a token.
* You receive the token and approve the transfer.
* Evil haxor makes the money disappear.
* When you complain to the bank that your account is ONE MILLION DOLLARS
  overdrawn, they insist that you authorized the transfer so their 
  liability is limited to exactly Sweet FA.

(I am very cynical about most of the "security features" the banks are
pushing for, since in my opinion they are more about giving the banks
plausible deniablity so they can push responsibility for security breaches
onto the customer.)


As soon as I heard that banks were turning to two-factor authentication I
predicted that attackers would trivially move to man-in-the-middle and
man-in-the-browser attacks to get around them. And sure enough, as long ago
as 2006 that's exactly what happened:

http://blog.washingtonpost.com/securityfix/2006/07/citibank_phish_spoofs_2factor_1.html

More here:

https://www.schneier.com/blog/archives/2012/09/man-in-the-midd_5.html

(read the comments for more examples)

All of the MITM attacks I know of involve social engineering attacks, but if
and when customers get too sophisticated to fall for phishing attacks[1],
the bad guys will move to scenarios like the one I described, where they
hijack your own legitimate transactions.




[1] Try not to laugh. It could happen.

-- 
Steven



From python.list at tim.thechases.com  Sat Jan 17 22:50:54 2015
From: python.list at tim.thechases.com (Tim Chase)
Date: Sat, 17 Jan 2015 21:50:54 -0600
Subject: Hello World
In-Reply-To: <roy-6A98A2.22182117012015@news.panix.com>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <54baa4b1$0$15857$e4fe514c@dreader35.news.xs4all.nl>
 <54bb1c83$0$12979$c3e8da3$5496439d@news.astraweb.com>
 <roy-6A98A2.22182117012015@news.panix.com>
Message-ID: <20150117215054.2269ab1c@bigbox.christie.dr>

On 2015-01-17 22:18, Roy Smith wrote:
> Tell me about it.  I have an E-Trade ATM card.  When I first got
> it, I set it up with a 6 digit PIN.  I was shocked to discover some
> time later that it actually only looks at the first 4 digits.  And,
> no, I'm not talking *characters*, I'm talking *digits*.  There are
> 10**4 possible PINs.  The mind boggles.

You think that's bad, one million Google Authenticator 2-factor
verification codes were leaked:

https://twitter.com/paulmutton/status/509991378647277568

Those hackers are a wily bunch.  ;-)


-tkc






From rosuav at gmail.com  Sun Jan 18 02:44:01 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 18 Jan 2015 18:44:01 +1100
Subject: Hello World
In-Reply-To: <20150117215054.2269ab1c@bigbox.christie.dr>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <54baa4b1$0$15857$e4fe514c@dreader35.news.xs4all.nl>
 <54bb1c83$0$12979$c3e8da3$5496439d@news.astraweb.com>
 <roy-6A98A2.22182117012015@news.panix.com>
 <20150117215054.2269ab1c@bigbox.christie.dr>
Message-ID: <CAPTjJmq+PXY_ia0Bhq_T3k-Jca21vcyUa4nUQF8s2=t-8eGV=g@mail.gmail.com>

On Sun, Jan 18, 2015 at 2:50 PM, Tim Chase
<python.list at tim.thechases.com> wrote:
> You think that's bad, one million Google Authenticator 2-factor
> verification codes were leaked:
>
> https://twitter.com/paulmutton/status/509991378647277568
>
> Those hackers are a wily bunch.  ;-)

http://torrent-city.net/download/Li/List-of-ALL-ip-addresses-[hacking-tool]-[source-code-included].5185923.html

ChrisA


From rosuav at gmail.com  Sun Jan 18 02:45:21 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 18 Jan 2015 18:45:21 +1100
Subject: Hello World
In-Reply-To: <54bb2c5f$0$12977$c3e8da3$5496439d@news.astraweb.com>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <54baa4b1$0$15857$e4fe514c@dreader35.news.xs4all.nl>
 <54bb1c83$0$12979$c3e8da3$5496439d@news.astraweb.com>
 <roy-6A98A2.22182117012015@news.panix.com>
 <54bb2c5f$0$12977$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmprAA3Z9NM_ZLv87VgiNsjRP+uktPJcqU4p-eBRf-ex4w@mail.gmail.com>

On Sun, Jan 18, 2015 at 2:45 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> (I am very cynical about most of the "security features" the banks are
> pushing for, since in my opinion they are more about giving the banks
> plausible deniablity so they can push responsibility for security breaches
> onto the customer.)

Definitely they are. Banks don't care about customers, they care about profits.

James Hacker: I see, it's just profits, isn't it, Sir Desmond?
Sir Desmond: It's not "just" profits - it's profits!
-- Yes Minister


ChrisA


From ian.g.kelly at gmail.com  Sun Jan 18 03:24:14 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Sun, 18 Jan 2015 01:24:14 -0700
Subject: numpy.allclose()
In-Reply-To: <54bb2407$0$13002$c3e8da3$5496439d@news.astraweb.com>
References: <54ba7113$0$12985$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17816.1421520205.18130.python-list@python.org>
 <54bb2407$0$13002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CALwzidkkdWO6p3YKDU9yg9Pykxp075YmPwM+wsUa8EE6U1cTuQ@mail.gmail.com>

On Sat, Jan 17, 2015 at 8:09 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> I'm guessing that can only have come from the mindset of C/C++ programmers,
> where this sort of thing is considered acceptable:

Maybe. The journal reference in the second link I posted dates the
practice back to at least 1975, a time predating K&R C, when it was
most notable as the language that Unix was written in. I wouldn't be
surprised if this actually originated from Fortran.


From rosuav at gmail.com  Sun Jan 18 05:00:54 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 18 Jan 2015 21:00:54 +1100
Subject: Hello World
In-Reply-To: <54BB16E4.90704@gmail.com>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <mailman.17815.1421519526.18130.python-list@python.org>
 <54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmps7zjqqde_nKe2=g18xoL4QG+_n1SctANojWYeyCGxTw@mail.gmail.com>
 <54BB16E4.90704@gmail.com>
Message-ID: <CAPTjJmqVpm2BZkcWMWz_faxko5a3Bfif0sxz_dJv1KvowWVetA@mail.gmail.com>

On Sun, Jan 18, 2015 at 1:13 PM, Michael Torrie <torriem at gmail.com> wrote:
> Like many of you I use a password manager these days.  It's pretty
> slick.  But really it shows the absurdity of the situation.  Instead of
> passwords we should all just use private/public keypairs and store the
> private keys in a digital wallet.  Forget this password garbage with
> it's 50-70 bits of entropy.  Let's go for 2048-bit keys and be done with
> it, if we're going to require the use of password managers.

Easy way to do a lot of that is to layer most things on top of SSH. I
can pull/push git repositories using my SSH keypairs, I can access the
local network mounts that way, all sorts of things can be done with a
system that's already deployed. It's easy to put your own service on
top of SSH too. Want simplicity? Passwords are fine. Want security?
Push the encryption and authentication down to a lower layer, and save
yourself the trouble.

ChrisA


From marko at pacujo.net  Sun Jan 18 05:03:44 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sun, 18 Jan 2015 12:03:44 +0200
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <mailman.17815.1421519526.18130.python-list@python.org>
 <54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmps7zjqqde_nKe2=g18xoL4QG+_n1SctANojWYeyCGxTw@mail.gmail.com>
 <mailman.17831.1421574655.18130.python-list@python.org>
Message-ID: <87bnlwl81r.fsf@elektro.pacujo.net>

Michael Torrie <torriem at gmail.com>:

> Most password policies are the wrong solution.

I believe passwords themselves are the wrong solution. I believe in a
physical, government-issue object capable of challenge-response. It can
then be beefed up with extra measures depending on the need.


Marko


From rosuav at gmail.com  Sun Jan 18 05:10:06 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 18 Jan 2015 21:10:06 +1100
Subject: Hello World
In-Reply-To: <87bnlwl81r.fsf@elektro.pacujo.net>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <mailman.17815.1421519526.18130.python-list@python.org>
 <54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmps7zjqqde_nKe2=g18xoL4QG+_n1SctANojWYeyCGxTw@mail.gmail.com>
 <mailman.17831.1421574655.18130.python-list@python.org>
 <87bnlwl81r.fsf@elektro.pacujo.net>
Message-ID: <CAPTjJmonv+s6y7ezxjZF9VaCm5Y+RkM7RSvKcaTkdJDEjOVVOA@mail.gmail.com>

On Sun, Jan 18, 2015 at 9:03 PM, Marko Rauhamaa <marko at pacujo.net> wrote:
> Michael Torrie <torriem at gmail.com>:
>
>> Most password policies are the wrong solution.
>
> I believe passwords themselves are the wrong solution. I believe in a
> physical, government-issue object capable of challenge-response. It can
> then be beefed up with extra measures depending on the need.

I can't tell whether you're serious or not. Do you actually trust
"government-issue" more than anything else, or is your tongue firmly
in your cheek?

Also, which government?

ChrisA


From steve+comp.lang.python at pearwood.info  Sun Jan 18 05:25:39 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 18 Jan 2015 21:25:39 +1100
Subject: numpy.allclose()
References: <54ba7113$0$12985$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17816.1421520205.18130.python-list@python.org>
 <54bb2407$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17826.1421569503.18130.python-list@python.org>
Message-ID: <54bb8a24$0$12980$c3e8da3$5496439d@news.astraweb.com>

Ian Kelly wrote:

> On Sat, Jan 17, 2015 at 8:09 PM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> I'm guessing that can only have come from the mindset of C/C++
>> programmers, where this sort of thing is considered acceptable:
> 
> Maybe. The journal reference in the second link I posted dates the
> practice back to at least 1975, a time predating K&R C, when it was
> most notable as the language that Unix was written in. I wouldn't be
> surprised if this actually originated from Fortran.

Ah, the good old days, when computer designers built machines where 1.0*X
could overflow and X-0.0 could underflow.




-- 
Steven



From laurent.pointal at laposte.net  Sun Jan 18 07:00:09 2015
From: laurent.pointal at laposte.net (Laurent Pointal)
Date: Sun, 18 Jan 2015 13:00:09 +0100
Subject: [Annonce] Une introduction =?UTF-8?B?w6A=?= Python 3 - nouvelle
 version
Message-ID: <54bba04a$0$1989$426a74cc@news.free.fr>

[updated book in french]

Bonjour,

L'ouvrage d'introduction ? la programmation avec Python3 de B.Cordeau et 
L.Pointal a ?t? mis ? jour en version 1.618. Outre des am?liorations dans la 
mise en page, les modifications suivantes ont ?t? r?alis?es:

* Tous les dessins ont ?t? refaits en utilisant le module LaTeX TikZ
* Changement de la pr?sentation des scripts et codes interpr?t?s Python
* Paragraphe 5.2.1 : corrections param?tres/arguments
* Ajout, paragraphe 6, d'une partie ?Python scientifique?
* Ajout, paragraphe 8.3.4, d'un exemple d'interface graphique
* Ajout, paragraphe 9.1.4, de ?La r?cursivit? terminale?
* Quelques mots, paragraphe 9.2.3, sur le ?duck tiping? et les annotations
* R??criture de l'annexe C : ?Jeux de caract?res et encodage?
* La table des mati?res d?taill?e est d?plac?e en fin de document
* Un ?Sommaire? est ajout? en d?but de document
* D?placement du glossaire en fin de document et ajout de liens aux entr?es
* Ajout de l'Abr?g? Dense
* Et aussi tout plein d'am?liorations et de corrections typos

L'ouvrage est distribu? suivant la licence Creative Commons BY-NC-SA-3.0. 
Il est disponible en version PDF, avec ses sources, sur la page: 
http://perso.limsi.fr/pointal/python:courspython3

Bonne lecture.

B.Cordeau & L.Pointal


From jerry.rocteur at gmail.com  Sun Jan 18 07:07:37 2015
From: jerry.rocteur at gmail.com (Jerry Rocteur)
Date: Sun, 18 Jan 2015 13:07:37 +0100
Subject: Trying to parse matchup.io (lxml, SGMLParser, urlparse)
Message-ID: <CAGAAoy0t3iWMiXY1gf1_tvdOg=HNOACLrC5b+JgNmiC3MeSY4w@mail.gmail.com>

Hi,

I'm trying to parse https://matchup.io/players/rocteur/friends

The body source I'm interested in contains blocks exactly like this

<tr class='friend'>
<td class='text--left'>
<a href="/players/mizucci0"><img alt="mizucci0" class="media__avatar"
src="https://matchup-io.s3.amazonaws.com/uploads/player/avatar/7651/7651_profile_150_square.jpeg"
/>
<div class='friend__info'>
<span>mizucci0</span>
<span>Mizuho</span>
</div>
</a></td>
<td class='delta-alt'>
29,646
<br>
steps
</td>
<td class='delta-alt'>
35,315
<br>
steps
</td>
<td class='delta-alt'>
818.7
<br>
Miles
</td>
</tr>

I wanted to do it Python as I'm learning and I looked at the different
modules but it isn't easy for me to work out the best way to do this
as most tutorials I see use complicated classes and I just want to
parse this one paragraph at a time (as I would do in Perl) and print

1 mizuho 26648 35315
2 xxxxxx  99999 99999
3 xxxxxx 99999 99999

etc. (in the above case I'm ignoring 818.7 and Miles.

The best way I found so far is this:

from lxml import html
import requests
page = requests.get("https://matchup.io/players/rocteur/friends/week/")
tree = html.fromstring(page.text)
a = tree.xpath('//span/text()')
b = tree.xpath('//td/text()')

And the manipulating indices

e.g.
print "%s %s %s %s" % (a[usern], a[users], b[tots], b[weekb])
    tots += 4
    weekb += 4
    usern += 2
    users += 2

But it isn't very scientific ;-)

Which module would you use and how would you suggest is the best way to do it ?

Thanks very much in advance, I haven't done a lot of HTML parsing.. I
would much prefer using WebServices and an API but unfortunately they
don't have it.
-- 
Jerry Rocteur


From roy at panix.com  Sun Jan 18 07:26:53 2015
From: roy at panix.com (Roy Smith)
Date: Sun, 18 Jan 2015 07:26:53 -0500
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <54baa4b1$0$15857$e4fe514c@dreader35.news.xs4all.nl>
 <54bb1c83$0$12979$c3e8da3$5496439d@news.astraweb.com>
 <roy-6A98A2.22182117012015@news.panix.com>
 <54bb2c5f$0$12977$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <roy-120F05.07262318012015@news.panix.com>

In article <54bb2c5f$0$12977$c3e8da3$5496439d at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> You know that two-factor authentication doesn't offer any real security
> against Man In The Middle attacks?

The fact that TFA doesn't solve all problems doesn't change the fact 
that it solves some of them.


From michael at stroeder.com  Sun Jan 18 08:30:59 2015
From: michael at stroeder.com (=?UTF-8?Q?Michael_Str=c3=b6der?=)
Date: Sun, 18 Jan 2015 14:30:59 +0100
Subject: Hello World
In-Reply-To: <54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <mailman.17815.1421519526.18130.python-list@python.org>
 <54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <m9gchn$kgf$1@dont-email.me>

Steven D'Aprano wrote:
> Mark Lawrence wrote:
> 
>> Bah humbug, this has reminded me of doing secure work whereby each
>> individual had two passwords, both of which had to be changed every
>> thirty days, and rules were enforced so you couldn't just increment the
>> number at the end of a word or similar.
> 
> I hate and despise systems that force you to arbitrarily change a good
> strong password after N days for no good reason.
> 
> The utterly bad reason often given by people who don't understand
> probability is that if hackers try to guess your password by brute-force,
> changing the password regularly will make it harder for them. That's simply
> wrong, and is based on a misunderstanding of probability.

But there's a probability > 0 that one of the systems where an admin has to
use his/her password was hacked and that passwords gets stolen there. It's
hard to find out in case of skilled hackers.

=> have more than one account for different security areas and have password
aging in place.

Ciao, Michael.


From michael at stroeder.com  Sun Jan 18 08:32:57 2015
From: michael at stroeder.com (=?UTF-8?Q?Michael_Str=c3=b6der?=)
Date: Sun, 18 Jan 2015 14:32:57 +0100
Subject: Hello World
In-Reply-To: <mailman.17831.1421574655.18130.python-list@python.org>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <mailman.17815.1421519526.18130.python-list@python.org>
 <54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmps7zjqqde_nKe2=g18xoL4QG+_n1SctANojWYeyCGxTw@mail.gmail.com>
 <mailman.17831.1421574655.18130.python-list@python.org>
Message-ID: <m9gclb$kgf$2@dont-email.me>

Michael Torrie wrote:
> Like many of you I use a password manager these days.  It's pretty
> slick.  But really it shows the absurdity of the situation.  Instead of
> passwords we should all just use private/public keypairs and store the
> private keys in a digital wallet.  Forget this password garbage with
> it's 50-70 bits of entropy.  Let's go for 2048-bit keys and be done with
> it, if we're going to require the use of password managers.

Yes, and that's easy e.g. with SSH. And in theory it's easy with SSL/TLS. But
support for client certs in browsers really suck (try to change the login once
you've chosen a client cert without closing the browser).

Ciao, Michael.



From michael at stroeder.com  Sun Jan 18 08:34:00 2015
From: michael at stroeder.com (=?UTF-8?Q?Michael_Str=c3=b6der?=)
Date: Sun, 18 Jan 2015 14:34:00 +0100
Subject: Hello World
In-Reply-To: <87bnlwl81r.fsf@elektro.pacujo.net>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>	<mailman.17077.1419144290.18130.python-list@python.org>	<54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>	<mailman.17471.1420721626.18130.python-list@python.org>	<54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>	<mailman.17814.1421512178.18130.python-list@python.org>	<h9gqob-c3e.ln1@esprimo.zbmc.eu>	<mailman.17815.1421519526.18130.python-list@python.org>	<54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>	<CAPTjJmps7zjqqde_nKe2=g18xoL4QG+_n1SctANojWYeyCGxTw@mail.gmail.com>	<mailman.17831.1421574655.18130.python-list@python.org>
 <87bnlwl81r.fsf@elektro.pacujo.net>
Message-ID: <m9gcna$kgf$3@dont-email.me>

Marko Rauhamaa wrote:
> I believe in a
> physical, government-issue object
            ^^^^^^^^^^^^^^^^
Did you forget the smiley? Or where were you during the last 1,5 years?

Ciao, Michael.



From michael at stroeder.com  Sun Jan 18 08:35:43 2015
From: michael at stroeder.com (=?UTF-8?Q?Michael_Str=c3=b6der?=)
Date: Sun, 18 Jan 2015 14:35:43 +0100
Subject: Hello World
In-Reply-To: <mailman.17832.1421575264.18130.python-list@python.org>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <mailman.17815.1421519526.18130.python-list@python.org>
 <54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmps7zjqqde_nKe2=g18xoL4QG+_n1SctANojWYeyCGxTw@mail.gmail.com>
 <54BB16E4.90704@gmail.com>
 <mailman.17832.1421575264.18130.python-list@python.org>
Message-ID: <m9gcqh$kgf$4@dont-email.me>

Chris Angelico wrote:
> Want security?
> Push the encryption and authentication down to a lower layer, and save
> yourself the trouble.

Yes. And now for the next level: How to prevent unauthorized machines to
connect to your network?

Ciao, Michael.



From rosuav at gmail.com  Sun Jan 18 08:57:07 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 19 Jan 2015 00:57:07 +1100
Subject: Hello World
In-Reply-To: <m9gcqh$kgf$4@dont-email.me>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <mailman.17815.1421519526.18130.python-list@python.org>
 <54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmps7zjqqde_nKe2=g18xoL4QG+_n1SctANojWYeyCGxTw@mail.gmail.com>
 <54BB16E4.90704@gmail.com>
 <mailman.17832.1421575264.18130.python-list@python.org>
 <m9gcqh$kgf$4@dont-email.me>
Message-ID: <CAPTjJmqAwDeb-A3QoC28UmrZjWsWpyVdoHEch1gUxemmxckGew@mail.gmail.com>

On Mon, Jan 19, 2015 at 12:35 AM, Michael Str?der <michael at stroeder.com> wrote:
> Chris Angelico wrote:
>> Want security?
>> Push the encryption and authentication down to a lower layer, and save
>> yourself the trouble.
>
> Yes. And now for the next level: How to prevent unauthorized machines to
> connect to your network?

Extremely difficult, and in many cases quite unnecessary. No, you let
them on the network, and then make sure that won't hurt you more than
you're prepared to accept. For instance, someone could join my wifi
network - all they need is the WPA2 PSK, which is well known around
the place - and use/abuse our internet connection; but they couldn't
access my PostgreSQL databases, because the firewall doesn't permit
access to port 5432.

ChrisA


From michael at stroeder.com  Sun Jan 18 10:48:37 2015
From: michael at stroeder.com (=?UTF-8?Q?Michael_Str=c3=b6der?=)
Date: Sun, 18 Jan 2015 16:48:37 +0100
Subject: Hello World
In-Reply-To: <mailman.17833.1421589430.18130.python-list@python.org>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <mailman.17815.1421519526.18130.python-list@python.org>
 <54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmps7zjqqde_nKe2=g18xoL4QG+_n1SctANojWYeyCGxTw@mail.gmail.com>
 <54BB16E4.90704@gmail.com>
 <mailman.17832.1421575264.18130.python-list@python.org>
 <m9gcqh$kgf$4@dont-email.me>
 <mailman.17833.1421589430.18130.python-list@python.org>
Message-ID: <m9gkjo$l8h$1@dont-email.me>

Chris Angelico wrote:
> On Mon, Jan 19, 2015 at 12:35 AM, Michael Str?der <michael at stroeder.com> wrote:
>> Chris Angelico wrote:
>>> Want security?
>>> Push the encryption and authentication down to a lower layer, and save
>>> yourself the trouble.
>>
>> Yes. And now for the next level: How to prevent unauthorized machines to
>> connect to your network?
> 
> Extremely difficult, and in many cases quite unnecessary. No, you let
> them on the network, and then make sure that won't hurt you more than
> you're prepared to accept.

Somewhat true?

> For instance, someone could join my wifi
> network - all they need is the WPA2 PSK, which is well known around
> the place - and use/abuse our internet connection; but they couldn't
> access my PostgreSQL databases, because the firewall doesn't permit
> access to port 5432.

?but your firewall relies on authenticity of IP addresses. Fail!

Ciao, Michael.



From marko at pacujo.net  Sun Jan 18 11:03:43 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sun, 18 Jan 2015 18:03:43 +0200
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <mailman.17815.1421519526.18130.python-list@python.org>
 <54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmps7zjqqde_nKe2=g18xoL4QG+_n1SctANojWYeyCGxTw@mail.gmail.com>
 <mailman.17831.1421574655.18130.python-list@python.org>
 <87bnlwl81r.fsf@elektro.pacujo.net> <m9gcna$kgf$3@dont-email.me>
Message-ID: <871tmskrds.fsf@elektro.pacujo.net>

Michael Str?der <michael at stroeder.com>:

> Marko Rauhamaa wrote:
>> I believe in a
>> physical, government-issue object
>             ^^^^^^^^^^^^^^^^
> Did you forget the smiley? Or where were you during the last 1,5 years?

You can juggle the issues all you want. In the end, there's no escaping
the governments' underwriting role. The TLS "chain of trust" we have
today is a joke and can be spoofed easily not only by governments but
really by anybody.

Authentication is still separate from privacy, which could be secured
from the governments if there were a will.


Marko


From jerry.rocteur at gmail.com  Sun Jan 18 11:04:57 2015
From: jerry.rocteur at gmail.com (Jerry Rocteur)
Date: Sun, 18 Jan 2015 17:04:57 +0100
Subject: Formatting string with accented characters for printing
Message-ID: <CAGAAoy3kyhwTexNNv3Bs0of=6h2dT6OD5kvZF-PUzauUCociQg@mail.gmail.com>

Hi,

When I try and format output when there are accented characters the
output does not look right.

e.g.

27 Angie Dickons                       67,638
28 Anne M?RESSE                 64,825

So the strings containing accented characters print one less than
those that don't.

I've tried both:

    print '{0:2} {1:25} {2} '.format( cnt, nam[num].encode('utf-8'),
steps[ind1])
    print "%3d %-25s %-7s" % ( cnt, nam[num].encode('utf-8'), steps[ind1])

I've searched but I can't see a solution..

I guess it is the way I'm printing nam[num].encode('utf-8') perhaps I
have to convert it first ?

Can someone please help.

Thanks

-- 
Jerry Rocteur

Jerry at rocteur.com


From quaker2012 at gmail.com  Sun Jan 18 11:45:06 2015
From: quaker2012 at gmail.com (Jo Barton)
Date: Sun, 18 Jan 2015 08:45:06 -0800 (PST)
Subject: How to use Pycharm to display the stack and heap python?
Message-ID: <676362c0-72bd-4249-83ea-80b91f3f3bf6@googlegroups.com>

I am new to programming. Difficult for me to understand code using http://www.pythontutor.com/visualize.html#. How to use Pycharm to display the stack and heap python?


From breamoreboy at yahoo.co.uk  Sun Jan 18 12:05:14 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 18 Jan 2015 17:05:14 +0000
Subject: How to use Pycharm to display the stack and heap python?
In-Reply-To: <676362c0-72bd-4249-83ea-80b91f3f3bf6@googlegroups.com>
References: <676362c0-72bd-4249-83ea-80b91f3f3bf6@googlegroups.com>
Message-ID: <m9gp4e$1an$1@ger.gmane.org>

On 18/01/2015 16:45, Jo Barton wrote:
> I am new to programming. Difficult for me to understand code using http://www.pythontutor.com/visualize.html#. How to use Pycharm to display the stack and heap python?
>

Hello and welcome :)

As you are new to programming please abandon all thoughts of looking at 
the stack and heap with Pycharm or any other tool.  Instead concentrate 
on writing code that can be easily tested at the interactive prompt.  As 
a beginner you might also be more comfortable on the tutor mailing list 
https://mail.python.org/mailman/listinfo/tutor

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rosuav at gmail.com  Sun Jan 18 12:08:56 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 19 Jan 2015 04:08:56 +1100
Subject: Hello World
In-Reply-To: <m9gkjo$l8h$1@dont-email.me>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <mailman.17815.1421519526.18130.python-list@python.org>
 <54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmps7zjqqde_nKe2=g18xoL4QG+_n1SctANojWYeyCGxTw@mail.gmail.com>
 <54BB16E4.90704@gmail.com>
 <mailman.17832.1421575264.18130.python-list@python.org>
 <m9gcqh$kgf$4@dont-email.me>
 <mailman.17833.1421589430.18130.python-list@python.org>
 <m9gkjo$l8h$1@dont-email.me>
Message-ID: <CAPTjJmpSbVoh04HPuit+yWbtzZy4ah-JXEjF_GpEJ+ENMnkNog@mail.gmail.com>

On Mon, Jan 19, 2015 at 2:48 AM, Michael Str?der <michael at stroeder.com> wrote:
>> For instance, someone could join my wifi
>> network - all they need is the WPA2 PSK, which is well known around
>> the place - and use/abuse our internet connection; but they couldn't
>> access my PostgreSQL databases, because the firewall doesn't permit
>> access to port 5432.
>
> ?but your firewall relies on authenticity of IP addresses. Fail!

No; I have two completely separate networks. If you're on the one that
anyone can easily get onto, it doesn't matter what your IP is, you do
not get access to certain ports on computers on the other side of the
firewall.

ChrisA


From __peter__ at web.de  Sun Jan 18 13:10:05 2015
From: __peter__ at web.de (Peter Otten)
Date: Sun, 18 Jan 2015 19:10:05 +0100
Subject: Trying to parse matchup.io (lxml, SGMLParser, urlparse)
References: <CAGAAoy0t3iWMiXY1gf1_tvdOg=HNOACLrC5b+JgNmiC3MeSY4w@mail.gmail.com>
Message-ID: <m9gstv$t2g$1@ger.gmane.org>

Jerry Rocteur wrote:

> Hi,
> 
> I'm trying to parse https://matchup.io/players/rocteur/friends
> 
> The body source I'm interested in contains blocks exactly like this
> 
> <tr class='friend'>
> <td class='text--left'>
> <a href="/players/mizucci0"><img alt="mizucci0" class="media__avatar"
> src="https://matchup-io.s3.amazonaws.com/uploads/player/avatar/7651/7651_profile_150_square.jpeg"
> />
> <div class='friend__info'>
> <span>mizucci0</span>
> <span>Mizuho</span>
> </div>
> </a></td>
> <td class='delta-alt'>
> 29,646
> <br>
> steps
> </td>
> <td class='delta-alt'>
> 35,315
> <br>
> steps
> </td>
> <td class='delta-alt'>
> 818.7
> <br>
> Miles
> </td>
> </tr>
> 
> I wanted to do it Python as I'm learning and I looked at the different
> modules but it isn't easy for me to work out the best way to do this
> as most tutorials I see use complicated classes and I just want to
> parse this one paragraph at a time (as I would do in Perl) and print
> 
> 1 mizuho 26648 35315
> 2 xxxxxx  99999 99999
> 3 xxxxxx 99999 99999
> 
> etc. (in the above case I'm ignoring 818.7 and Miles.
> 
> The best way I found so far is this:
> 
> from lxml import html
> import requests
> page = requests.get("https://matchup.io/players/rocteur/friends/week/")
> tree = html.fromstring(page.text)
> a = tree.xpath('//span/text()')
> b = tree.xpath('//td/text()')
> 
> And the manipulating indices
> 
> e.g.
> print "%s %s %s %s" % (a[usern], a[users], b[tots], b[weekb])
>     tots += 4
>     weekb += 4
>     usern += 2
>     users += 2
> 
> But it isn't very scientific ;-)

In my experience scraping data from a web page never is. The trick is to not 
waste too much time on your script once you have it working. The next 
overhaul of the scraped page is already on the way, and yes, it will heavily  
use javascript ;)

> Which module would you use and how would you suggest is the best way to do
> it ?

I think lxml is a good choice. Is there something with an API you prefer in 
Perl?

> Thanks very much in advance, I haven't done a lot of HTML parsing.. I
> would much prefer using WebServices and an API but unfortunately they
> don't have it.

PS: Here's my take:

import requests
import lxml.html

def get_html():
    return 
requests.get("https://matchup.io/players/rocteur/friends/week/").text

def fix(value):
    return value.text.strip().replace(",", "")

tree = lxml.html.fromstring(get_html())
for friend in tree.xpath('//tr[@class="friend"]'):
    values = friend.xpath('.//td[@class="delta-alt"]')
    print(
        friend.xpath('.//div/span[2]/text()')[0],
        fix(values[0]),
        fix(values[1])
    )




From rosuav at gmail.com  Sun Jan 18 13:13:54 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 19 Jan 2015 05:13:54 +1100
Subject: Formatting string with accented characters for printing
In-Reply-To: <CAGAAoy3kyhwTexNNv3Bs0of=6h2dT6OD5kvZF-PUzauUCociQg@mail.gmail.com>
References: <CAGAAoy3kyhwTexNNv3Bs0of=6h2dT6OD5kvZF-PUzauUCociQg@mail.gmail.com>
Message-ID: <CAPTjJmpXhVw4qtNDbdQLYmq=T-A-Fjg65Y7fWg88bR70WtjzBg@mail.gmail.com>

On Mon, Jan 19, 2015 at 3:04 AM, Jerry Rocteur <jerry.rocteur at gmail.com> wrote:
>
> I've tried both:
>
>     print '{0:2} {1:25} {2} '.format( cnt, nam[num].encode('utf-8'),
> steps[ind1])
>     print "%3d %-25s %-7s" % ( cnt, nam[num].encode('utf-8'), steps[ind1])
>
> I've searched but I can't see a solution..
>
> I guess it is the way I'm printing nam[num].encode('utf-8') perhaps I
> have to convert it first ?

Do the formatting on a Unicode string, and then encode the entire
string at the end. Or, better still, just work entirely with Unicode
all the way; if you switch to Python 3.4 (or anything else in the 3.x
line), print() takes Unicode strings. This kind of thing becomes easy.

ChrisA


From __peter__ at web.de  Sun Jan 18 13:28:52 2015
From: __peter__ at web.de (Peter Otten)
Date: Sun, 18 Jan 2015 19:28:52 +0100
Subject: Formatting string with accented characters for printing
References: <CAGAAoy3kyhwTexNNv3Bs0of=6h2dT6OD5kvZF-PUzauUCociQg@mail.gmail.com>
Message-ID: <m9gu14$d52$1@ger.gmane.org>

Jerry Rocteur wrote:

> When I try and format output when there are accented characters the
> output does not look right.
> 
> e.g.
> 
> 27 Angie Dickons                       67,638
> 28 Anne M?RESSE                 64,825
> 
> So the strings containing accented characters print one less than
> those that don't.
> 
> I've tried both:
> 
>     print '{0:2} {1:25} {2} '.format( cnt, nam[num].encode('utf-8'),
> steps[ind1])
>     print "%3d %-25s %-7s" % ( cnt, nam[num].encode('utf-8'), steps[ind1])
> 
> I've searched but I can't see a solution..
> 
> I guess it is the way I'm printing nam[num].encode('utf-8') perhaps I
> have to convert it first ?

If you have a byte string (the standard in Python 2) you have to decode(), 
i. e. convert it to unicode) before you format it. Compare:

>>> names = "Angie Dickons", "Anne M?resse"
>>> for name in names:
...     print "|{:20}|".format(name)
... 
|Angie Dickons       |
|Anne M?resse       |
>>> for name in names:
...     name = name.decode("utf-8")
...     print u"|{:20}|".format(name)
... 
|Angie Dickons       |
|Anne M?resse        |

The best approach is to convert your data to unicode as soon as you read it 
and perform all string operations with unicode. This also avoids breaking 
characters:

>>> print "M?resse"[:2]
M?                                                                                                                                                    
>>> print u"M?resse"[:2]
M?

There are still problems (e. g. with narrow builds), and the best way to 
avoid a few string-related inconviences is to switch to Python 3.



From michael at stroeder.com  Sun Jan 18 13:39:14 2015
From: michael at stroeder.com (=?UTF-8?Q?Michael_Str=c3=b6der?=)
Date: Sun, 18 Jan 2015 19:39:14 +0100
Subject: Hello World
In-Reply-To: <871tmskrds.fsf@elektro.pacujo.net>
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>	<mailman.17077.1419144290.18130.python-list@python.org>	<54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>	<mailman.17471.1420721626.18130.python-list@python.org>	<54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>	<mailman.17814.1421512178.18130.python-list@python.org>	<h9gqob-c3e.ln1@esprimo.zbmc.eu>	<mailman.17815.1421519526.18130.python-list@python.org>	<54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>	<CAPTjJmps7zjqqde_nKe2=g18xoL4QG+_n1SctANojWYeyCGxTw@mail.gmail.com>	<mailman.17831.1421574655.18130.python-list@python.org>	<87bnlwl81r.fsf@elektro.pacujo.net>
 <m9gcna$kgf$3@dont-email.me> <871tmskrds.fsf@elektro.pacujo.net>
Message-ID: <m9gujm$5bu$1@dont-email.me>

Marko Rauhamaa wrote:
> Michael Str?der <michael at stroeder.com>:
> 
>> Marko Rauhamaa wrote:
>>> I believe in a
>>> physical, government-issue object
>>             ^^^^^^^^^^^^^^^^
>> Did you forget the smiley? Or where were you during the last 1,5 years?
> 
> You can juggle the issues all you want. In the end, there's no escaping
> the governments' underwriting role. The TLS "chain of trust" we have
> today is a joke and can be spoofed easily not only by governments but
> really by anybody.

That's why I'm internally using my own private CA and limit the trust stores
of various services to this CA.

> Authentication is still separate from privacy,

Not true because there's no authorization without authentication.

Ciao, Michael.


From marko at pacujo.net  Sun Jan 18 15:50:26 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sun, 18 Jan 2015 22:50:26 +0200
Subject: Hello World
References: <54957226$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17077.1419144290.18130.python-list@python.org>
 <54ae7b75$0$15900$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17471.1420721626.18130.python-list@python.org>
 <54ba76e0$0$15897$e4fe514c@dreader35.news.xs4all.nl>
 <mailman.17814.1421512178.18130.python-list@python.org>
 <h9gqob-c3e.ln1@esprimo.zbmc.eu>
 <mailman.17815.1421519526.18130.python-list@python.org>
 <54baf443$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmps7zjqqde_nKe2=g18xoL4QG+_n1SctANojWYeyCGxTw@mail.gmail.com>
 <mailman.17831.1421574655.18130.python-list@python.org>
 <87bnlwl81r.fsf@elektro.pacujo.net>
 <mailman.17834.1421597461.18130.python-list@python.org>
Message-ID: <87vbk3ke3x.fsf@elektro.pacujo.net>

Chris Angelico <rosuav at gmail.com>:
> On Sun, Jan 18, 2015 at 9:03 PM, Marko Rauhamaa <marko at pacujo.net> wrote:
>> I believe passwords themselves are the wrong solution. I believe in a
>> physical, government-issue object capable of challenge-response. It
>> can then be beefed up with extra measures depending on the need.
>
> I can't tell whether you're serious or not. Do you actually trust
> "government-issue" more than anything else, or is your tongue firmly
> in your cheek?

I'm serious.

> Also, which government?

For example, the State of Finland (the place where I happen to reside).
Then, you would know you would be dealing with someone who is holding a
physical ID guaranteed by the Finnish government. After all, that's how
passports work; passports are trusted everywhere in the world.

That would be better than anything we have right now. As far as I know,
a system like that is in use in Estonia. In principle, an analogous
system is also there in Finland, but it is barely used yet (chicken and
egg). The practical online authentication in Finland is provided by
private banks. The private solution is effective but it costs businesses
money to use making it unavailable for individuals and nonprofits.


Marko


From prajapatimahendra at ymail.com  Sun Jan 18 15:50:49 2015
From: prajapatimahendra at ymail.com (Mahendra Prajapati)
Date: Sun, 18 Jan 2015 20:50:49 +0000 (UTC)
Subject: Attribute error
Message-ID: <1011993346.1782746.1421614249388.JavaMail.yahoo@jws100126.mail.ne1.yahoo.com>

Hello,
I'm facing this problem with python class, while practising the python programming language.It creates an attribute error.?I use windows 7 OS. i don't why.I just need to know why it gives such an error.please let me know.
Regards?
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From rosuav at gmail.com  Sun Jan 18 16:30:41 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 19 Jan 2015 08:30:41 +1100
Subject: Attribute error
In-Reply-To: <1011993346.1782746.1421614249388.JavaMail.yahoo@jws100126.mail.ne1.yahoo.com>
References: <1011993346.1782746.1421614249388.JavaMail.yahoo@jws100126.mail.ne1.yahoo.com>
Message-ID: <CAPTjJmpqrF-7jVAJ+uS0T5AjwK0g2eHocuXufc6Vs1KDj-X6qQ@mail.gmail.com>

On Mon, Jan 19, 2015 at 7:50 AM, Mahendra Prajapati
<prajapatimahendra at ymail.com> wrote:
> I'm facing this problem with python class, while practising the python
> programming language.It creates an attribute error.
>  I use windows 7 OS. i don't why.
> I just need to know why it gives such an error.
> please let me know.

It'd be easier to help you if you post your code and the entire
exception, from the beginning of the traceback to the message. Armed
with that, we'll be better able to advise!

ChrisA


From denismfmcmahon at gmail.com  Sun Jan 18 18:07:30 2015
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Sun, 18 Jan 2015 23:07:30 +0000 (UTC)
Subject: Attribute error
References: <mailman.17843.1421614370.18130.python-list@python.org>
Message-ID: <m9hebi$94k$1@dont-email.me>

On Sun, 18 Jan 2015 20:50:49 +0000, Mahendra Prajapati wrote:

> Hello,
> I'm facing this problem with python class, while practising the python
> programming language.It creates an attribute error.?I use windows 7 OS.
> i don't why.I just need to know why it gives such an error.please let me
> know.
> Regards

The python docs https://docs.python.org/2/library/exceptions.html say the 
following about AttributeError:

exception AttributeError

Raised when an attribute reference (see Attribute references) or 
assignment fails. (When an object does not support attribute references 
or attribute assignments at all, TypeError is raised.)

Given your description of the problem, the best guess I can make is that 
you are trying to reference a non existent attribute, possibly because 
you have mistyped the name of the attribute you are trying to access.

-- 
Denis McMahon, denismfmcmahon at gmail.com


From steve+comp.lang.python at pearwood.info  Sun Jan 18 18:31:47 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Mon, 19 Jan 2015 10:31:47 +1100
Subject: Attribute error
References: <mailman.17843.1421614370.18130.python-list@python.org>
Message-ID: <54bc4264$0$12993$c3e8da3$5496439d@news.astraweb.com>

Mahendra Prajapati wrote:

> Hello,
> I'm facing this problem with python class, while practising the python
> programming language.It creates an attribute error.?I use windows 7 OS. i
> don't why.I just need to know why it gives such an error.please let me
> know. Regards

An attribute error is a bug in your code. Fix the bug.

It might be a spelling error:

s = "Hello World!"
s.uper()  # Oops, I meant "upper"

or it might be that you have the wrong object:

alist = [2, 4, 1]
alist = alist.sort()  # Oops, replaces alist with None
alist.index(2)  # None has no index method.

Either way, it is a bug in your code that needs to be fixed.




-- 
Steven



From unknown3000 at gmail.com  Sun Jan 18 19:20:01 2015
From: unknown3000 at gmail.com (unknown3000 at gmail.com)
Date: Sun, 18 Jan 2015 16:20:01 -0800 (PST)
Subject: multiprocessing.Queue & vim python interpreter
Message-ID: <d4aeba08-023d-4e57-8a30-367a128a8e50@googlegroups.com>

Hi,

I am experimenting on a fork of vim-plug for managing vim plugins. I wanted to add parallel update support for python since ruby isn't nearly as common. I've come across a weird bug that only seems to happen when I'm inside vim, I'm wondering if someone could tell me why. 

This problem can be reproduced by sourcing a vim file with the following snippet. Then execute the command PyCrash.
command! -nargs=0 PyCrash call s:py_crash()
function! s:py_crash()
    python << EOF
import multiprocessing as multi
queue = multi.Queue()
queue.put('a')
queue.close()
EOF
endfunction

This prints to messages the following:
Traceback (most recent call last):
  File "/usr/lib/python2.7/multiprocessing/queues.py", line 266, in _feed
    send(obj)
IOError: [Errno 32] Broken pipe

Any thoughts?


From rustompmody at gmail.com  Mon Jan 19 00:37:35 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Sun, 18 Jan 2015 21:37:35 -0800 (PST)
Subject: Attribute error
In-Reply-To: <54bc4264$0$12993$c3e8da3$5496439d@news.astraweb.com>
References: <mailman.17843.1421614370.18130.python-list@python.org>
 <54bc4264$0$12993$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <7d078078-6019-4fa7-af05-3e5e914863d4@googlegroups.com>

On Monday, January 19, 2015 at 5:02:01 AM UTC+5:30, Steven D'Aprano wrote:
> Mahendra Prajapati wrote:
> 
> > Hello,
> > I'm facing this problem with python class, while practising the python
> > programming language.It creates an attribute error.?I use windows 7 OS. i
> > don't why.I just need to know why it gives such an error.please let me
> > know. Regards
> 
> An attribute error is a bug in your code. Fix the bug.
> 
> It might be a spelling error:
> 
> s = "Hello World!"
> s.uper()  # Oops, I meant "upper"
> 
> or it might be that you have the wrong object:
> 
> alist = [2, 4, 1]
> alist = alist.sort()  # Oops, replaces alist with None
> alist.index(2)  # None has no index method.
> 
> Either way, it is a bug in your code that needs to be fixed.

Most often it is because you got lost in a maze of dots. ie
x.y.attr works
but you wrote
x.attr
or
a.y.z.attr

Your tools for figuring out (apart from following what Chris suggested)

1. Use the interpreter
2. Use help
3. Use dir
4. Use type

Like so
>>> l=[1,2]
>>> d={1:2}
>>> dir(d)
['__class__', '__cmp__', '__contains__', '__delattr__', '__delitem__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__gt__', '__hash__', '__init__', '__iter__', '__le__', '__len__', '__lt__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__setitem__', '__sizeof__', '__str__', '__subclasshook__', 'clear', 'copy', 'fromkeys', 'get', 'has_key', 'items', 'iteritems', 'iterkeys', 'itervalues', 'keys', 'pop', 'popitem', 'setdefault', 'update', 'values', 'viewitems', 'viewkeys', 'viewvalues']
>>> type(l)
<type 'list'>

>>> help(l)
[Not shown]
>>> help(l.append)
[Not shown]


From wuwei23 at gmail.com  Mon Jan 19 01:19:57 2015
From: wuwei23 at gmail.com (alex23)
Date: Mon, 19 Jan 2015 16:19:57 +1000
Subject: How to "wow" someone new to Python
In-Reply-To: <mailman.17792.1421420646.18130.python-list@python.org>
References: <mailman.17792.1421420646.18130.python-list@python.org>
Message-ID: <m9i7lf$8d2$1@dont-email.me>

On 17/01/2015 1:03 AM, Chris Angelico wrote:
> Scenario: You're introducing someone to Python for the first time.
> S/he may have some previous programming experience, or may be new to
> the whole idea of giving a computer instructions. You have a couple of
> minutes to show off how awesome Python is. What do you do?

When demoing to people with a reasonable amount of experience, I've 
found they're often impressed by showing them list comprehensions, then 
generators, then chained generators.



From contropinion at gmail.com  Mon Jan 19 04:01:31 2015
From: contropinion at gmail.com (contro opinion)
Date: Mon, 19 Jan 2015 17:01:31 +0800
Subject: How to change the number into the same expression's string and vice
 versa?
Message-ID: <CA+YdQ_651X0NDPw1j203WGbeDTxy_Mw7g0w3VH1WoaGR1iv-Cg@mail.gmail.com>

In the python3 console:

    >>> a=18
    >>> b='18'
    >>> str(a) == b
    True
    >>> int(b) == a
    True


Now how to change a1,a2,a3  into b1,b2,b3 and vice versa?
a1=0xf4
a2=0o36
a3=011

b1='0xf4'
b2='0o36'
b3='011'
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From __peter__ at web.de  Mon Jan 19 04:24:17 2015
From: __peter__ at web.de (Peter Otten)
Date: Mon, 19 Jan 2015 10:24:17 +0100
Subject: How to change the number into the same expression's string and
 vice versa?
References: <CA+YdQ_651X0NDPw1j203WGbeDTxy_Mw7g0w3VH1WoaGR1iv-Cg@mail.gmail.com>
Message-ID: <m9iig1$hh4$1@ger.gmane.org>

contro opinion wrote:

> In the python3 console:
> 
>     >>> a=18
>     >>> b='18'
>     >>> str(a) == b
>     True
>     >>> int(b) == a
>     True
> 
> 
> Now how to change a1,a2,a3  into b1,b2,b3 and vice versa?
> a1=0xf4
> a2=0o36
> a3=011
> 
> b1='0xf4'
> b2='0o36'
> b3='011'

Python 3.4.0 (default, Apr 11 2014, 13:05:11) 
[GCC 4.8.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> "{:o}".format(0xf4)
'364'
>>> "{:x}".format(0xf4)
'f4'
>>> "{}".format(0xf4)
'244'

To add a prefix just put it into the format string.

You can specify the base for int() or trigger automatic base recognition by 
passing a base of 0:

>>> int("f4", 16)
244
>>> int("0xf4", 0)
244
>>> int("0o36", 0)
30

The classical prefix for base-8 numbers is no longer recognised in Python 3:

>>> int("011", 0)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid literal for int() with base 0: '011'
>>> int("011")
11
>>> int("011", 8)
9




From frank at chagford.com  Mon Jan 19 04:26:30 2015
From: frank at chagford.com (Frank Millman)
Date: Mon, 19 Jan 2015 11:26:30 +0200
Subject: How to change the number into the same expression's string and
 vice versa?
References: <CA+YdQ_651X0NDPw1j203WGbeDTxy_Mw7g0w3VH1WoaGR1iv-Cg@mail.gmail.com>
Message-ID: <m9iik2$mjh$1@ger.gmane.org>


"contro opinion" <contropinion at gmail.com> wrote in message 
news:CA+YdQ_651X0NDPw1j203WGbeDTxy_Mw7g0w3VH1WoaGR1iv-Cg at mail.gmail.com...
> In the python3 console:
>
>    >>> a=18
>    >>> b='18'
>    >>> str(a) == b
>    True
>    >>> int(b) == a
>    True
>
>
> Now how to change a1,a2,a3  into b1,b2,b3 and vice versa?
> a1=0xf4
> a2=0o36
> a3=011
>
> b1='0xf4'
> b2='0o36'
> b3='011'
>
I am no expert, but does this answer your question ?

C:\>python
Python 3.4.1 (v3.4.1:c0e311e010fc, May 18 2014, 10:38:22) [MSC v.1600 32 bit 
(Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.


>>> a1 = 0xf4
>>> a1
244
>>> b1 = '0x{:x}'.format(a1)
>>> b1
'0xf4'
>>> int(b1, 16)
244


>>> a2 = 0o36
>>> a2
30
>>> b2 = '0o{:o}'.format(a2)
>>> b2
'0o36'
>>> int(b2, 8)
30


>>> a3 = 011
  File "<stdin>", line 1
    a3 = 011
           ^
SyntaxError: invalid token
>>>

Frank Millman







From jpiitula at ling.helsinki.fi  Mon Jan 19 04:36:50 2015
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 19 Jan 2015 11:36:50 +0200
Subject: How to change the number into the same expression's string and
 vice versa?
References: <CA+YdQ_651X0NDPw1j203WGbeDTxy_Mw7g0w3VH1WoaGR1iv-Cg@mail.gmail.com>
 <mailman.17846.1421659473.18130.python-list@python.org>
Message-ID: <qot8ugzqfgt.fsf@ruuvi.it.helsinki.fi>

Peter Otten writes:
> contro opinion wrote:

> > Now how to change a1,a2,a3  into b1,b2,b3 and vice versa?
> > a1=0xf4
> > a2=0o36
> > a3=011
> > 
> > b1='0xf4'
> > b2='0o36'
> > b3='011'
> 
> Python 3.4.0 (default, Apr 11 2014, 13:05:11) 
> [GCC 4.8.2] on linux
> Type "help", "copyright", "credits" or "license" for more information.
> >>> "{:o}".format(0xf4)
> '364'
> >>> "{:x}".format(0xf4)
> 'f4'
> >>> "{}".format(0xf4)
> '244'
> 
> To add a prefix just put it into the format string.

There's also these (in Python 3.2.3):

  >>> hex(0xf4)
  '0xf4'
  >>> oct(0xf4)
  '0o364'
  >>> bin(0xf4)
  '0b11110100'


From josemlv83 at gmail.com  Mon Jan 19 05:16:51 2015
From: josemlv83 at gmail.com (Jose)
Date: Mon, 19 Jan 2015 02:16:51 -0800 (PST)
Subject: Storing dataset from Condtional FreqDist
Message-ID: <bd1c0f0d-febf-482c-a53d-a980d2f091cd@googlegroups.com>

Hello i have trying to store information in arff file but i has been really. Any ideas of how can i do that?


with open('fileids3.txt', 'r') as f:
   
	genres=[word.strip() for word in f.next().split(',')]  

with open('adjectifs2.txt', 'r') as g:
	adj = [word.strip() for word in g.next().split(',')]
	
freq = nltk.ConditionalFreqDist(
     (genre, m)
      for genre in brown.fileids()
      for m in brown.words(fileids=genre))


freq.tabulate(conditions=genres, samples=adj)


From info at egenix.com  Mon Jan 19 05:37:45 2015
From: info at egenix.com (eGenix Team: M.-A. Lemburg)
Date: Mon, 19 Jan 2015 11:37:45 +0100
Subject: ANN: eGenix Talks & Videos: Advanced Database Programming
Message-ID: <54BCDE79.9050603@egenix.com>

________________________________________________________________________

ANNOUNCING
                         eGenix Talks & Videos

		    "Advanced Database Programming"

This announcement is also available on our web-site for online reading:
http://www.egenix.com/company/news/EuroPython-2014-Advanced-Database-Programming.html
________________________________________________________________________

eGenix Talk "Advanced Database Programming"

At last year's EuroPython 2014 conference in Berlin, Marc-Andr? Lemburg,
CEO of eGenix, gave the following talk on database programming in
Python. We have now turned the talk into video presentation for easy
viewing and also released the presentation slides:

EuroPython 2014 - Advanced Database Programming
-----------------------------------------------

    Advanced concepts in Python database programming.

    The Python DB-API 2.0 provides a direct interface to many popular
    database backends. It makes interaction with relational database
    very straight forward and allows tapping into the full set of
    features these databases provide.

    This talk covers advanced database topics which are relevant in
    production environments such as locks, distributed transactions
    and transaction isolation. We also give advice on how to deal with
    common problems you face when working with complex database systems.

    http://www.egenix.com/library/presentations/EuroPython-2014-Advanced-Database-Programming/

Related Python Coaching and Consulting
--------------------------------------

If you are interested in learning more about these advanced
techniques, eGenix now offers Python project coaching and consulting
services to give your project teams advice on how to implement complex
database architectures in Python. Please contact our eGenix Sales Team
(sales at egenix.com) for information.

    http://www.egenix.com/services/coaching/

More interesting eGenix presentations are available in the presentations
and talks section of the library on our website:

    http://www.egenix.com/library/presentations/

Enjoy,
-- 
Marc-Andre Lemburg
eGenix.com

Professional Python Services directly from the Source  (#1, Jan 19 2015)
>>> Python Projects, Coaching and Consulting ...  http://www.egenix.com/
>>> mxODBC Plone/Zope Database Adapter ...       http://zope.egenix.com/
>>> mxODBC, mxDateTime, mxTextTools ...        http://python.egenix.com/
________________________________________________________________________
2015-01-09: Released eGenix pyOpenSSL 0.13.7 ...  http://egenix.com/go68
2015-01-20: Python Meeting Duesseldorf ...        http://egenix.com/go69

::::: Try our mxODBC.Connect Python Database Interface for free ! ::::::

   eGenix.com Software, Skills and Services GmbH  Pastor-Loeh-Str.48
    D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg
           Registered at Amtsgericht Duesseldorf: HRB 46611
               http://www.egenix.com/company/contact/


From __peter__ at web.de  Mon Jan 19 06:46:33 2015
From: __peter__ at web.de (Peter Otten)
Date: Mon, 19 Jan 2015 12:46:33 +0100
Subject: How to change the number into the same expression's string and
 vice versa?
References: <CA+YdQ_651X0NDPw1j203WGbeDTxy_Mw7g0w3VH1WoaGR1iv-Cg@mail.gmail.com>
 <mailman.17846.1421659473.18130.python-list@python.org>
 <qot8ugzqfgt.fsf@ruuvi.it.helsinki.fi>
Message-ID: <m9iqqp$smq$1@ger.gmane.org>

Jussi Piitulainen wrote:

> Peter Otten writes:

>> >>> "{:o}".format(0xf4)
>> '364'

>> To add a prefix just put it into the format string.
 
> There's also these (in Python 3.2.3):
> 
>   >>> hex(0xf4)
>   '0xf4'

D'oh!



From ned at nedbatchelder.com  Mon Jan 19 08:34:38 2015
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Mon, 19 Jan 2015 08:34:38 -0500
Subject: How to "wow" someone new to Python
In-Reply-To: <CAPTjJmpTbbj=Dqc6PN-ec4n6-WdFjpSAzwawObSd3Dvwbkpi=A@mail.gmail.com>
References: <CAPTjJmpTbbj=Dqc6PN-ec4n6-WdFjpSAzwawObSd3Dvwbkpi=A@mail.gmail.com>
Message-ID: <m9j15f$c34$1@ger.gmane.org>

On 1/16/15 10:03 AM, Chris Angelico wrote:
> Scenario: You're introducing someone to Python for the first time.
> S/he may have some previous programming experience, or may be new to
> the whole idea of giving a computer instructions. You have a couple of
> minutes to show off how awesome Python is. What do you do?
>
> I was thinking along the lines of a simple demo in the REPL, showing
> off some of Python's coolest features. But then I got stuck on the
> specifics. What are Python's best coolnesses? What makes for a good
> demo?
>
> Ideally, this should be something that can be demo'd quickly and
> easily, and it should be impressive without going into great details
> of "and see, this is how it works on the inside". So, how would you
> brag about this language?
>
> ChrisA
>

Peter Norvig's spell corrector is a compact example of a lot of Python 
power: http://norvig.com/spell-correct.html

I used it as a walk-through example for a presentation about Python at 
the DevDays conference: http://nedbatchelder.com/text/devdays.html

The second half of the presentation is a 25-line nano-templating engine 
which shows off some other good characteristics of the language.

-- 
Ned Batchelder, http://nedbatchelder.com



From jcasale at activenetwerx.com  Mon Jan 19 09:13:29 2015
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Mon, 19 Jan 2015 14:13:29 +0000
Subject: Hashed lookups for tabular data
Message-ID: <84c6e1d5671842038e81994478fb5476@exch.activenetwerx.com>

I have some tabular data for example 3 tuples that I need to build a container
for where lookups into any one of the three fields are O(1). Does something
in the base library exist, or if not is there an efficient implementation of such
a container that has been implemented before I give it a go?

It complicates slightly by the fact that for the some of the collections, one of
the fields may be duplicated, think (make, model, year) for example which
closely resembles the pattern of one the data sets. When asking for position
0 of the set, I'd expect to get an iterable of length "n" but some of the containers
will be inherently unique for the rows that will be accessed so I'd return a single
row.

No surprise the data originates from a database however the data is utilized in
a recursive processing loop where the user accessing the data benefits from a
simplified and quick means to access it. Currently its done with classes that
resemble named tuples equating to a row, but it goes pear shaped with the outer
container. Grouping these similar objects and providing the sql like query into
the collection in some cases is O(n)...

Thanks,
jlc


From rosuav at gmail.com  Mon Jan 19 09:26:46 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 20 Jan 2015 01:26:46 +1100
Subject: Hashed lookups for tabular data
In-Reply-To: <84c6e1d5671842038e81994478fb5476@exch.activenetwerx.com>
References: <84c6e1d5671842038e81994478fb5476@exch.activenetwerx.com>
Message-ID: <CAPTjJmr1YXTXGi+YE0yjUxgdoy2iOWDq_th4u6ghiQ+QOouNvg@mail.gmail.com>

On Tue, Jan 20, 2015 at 1:13 AM, Joseph L. Casale
<jcasale at activenetwerx.com> wrote:
> No surprise the data originates from a database however the data is utilized in
> a recursive processing loop where the user accessing the data benefits from a
> simplified and quick means to access it. Currently its done with classes that
> resemble named tuples equating to a row, but it goes pear shaped with the outer
> container. Grouping these similar objects and providing the sql like query into
> the collection in some cases is O(n)...

So presumably your data's small enough to fit into memory, right? If
it isn't, going back to the database every time would be the best
option. But if it is, can you simply keep three dictionaries in sync?

row = (foo, bar, quux) # there could be duplicate quuxes but not foos or bars
foo_dict = {}
bar_dict = {}
quux_dict = collections.defaultdict(set)

foo_dict[row[0]] = row
bar_dict[row[1]] = row
quux_dict[row[2]].add(row)

You can now look up anything by any key. If you use the quux_dict,
you'll get back a list (zero elements if you've never seen one,
otherwise all elements ever seen, in arbitrary order). Adding, in this
way, is idempotent.

Finding an item by foo or bar is easy - use either of:
row = foo_dict["asdf"] # will raise KeyError if it isn't there
row = foo_dict.get("qwer") # will return None if it isn't there

Finding items by quux is a matter of iteration:
for row in quux_dict["zxcv"]:
    do something

It's up to you to decide whether it's an error to get back an empty set or not.

Does this give a basic idea of what you can do?

The memory requirements wouldn't be much more than your existing data.
You have three lookup dictionaries, but the actual keys and values
would be shared. The main consideration is that you'd need to update
in lots of places if you remove a row. If you're working with stable
data across one run of the program, though, that should be safe.

ChrisA


From breamoreboy at yahoo.co.uk  Mon Jan 19 11:41:36 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 19 Jan 2015 16:41:36 +0000
Subject: How to change the number into the same expression's string and
 vice versa?
In-Reply-To: <CA+YdQ_651X0NDPw1j203WGbeDTxy_Mw7g0w3VH1WoaGR1iv-Cg@mail.gmail.com>
References: <CA+YdQ_651X0NDPw1j203WGbeDTxy_Mw7g0w3VH1WoaGR1iv-Cg@mail.gmail.com>
Message-ID: <m9jc45$clj$1@ger.gmane.org>

On 19/01/2015 09:01, contro opinion wrote:
>
> In the python3 console:
>
>      >>> a=18
>      >>> b='18'
>      >>> str(a) == b
>      True
>      >>> int(b) == a
>      True
>
>
> Now how to change a1,a2,a3  into b1,b2,b3 and vice versa?
> a1=0xf4
> a2=0o36
> a3=011
>
> b1='0xf4'
> b2='0o36'
> b3='011'
>
>

Giving a completely different take on previous answers how about.

a1, b1 = b1, a1
a2, b2 = b2, a2
a3, b3 = b3, a3

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From gianniboncompagni at mail.com  Mon Jan 19 11:42:58 2015
From: gianniboncompagni at mail.com (MICHELE CALZOLARI CREDIT SUISSE ASSOSIM)
Date: Mon, 19 Jan 2015 08:42:58 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
References: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
Message-ID: <54ca3da9-6191-4c62-b46c-9fb2e6adc04d@googlegroups.com>

-- redacted --


From jcasale at activenetwerx.com  Mon Jan 19 12:09:05 2015
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Mon, 19 Jan 2015 17:09:05 +0000
Subject: Hashed lookups for tabular data
In-Reply-To: <CAPTjJmr1YXTXGi+YE0yjUxgdoy2iOWDq_th4u6ghiQ+QOouNvg@mail.gmail.com>
References: <84c6e1d5671842038e81994478fb5476@exch.activenetwerx.com>,
 <CAPTjJmr1YXTXGi+YE0yjUxgdoy2iOWDq_th4u6ghiQ+QOouNvg@mail.gmail.com>
Message-ID: <1421687345419.39659@activenetwerx.com>

> So presumably your data's small enough to fit into memory, right? If
> it isn't, going back to the database every time would be the best
> option. But if it is, can you simply keep three dictionaries in sync?

Hi Chris,
Yeah the data can fit in memory and hence the desire to avoid a trip here.

> row = (foo, bar, quux) # there could be duplicate quuxes but not foos or bars
> foo_dict = {}
> bar_dict = {}
> quux_dict = collections.defaultdict(set)
> 
> foo_dict[row[0]] = row
> bar_dict[row[1]] = row
> quux_dict[row[2]].add(row)

This is actually far simpler than I had started imagining, however the row data
is duplicated. I am hacking away at an attempt with references to one copy of
the row.

Its kind of hard to recreate an sql like object in Python with indexes and the
inherent programmability against a single copy of data.

I'll mock this up and see what it profiles like.
Thanks!
jlc

From rosuav at gmail.com  Mon Jan 19 12:17:57 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 20 Jan 2015 04:17:57 +1100
Subject: Hashed lookups for tabular data
In-Reply-To: <1421687345419.39659@activenetwerx.com>
References: <84c6e1d5671842038e81994478fb5476@exch.activenetwerx.com>
 <CAPTjJmr1YXTXGi+YE0yjUxgdoy2iOWDq_th4u6ghiQ+QOouNvg@mail.gmail.com>
 <1421687345419.39659@activenetwerx.com>
Message-ID: <CAPTjJmpQRS8NAVcTO4akN94Cjyi34CW05FhN_CeUyGOAMjV5Xw@mail.gmail.com>

On Tue, Jan 20, 2015 at 4:09 AM, Joseph L. Casale
<jcasale at activenetwerx.com> wrote:
>> row = (foo, bar, quux) # there could be duplicate quuxes but not foos or bars
>> foo_dict = {}
>> bar_dict = {}
>> quux_dict = collections.defaultdict(set)
>>
>> foo_dict[row[0]] = row
>> bar_dict[row[1]] = row
>> quux_dict[row[2]].add(row)
>
> This is actually far simpler than I had started imagining, however the row data
> is duplicated. I am hacking away at an attempt with references to one copy of
> the row.

As long as you start with an actual tuple that you then assign in that
way, they will all be references to one copy of the row. Here's a
concrete example:

$ python3
Python 3.5.0a0 (default:1c51f1650c42+, Dec 29 2014, 02:29:06)
[GCC 4.7.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> row = ("abc","def","ghi")
>>> foo_dict = {}
>>> bar_dict = {}
>>> import collections
>>> quux_dict = collections.defaultdict(set)
>>> foo_dict[row[0]] = row
>>> bar_dict[row[1]] = row
>>> quux_dict[row[2]].add(row)
>>> id(foo_dict["abc"])
140127396717840
>>> id(bar_dict["def"])
140127396717840
>>> id(next(iter(quux_dict["ghi"])))
140127396717840

The IDs of the objects prove that they're actually all the same
object. The memory requirement for this is just what the dictionaries
themselves require; their keys and values are all shared with other
usage.

ChrisA


From breamoreboy at yahoo.co.uk  Mon Jan 19 12:26:24 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 19 Jan 2015 17:26:24 +0000
Subject: Hashed lookups for tabular data
In-Reply-To: <1421687345419.39659@activenetwerx.com>
References: <84c6e1d5671842038e81994478fb5476@exch.activenetwerx.com>,
 <CAPTjJmr1YXTXGi+YE0yjUxgdoy2iOWDq_th4u6ghiQ+QOouNvg@mail.gmail.com>
 <1421687345419.39659@activenetwerx.com>
Message-ID: <m9jeo5$r3u$1@ger.gmane.org>

On 19/01/2015 17:09, Joseph L. Casale wrote:
>
> This is actually far simpler than I had started imagining, however the row data
> is duplicated. I am hacking away at an attempt with references to one copy of
> the row.
>
> Its kind of hard to recreate an sql like object in Python with indexes and the
> inherent programmability against a single copy of data.
>
> I'll mock this up and see what it profiles like.
> Thanks!
> jlc
>

Why not take a look at pandas as see if there's anything there you could 
use?  Excellent docs here http://pandas.pydata.org/pandas-docs/stable/ 
and the mailing list is available at gmane.comp.python.pydata amongst 
other places.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From kushal at locationd.net  Mon Jan 19 12:44:31 2015
From: kushal at locationd.net (Kushal Kumaran)
Date: Mon, 19 Jan 2015 23:14:31 +0530
Subject: Hashed lookups for tabular data
In-Reply-To: <1421687345419.39659@activenetwerx.com> (Joseph L. Casale's
 message of "Mon, 19 Jan 2015 17:09:05 +0000")
References: <84c6e1d5671842038e81994478fb5476@exch.activenetwerx.com>
 <CAPTjJmr1YXTXGi+YE0yjUxgdoy2iOWDq_th4u6ghiQ+QOouNvg@mail.gmail.com>
 <1421687345419.39659@activenetwerx.com>
Message-ID: <8761c2k6m8.fsf@mercury.locationd.net>

"Joseph L. Casale" <jcasale at activenetwerx.com> writes:

>> So presumably your data's small enough to fit into memory, right? If
>> it isn't, going back to the database every time would be the best
>> option. But if it is, can you simply keep three dictionaries in sync?
>
> Hi Chris,
> Yeah the data can fit in memory and hence the desire to avoid a trip here.
>
>> row = (foo, bar, quux) # there could be duplicate quuxes but not foos or bars
>> foo_dict = {}
>> bar_dict = {}
>> quux_dict = collections.defaultdict(set)
>> 
>> foo_dict[row[0]] = row
>> bar_dict[row[1]] = row
>> quux_dict[row[2]].add(row)
>
> This is actually far simpler than I had started imagining, however the row data
> is duplicated. I am hacking away at an attempt with references to one copy of
> the row.
>
> Its kind of hard to recreate an sql like object in Python with indexes and the
> inherent programmability against a single copy of data.
>

If you want an sql-like interface, you can simply create an in-memory
sqlite3 database.

 import sqlite3
 db = sqlite3.Connection(':memory:')

You can create indexes as you need, and query using SQL.  Later, if you
find the data getting too big to fit in memory, you can switch to using
an on-disk database instead without significant changes to the code.

-- 
regards,
kushal


From jcasale at activenetwerx.com  Mon Jan 19 13:54:46 2015
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Mon, 19 Jan 2015 18:54:46 +0000
Subject: Hashed lookups for tabular data
In-Reply-To: <CAPTjJmpQRS8NAVcTO4akN94Cjyi34CW05FhN_CeUyGOAMjV5Xw@mail.gmail.com>
References: <84c6e1d5671842038e81994478fb5476@exch.activenetwerx.com>
 <CAPTjJmr1YXTXGi+YE0yjUxgdoy2iOWDq_th4u6ghiQ+QOouNvg@mail.gmail.com>
 <1421687345419.39659@activenetwerx.com>,
 <CAPTjJmpQRS8NAVcTO4akN94Cjyi34CW05FhN_CeUyGOAMjV5Xw@mail.gmail.com>
Message-ID: <1421693685914.61201@activenetwerx.com>

> The IDs of the objects prove that they're actually all the same
> object. The memory requirement for this is just what the dictionaries
> themselves require; their keys and values are all shared with other
> usage.

Chris,
I would have never imagined that, much appreciated for that!

jlc

From jcasale at activenetwerx.com  Mon Jan 19 13:58:30 2015
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Mon, 19 Jan 2015 18:58:30 +0000
Subject: Hashed lookups for tabular data
In-Reply-To: <m9jeo5$r3u$1@ger.gmane.org>
References: <84c6e1d5671842038e81994478fb5476@exch.activenetwerx.com>,
 <CAPTjJmr1YXTXGi+YE0yjUxgdoy2iOWDq_th4u6ghiQ+QOouNvg@mail.gmail.com>
 <1421687345419.39659@activenetwerx.com>,<m9jeo5$r3u$1@ger.gmane.org>
Message-ID: <1421693909933.23788@activenetwerx.com>

> Why not take a look at pandas as see if there's anything there you could
> use?  Excellent docs here http://pandas.pydata.org/pandas-docs/stable/
> and the mailing list is available at gmane.comp.python.pydata amongst
> other places.

Mark,
Actually it was the first thing that came to mind. I did want to avoid another
dependency unless it was for a good reason and I suspect anything from that
project would merit it one. I have been looking for a reason to use it for a
project and this might be it. I probably wont be up to speed in time but I
will give it a look.

Thanks,
jlc

From jcasale at activenetwerx.com  Mon Jan 19 13:59:49 2015
From: jcasale at activenetwerx.com (Joseph L. Casale)
Date: Mon, 19 Jan 2015 18:59:49 +0000
Subject: Hashed lookups for tabular data
In-Reply-To: <8761c2k6m8.fsf@mercury.locationd.net>
References: <84c6e1d5671842038e81994478fb5476@exch.activenetwerx.com>
 <CAPTjJmr1YXTXGi+YE0yjUxgdoy2iOWDq_th4u6ghiQ+QOouNvg@mail.gmail.com>
 <1421687345419.39659@activenetwerx.com>, <8761c2k6m8.fsf@mercury.locationd.net>
Message-ID: <1421693988972.60663@activenetwerx.com>

> If you want an sql-like interface, you can simply create an in-memory
> sqlite3 database.
> 
>  import sqlite3
>  db = sqlite3.Connection(':memory:')
> 
> You can create indexes as you need, and query using SQL.  Later, if you
> find the data getting too big to fit in memory, you can switch to using
> an on-disk database instead without significant changes to the code.

Hey kushal,
For the effort it would take, I'll add an implementation using this this
when I start profiling for the sake of curiosity.

Thanks,
jlc

From zacharygilmartin at gmail.com  Mon Jan 19 17:06:12 2015
From: zacharygilmartin at gmail.com (Zachary Gilmartin)
Date: Mon, 19 Jan 2015 17:06:12 -0500
Subject: Trees
Message-ID: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>

Why aren't there trees in the python standard library?
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From manimgoindowndown at gmail.com  Mon Jan 19 17:10:32 2015
From: manimgoindowndown at gmail.com (MK)
Date: Mon, 19 Jan 2015 17:10:32 -0500
Subject: Student looking for a Scitki-Learn Numpy Tutor with a strong
 background in data science?
Message-ID: <CAKG1dBym4QCYC9-7WpPJNy7nJpUxHsjsWeEwy3kzetz19kCHKw@mail.gmail.com>

In a Masters for Data Science and need the help using Python/R mainly.

Please forward background(education, work) teaching experence in stats,
linear algebra, programming (Scikit, Panda, Numpy), timezone, and rates.
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From ben+python at benfinney.id.au  Mon Jan 19 17:16:09 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Tue, 20 Jan 2015 09:16:09 +1100
Subject: Trees
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
Message-ID: <851tmqquvq.fsf@benfinney.id.au>

Zachary Gilmartin <zacharygilmartin at gmail.com> writes:

> Why aren't there trees in the python standard library?

What sort of answer are you looking for? There are many ways that
question could be intended.

If you're asking about what could be keeping a particular tree
implementation out of the standard library: that depends on what
particular implementations you have in mind. Are there any which exist
that you think belong in the standard library?

If you're asking about some policy that prevents any such inclusion, I'm
not aware of such a policy.

If you're asking because you think all data structures magically appear
in the standard library by wishing it so, I think you over-estimate the
powers of the standard library maintainers.

If you're asking something else, you'll need to be more explicit.

-- 
 \                ?Every sentence I utter must be understood not as an |
  `\                      affirmation, but as a question.? ?Niels Bohr |
_o__)                                                                  |
Ben Finney



From rosuav at gmail.com  Mon Jan 19 17:25:31 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 20 Jan 2015 09:25:31 +1100
Subject: Trees
In-Reply-To: <851tmqquvq.fsf@benfinney.id.au>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <851tmqquvq.fsf@benfinney.id.au>
Message-ID: <CAPTjJmrV04ByquoS2kiu_PZQ3=vdDYnMrvqofYhsf+5rSMa1sw@mail.gmail.com>

On Tue, Jan 20, 2015 at 9:16 AM, Ben Finney <ben+python at benfinney.id.au> wrote:
> If you're asking because you think all data structures magically appear
> in the standard library by wishing it so, I think you over-estimate the
> powers of the standard library maintainers.

Oh come on Ben. Guido has a time machine; TimSort is pure magic
coalesced into code form; and there's an army of buildbots standing by
for every change that gets made. How can anyone over-estimate the
powers of python-dev?!

ChrisA


From breamoreboy at yahoo.co.uk  Mon Jan 19 18:01:44 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 19 Jan 2015 23:01:44 +0000
Subject: Trees
In-Reply-To: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
Message-ID: <m9k2cs$pk$1@ger.gmane.org>

On 19/01/2015 22:06, Zachary Gilmartin wrote:
> Why aren't there trees in the python standard library?
>

Probably because you'd never get agreement as to which specific tree and 
which specific implementation was the most suitable for inclusion.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From steve+comp.lang.python at pearwood.info  Mon Jan 19 18:08:25 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 20 Jan 2015 10:08:25 +1100
Subject: Trees
References: <mailman.17862.1421705173.18130.python-list@python.org>
Message-ID: <54bd8e6a$0$13009$c3e8da3$5496439d@news.astraweb.com>

Zachary Gilmartin wrote:

> Why aren't there trees in the python standard library?

Possibly because they aren't needed? Under what circumstances would you use
a tree instead of a list or a dict or combination of both?

That's not a rhetorical question. I am genuinely curious, what task do you
have that you think must be solved by a tree?

Also, what sort of tree? Binary tree? Binary search tree? Red/black tree?
AVL tree? Splay tree? B-tree? T-tree? Scapegoat tree? General n-ary tree?
Every possible type of tree yet invented?



-- 
Steven



From torriem at gmail.com  Mon Jan 19 18:19:54 2015
From: torriem at gmail.com (Michael Torrie)
Date: Mon, 19 Jan 2015 16:19:54 -0700
Subject: Trees
In-Reply-To: <54bd8e6a$0$13009$c3e8da3$5496439d@news.astraweb.com>
References: <mailman.17862.1421705173.18130.python-list@python.org>
 <54bd8e6a$0$13009$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <54BD911A.1050206@gmail.com>

On 01/19/2015 04:08 PM, Steven D'Aprano wrote:
> Zachary Gilmartin wrote:
> 
>> Why aren't there trees in the python standard library?
> 
> Possibly because they aren't needed? Under what circumstances would you use
> a tree instead of a list or a dict or combination of both?
> 
> That's not a rhetorical question. I am genuinely curious, what task do you
> have that you think must be solved by a tree?
> 
> Also, what sort of tree? Binary tree? Binary search tree? Red/black tree?
> AVL tree? Splay tree? B-tree? T-tree? Scapegoat tree? General n-ary tree?
> Every possible type of tree yet invented?

Don't forget left-child,right-sibling trees.

As I go through your list of trees, I can't find any tree type that
cannot be easily and efficiently constructed with lists, possibly with
dicts.


From jeanpierreda at gmail.com  Mon Jan 19 18:52:41 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Mon, 19 Jan 2015 15:52:41 -0800
Subject: Trees
In-Reply-To: <54bd8e6a$0$13009$c3e8da3$5496439d@news.astraweb.com>
References: <mailman.17862.1421705173.18130.python-list@python.org>
 <54bd8e6a$0$13009$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CABicbJK1TzXSoFQFUPXSkafzwMkYfByUfpw8QiaXiHwROOMo+Q@mail.gmail.com>

On Mon, Jan 19, 2015 at 3:08 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Zachary Gilmartin wrote:
>
>> Why aren't there trees in the python standard library?
>
> Possibly because they aren't needed? Under what circumstances would you use
> a tree instead of a list or a dict or combination of both?
>
> That's not a rhetorical question. I am genuinely curious, what task do you
> have that you think must be solved by a tree?

In general, any time you want to maintain a sorted list or mapping,
balanced search tree structures come in handy.

Here's an example task: suppose you want to represent a calendar,
where timeslots can be reserved for something. Calendar events are not
allowed to intersect.

The most important query is: What events are there that intersect with
the timespan between datetimes d1 and d2? (To draw a daily agenda,
figure out if you should display an alert to the user that an event is
ongoing or imminent, etc.)

You also want to be able to add a new event to the calendar, that
takes place between d1 and d2, and to remove a event.

I leave it to the reader to implement this using a sorted map. (hint:
sort by start.)

This maybe seems contrived, but I've used this exact datatype, or a
remarkably similar one, in a few different circumstances: sequenced
actions of characters in a strategy game, animation, motion
planning...

There are a few possible implementations using Python data structures.
You can do it using a linear scan, which gets a little slow pretty
quickly. You can make insertion slow (usually OK) by sorting on
insertion, but if you ever forget to resort your list you will get a
subtle bug you might not notice for a while. And so on. It's better in
every way to use the third-party blist module, so why bother?

-- Devin


From python.list at tim.thechases.com  Mon Jan 19 19:00:51 2015
From: python.list at tim.thechases.com (Tim Chase)
Date: Mon, 19 Jan 2015 18:00:51 -0600
Subject: Trees
In-Reply-To: <54BD911A.1050206@gmail.com>
References: <mailman.17862.1421705173.18130.python-list@python.org>
 <54bd8e6a$0$13009$c3e8da3$5496439d@news.astraweb.com>
 <54BD911A.1050206@gmail.com>
Message-ID: <20150119180051.074270ac@bigbox.christie.dr>

On 2015-01-19 16:19, Michael Torrie wrote:
> On 01/19/2015 04:08 PM, Steven D'Aprano wrote:
> > Zachary Gilmartin wrote:
> >> Why aren't there trees in the python standard library?
> > 
> > Possibly because they aren't needed? Under what circumstances
> > would you use a tree instead of a list or a dict or combination
> > of both?

While not an abundance of times, I've had a plurality of occasions
when I've wanted characteristics of a red/black tree where I wanted
O(log n) insertion/deletion/initial-access and O(1) access to
neighbors.

> > Also, what sort of tree? Binary tree? Binary search tree?
> > Red/black tree? AVL tree? Splay tree? B-tree? T-tree? Scapegoat
> > tree? General n-ary tree? Every possible type of tree yet
> > invented?
> 
> Don't forget left-child,right-sibling trees.
> 
> As I go through your list of trees, I can't find any tree type that
> cannot be easily and efficiently constructed with lists, possibly
> with dicts.

While the data-structures can easily be composed out of lists/dicts,
the algorithms that go along with them (such as red/black trees with
their insertion/deletion gymnastics) would be nice to have in the
stdlib so they wouldn't have to be reimplemented (or sought out and
downloaded, and added to the configuration/distribution) every time
someone wanted that particular tree's characteristics.   Much of that
could be addressed with a library of algorithms much like heapq
operates on a list.

-tkc




From luketomaneng at gmail.com  Mon Jan 19 19:12:57 2015
From: luketomaneng at gmail.com (Luke Tomaneng)
Date: Mon, 19 Jan 2015 16:12:57 -0800 (PST)
Subject: Concerning Dictionaries and += in Python 2.x
Message-ID: <bc9e302a-356c-4223-9c25-6a8003db48e6@googlegroups.com>

I have been having a bit of trouble with the things mentioned in the title. I have written the following script for a Codecademy course:
stock = {
    "banana": 6,
    "apple": 0,
    "orange": 32,
    "pear": 15
}
    
prices = {
    "banana": 4,
    "apple": 2,
    "orange": 1.5,
    "pear": 3
}

def compute_bill(food):
    total = 0
    for item in food:
        if stock[item] > 0:
            total += prices[item]
            stock[item] = stock[item] - 1
            return total
Whenever I run this script, "4" is returned. It does not seem to matter what in in the list the script is run on. I have tried this on the Codecademy interpreter/emulator (I'm not sure which they use) and the repl.it interpreter, but for the same result. If anyone could find the glitch in my code, please let me know. Thanks!


From luketomaneng at gmail.com  Mon Jan 19 19:15:58 2015
From: luketomaneng at gmail.com (Luke Tomaneng)
Date: Mon, 19 Jan 2015 16:15:58 -0800 (PST)
Subject: Random ALL CAPS posts on this group
Message-ID: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>

Has anyone noticed these? There have been about three of them recently and they don't seem to have anything to do with Python at all. Does anyone know if there is a good reason they are here? 


From rosuav at gmail.com  Mon Jan 19 19:21:37 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 20 Jan 2015 11:21:37 +1100
Subject: Concerning Dictionaries and += in Python 2.x
In-Reply-To: <bc9e302a-356c-4223-9c25-6a8003db48e6@googlegroups.com>
References: <bc9e302a-356c-4223-9c25-6a8003db48e6@googlegroups.com>
Message-ID: <CAPTjJmrotPs9vBzjN_t=kR=LY7S+ORAzxjvoi68OGmtZJ_tKBw@mail.gmail.com>

On Tue, Jan 20, 2015 at 11:12 AM, Luke Tomaneng <luketomaneng at gmail.com> wrote:
> def compute_bill(food):
>     total = 0
>     for item in food:
>         if stock[item] > 0:
>             total += prices[item]
>             stock[item] = stock[item] - 1
>             return total
> Whenever I run this script, "4" is returned. It does not seem to matter what in in the list the script is run on. I have tried this on the Codecademy interpreter/emulator (I'm not sure which they use) and the repl.it interpreter, but for the same result. If anyone could find the glitch in my code, please let me know. Thanks!
>

In Python, indentation determines block structure. Have another look
at this function, and see if you can figure out where the problem is;
hint: try printing something out every time you claim a piece of
stock.

ChrisA


From rosuav at gmail.com  Mon Jan 19 19:22:35 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 20 Jan 2015 11:22:35 +1100
Subject: Random ALL CAPS posts on this group
In-Reply-To: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
Message-ID: <CAPTjJmpr5LvuN1YXN1D4HD2WsTyh05YiuRZAqFL9G3sqGuk6pA@mail.gmail.com>

On Tue, Jan 20, 2015 at 11:15 AM, Luke Tomaneng <luketomaneng at gmail.com> wrote:
> Has anyone noticed these? There have been about three of them recently and they don't seem to have anything to do with Python at all. Does anyone know if there is a good reason they are here?
>

I haven't seen them. My guess is they're straight-up spam; just ignore
them, or mark them as spam if your client supports it.

ChrisA


From python at mrabarnett.plus.com  Mon Jan 19 19:27:53 2015
From: python at mrabarnett.plus.com (MRAB)
Date: Tue, 20 Jan 2015 00:27:53 +0000
Subject: Concerning Dictionaries and += in Python 2.x
In-Reply-To: <bc9e302a-356c-4223-9c25-6a8003db48e6@googlegroups.com>
References: <bc9e302a-356c-4223-9c25-6a8003db48e6@googlegroups.com>
Message-ID: <54BDA109.2070608@mrabarnett.plus.com>

On 2015-01-20 00:12, Luke Tomaneng wrote:
> I have been having a bit of trouble with the things mentioned in the title. I have written the following script for a Codecademy course:
> stock = {
>      "banana": 6,
>      "apple": 0,
>      "orange": 32,
>      "pear": 15
> }
>
> prices = {
>      "banana": 4,
>      "apple": 2,
>      "orange": 1.5,
>      "pear": 3
> }
>
> def compute_bill(food):
>      total = 0
>      for item in food:
>          if stock[item] > 0:
>              total += prices[item]
>              stock[item] = stock[item] - 1
>              return total
> Whenever I run this script, "4" is returned. It does not seem to matter what in in the list the script is run on. I have tried this on the Codecademy interpreter/emulator (I'm not sure which they use) and the repl.it interpreter, but for the same result. If anyone could find the glitch in my code, please let me know. Thanks!
>
Work through it a step at a time.

You haven't said what 'food' is when 'compute_bill is called, but I'm
guessing that the first item it checks is "banana".

stock["banana"] == 6, so it adds prices["banana"] to total, subtracts 1
from stock["banana"], and then returns the total, 4, because that's
what you've told it to do.



From luketomaneng at gmail.com  Mon Jan 19 19:31:09 2015
From: luketomaneng at gmail.com (Luke Tomaneng)
Date: Mon, 19 Jan 2015 16:31:09 -0800 (PST)
Subject: Concerning Dictionaries and += in Python 2.x
In-Reply-To: <mailman.17869.1421713307.18130.python-list@python.org>
References: <bc9e302a-356c-4223-9c25-6a8003db48e6@googlegroups.com>
 <mailman.17869.1421713307.18130.python-list@python.org>
Message-ID: <78ab68ee-d00c-4c0e-9e86-ebbbc06e4452@googlegroups.com>

On Monday, January 19, 2015 at 4:21:58 PM UTC-8, Chris Angelico wrote:
> On Tue, Jan 20, 2015 at 11:12 AM, Luke Tomaneng wrote:
> > def compute_bill(food):
> >     total = 0
> >     for item in food:
> >         if stock[item] > 0:
> >             total += prices[item]
> >             stock[item] = stock[item] - 1
> >             return total
> > Whenever I run this script, "4" is returned. It does not seem to matter what in in the list the script is run on. I have tried this on the Codecademy interpreter/emulator (I'm not sure which they use) and the repl.it interpreter, but for the same result. If anyone could find the glitch in my code, please let me know. Thanks!
> >
> 
> In Python, indentation determines block structure. Have another look
> at this function, and see if you can figure out where the problem is;
> hint: try printing something out every time you claim a piece of
> stock.
> 
> ChrisA

Hm. I fixed the indentation like you said, and it worked fine. The only reason I changed the indentation to what you saw in the first place is because Codecademy's Python engine registered an error. However, repl.it accepted the script. I have concluded that the original mistake was actually on the Codecademy site instead of my script. Thanks for helping me out.


From rustompmody at gmail.com  Mon Jan 19 19:31:38 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Mon, 19 Jan 2015 16:31:38 -0800 (PST)
Subject: Random ALL CAPS posts on this group
In-Reply-To: <mailman.17870.1421713364.18130.python-list@python.org>
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
 <mailman.17870.1421713364.18130.python-list@python.org>
Message-ID: <df99fc99-b370-496a-b925-c702b17627b5@googlegroups.com>

On Tuesday, January 20, 2015 at 5:52:54 AM UTC+5:30, Chris Angelico wrote:
> On Tue, Jan 20, 2015 at 11:15 AM, Luke Tomaneng  wrote:
> > Has anyone noticed these? There have been about three of them recently and they don't seem to have anything to do with Python at all. Does anyone know if there is a good reason they are here?
> >
> 
> I haven't seen them. My guess is they're straight-up spam; just ignore
> them, or mark them as spam if your client supports it.
> 
> ChrisA

In google groups you can mark spam by clicking the tiny downward triangle next
to the Reply-arrow -> "Report abuse" -> spam


From luketomaneng at gmail.com  Mon Jan 19 19:34:34 2015
From: luketomaneng at gmail.com (Luke Tomaneng)
Date: Mon, 19 Jan 2015 16:34:34 -0800 (PST)
Subject: Concerning Dictionaries and += in Python 2.x
In-Reply-To: <bc9e302a-356c-4223-9c25-6a8003db48e6@googlegroups.com>
References: <bc9e302a-356c-4223-9c25-6a8003db48e6@googlegroups.com>
Message-ID: <78c7d3ea-0bff-4716-acc9-1ff38d52dfe2@googlegroups.com>

Thanks Chris / Mr. Angelico / whatever you prefer. I attempted to post a reply to you before but it could not be viewed even after refreshing several times. You've been helpful.


From marfig at gmail.com  Mon Jan 19 19:35:29 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Tue, 20 Jan 2015 00:35:29 +0000 (UTC)
Subject: Trees
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
Message-ID: <loom.20150120T013430-46@post.gmane.org>

In article <mailman.17862.1421705173.18130.python-list at python.org>, 
zacharygilmartin at gmail.com says...
> 
> Why aren't there trees in the python standard library?

I don't know much about python development process and strategies, but I 
suspect it shouldn't be much different from any other language I know 
of. So here's my tentative answer:

Once general purpose programming languages become established, the STL 
maintainers tend to greatly decrease additions to the standard library, 
except when this is required to support new language features. Most of 
development on the STL shifts to code maintenance in order to improve 
the quality of the code (usually to address memory usage and performance 
concerns) and solve any existing bugs on the STL.

Instead the language maintainers start to rely on third-party libraries 
as a continuation of the effort to extend the programming language 
further. Any new additions to the STL are carefully pondered. The reason 
is twofold:

1) Just like with the matter of data structures, many additions are 
implementation-contentious. Trees, for instance, can be implemented in 
any number of ways, some with an emphasis on performance, others on 
memory usage. The decision of which implementation to choose isn't easy. 
And if users can already choose different types of implementations from 
the external libraries, then this is is probably motivation enough to 
delay the decision for another day.

2) A standard library should focus first and foremost on support of the 
language features. If for some reason this takes time away from adding 
new entries into the STL, that's fine.

There's also the problem of how one should look at a standard library. 
Some maintainers don't look very well at the idea of a monolithic 
approach, while others, like Guido, like to think of a "batteries-
included" programming language, indicating a desire to build a large 
STL. And this is why perhaps your question arises. But "batteries 
included" doesn't mean build a "Total Library". That would be a vain 
attempt for any general purpose language.



From rantingrickjohnson at gmail.com  Mon Jan 19 19:38:08 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Mon, 19 Jan 2015 16:38:08 -0800 (PST)
Subject: Random ALL CAPS posts on this group
In-Reply-To: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
Message-ID: <38b9177e-e947-4a62-9823-554e5e266c4e@googlegroups.com>

On Monday, January 19, 2015 at 6:16:13 PM UTC-6, Luke Tomaneng wrote:
> Has anyone noticed [uppercase post content]? There have
> been about three of them recently and they don't seem to
> have anything to do with Python at all. Does anyone know
> if there is a good reason they are here?

A "good reason"...? Nope.

Using all-caps when writing is understood as shouting. I
sometimes use caps myself on intermittent words that need
special emphasis, but using nothing but caps is so annoying
that most people won't even bother to read your posts.

Apparently the author has something "so important" to say,
they he thinks he needs to "shout from the rafters" so
everybody can hear his "important message".  Although, he's
failed to notice that this is a group who's primary focus is
the Python Programming language, or at minimum, a discussion
of technical issues, and so most people are not going to be
interested -- and by "most" i mean *ALL*. ;-)

However, as is the case with most of these "troll-spammers",
the author is most likely posting this crap to multiple
message boards in hopes that someone will engage him or
click one of his malware installing links. Just ignore them.

That's the beauty of free speech: "We have right to be
annoyed, and the author has the right not to give a damn".
The only alternative is fascist censorship, and I'll happily
endure these annoyances to prevent that! You see, with
fascism you just trade one annoying jerk who has no power,
for another annoying jerk who has the absolute power of the
state behind him -- and you know the old adage about power
and corruption don't you?


From steve+comp.lang.python at pearwood.info  Mon Jan 19 19:40:45 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 20 Jan 2015 11:40:45 +1100
Subject: Random ALL CAPS posts on this group
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
Message-ID: <54bda40e$0$12995$c3e8da3$5496439d@news.astraweb.com>

Luke Tomaneng wrote:

> Has anyone noticed these? There have been about three of them recently and
> they don't seem to have anything to do with Python at all. Does anyone
> know if there is a good reason they are here?


They're spam, and depending on how you are accessing this group you may or
may not see them. Alas I do see them.

Just delete them, please please please please do not reply to them and try
to argue with the spammer. Occasionally we have either well-meaning but
foolish people who think that replying to spam, quoting the entire spam
message in their email, and sending to the list is somehow helping. Of
course the spammer isn't reading replies!

Either that, or they are actually spammers themselves, and their cunning
ploy is to *pretend* to be replying to spam in order to get their message
past the spam filters.

So don't be one of those guys.


-- 
Steven



From rosuav at gmail.com  Mon Jan 19 19:46:26 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 20 Jan 2015 11:46:26 +1100
Subject: Concerning Dictionaries and += in Python 2.x
In-Reply-To: <78c7d3ea-0bff-4716-acc9-1ff38d52dfe2@googlegroups.com>
References: <bc9e302a-356c-4223-9c25-6a8003db48e6@googlegroups.com>
 <78c7d3ea-0bff-4716-acc9-1ff38d52dfe2@googlegroups.com>
Message-ID: <CAPTjJmp9z4-9H9ZVaysoSTeYHW6ffz6UxJPAnMGxRhey35NRYQ@mail.gmail.com>

On Tue, Jan 20, 2015 at 11:34 AM, Luke Tomaneng <luketomaneng at gmail.com> wrote:
> Thanks Chris / Mr. Angelico / whatever you prefer. I attempted to post a reply to you before but it could not be viewed even after refreshing several times. You've been helpful.
>

My pleasure! Your earlier email did come through; sometimes there are
short delays, it's not a big deal.

As to a mode of address, most people use first names around here, so
"Chris" is common. But when lots of Chrises get to talking, that can
get ambiguous, so I might be referred to as ChrisA, or as Rosuav (my
email address). But Mr Angelico is fine, if a little formal :)

ChrisA


From drsalists at gmail.com  Mon Jan 19 19:49:47 2015
From: drsalists at gmail.com (Dan Stromberg)
Date: Mon, 19 Jan 2015 16:49:47 -0800
Subject: Trees
In-Reply-To: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
Message-ID: <CAGGBd_pMdYZwt-ksdSpDFNVxXwkekGsJFi=2C66PStTFzS0R+w@mail.gmail.com>

On Mon, Jan 19, 2015 at 2:06 PM, Zachary Gilmartin
<zacharygilmartin at gmail.com> wrote:
> Why aren't there trees in the python standard library?

Trees are kind of specialized datastructures; no one type of tree
solves all tree-related problems suitably well.

I think probably the most common need for a tree is implementing a
cache, but most times you're tempted to sort inside a loop you're
better off with a tree.

I've put some time into python trees; most of them are on pypi and at:
http://stromberg.dnsalias.org/~dstromberg/datastructures/
and:
http://stromberg.dnsalias.org/~strombrg/python-tree-and-heap-comparison/

HTH


From drsalists at gmail.com  Mon Jan 19 19:54:24 2015
From: drsalists at gmail.com (Dan Stromberg)
Date: Mon, 19 Jan 2015 16:54:24 -0800
Subject: Concerning Dictionaries and += in Python 2.x
In-Reply-To: <bc9e302a-356c-4223-9c25-6a8003db48e6@googlegroups.com>
References: <bc9e302a-356c-4223-9c25-6a8003db48e6@googlegroups.com>
Message-ID: <CAGGBd_ra0g=fUPfOOPJ0oU0Pj4j7WHBR0wmt+WGBLf8RvXyQnw@mail.gmail.com>

On Mon, Jan 19, 2015 at 4:12 PM, Luke Tomaneng <luketomaneng at gmail.com> wrote:
> I have been having a bit of trouble with the things mentioned in the title. I have written the following script for a Codecademy course:
> stock = {
>     "banana": 6,
>     "apple": 0,
>     "orange": 32,
>     "pear": 15
> }
>
> prices = {
>     "banana": 4,
>     "apple": 2,
>     "orange": 1.5,
>     "pear": 3
> }
>
> def compute_bill(food):
>     total = 0
>     for item in food:
>         if stock[item] > 0:
>             total += prices[item]
>             stock[item] = stock[item] - 1
>             return total
> Whenever I run this script, "4" is returned. It does not seem to matter what in in the list the script is run on. I have tried this on the Codecademy interpreter/emulator (I'm not sure which they use) and the repl.it interpreter, but for the same result. If anyone could find the glitch in my code, please let me know. Thanks!

You're returning total inappropriately - the first time stock[item] is > 0.


From rosuav at gmail.com  Mon Jan 19 20:50:10 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 20 Jan 2015 12:50:10 +1100
Subject: Random ALL CAPS posts on this group
In-Reply-To: <38b9177e-e947-4a62-9823-554e5e266c4e@googlegroups.com>
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
 <38b9177e-e947-4a62-9823-554e5e266c4e@googlegroups.com>
Message-ID: <CAPTjJmqMF7SDhwbSO28n_NzJsoxZjA0Aj9D=Nq3NZyX3rO2VDA@mail.gmail.com>

On Tue, Jan 20, 2015 at 11:38 AM, Rick Johnson
<rantingrickjohnson at gmail.com> wrote:
> That's the beauty of free speech: "We have right to be
> annoyed, and the author has the right not to give a damn".
> The only alternative is fascist censorship, and I'll happily
> endure these annoyances to prevent that!

Free speech also gives the freedom to not listen. Maybe it's less
trouble to skip them manually than to filter them out reliably, but
you do still have that option.

ChrisA


From ben+python at benfinney.id.au  Mon Jan 19 21:15:50 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Tue, 20 Jan 2015 13:15:50 +1100
Subject: Random ALL CAPS posts on this group
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
 <38b9177e-e947-4a62-9823-554e5e266c4e@googlegroups.com>
 <CAPTjJmqMF7SDhwbSO28n_NzJsoxZjA0Aj9D=Nq3NZyX3rO2VDA@mail.gmail.com>
Message-ID: <85lhkyp57t.fsf@benfinney.id.au>

Chris Angelico <rosuav at gmail.com> writes:

> On Tue, Jan 20, 2015 at 11:38 AM, Rick Johnson
> <rantingrickjohnson at gmail.com> wrote:
> > That's the beauty of free speech: "We have right to be annoyed, and
> > the author has the right not to give a damn". The only alternative
> > is fascist censorship, and I'll happily endure these annoyances to
> > prevent that!
>
> Free speech also gives the freedom to not listen.

Freedom of expression entails an obligation on the state to not quash
anyone's expression. It does not affect anyone who is not the state; it
imposes no obligation on the PSF.

Freedom of expression has no implication that anyone else is obligated
to listen, as you say. It also has no implication that anyone is
obligated to carry that expression further.

So a forum such as this can block obnoxious spam, and that choice does
not impact anyone's freedom of expression.

-- 
 \         ?I planted some bird seed. A bird came up. Now I don't know |
  `\                                  what to feed it.? ?Steven Wright |
_o__)                                                                  |
Ben Finney



From jsf80238 at gmail.com  Mon Jan 19 21:40:18 2015
From: jsf80238 at gmail.com (Jason Friedman)
Date: Mon, 19 Jan 2015 19:40:18 -0700
Subject: Storing dataset from Condtional FreqDist
In-Reply-To: <bd1c0f0d-febf-482c-a53d-a980d2f091cd@googlegroups.com>
References: <bd1c0f0d-febf-482c-a53d-a980d2f091cd@googlegroups.com>
Message-ID: <CANy1k1jWUAOXG96ZXAbME4fCU+GiM7ExBf2pUm0T8SatBSdZRg@mail.gmail.com>

> Hello i have trying to store information in arff file but i has been really. Any ideas of how can i do that?
>
>
> with open('fileids3.txt', 'r') as f:
>
>         genres=[word.strip() for word in f.next().split(',')]
>
> with open('adjectifs2.txt', 'r') as g:
>         adj = [word.strip() for word in g.next().split(',')]
>
> freq = nltk.ConditionalFreqDist(
>      (genre, m)
>       for genre in brown.fileids()
>       for m in brown.words(fileids=genre))
>
>
> freq.tabulate(conditions=genres, samples=adj)

What do fileids3.txt and adjectifs2.txt contain (perhaps give us the
first few lines of each)?

What do you want your AARF file to look like (show us what the header
should look like and then the first few lines of data)?


From breamoreboy at yahoo.co.uk  Mon Jan 19 21:46:01 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Tue, 20 Jan 2015 02:46:01 +0000
Subject: Trees
In-Reply-To: <CAGGBd_pMdYZwt-ksdSpDFNVxXwkekGsJFi=2C66PStTFzS0R+w@mail.gmail.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <CAGGBd_pMdYZwt-ksdSpDFNVxXwkekGsJFi=2C66PStTFzS0R+w@mail.gmail.com>
Message-ID: <m9kfhe$vh$1@ger.gmane.org>

On 20/01/2015 00:49, Dan Stromberg wrote:
> On Mon, Jan 19, 2015 at 2:06 PM, Zachary Gilmartin
> <zacharygilmartin at gmail.com> wrote:
>> Why aren't there trees in the python standard library?
>
> Trees are kind of specialized datastructures; no one type of tree
> solves all tree-related problems suitably well.
>
> I think probably the most common need for a tree is implementing a
> cache, but most times you're tempted to sort inside a loop you're
> better off with a tree.
>
> I've put some time into python trees; most of them are on pypi and at:
> http://stromberg.dnsalias.org/~dstromberg/datastructures/
> and:
> http://stromberg.dnsalias.org/~strombrg/python-tree-and-heap-comparison/
>
> HTH
>

I don't know if you've seen this http://kmike.ru/python-data-structures/ 
but maybe of interest.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From breamoreboy at yahoo.co.uk  Mon Jan 19 21:48:58 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Tue, 20 Jan 2015 02:48:58 +0000
Subject: Random ALL CAPS posts on this group
In-Reply-To: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
Message-ID: <m9kfmv$vh$2@ger.gmane.org>

On 20/01/2015 00:15, Luke Tomaneng wrote:
> Has anyone noticed these? There have been about three of them recently and they don't seem to have anything to do with Python at all. Does anyone know if there is a good reason they are here?
>

I've never seen any of these reading gmane.comp.python.general using 
Thunderbird.  The only annoying things I recall recently are bvbvbvbv 
and the Italian Mob.  Whenever I spot them I'm straight onto gg to flag 
them as abuse.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rantingrickjohnson at gmail.com  Mon Jan 19 22:50:48 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Mon, 19 Jan 2015 19:50:48 -0800 (PST)
Subject: Random ALL CAPS posts on this group
In-Reply-To: <mailman.17876.1421718613.18130.python-list@python.org>
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
 <38b9177e-e947-4a62-9823-554e5e266c4e@googlegroups.com>
 <mailman.17876.1421718613.18130.python-list@python.org>
Message-ID: <fef59ccf-a1af-408d-bc41-842f5e971a2d@googlegroups.com>

On Monday, January 19, 2015 at 7:55:11 PM UTC-6, Chris Angelico wrote:
> On Tue, Jan 20, 2015 at 11:38 AM, Rick Johnson wrote:
> > That's the beauty of free speech: "We have right to be
> > annoyed, and the author has the right not to give a damn".
> > The only alternative is fascist censorship, and I'll happily
> > endure these annoyances to prevent that!
> 
> Free speech also gives the freedom to not listen. Maybe it's less
> trouble to skip them manually than to filter them out reliably, but
> you do still have that option.

Agreed. Listening is not compulsory. Fingers stuck firmly in
the ear canals or utilizing the natural phenomenon that sound
waves tend to diminish over distances, or when passing
through physical obstructions, are all effective techniques!
Of course the "kill file" has such a gloriously revengeful
sound to it though! ;-)


From rosuav at gmail.com  Mon Jan 19 22:58:08 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 20 Jan 2015 14:58:08 +1100
Subject: Random ALL CAPS posts on this group
In-Reply-To: <fef59ccf-a1af-408d-bc41-842f5e971a2d@googlegroups.com>
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
 <38b9177e-e947-4a62-9823-554e5e266c4e@googlegroups.com>
 <mailman.17876.1421718613.18130.python-list@python.org>
 <fef59ccf-a1af-408d-bc41-842f5e971a2d@googlegroups.com>
Message-ID: <CAPTjJmrJqM+SxPB_0CUjrzyzeHCabuy_k97Vr3jyAxK9d5mirQ@mail.gmail.com>

On Tue, Jan 20, 2015 at 2:50 PM, Rick Johnson
<rantingrickjohnson at gmail.com> wrote:
> Of course the "kill file" has such a gloriously revengeful
> sound to it though! ;-)

http://bofh.ntk.net/BOFH/0000/bastard-sm2.php

ChrisA


From rantingrickjohnson at gmail.com  Mon Jan 19 23:06:29 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Mon, 19 Jan 2015 20:06:29 -0800 (PST)
Subject: Random ALL CAPS posts on this group
In-Reply-To: <mailman.17877.1421720150.18130.python-list@python.org>
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
 <38b9177e-e947-4a62-9823-554e5e266c4e@googlegroups.com>
 <CAPTjJmqMF7SDhwbSO28n_NzJsoxZjA0Aj9D=Nq3NZyX3rO2VDA@mail.gmail.com>
 <mailman.17877.1421720150.18130.python-list@python.org>
Message-ID: <e34e12d1-c260-4520-9dc8-4ae9b7faf02b@googlegroups.com>

On Monday, January 19, 2015 at 8:16:01 PM UTC-6, Ben Finney wrote:
> Freedom of expression entails an obligation on the state
> to not quash anyone's expression. It does not affect
> anyone who is not the state; it imposes no obligation on
> the PSF. [...] So a forum such as this can block obnoxious
> spam, and that choice does not impact anyone's freedom of
> expression.

Ben, i know we have not agreed much in the past, and you may
be thinking that i intend to pick a fight with you here (and
i don't), however i implore you to give more thought to the
vital importance of free expression.

I believe that free speech is so important, so vital to the
existence of free societies, that it's practice *MUST*
extend far beyond the boundaries of the state's rule, and be
fostered by *ANY* group who is in the public domain.

No one here would justify a public business refusing to
serve or employ a person based on race, religion, sex, or
otherwise. So why would you so easily discriminate against
speech?

I agree that these spam posts are annoying, but that is not
enough of an excuse to start limiting people's speech in a
*PUBLIC* forum. If python-list were a private group for
"members only", then by all means make up whatever rules you
want to. But when shared publicly, we have a duty to support
freedom for *ALL*. We must suffer the annoyances if we want
to enjoy freedom for all.


From drsalists at gmail.com  Mon Jan 19 23:21:52 2015
From: drsalists at gmail.com (Dan Stromberg)
Date: Mon, 19 Jan 2015 20:21:52 -0800
Subject: Trees
In-Reply-To: <m9kfhe$vh$1@ger.gmane.org>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <CAGGBd_pMdYZwt-ksdSpDFNVxXwkekGsJFi=2C66PStTFzS0R+w@mail.gmail.com>
 <m9kfhe$vh$1@ger.gmane.org>
Message-ID: <CAGGBd_rPSxSK1HCkdmwzu5MS_bBtA9X+hgx6VHKsvWYiAG9AOg@mail.gmail.com>

On Mon, Jan 19, 2015 at 6:46 PM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> On 20/01/2015 00:49, Dan Stromberg wrote:
>>
>> On Mon, Jan 19, 2015 at 2:06 PM, Zachary Gilmartin
>> <zacharygilmartin at gmail.com> wrote:
>>>
>>> Why aren't there trees in the python standard library?
>>
>>
>> Trees are kind of specialized datastructures; no one type of tree
>> solves all tree-related problems suitably well.
>>
>> I think probably the most common need for a tree is implementing a
>> cache, but most times you're tempted to sort inside a loop you're
>> better off with a tree.
>>
>> I've put some time into python trees; most of them are on pypi and at:
>> http://stromberg.dnsalias.org/~dstromberg/datastructures/
>> and:
>> http://stromberg.dnsalias.org/~strombrg/python-tree-and-heap-comparison/
>>
>> HTH
>>
>
> I don't know if you've seen this http://kmike.ru/python-data-structures/ but
> maybe of interest.

I've seen it. It's a nice page.

I attempted to get my treap port in there since it has a Cython
version, but it didn't seem to take.

I've mostly focused on pure python that runs on CPython 2.x, CPython
3.x, Pypy, Pypy3 and Jython.


From joel.goldstick at gmail.com  Mon Jan 19 23:49:29 2015
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Mon, 19 Jan 2015 23:49:29 -0500
Subject: Trees
In-Reply-To: <CAGGBd_rPSxSK1HCkdmwzu5MS_bBtA9X+hgx6VHKsvWYiAG9AOg@mail.gmail.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <CAGGBd_pMdYZwt-ksdSpDFNVxXwkekGsJFi=2C66PStTFzS0R+w@mail.gmail.com>
 <m9kfhe$vh$1@ger.gmane.org>
 <CAGGBd_rPSxSK1HCkdmwzu5MS_bBtA9X+hgx6VHKsvWYiAG9AOg@mail.gmail.com>
Message-ID: <CAPM-O+y70YWWL5yPiAgX5ap5TnHC6S4VtDuoimZR3TvkL=r7VQ@mail.gmail.com>

On Mon, Jan 19, 2015 at 11:21 PM, Dan Stromberg <drsalists at gmail.com> wrote:

> On Mon, Jan 19, 2015 at 6:46 PM, Mark Lawrence <breamoreboy at yahoo.co.uk>
> wrote:
> > On 20/01/2015 00:49, Dan Stromberg wrote:
> >>
>

apropos of nothing, I went to stonybrook too. beee 1978



> >> On Mon, Jan 19, 2015 at 2:06 PM, Zachary Gilmartin
> >> <zacharygilmartin at gmail.com> wrote:
> >>>
> >>> Why aren't there trees in the python standard library?
> >>
> >>
> >> Trees are kind of specialized datastructures; no one type of tree
> >> solves all tree-related problems suitably well.
> >>
> >> I think probably the most common need for a tree is implementing a
> >> cache, but most times you're tempted to sort inside a loop you're
> >> better off with a tree.
> >>
> >> I've put some time into python trees; most of them are on pypi and at:
> >> http://stromberg.dnsalias.org/~dstromberg/datastructures/
> >> and:
> >>
> http://stromberg.dnsalias.org/~strombrg/python-tree-and-heap-comparison/
> >>
> >> HTH
> >>
> >
> > I don't know if you've seen this http://kmike.ru/python-data-structures/
> but
> > maybe of interest.
>
> I've seen it. It's a nice page.
>
> I attempted to get my treap port in there since it has a Cython
> version, but it didn't seem to take.
>
> I've mostly focused on pure python that runs on CPython 2.x, CPython
> 3.x, Pypy, Pypy3 and Jython.
> --
> https://mail.python.org/mailman/listinfo/python-list
>



-- 
Joel Goldstick
http://joelgoldstick.com
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From marko at pacujo.net  Tue Jan 20 00:19:14 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Tue, 20 Jan 2015 07:19:14 +0200
Subject: Trees
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17865.1421708518.18130.python-list@python.org>
Message-ID: <87k30ihvvx.fsf@elektro.pacujo.net>

Mark Lawrence <breamoreboy at yahoo.co.uk>:

> On 19/01/2015 22:06, Zachary Gilmartin wrote:
>> Why aren't there trees in the python standard library?
>
> Probably because you'd never get agreement as to which specific tree
> and which specific implementation was the most suitable for inclusion.

Most programming languages provide one standard sorted mapping
implementation.

GvR is highly suspicious of the utility of trees and wouldn't like to
take the burden of maintaining them in the stdlib.

So in my Python software (both at work and at home) needs, I use a
Python AVL tree implementation of my own. My use case is timers. (GvR
uses heapq for the purpose.)


Marko


From nedraskeating at yahoo.com  Tue Jan 20 01:07:19 2015
From: nedraskeating at yahoo.com (nedraskeating)
Date: Mon, 19 Jan 2015 22:07:19 -0800 (PST)
Subject: Bodybuilding Helpful Advice
Message-ID: <1421734039695-5083763.post@n6.nabble.com>

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--
View this message in context: http://python.6.x6.nabble.com/Bodybuilding-Helpful-Advice-tp5083763.html
Sent from the Python - python-list mailing list archive at Nabble.com.


From tjreedy at udel.edu  Tue Jan 20 01:08:02 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Tue, 20 Jan 2015 01:08:02 -0500
Subject: Trees
In-Reply-To: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
Message-ID: <m9krc3$ema$1@ger.gmane.org>

On 1/19/2015 5:06 PM, Zachary Gilmartin wrote:
> Why aren't there trees in the python standard library?

Sequences nested withing sequences can be regarded as trees, and Python 
has these.  I regard Lisp as a tree processing languages, as it must be 
to manipulate, for example, code with nested structures.

Nested structures in general represent trees or more general graph 
forms.  The ast module uses Nodes with lists of subnodes to represent 
Abstract Syntax Trees.

Priority queues are specialized trees implemented on top of lists.  The 
heapq module is imported into 6 other modules.

Others have answered as to why other special-purpose 
constrained-structure trees have not been added to the stdlib.

It might possibly be useful to add a general Tree base class with pre-, 
in-, and post-order generators, and maybe interior and leaf node 
counters and max depth method.  Finding uses for such a thing in the 
stdlib (ast?) would be a plus in favor.

-- 
Terry Jan Reedy




From nicholas.cole at gmail.com  Tue Jan 20 04:23:50 2015
From: nicholas.cole at gmail.com (Nicholas Cole)
Date: Tue, 20 Jan 2015 09:23:50 +0000
Subject: Trees
In-Reply-To: <CABicbJK1TzXSoFQFUPXSkafzwMkYfByUfpw8QiaXiHwROOMo+Q@mail.gmail.com>
References: <mailman.17862.1421705173.18130.python-list@python.org>
 <54bd8e6a$0$13009$c3e8da3$5496439d@news.astraweb.com>
 <CABicbJK1TzXSoFQFUPXSkafzwMkYfByUfpw8QiaXiHwROOMo+Q@mail.gmail.com>
Message-ID: <CAAu18hed4W-2qaaMvW1S-gGL25SDWQbxevnyYmbrjQLh881TZA@mail.gmail.com>

On Mon, Jan 19, 2015 at 11:52 PM, Devin Jeanpierre
<jeanpierreda at gmail.com> wrote:
> On Mon, Jan 19, 2015 at 3:08 PM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> Zachary Gilmartin wrote:
>>
>>> Why aren't there trees in the python standard library?
>>
>> Possibly because they aren't needed? Under what circumstances would you use
>> a tree instead of a list or a dict or combination of both?
>>
>> That's not a rhetorical question. I am genuinely curious, what task do you
>> have that you think must be solved by a tree?
>
> In general, any time you want to maintain a sorted list or mapping,
> balanced search tree structures come in handy.
>
> Here's an example task: suppose you want to represent a calendar,
> where timeslots can be reserved for something. Calendar events are not
> allowed to intersect.

Maybe because I'm not a computer scientist, I can't immediately see
why this is a "Tree" problem and not a "Database" problem.  Genuinely
interested.


From marko at pacujo.net  Tue Jan 20 04:45:54 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Tue, 20 Jan 2015 11:45:54 +0200
Subject: Trees
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
Message-ID: <87ppa9944t.fsf@elektro.pacujo.net>

Terry Reedy <tjreedy at udel.edu>:

> Others have answered as to why other special-purpose
> constrained-structure trees have not been added to the stdlib.

Ordered O(log n) mappings are not special-purpose data structures. I'd
say strings and floats are much more special-purpose than ordered
mappings, and yet Python has direct support for those.

As I said, I use ordered mappings to implement timers. GvR uses the
heapq module for the purpose. The downside of heapq is that canceled
timers often flood the heapq structure; in networking you can easily
start a thousand timers a second but virtually no timer ever expires.
Python's asyncio ignores the problem, but GvR mentioned a periodic
"garbage collection" as a potentially effective solution. I tested the
garbage collection trick and it did seem very effective.


Marko


From rustompmody at gmail.com  Tue Jan 20 08:33:37 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Tue, 20 Jan 2015 05:33:37 -0800 (PST)
Subject: Trees
In-Reply-To: <mailman.17884.1421734095.18130.python-list@python.org>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
Message-ID: <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>

On Tuesday, January 20, 2015 at 11:38:27 AM UTC+5:30, Terry Reedy wrote:
> On 1/19/2015 5:06 PM, Zachary Gilmartin wrote:
> > Why aren't there trees in the python standard library?
> 
> Sequences nested withing sequences can be regarded as trees, and Python 
> has these.  I regard Lisp as a tree processing languages, as it must be 
> to manipulate, for example, code with nested structures.

Yeah python has trees alright.

Heres' some simple tree-code

from enum import Enum
class TreeTag(Enum):
    I = 0  # An internal node
    L = 1  # A leaf node
    def __repr__(self):  return self.name
    
I = TreeTag.I
L = TreeTag.L


def dfs(t):
    if t[0] == L:
        return [t[1]]
    else:
        return [t[1]] + dfs(t[2]) + dfs(t[3])

# Converting to generators is trivial
=====================

# Example tree
# From http://www-math.ucdenver.edu/~wcherowi/courses/m4408/gtln8.html

t1 = [L, 1]
t4 = [I, 4, [L, 3],[L,5]]
t2 = [I, 2, t1, t4]
t8 = [I, 8, [L, 7], [L, 9]]

# Top level tree
t = [I, 6, t2, t8]


======================
An REPL session

>>> t
[I, 6, [I, 2, [L, 1], [I, 4, [L, 3], [L, 5]]], [I, 8, [L, 7], [L, 9]]]
>>> dfs(t)
[6, 2, 1, 4, 3, 5, 8, 7, 9]
>>> t8
[I, 8, [L, 7], [L, 9]]
>>> dfs(t8)
[8, 7, 9]
>>> 


From rustompmody at gmail.com  Tue Jan 20 08:51:41 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Tue, 20 Jan 2015 05:51:41 -0800 (PST)
Subject: Trees
In-Reply-To: <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
Message-ID: <fb48919c-f1e9-466e-a9b9-4adc9b65e2ab@googlegroups.com>

On Tuesday, January 20, 2015 at 7:03:56 PM UTC+5:30, Rustom Mody wrote:
> On Tuesday, January 20, 2015 at 11:38:27 AM UTC+5:30, Terry Reedy wrote:
> > On 1/19/2015 5:06 PM, Zachary Gilmartin wrote:
> > > Why aren't there trees in the python standard library?
> > 
> > Sequences nested withing sequences can be regarded as trees, and Python 
> > has these.  I regard Lisp as a tree processing languages, as it must be 
> > to manipulate, for example, code with nested structures.
> 
> Yeah python has trees alright.

It may be best to read my example above in this order:
1. See the picture at http://www-math.ucdenver.edu/~wcherowi/courses/m4408/gtln8.html

2. Take the python representation of that

>>> t
[I, 6, [I, 2, [L, 1], [I, 4, [L, 3], [L, 5]]], [I, 8, [L, 7], [L, 9]]] 

Indent that a bit:

[I, 6, 
   [I, 2, 
       [L, 1], 
       [I, 4, 
           [L, 3], 
           [L, 5]]], 
   [I, 8, 
       [L, 7], 
       [L, 9]]] 

Now compare with the picture above
Only catch is you must see it 'lying down'
Shouldn't be too hard given that we've all got used to seeing :-) as a smiley :-)


From wingusr at gmail.com  Tue Jan 20 09:06:29 2015
From: wingusr at gmail.com (TP)
Date: Tue, 20 Jan 2015 06:06:29 -0800
Subject: Trees
In-Reply-To: <m9kfhe$vh$1@ger.gmane.org>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <CAGGBd_pMdYZwt-ksdSpDFNVxXwkekGsJFi=2C66PStTFzS0R+w@mail.gmail.com>
 <m9kfhe$vh$1@ger.gmane.org>
Message-ID: <CAMEax75HE-Gw2nEPNKpFAK03DeuY4HcNViumnfmDpX2SUtnGhA@mail.gmail.com>

On Mon, Jan 19, 2015 at 6:46 PM, Mark Lawrence <breamoreboy at yahoo.co.uk>
wrote:

> I don't know if you've seen this http://kmike.ru/python-data-structures/
> but maybe of interest.
>

I haven't read but also possibly of interest:

Data Structures and Algorithms in Python by Michael T. Goodrich, Roberto
Tamassia, Michael H. Goldwasser (Wiley, 2013) [1]

Python Algorithms: Mastering Basic Algorithms in the Python Language, 2nd
Edition by Magnus Lie Hetland (Apress, 2014) [2]

[1] http://www.wiley.com/WileyCDA/WileyTitle/productCd-EHEP002510.html

[2] http://www.apress.com/9781484200568
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From paul.nospam at rudin.co.uk  Tue Jan 20 09:14:29 2015
From: paul.nospam at rudin.co.uk (Paul Rudin)
Date: Tue, 20 Jan 2015 14:14:29 +0000
Subject: Random ALL CAPS posts on this group
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
 <38b9177e-e947-4a62-9823-554e5e266c4e@googlegroups.com>
 <CAPTjJmqMF7SDhwbSO28n_NzJsoxZjA0Aj9D=Nq3NZyX3rO2VDA@mail.gmail.com>
 <mailman.17877.1421720150.18130.python-list@python.org>
 <e34e12d1-c260-4520-9dc8-4ae9b7faf02b@googlegroups.com>
Message-ID: <86d269v8sa.fsf@rudin.co.uk>

Rick Johnson <rantingrickjohnson at gmail.com> writes:


> No one here would justify a public business refusing to
> serve or employ a person based on race, religion, sex, or
> otherwise.

Depends on what you mean by "or otherwise".

> So why would you so easily discriminate against speech?

People discriminate amongst prospective employees on the basis of what
the say all the time. It's the principle method by which you assess
candidates.


Freedom of expression is not about requiring others to publish your
words. It would be completely impractical - where would it end? Your own
slot on prime time TV to rant as you choose?




From marko at pacujo.net  Tue Jan 20 09:15:48 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Tue, 20 Jan 2015 16:15:48 +0200
Subject: Trees
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
Message-ID: <87fvb58rmz.fsf@elektro.pacujo.net>

Rustom Mody <rustompmody at gmail.com>:

> Yeah python has trees alright.

Does Python balance them for you?


Marko


From breamoreboy at yahoo.co.uk  Tue Jan 20 09:21:14 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Tue, 20 Jan 2015 14:21:14 +0000
Subject: Trees
In-Reply-To: <87k30ihvvx.fsf@elektro.pacujo.net>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17865.1421708518.18130.python-list@python.org>
 <87k30ihvvx.fsf@elektro.pacujo.net>
Message-ID: <m9lo8v$cg5$1@ger.gmane.org>

On 20/01/2015 05:19, Marko Rauhamaa wrote:
> Mark Lawrence <breamoreboy at yahoo.co.uk>:
>
>> On 19/01/2015 22:06, Zachary Gilmartin wrote:
>>> Why aren't there trees in the python standard library?
>>
>> Probably because you'd never get agreement as to which specific tree
>> and which specific implementation was the most suitable for inclusion.
>
> Most programming languages provide one standard sorted mapping
> implementation.
>

I'd have thought it would be the standard library and not the language 
that provided a sorted mapping.  Are you also saying that this has to be 
implemented as a tree, such that this has to be provided by cPython, 
Jython, IronPython, Pypy and so on and so forth?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rustompmody at gmail.com  Tue Jan 20 09:35:09 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Tue, 20 Jan 2015 06:35:09 -0800 (PST)
Subject: Trees
In-Reply-To: <87fvb58rmz.fsf@elektro.pacujo.net>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
 <87fvb58rmz.fsf@elektro.pacujo.net>
Message-ID: <915e5162-ae50-4af0-a2e3-8a81e2d0ba79@googlegroups.com>

On Tuesday, January 20, 2015 at 7:46:02 PM UTC+5:30, Marko Rauhamaa wrote:
> Rustom Mody :
> 
> > Yeah python has trees alright.
> 
> Does Python balance them for you?

No

Does python support a menagerie of lists like C
- singly linked, doubly linked, with header, without header etc?

Or access to machine registers like assembly?

And are these differences from C/Assembly in favor or against python?


From cirillobolello at mail.com  Tue Jan 20 12:16:21 2015
From: cirillobolello at mail.com (COLLABORATORE DI MICHELE RAGAZZI ODEY GIANO)
Date: Tue, 20 Jan 2015 09:16:21 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
References: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
Message-ID: <0bf0f094-dd9c-46b2-9ae4-13c12e06d1f7@googlegroups.com>

-- redacted --


From ian.g.kelly at gmail.com  Tue Jan 20 12:19:40 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Tue, 20 Jan 2015 10:19:40 -0700
Subject: Trees
In-Reply-To: <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
Message-ID: <CALwzidmdsscEEGMM1c_sDdv4Sbe2xCOMRaZP1Zk4FTp1yaMuLw@mail.gmail.com>

On Tue, Jan 20, 2015 at 6:33 AM, Rustom Mody <rustompmody at gmail.com> wrote:
> from enum import Enum
> class TreeTag(Enum):
>     I = 0  # An internal node
>     L = 1  # A leaf node
>     def __repr__(self):  return self.name
>
> I = TreeTag.I
> L = TreeTag.L

Explicitly tagging nodes as internal or leaves is kind of ugly and
also prone to getting out of sync with the reality, which is that a
node is a leaf if it doesn't have any other nodes hanging off of it.

> def dfs(t):
>     if t[0] == L:
>         return [t[1]]
>     else:
>         return [t[1]] + dfs(t[2]) + dfs(t[3])

Over the entire tree, this will do O(n) list additions which implies
O(n) list *copies*, which is rather inefficient. This would probably
be better implemented as a recursive generator.

def dfs(t):
    yield t[0]
    yield from chain.from_iterable(map(dfs, islice(t, 1, None)))

> # Converting to generators is trivial
> =====================

:-)


From no.email at nospam.invalid  Tue Jan 20 12:42:03 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Tue, 20 Jan 2015 09:42:03 -0800
Subject: Trees
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17865.1421708518.18130.python-list@python.org>
 <87k30ihvvx.fsf@elektro.pacujo.net>
Message-ID: <87fvb5bb84.fsf@jester.gateway.sonic.net>

Marko Rauhamaa <marko at pacujo.net> writes:
> So in my Python software (both at work and at home) needs, I use a
> Python AVL tree implementation of my own. My use case is timers. (GvR
> uses heapq for the purpose.)

Have you benchmarked your version against heapq or even the builtin
sorting functions?


From crk at godblessthe.us  Tue Jan 20 12:53:27 2015
From: crk at godblessthe.us (Clayton Kirkwood)
Date: Tue, 20 Jan 2015 09:53:27 -0800
Subject: Random ALL CAPS posts on this group
In-Reply-To: <e34e12d1-c260-4520-9dc8-4ae9b7faf02b@googlegroups.com>
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
 <38b9177e-e947-4a62-9823-554e5e266c4e@googlegroups.com>
 <CAPTjJmqMF7SDhwbSO28n_NzJsoxZjA0Aj9D=Nq3NZyX3rO2VDA@mail.gmail.com>
 <mailman.17877.1421720150.18130.python-list@python.org>
 <e34e12d1-c260-4520-9dc8-4ae9b7faf02b@googlegroups.com>
Message-ID: <01c701d034da$01260c50$037224f0$@us>



>-----Original Message-----
>From: Python-list [mailto:python-list-
>bounces+crk=godblessthe.us at python.org] On Behalf Of Rick Johnson
>Sent: Monday, January 19, 2015 8:06 PM
>To: python-list at python.org
>Subject: Re: Random ALL CAPS posts on this group
>
>On Monday, January 19, 2015 at 8:16:01 PM UTC-6, Ben Finney wrote:
>> Freedom of expression entails an obligation on the state to not quash
>> anyone's expression. It does not affect anyone who is not the state;
>> it imposes no obligation on the PSF. [...] So a forum such as this can
>> block obnoxious spam, and that choice does not impact anyone's freedom
>> of expression.
>
>Ben, i know we have not agreed much in the past, and you may be thinking
>that i intend to pick a fight with you here (and i don't), however i
>implore you to give more thought to the vital importance of free
>expression.
>
>I believe that free speech is so important, so vital to the existence of
>free societies, that it's practice *MUST* extend far beyond the
>boundaries of the state's rule, and be fostered by *ANY* group who is in
>the public domain.
>
>No one here would justify a public business refusing to serve or employ
>a person based on race, religion, sex, or otherwise. So why would you so
>easily discriminate against speech?
>
>I agree that these spam posts are annoying, but that is not enough of an
>excuse to start limiting people's speech in a
>*PUBLIC* forum. If python-list were a private group for "members only",
>then by all means make up whatever rules you want to. But when shared
>publicly, we have a duty to support freedom for *ALL*. We must suffer
>the annoyances if we want to enjoy freedom for all.
>--
>https://mail.python.org/mailman/listinfo/python-list
This is not a public forum; it ia quasi-public forum. It has a structure and
understanding of what the topics are. Freedom of speech does not include
anytime and anyplace. This is a captive audience and we can't choose what
some fool is going to bore us with. Yes we can hit the delete key in one
form or another. As much as I don't want to hear our Dear Leader tonight, I
will choose to listen. (and then ridicule:<)) But I don't want some psycho
Islam Terrorist to stand up and commandeer the TSOTU speech just because he
believes that he has the right to drivel on and on. We all agree that that
is not the time, place, or topic for the speech. In civilized society, being
a captive audience is not really associated with free speech. In civilized
society we have a time and a place for a topic, and those that want to hear
the pontificator are free to listen. You don't have the right to come in to
my house and drivel: it is not the right time or place.

Clayton




From no.email at nospam.invalid  Tue Jan 20 13:02:17 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Tue, 20 Jan 2015 10:02:17 -0800
Subject: Trees
References: <mailman.17862.1421705173.18130.python-list@python.org>
 <54bd8e6a$0$13009$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <87bnltbaae.fsf@jester.gateway.sonic.net>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:
> Possibly because they aren't needed? Under what circumstances would
> you use a tree instead of a list or a dict or combination of both?

I've sometimes wanted a functional tree in the sense of functional
programming.  That means the tree structure is immutable and you insert
or delete nodes in O(log n) operations, by creating new trees that share
almost all their data with the old tree.  Once you release the old root,
garbage collection frees any nodes that were in the old tree but not the
new one.

Use case inspired by Haskell's Happstack-store (formerly called MACID):
you want a Prevayler-style in-memory key-value database.  First idea:
all read queries are served by pure in-memory lookups in a Python dict.
Write queries update the dict and also append the command to a serial
log on disk (one disk write, no seeks).  If the system crashes, restart
it empty, and play back the log from the beginning to restore the
in-memory data.

Problem with first idea: the database might be a few thousand entries
but take millions of updates, if entries are modified frequently.  You
don't want to reload the million updates from the beginning.  Next idea:
dump a snapshot of the dictionary now and then, and then just reload
updates starting from the last snapshot.  Trouble here is that the
dictionary is big enough that writing out the snapshot takes time, and
you don't want to lock the whole dict against more updates while the
snapshot is writing.  If you do this the Java way, welcome to
concurrency hell as you make finer and finer grained locks and deal with
resulting deadlocks, race conditions, etc.  And the dictionary still has
to be synchronized to avoid reads simultaneous with updates.

MACID solution: use a functional red-black tree instead of a dict.  To
add or update an entry, make a new tree that replaces the old tree by
updating a single pointer.  That allows unlimited read concurrency
(reading means getting the current tree pointer and navigating the tree
that you get: since that tree is immutable you can keep using it while
other threads make new trees).  Updates are managed by a single thread
that can take its time making the new tree and writing the log, and then
atomically updating the in-memory root pointer that's shared with other
threads.  Finally, to take a snapshot, you can just get the current root
and write out its contents: since it's immutable you can do that
concurrently with anything else (including updates) that might be
happening.  You just have a small interaction with the update thread to
remember where in the log to start reading from in case of a crash and
reload.

Finding out about this was one of the "wow" moments that made me realize
I had to learn Haskell.


From no.email at nospam.invalid  Tue Jan 20 13:14:47 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Tue, 20 Jan 2015 10:14:47 -0800
Subject: Trees
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <87ppa9944t.fsf@elektro.pacujo.net>
Message-ID: <877fwhb9pk.fsf@jester.gateway.sonic.net>

Marko Rauhamaa <marko at pacujo.net> writes:
> As I said, I use ordered mappings to implement timers... The downside
> of heapq is that canceled timers often flood the heapq structure...,
> GvR mentioned a periodic "garbage collection" as a potentially
> effective solution. 

You could look up the "timer wheel" approach used by the Linux kernel
and by Erlang.  It's less general than an ordered map, but probably
faster in practice.

  https://lkml.org/lkml/2005/10/19/46 

Has some info.  I think the kernel uses a different method now though.

Fwiw, I believe that the Haskell i/o manager uses an ordered map, and it
gets monstrous performance:

http://haskell.cs.yale.edu/wp-content/uploads/2013/08/hask035-voellmy.pdf

Some comments:
http://ezyang.tumblr.com/post/62152700458/haskell-mio-a-high-performance-multicore-io


From rustompmody at gmail.com  Tue Jan 20 13:15:58 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Tue, 20 Jan 2015 10:15:58 -0800 (PST)
Subject: Trees
In-Reply-To: <mailman.17892.1421774424.18130.python-list@python.org>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
 <mailman.17892.1421774424.18130.python-list@python.org>
Message-ID: <18bed5f3-87d5-404a-9fb8-c2e84e5ab78f@googlegroups.com>

On Tuesday, January 20, 2015 at 10:51:13 PM UTC+5:30, Ian wrote:
> On Tue, Jan 20, 2015 at 6:33 AM, Rustom Mody  wrote:
> > from enum import Enum
> > class TreeTag(Enum):
> >     I = 0  # An internal node
> >     L = 1  # A leaf node
> >     def __repr__(self):  return self.name
> >
> > I = TreeTag.I
> > L = TreeTag.L
> 
> Explicitly tagging nodes as internal or leaves is kind of ugly and
> also prone to getting out of sync with the reality, which is that a
> node is a leaf if it doesn't have any other nodes hanging off of it.

Yeah...

Just demoing a technique for more variegated trees eg
an AST for some toy DSL or some such.
Imagine you have 10 types of nodes and one defaults to tagless

> 
> > def dfs(t):
> >     if t[0] == L:
> >         return [t[1]]
> >     else:
> >         return [t[1]] + dfs(t[2]) + dfs(t[3])
> 
> Over the entire tree, this will do O(n) list additions which implies
> O(n) list *copies*, which is rather inefficient. This would probably
> be better implemented as a recursive generator.

Yeah

> 
> def dfs(t):
>     yield t[0]
>     yield from chain.from_iterable(map(dfs, islice(t, 1, None)))
> 
> > # Converting to generators is trivial
> > =====================
> 
> :-)

Less trivial than I thought...
Why does this not work?

def dfsg(t):
    if t[0] == L:
        yield t[1]
    else:
         yield from dfsg(t[2])
         yield from dfsg(t[3])


From bjlockie at lockie.ca  Tue Jan 20 13:22:42 2015
From: bjlockie at lockie.ca (James Smith)
Date: Tue, 20 Jan 2015 10:22:42 -0800 (PST)
Subject: pickle and then object changes
Message-ID: <b0b31f6a-48ca-474f-9829-0bef3c575aaf@googlegroups.com>

Say an object like this exists:
class test:
    a = ""
    b = ""

You pickle it.

You change the object definition to have a new field:
class test
    a = ""
    b = ""
    c = ""

You read the pickled object.
Will it load but ignore the new field?
That is what I want.


From rustompmody at gmail.com  Tue Jan 20 13:35:25 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Tue, 20 Jan 2015 10:35:25 -0800 (PST)
Subject: Trees
In-Reply-To: <18bed5f3-87d5-404a-9fb8-c2e84e5ab78f@googlegroups.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
 <mailman.17892.1421774424.18130.python-list@python.org>
 <18bed5f3-87d5-404a-9fb8-c2e84e5ab78f@googlegroups.com>
Message-ID: <e8c98ce2-81d1-4ce8-b786-738d2bc88a46@googlegroups.com>

On Tuesday, January 20, 2015 at 11:46:11 PM UTC+5:30, Rustom Mody wrote:
> On Tuesday, January 20, 2015 at 10:51:13 PM UTC+5:30, Ian wrote:
> > On Tue, Jan 20, 2015 at 6:33 AM, Rustom Mody  wrote:
> > > # Converting to generators is trivial
> > > =====================
> > 
> > :-)
> 
> Less trivial than I thought...
> Why does this not work?
> 
> def dfsg(t):
>     if t[0] == L:
>         yield t[1]
>     else:
>          yield from dfsg(t[2])
>          yield from dfsg(t[3])

Ok got it
Forgot the
?yield t[1]?
before the two yield-from's


From __peter__ at web.de  Tue Jan 20 13:41:25 2015
From: __peter__ at web.de (Peter Otten)
Date: Tue, 20 Jan 2015 19:41:25 +0100
Subject: pickle and then object changes
References: <b0b31f6a-48ca-474f-9829-0bef3c575aaf@googlegroups.com>
Message-ID: <m9m7gm$nj$1@ger.gmane.org>

James Smith wrote:

> Say an object like this exists:
> class test:
>     a = ""
>     b = ""
> 
> You pickle it.
> 
> You change the object definition to have a new field:
> class test
>     a = ""
>     b = ""
>     c = ""
> 
> You read the pickled object.
> Will it load but ignore the new field?
> That is what I want.

Classes are pickled by name. You are free to replace them with whatever you 
want:

>>> class Test:
...     a = 1
...     b = 2
... 
>>> import pickle
>>> p = pickle.dumps(Test)
>>> class Test:
...     a = 10
...     b = 20
...     c = 30
... 
>>> P = pickle.loads(p)
>>> P.c
30
>>> P.a
10
>>> P is Test
True

If you introduce a new *instance* attribute that will not magically appear 
on unpickling:

>>> class T:
...     def __init__(self, a, b):
...         self.a = a
...         self.b = b
...     def __str__(self): return "T(a={0.a}, b={0.b})".format(self)
... 
>>> t = T(1, 2)
>>> print(t)
T(a=1, b=2)
>>> p = pickle.dumps(t)
>>> class T:
...     def __init__(self, a, b, c):
...          self.a = a
...          self.b = b
...          self.c = c
...     def __str__(self): return "T(a={0.a}, b={0.b}, 
c={0.c})".format(self)
... 
>>> print(T(10, 20, 30))
T(a=10, b=20, c=30)
>>> v = pickle.loads(p)

No problem so far as the initializer is not called so that the missing c is 
not a problem. But then:

>>> print(v)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 6, in __str__
AttributeError: 'T' object has no attribute 'c'

One easy fix is to use a class attribute as the fallback:

>>> T.c = "class attribute"
>>> print(v)
T(a=1, b=2, c=class attribute)

But remember not to try this with mutable attributes. When `c` is a list

v.c.append(42)

will affect all instances with a missing `c` instance attribute.



From ken at seehart.com  Tue Jan 20 15:15:01 2015
From: ken at seehart.com (Ken Seehart)
Date: Tue, 20 Jan 2015 12:15:01 -0800
Subject: Trees
In-Reply-To: <m9k2cs$pk$1@ger.gmane.org>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <m9k2cs$pk$1@ger.gmane.org>
Message-ID: <54BEB745.2030309@seehart.com>

Exactly. There are over 23,000 different kinds of trees. There's no way 
you could get all of them to fit in a library, especially a standard 
one. Instead, we prefer to provide people with the tools they need to 
grow their own trees.

http://caseytrees.org/programs/planting/ctp/
http://www.ncsu.edu/project/treesofstrength/treefact.htm
http://en.wikipedia.org/wiki/Tree

On 1/19/2015 3:01 PM, Mark Lawrence wrote:
> On 19/01/2015 22:06, Zachary Gilmartin wrote:
>> Why aren't there trees in the python standard library?
>>
>
> Probably because you'd never get agreement as to which specific tree 
> and which specific implementation was the most suitable for inclusion.
>



From jeanpierreda at gmail.com  Tue Jan 20 15:19:06 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Tue, 20 Jan 2015 12:19:06 -0800
Subject: Trees
In-Reply-To: <54BEB745.2030309@seehart.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <m9k2cs$pk$1@ger.gmane.org> <54BEB745.2030309@seehart.com>
Message-ID: <CABicbJJz14bCEX0zg+pPojhn5D8kWT=xQGOWfqUS2FEf6NBusg@mail.gmail.com>

There are similarly many kinds of hash tables.

For a given use case (e.g. a sorted dict, or a list with efficient
removal, etc.), there's a few data structures that make sense, and a
library (even the standard library) doesn't have to expose which one
was picked as long as the performance is good.

-- Devin

On Tue, Jan 20, 2015 at 12:15 PM, Ken Seehart <ken at seehart.com> wrote:
> Exactly. There are over 23,000 different kinds of trees. There's no way you
> could get all of them to fit in a library, especially a standard one.
> Instead, we prefer to provide people with the tools they need to grow their
> own trees.
>
> http://caseytrees.org/programs/planting/ctp/
> http://www.ncsu.edu/project/treesofstrength/treefact.htm
> http://en.wikipedia.org/wiki/Tree
>
> On 1/19/2015 3:01 PM, Mark Lawrence wrote:
>>
>> On 19/01/2015 22:06, Zachary Gilmartin wrote:
>>>
>>> Why aren't there trees in the python standard library?
>>>
>>
>> Probably because you'd never get agreement as to which specific tree and
>> which specific implementation was the most suitable for inclusion.
>>
>
> --
> https://mail.python.org/mailman/listinfo/python-list


From rosuav at gmail.com  Tue Jan 20 15:23:35 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 21 Jan 2015 07:23:35 +1100
Subject: Trees
In-Reply-To: <54BEB745.2030309@seehart.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <m9k2cs$pk$1@ger.gmane.org> <54BEB745.2030309@seehart.com>
Message-ID: <CAPTjJmrbE5CG1NCVnHjWueVxOyMsbb2SuGmP4N-zNUs8La-K9A@mail.gmail.com>

On Wed, Jan 21, 2015 at 7:15 AM, Ken Seehart <ken at seehart.com> wrote:
> Exactly. There are over 23,000 different kinds of trees. There's no way you
> could get all of them to fit in a library, especially a standard one.
> Instead, we prefer to provide people with the tools they need to grow their
> own trees.

I'm not sure whether you're talking about algorithmic or arboreal
trees here... I'm fairly sure the State Library of Victoria contains
23,000 trees, albeit in a slightly modified form. But the State
Library is not a standard one.

ChrisA


From marko at pacujo.net  Tue Jan 20 15:25:34 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Tue, 20 Jan 2015 22:25:34 +0200
Subject: Trees
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17865.1421708518.18130.python-list@python.org>
 <87k30ihvvx.fsf@elektro.pacujo.net>
 <87fvb5bb84.fsf@jester.gateway.sonic.net>
Message-ID: <87a91di4ht.fsf@elektro.pacujo.net>

Paul Rubin <no.email at nospam.invalid>:

> Marko Rauhamaa <marko at pacujo.net> writes:
>> So in my Python software (both at work and at home) needs, I use a
>> Python AVL tree implementation of my own. My use case is timers. (GvR
>> uses heapq for the purpose.)
>
> Have you benchmarked your version against heapq or even the builtin
> sorting functions?

Yes, I did (as I mentioned in an earlier posting). For the use case I
was interested in (timers in a busy server), heapq beefed with the
"garbage collection" trick came out about the same as my AVL tree
(native module).


Marko


From marko at pacujo.net  Tue Jan 20 15:26:45 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Tue, 20 Jan 2015 22:26:45 +0200
Subject: Trees
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <87ppa9944t.fsf@elektro.pacujo.net>
 <877fwhb9pk.fsf@jester.gateway.sonic.net>
Message-ID: <8761c1i4fu.fsf@elektro.pacujo.net>

Paul Rubin <no.email at nospam.invalid>:

> You could look up the "timer wheel" approach used by the Linux kernel
> and by Erlang.  It's less general than an ordered map, but probably
> faster in practice.
>
>   https://lkml.org/lkml/2005/10/19/46 
>
> Has some info.  I think the kernel uses a different method now though.

I haven't followed it closely, but I believe the realtime timers use a
red-black tree.


Marko


From ken at seehart.com  Tue Jan 20 15:45:17 2015
From: ken at seehart.com (Ken Seehart)
Date: Tue, 20 Jan 2015 12:45:17 -0800
Subject: Trees
In-Reply-To: <CABicbJJz14bCEX0zg+pPojhn5D8kWT=xQGOWfqUS2FEf6NBusg@mail.gmail.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <m9k2cs$pk$1@ger.gmane.org> <54BEB745.2030309@seehart.com>
 <CABicbJJz14bCEX0zg+pPojhn5D8kWT=xQGOWfqUS2FEf6NBusg@mail.gmail.com>
Message-ID: <54BEBE5D.9080901@seehart.com>

Hash Table, Christiania
(a table with many kinds of hash)

On 1/20/2015 12:19 PM, Devin Jeanpierre wrote:
> There are similarly many kinds of hash tables.
>
> For a given use case (e.g. a sorted dict, or a list with efficient
> removal, etc.), there's a few data structures that make sense, and a
> library (even the standard library) doesn't have to expose which one
> was picked as long as the performance is good.
>
> -- Devin
>
> On Tue, Jan 20, 2015 at 12:15 PM, Ken Seehart <ken at seehart.com> wrote:
>> Exactly. There are over 23,000 different kinds of trees. There's no way you
>> could get all of them to fit in a library, especially a standard one.
>> Instead, we prefer to provide people with the tools they need to grow their
>> own trees.
>>
>> http://caseytrees.org/programs/planting/ctp/
>> http://www.ncsu.edu/project/treesofstrength/treefact.htm
>> http://en.wikipedia.org/wiki/Tree
>>
>> On 1/19/2015 3:01 PM, Mark Lawrence wrote:
>>> On 19/01/2015 22:06, Zachary Gilmartin wrote:
>>>> Why aren't there trees in the python standard library?
>>>>
>>> Probably because you'd never get agreement as to which specific tree and
>>> which specific implementation was the most suitable for inclusion.
>>>
>> --
>> https://mail.python.org/mailman/listinfo/python-list

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From faiz.lotfy at gmail.com  Tue Jan 20 16:11:42 2015
From: faiz.lotfy at gmail.com (faiz.lotfy at gmail.com)
Date: Tue, 20 Jan 2015 13:11:42 -0800 (PST)
Subject: How to run a python script with functions
Message-ID: <94d7b218-7195-4d2a-b886-8edb3ceca6ae@googlegroups.com>

Hi

I have a file with a python scripts that has many functions in it. To run the script I did the following:
1. $ python (to initiate python, using the python command)
2. >>> import file_name (without .py)
3. >>> file_name.function_name(argument) (to run the function_name with argument (argument)

My question is: Is there any other way that I can just use the function name (function_name) without having to use the file_name. part? That is, use only:
>>> function_name(argument)

~faizlo


From andre.roberge at gmail.com  Tue Jan 20 16:22:41 2015
From: andre.roberge at gmail.com (=?ISO-8859-1?Q?Andr=E9_Roberge?=)
Date: Tue, 20 Jan 2015 13:22:41 -0800 (PST)
Subject: How to run a python script with functions
In-Reply-To: <94d7b218-7195-4d2a-b886-8edb3ceca6ae@googlegroups.com>
References: <94d7b218-7195-4d2a-b886-8edb3ceca6ae@googlegroups.com>
Message-ID: <0cd2c99f-30a2-4e7a-b30d-444ee44a59cb@googlegroups.com>

On Tuesday, 20 January 2015 17:11:58 UTC-4, faiz.... at gmail.com  wrote:
> Hi
> 
> I have a file with a python scripts that has many functions in it. To run the script I did the following:
> 1. $ python (to initiate python, using the python command)
> 2. >>> import file_name (without .py)
> 3. >>> file_name.function_name(argument) (to run the function_name with argument (argument)
> 
> My question is: Is there any other way that I can just use the function name (function_name) without having to use the file_name. part? That is, use only:
> >>> function_name(argument)
> 

from file_name import function1, function2

> ~faizlo



From marfig at gmail.com  Tue Jan 20 16:47:47 2015
From: marfig at gmail.com (Mario)
Date: Tue, 20 Jan 2015 22:47:47 +0100
Subject: Trees
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
Message-ID: <MPG.2f28eb55d73ef68c989680@nntp.aioe.org>

In article <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd at googlegroups.com>, 
rustompmody at gmail.com says...
> 
> Yeah python has trees alright.
> 
> Heres' some simple tree-code

Didn't you just demonstrate that Python has no trees and instead you 
have to implement them yourself (or use a third-party implementation)?

I don't know what's the point of all this vain and misleading play with 
words. Not only most languages don't implement trees in their standard 
libraries (its no shame, it's no sin), but also it's quite evident that 
there's a big difference between implementing a data structure yourself 
through the application of language facilities and seeing that data 
structure already implemented for you in the standard library.


From faiz.lotfy at gmail.com  Tue Jan 20 16:49:27 2015
From: faiz.lotfy at gmail.com (faiz.lotfy at gmail.com)
Date: Tue, 20 Jan 2015 13:49:27 -0800 (PST)
Subject: How to run a python script with functions
In-Reply-To: <0cd2c99f-30a2-4e7a-b30d-444ee44a59cb@googlegroups.com>
References: <94d7b218-7195-4d2a-b886-8edb3ceca6ae@googlegroups.com>
 <0cd2c99f-30a2-4e7a-b30d-444ee44a59cb@googlegroups.com>
Message-ID: <7d453c83-62ba-4a47-b3ab-025c8b4f4f7b@googlegroups.com>

On Tuesday, January 20, 2015 at 3:22:55 PM UTC-6, Andr? Roberge wrote:
> On Tuesday, 20 January 2015 17:11:58 UTC-4, faiz.... at gmail.com  wrote:
> > Hi
> > 
> > I have a file with a python scripts that has many functions in it. To run the script I did the following:
> > 1. $ python (to initiate python, using the python command)
> > 2. >>> import file_name (without .py)
> > 3. >>> file_name.function_name(argument) (to run the function_name with argument (argument)
> > 
> > My question is: Is there any other way that I can just use the function name (function_name) without having to use the file_name. part? That is, use only:
> > >>> function_name(argument)
> > 
> 
> from file_name import function1, function2
> 
> > ~faizlo

Thank you Andr?


From denismfmcmahon at gmail.com  Tue Jan 20 18:25:48 2015
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Tue, 20 Jan 2015 23:25:48 +0000 (UTC)
Subject: Random ALL CAPS posts on this group
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
Message-ID: <m9mo5s$1nd$1@dont-email.me>

On Mon, 19 Jan 2015 16:15:58 -0800, Luke Tomaneng wrote:

> Has anyone noticed these? There have been about three of them recently
> and they don't seem to have anything to do with Python at all. Does
> anyone know if there is a good reason they are here?

Abusive spam from idiots. I have a regex that simply ignores any posting 
with no lower case in the subject.

-- 
Denis McMahon, denismfmcmahon at gmail.com


From sturla.molden at gmail.com  Tue Jan 20 19:36:06 2015
From: sturla.molden at gmail.com (Sturla Molden)
Date: Wed, 21 Jan 2015 01:36:06 +0100
Subject: Trees
In-Reply-To: <CAGGBd_pMdYZwt-ksdSpDFNVxXwkekGsJFi=2C66PStTFzS0R+w@mail.gmail.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <CAGGBd_pMdYZwt-ksdSpDFNVxXwkekGsJFi=2C66PStTFzS0R+w@mail.gmail.com>
Message-ID: <m9ms9l$m42$1@ger.gmane.org>

On 20/01/15 01:49, Dan Stromberg wrote:

> I think probably the most common need for a tree is implementing a
> cache,

That is probably true, at least if you're a squirrel.





From joshua at landau.ws  Tue Jan 20 20:22:06 2015
From: joshua at landau.ws (Joshua Landau)
Date: Wed, 21 Jan 2015 01:22:06 +0000
Subject: Trees
In-Reply-To: <CAGGBd_rPSxSK1HCkdmwzu5MS_bBtA9X+hgx6VHKsvWYiAG9AOg@mail.gmail.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <CAGGBd_pMdYZwt-ksdSpDFNVxXwkekGsJFi=2C66PStTFzS0R+w@mail.gmail.com>
 <m9kfhe$vh$1@ger.gmane.org>
 <CAGGBd_rPSxSK1HCkdmwzu5MS_bBtA9X+hgx6VHKsvWYiAG9AOg@mail.gmail.com>
Message-ID: <CAN1F8qUnh_LhooBhHh7cDnFO6OxmqyroA1Zf3H_pQOnOo=-FNg@mail.gmail.com>

On 20 January 2015 at 04:21, Dan Stromberg <drsalists at gmail.com> wrote:
> On Mon, Jan 19, 2015 at 6:46 PM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
>>
>> I don't know if you've seen this http://kmike.ru/python-data-structures/ but
>> maybe of interest.
>
> I've seen it. It's a nice page.
>
> I attempted to get my treap port in there since it has a Cython
> version, but it didn't seem to take.
>
> I've mostly focused on pure python that runs on CPython 2.x, CPython
> 3.x, Pypy, Pypy3 and Jython.

http://www.grantjenks.com/docs/sortedcontainers/

SortedContainers is seriously great stuff; faster and lower memory
than the Cython variants yet pure Python and more featureful.


From rustompmody at gmail.com  Tue Jan 20 20:23:39 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Tue, 20 Jan 2015 17:23:39 -0800 (PST)
Subject: Trees
In-Reply-To: <MPG.2f28eb55d73ef68c989680@nntp.aioe.org>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
 <MPG.2f28eb55d73ef68c989680@nntp.aioe.org>
Message-ID: <ba69cad8-68c0-421e-af79-e381ca179015@googlegroups.com>

On Wednesday, January 21, 2015 at 3:18:03 AM UTC+5:30, Mario wrote:
> rustompmody says...
> > 
> > Yeah python has trees alright.
> > 
> > Heres' some simple tree-code
> 
> Didn't you just demonstrate that Python has no trees and instead you 
> have to implement them yourself (or use a third-party implementation)?
> 
> I don't know what's the point of all this vain and misleading play with 
> words. 

Point.

You snipped off Terry's lines which I was replying (rather adding) to:

> Sequences nested withing sequences can be regarded as trees, and Python
> has these.  I regard Lisp as a tree processing languages, as it must be
> to manipulate, for example, code with nested structures. 

To those who are familiar with Lisp this is not new.
To others it is likely too dense to be easily comprehensible.

> Not only most languages don't implement trees in their standard 
> libraries (its no shame, it's no sin), but also it's quite evident that 
> there's a big difference between implementing a data structure yourself 
> through the application of language facilities and seeing that data 
> structure already implemented for you in the standard library.

Its not a binary but a spectrum.

Do the equivalent of "implement yourself with language facilities"
in C or Java for the above code and you will see one end of the spectrum.

Here's Haskell at the other end of the spectrum:
[Renamed the (I)nternal tag to the (B)ranch tag because of I-1 visual clash]

===================

## The type

data Tree t = L t | B t (Tree t) (Tree t)

## The depth first algorithm

dfs (L x)   = [x]
dfs (B x lst rst) = [x]  ++  dfs lst  ++  dfs rst

## Example tree:

t = (B 6 (B 2 (L 1) (B 4 (L 3) (L 5))) (B 8 (L 7) (L 9)))

## Example run

*Main> dfs t
[6,2,1,4,3,5,8,7,9]

==================
The Haskell is bullseye? in capturing the essense of a tree because
conceptually a tree of type t is recursive in the sense that it can contain
2 subtrees -- (B x lst rst) -- or its a base case -- L x.

The same thing in C needs a mutually recursive data structure:

One needs two types ? a node *containing*  pointers; a pointer *pointing* to node

And then go from binary to n-ary trees and the shit hits the ceiling:
4-way mutual recursion: Tree-node, tree-node-pointer; list-node; list-pointer.

Completely transparent in Haskell:

data Nary t = Tr t [Nary t]

Python's not as trivial to get right as Haskell
[get one of the subtrees wrong and the error-messages are quite unhelpful]
However its way better than C.

So there's a spectrum C ? Java ? Python ? Haskell ? Tree-DSL?

============
? Well not quite bullseye because a mathematician would prefer a
*set* of subtrees where we get at best a *list*

? eg UUAG http://www.andres-loeh.de/AGee.pdf



From no.email at nospam.invalid  Tue Jan 20 20:49:23 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Tue, 20 Jan 2015 17:49:23 -0800
Subject: Trees
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
 <MPG.2f28eb55d73ef68c989680@nntp.aioe.org>
 <ba69cad8-68c0-421e-af79-e381ca179015@googlegroups.com>
Message-ID: <87iog0aonw.fsf@jester.gateway.sonic.net>

Rustom Mody <rustompmody at gmail.com> writes:
> ## The depth first algorithm
> dfs (L x)   = [x]
> dfs (B x lst rst) = [x]  ++  dfs lst  ++  dfs rst

Cute.  I can't resist posting the similar breadth first algorithm:

bfs (L x)   = [x]
bfs (B x lst rst) = bfs lst  ++ [x] ++  bfs rst

> *Main> dfs t
> [6,2,1,4,3,5,8,7,9]

*Main> bfs t
[1,2,3,4,5,6,7,8,9]

> The Haskell is bullseye? in capturing the essense of a tree because
> conceptually a tree of type t is recursive in the sense that it can contain
> 2 subtrees -- (B x lst rst) -- or its a base case -- L x.

You might like this discussion of a red-black tree implementation whose
datatype makes sure the RB tree invariants are preserved.  The data
definition is kind of verbose, but with more recent GHC versions it can
be made a lot crisper, with datakinds and type-level numeric literals.

https://www.reddit.com/r/haskell/comments/ti5il/redblack_trees_in_haskell_using_gadts_existential/


From rustompmody at gmail.com  Tue Jan 20 21:03:23 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Tue, 20 Jan 2015 18:03:23 -0800 (PST)
Subject: Trees
In-Reply-To: <87iog0aonw.fsf@jester.gateway.sonic.net>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
 <MPG.2f28eb55d73ef68c989680@nntp.aioe.org>
 <ba69cad8-68c0-421e-af79-e381ca179015@googlegroups.com>
 <87iog0aonw.fsf@jester.gateway.sonic.net>
Message-ID: <c30a53ac-8709-44a0-b1da-78ed6e447b11@googlegroups.com>

On Wednesday, January 21, 2015 at 7:19:39 AM UTC+5:30, Paul Rubin wrote:
> Rustom Mody  writes:
> > ## The depth first algorithm
> > dfs (L x)   = [x]
> > dfs (B x lst rst) = [x]  ++  dfs lst  ++  dfs rst
> 
> Cute.  I can't resist posting the similar breadth first algorithm:
> 
> bfs (L x)   = [x]
> bfs (B x lst rst) = bfs lst  ++ [x] ++  bfs rst
> 
> > *Main> dfs t
> > [6,2,1,4,3,5,8,7,9]
> 
> *Main> bfs t
> [1,2,3,4,5,6,7,8,9]

Eh??

Thats not bfs. That's inorder traversal

The bfs of http://www-math.ucdenver.edu/~wcherowi/courses/m4408/gtln8.html

is
[6,    2,8,      1,4,7,9,      3,5]


From tjreedy at udel.edu  Tue Jan 20 21:19:07 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Tue, 20 Jan 2015 21:19:07 -0500
Subject: Trees
In-Reply-To: <MPG.2f28eb55d73ef68c989680@nntp.aioe.org>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
 <MPG.2f28eb55d73ef68c989680@nntp.aioe.org>
Message-ID: <m9n2ar$f6s$1@ger.gmane.org>

On 1/20/2015 4:47 PM, Mario wrote:
> In article <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd at googlegroups.com>,
> rustompmody at gmail.com says...
>>
>> Yeah python has trees alright.
>>
>> Heres' some simple tree-code
>
> Didn't you just demonstrate that Python has no trees and instead you
> have to implement them yourself (or use a third-party implementation)?
>
> I don't know what's the point of all this vain and misleading play with
> words.

It is not play with words. A tree is a recursive - nested - hierachical 
data structure with the restriction of no cycles or alternate pathways. 
  Python collections whose members are general objects, including 
collections, can be nested.  The resulting structures *are* tree 
structures, if not more general directed graphs.  They are quite 
commonly used in Python.

The common question -- "How do I flatten a list" -- is asking "How to I 
turn a list from a tree (or DAG, but not a cyclic graph*) into a 
sequence of leaf objects".  The question illustrates what is missing - 
builtin functions or methods for nested collections.  I already 
suggested that there *might* be a useful addition in this direction.

* A Python interpreter needs to take special measures to even display an 
infinitely recursive list without raising or even segfaulting.  Most 
posted 'flatten' functions do not account for this possibility.

 >>> l = [1]
 >>> l.append(l)
 >>> l
[1, [...]]


 > Not only most languages don't implement trees in their standard
> libraries

Typically, built-in collection type C has members of type M that does 
not include type C.  Therefore a C instance cannot (directly) contain a 
C instance.  The result is that people write a 'design pattern' to 
overcome the limitation and enable a C to indirectly include a C.  Since 
this limitations does not exist in Python's generalized collections of 
objects, the pattern is unneeded in Python.

-- 
Terry Jan Reedy



From breamoreboy at yahoo.co.uk  Tue Jan 20 22:25:14 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Wed, 21 Jan 2015 03:25:14 +0000
Subject: Trees
In-Reply-To: <CAN1F8qUnh_LhooBhHh7cDnFO6OxmqyroA1Zf3H_pQOnOo=-FNg@mail.gmail.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <CAGGBd_pMdYZwt-ksdSpDFNVxXwkekGsJFi=2C66PStTFzS0R+w@mail.gmail.com>
 <m9kfhe$vh$1@ger.gmane.org>
 <CAGGBd_rPSxSK1HCkdmwzu5MS_bBtA9X+hgx6VHKsvWYiAG9AOg@mail.gmail.com>
 <CAN1F8qUnh_LhooBhHh7cDnFO6OxmqyroA1Zf3H_pQOnOo=-FNg@mail.gmail.com>
Message-ID: <m9n66v$9fb$1@ger.gmane.org>

On 21/01/2015 01:22, Joshua Landau wrote:
> On 20 January 2015 at 04:21, Dan Stromberg <drsalists at gmail.com> wrote:
>> On Mon, Jan 19, 2015 at 6:46 PM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
>>>
>>> I don't know if you've seen this http://kmike.ru/python-data-structures/ but
>>> maybe of interest.
>>
>> I've seen it. It's a nice page.
>>
>> I attempted to get my treap port in there since it has a Cython
>> version, but it didn't seem to take.
>>
>> I've mostly focused on pure python that runs on CPython 2.x, CPython
>> 3.x, Pypy, Pypy3 and Jython.
>
> http://www.grantjenks.com/docs/sortedcontainers/
>
> SortedContainers is seriously great stuff; faster and lower memory
> than the Cython variants yet pure Python and more featureful.
>

Assuming the above and the testimonials are correct how the hell on 
earth did the author manage it?  This is the one thing that *REALLY* 
annoys me about Python, my mind just doesn't stretch far enough to 
harness all of the power that's available in it.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From chandrakant.tiwari204 at gmail.com  Tue Jan 20 22:37:26 2015
From: chandrakant.tiwari204 at gmail.com (Chandrakant Tiwari)
Date: Tue, 20 Jan 2015 19:37:26 -0800 (PST)
Subject: python traceroute
Message-ID: <dd1c4ee0-a65d-4d0b-915e-b7c306126685@googlegroups.com>

in the program below i want it to make it work  the same way as TRACERT  command . but i am not able to make it  work the same way . for  which i need  your help thank  you 
 here is the program




#!/usr/bin/python
import socket
import struct
import sys

# We want unbuffered stdout so we can provide live feedback for
# each TTL. You could also use the "-u" flag to Python.
class flushfile(file):
    def __init__(self, f):
        self.f = f
    def write(self, x):
        self.f.write(x)
        self.f.flush()

sys.stdout = flushfile(sys.stdout)

def main(dest_name):
    dest_addr = socket.gethostbyname(dest_name)
    port = 33434
    max_hops = 10
    icmp = socket.getprotobyname('icmp')
    udp = socket.getprotobyname('udp')
    ttl = 1
    while True:
        recv_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp)
        send_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, udp)
        send_socket.setsockopt(socket.SOL_IP, socket.IP_TTL, ttl)
        
        # Build the GNU timeval struct (seconds, microseconds)
        timeout = struct.pack("ll", 5, 0)
        
        # Set the receive timeout so we behave more like regular traceroute
        recv_socket.setsockopt(socket.SOL_SOCKET, socket.SO_RCVTIMEO, timeout)
        
        recv_socket.bind(("", port))
        sys.stdout.write(" %d  " % ttl)
        send_socket.sendto("", (dest_name, port))
        curr_addr = None
        curr_name = None
        finished = False
        tries = 3
        while not finished and tries > 0:
            try:
                _, curr_addr = recv_socket.recvfrom(512)
                finished = True
                curr_addr = curr_addr[0]
                try:
                    curr_name = socket.gethostbyaddr(curr_addr)[0]
                except socket.error:
                    curr_name = curr_addr
            except socket.error as (errno, errmsg):
                tries = tries - 1
                sys.stdout.write("* ")
        
        send_socket.close()
        recv_socket.close()
        
        if not finished:
            pass
        
        if curr_addr is not None:
            curr_host = "%s (%s)" % (curr_name, curr_addr)
        else:
            curr_host = ""
        sys.stdout.write("%s\n" % (curr_host))

        ttl += 1
        if curr_addr == dest_addr or ttl > max_hops:
            break

if __name__ == "__main__":
    main('google.com')


From steve at pearwood.info  Tue Jan 20 23:02:31 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 21 Jan 2015 04:02:31 GMT
Subject: python traceroute
References: <dd1c4ee0-a65d-4d0b-915e-b7c306126685@googlegroups.com>
Message-ID: <54bf24d6$0$2738$c3e8da3$76491128@news.astraweb.com>

On Tue, 20 Jan 2015 19:37:26 -0800, Chandrakant Tiwari wrote:

> in the program below i want it to make it work  the same way as TRACERT 
> command . but i am not able to make it  work the same way . for  which i
> need  your help thank  you

What is the difference between TRACERT and your Python script?

What do you expect your script to do that it doesn't do, or what does it 
do that it shouldn't do? Please be explicit:


# Wrong, don't do this.
"Program should work just like TRACERT."

# A little better, but still wrong.
"Program should work just like TRACERT on operating system Foo version 7 
when running this command: tracert -options argument"

# Better.
"I tried to do <SOME TASK> where I expected to get <THESE RESULTS> which 
matches this TRACERT command <COMMAND> on <OPERATING SYSTEM>, but instead 
I got <THESE UNWANTED RESULTS>."


Otherwise, we have to:

- guess what results you want
- guess what results you got
- guess what causes the wrong results
- guess what changes you need to make




-- 
Steve


From drsalists at gmail.com  Tue Jan 20 23:21:11 2015
From: drsalists at gmail.com (Dan Stromberg)
Date: Tue, 20 Jan 2015 20:21:11 -0800
Subject: Trees
In-Reply-To: <CAN1F8qUnh_LhooBhHh7cDnFO6OxmqyroA1Zf3H_pQOnOo=-FNg@mail.gmail.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <CAGGBd_pMdYZwt-ksdSpDFNVxXwkekGsJFi=2C66PStTFzS0R+w@mail.gmail.com>
 <m9kfhe$vh$1@ger.gmane.org>
 <CAGGBd_rPSxSK1HCkdmwzu5MS_bBtA9X+hgx6VHKsvWYiAG9AOg@mail.gmail.com>
 <CAN1F8qUnh_LhooBhHh7cDnFO6OxmqyroA1Zf3H_pQOnOo=-FNg@mail.gmail.com>
Message-ID: <CAGGBd_pWNEC9i5KbRO9a1FjHzPZ4C2pmZp6iRW3MX-2C9VAXmA@mail.gmail.com>

On Tue, Jan 20, 2015 at 5:22 PM, Joshua Landau <joshua at landau.ws> wrote:
> On 20 January 2015 at 04:21, Dan Stromberg <drsalists at gmail.com> wrote:
>> On Mon, Jan 19, 2015 at 6:46 PM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
>>>
>>> I don't know if you've seen this http://kmike.ru/python-data-structures/ but
>>> maybe of interest.
>>
>> I've seen it. It's a nice page.
>>
>> I attempted to get my treap port in there since it has a Cython
>> version, but it didn't seem to take.
>>
>> I've mostly focused on pure python that runs on CPython 2.x, CPython
>> 3.x, Pypy, Pypy3 and Jython.
>
> http://www.grantjenks.com/docs/sortedcontainers/
>
> SortedContainers is seriously great stuff; faster and lower memory
> than the Cython variants yet pure Python and more featureful.

It has an interesting comparison.

I find myself wishing the graphs were higher resolution (the lines are
frequently overlapping to the point that I cannot read the graphs),
and that the maximum number of elements was greater than 10**6.  Some
of the timings end up taking less than a second even at the larger
sizes.


From denismfmcmahon at gmail.com  Wed Jan 21 00:01:39 2015
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Wed, 21 Jan 2015 05:01:39 +0000 (UTC)
Subject: Concerning Dictionaries and += in Python 2.x
References: <bc9e302a-356c-4223-9c25-6a8003db48e6@googlegroups.com>
Message-ID: <m9nbrj$i7h$1@dont-email.me>

On Mon, 19 Jan 2015 16:12:57 -0800, Luke Tomaneng wrote:

> I have been having a bit of trouble with the things mentioned in the
> title.

I've uploaded a slightly different approach to your code at:

http://www.sined.co.uk/tmp/shop.py.txt

-- 
Denis McMahon, denismfmcmahon at gmail.com


From denismfmcmahon at gmail.com  Wed Jan 21 00:06:20 2015
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Wed, 21 Jan 2015 05:06:20 +0000 (UTC)
Subject: python traceroute
References: <dd1c4ee0-a65d-4d0b-915e-b7c306126685@googlegroups.com>
Message-ID: <m9nc4c$i7h$2@dont-email.me>

On Tue, 20 Jan 2015 19:37:26 -0800, Chandrakant Tiwari wrote:

> in the program below i want it to make it work  the same way as TRACERT 
> command.

As an observation, you're re-inventing a wheel that already works 
perfectly well, in that any failings of tracert tend to be more down to 
the way routers are configured to handle icmp than the tracert 
application itself. Unless you're doing this purely as an exercise in 
socket programming with python, it might be better to find a new problem 
to solve.

-- 
Denis McMahon, denismfmcmahon at gmail.com


From me+python at ixokai.io  Wed Jan 21 02:56:56 2015
From: me+python at ixokai.io (Stephen Hansen)
Date: Tue, 20 Jan 2015 23:56:56 -0800
Subject: Trees
In-Reply-To: <87ppa9944t.fsf@elektro.pacujo.net>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <87ppa9944t.fsf@elektro.pacujo.net>
Message-ID: <CAM1gar5a8eUWZrrzEfDgWe0irPf1pptAMw4bCs98F5vj=Tp4kw@mail.gmail.com>

On Tue, Jan 20, 2015 at 1:45 AM, Marko Rauhamaa <marko at pacujo.net> wrote:

> Terry Reedy <tjreedy at udel.edu>:
>
> > Others have answered as to why other special-purpose
> > constrained-structure trees have not been added to the stdlib.
>
> Ordered O(log n) mappings are not special-purpose data structures. I'd
> say strings and floats are much more special-purpose than ordered
> mappings, and yet Python has direct support for those.
>

Your anecdote is strong, sir.

However, I use strings thousands of times, floats maybe a hundred of times,
and order mappings a few times.

My anecdote counters yours.

A tree structure is special purpose because there is a lot of options with
different characteristics that make certain implementations ideal in some
cases and not in others.

A float is a float, there's a standard (IEEE 754?), its not special at all.

A string, I suppose, could be special, but that's a pretty nonsense view of
the world since what most people use strings commonly.

I'm not arguing against including a tree, but I have no advice on which
one, and the one-- one!-- time I've needed a tree I got one off pypi. Not
everything needs to be in the stdlib.

But to call strings and floats special purpose is really a silly argument
to make.
-------------- next part --------------
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From marko at pacujo.net  Wed Jan 21 03:35:41 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Wed, 21 Jan 2015 10:35:41 +0200
Subject: Trees
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <87ppa9944t.fsf@elektro.pacujo.net>
 <mailman.17906.1421827045.18130.python-list@python.org>
Message-ID: <87bnls8raa.fsf@elektro.pacujo.net>

Stephen Hansen <me+python at ixokai.io>:

> On Tue, Jan 20, 2015 at 1:45 AM, Marko Rauhamaa <marko at pacujo.net> wrote:
>> Terry Reedy <tjreedy at udel.edu>:
>> > Others have answered as to why other special-purpose
>> > constrained-structure trees have not been added to the stdlib.
>>
>> Ordered O(log n) mappings are not special-purpose data structures. I'd
>> say strings and floats are much more special-purpose than ordered
>> mappings, and yet Python has direct support for those.
>
> [...]
>
> A string, I suppose, could be special, but that's a pretty nonsense view of
> the world since what most people use strings commonly.

I was reacting to the specific argument that has been made often in
Python circles: ordered mappings are special-purpose. That argument has
nothing to do with how often you need the data structure. It has to do
with how wide an abtract niche the data structure takes in the idea
space.

Now, you could make an argument that there's barely ever a practical
need for ordered mappings (whether right or wrong), and that would
elicit a different kind of response from me.

These and other arguments factor into whether the Python standard
library should contain a feature, ultimately it's GvR's arbitrary call.
He said you should first let it ripen in pypi and gain widespread
traction.


Marko


From __peter__ at web.de  Wed Jan 21 03:43:31 2015
From: __peter__ at web.de (Peter Otten)
Date: Wed, 21 Jan 2015 09:43:31 +0100
Subject: Concerning Dictionaries and += in Python 2.x
References: <bc9e302a-356c-4223-9c25-6a8003db48e6@googlegroups.com>
 <m9nbrj$i7h$1@dont-email.me>
Message-ID: <m9nork$s0k$1@ger.gmane.org>

Denis McMahon wrote:

> On Mon, 19 Jan 2015 16:12:57 -0800, Luke Tomaneng wrote:
> 
>> I have been having a bit of trouble with the things mentioned in the
>> title.
> 
> I've uploaded a slightly different approach to your code at:
> 
> http://www.sined.co.uk/tmp/shop.py.txt
> 
> def compute_bill(shopping):
>     """
>     Takes a dictionary of purchases requested in the form {item: quantity}
>     Returns a tuple of:
>         a dictionary of items supplied in the form {item: quantity}; and
>         the cost of the supplied items
>     """
>     # the invoice amount
>     invoice = 0
>     # what we were able to supply
>     sold = {k:0 for k in shopping.keys()}

There is also dict.from_keys()

>     # check each requested item
>     for item in shopping:
> 
>         # try and sell the requested qty
>         for i in range(shopping[item]):

The inner loop is not just inefficient for stock sold in large quantities, 
it will fail for stock sold by weight, volume etc.

>             # if we have stock remaining
>             if stock[item] > 0:
> 
>                 # reduce stock count for item by 1
>                 stock[item] = stock[item] - 1
>                 # add 1 item to the sale
>                 sold[item] += 1
>                 # add item cost to the invoice
>                 invoice += prices[item]
> 
>     # return the items supplied and their cost
>     return sold, invoice

Here is a possible alternative:

    sold = {}

    for item, wanted_quantity in shopping.iteritems(): # items() in Python 3
        available_quantity = stock.get(item, 0)
        sold_quantity = min(wanted_quantity, available_quantity)
        sold[item] = sold_quantity
        stock[item] -= sold_quantity
        invoice += sold_quantity * prices[item]




From __peter__ at web.de  Wed Jan 21 03:59:58 2015
From: __peter__ at web.de (Peter Otten)
Date: Wed, 21 Jan 2015 09:59:58 +0100
Subject: Concerning Dictionaries and += in Python 2.x
References: <bc9e302a-356c-4223-9c25-6a8003db48e6@googlegroups.com>
 <m9nbrj$i7h$1@dont-email.me> <m9nork$s0k$1@ger.gmane.org>
Message-ID: <m9npqf$8dj$1@ger.gmane.org>

Peter Otten wrote:

> Denis McMahon wrote:

>>     sold = {k:0 for k in shopping.keys()}
> 
> There is also dict.from_keys()

Sorry, fromkeys():

>>> shopping = {'orange': 5, 'pear': 5, 'banana': 5, 'apple': 4}
>>> dict.fromkeys(shopping, 0)
{'banana': 0, 'orange': 0, 'apple': 0, 'pear': 0}




From rustompmody at gmail.com  Wed Jan 21 07:09:06 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Wed, 21 Jan 2015 04:09:06 -0800 (PST)
Subject: Trees
In-Reply-To: <mailman.17906.1421827045.18130.python-list@python.org>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <87ppa9944t.fsf@elektro.pacujo.net>
 <mailman.17906.1421827045.18130.python-list@python.org>
Message-ID: <b37db482-1c2d-4b17-9b0b-0e37537482ef@googlegroups.com>

On Wednesday, January 21, 2015 at 1:27:39 PM UTC+5:30, Stephen Hansen wrote:
> On Tue, Jan 20, 2015 at 1:45 AM, Marko Rauhamaa <ma... at pacujo.net> wrote:
> Terry Reedy <tjr... at udel.edu>:
> 
> 
> 
> > Others have answered as to why other special-purpose
> 
> > constrained-structure trees have not been added to the stdlib.
> 
> 
> 
> Ordered O(log n) mappings are not special-purpose data structures. I'd
> 
> say strings and floats are much more special-purpose than ordered
> 
> mappings, and yet Python has direct support for those.
> 
> 
> 
> Your anecdote is strong, sir.
> 
> 
> However, I use strings thousands of times, floats maybe a hundred of times, and order mappings a few times.
> 
> 
> My anecdote counters yours.
> 
> 
> A tree structure is special purpose because there is a lot of options with different characteristics that make certain implementations ideal in some cases and not in others.
> 
> 
> A float is a float, there's a standard (IEEE 754?), its not special at all.
> 
> 
> A string, I suppose, could be special, but that's a pretty nonsense view of the world since what most people use strings commonly.?
> 
> 
> I'm not arguing against including a tree, but I have no advice on which one, and the one-- one!-- time I've needed a tree I got one off pypi. Not everything needs to be in the stdlib.
> 
> 
> But to call strings and floats special purpose is really a silly argument to make. 

Since we are trading anecdotes?

Among my teachers of CS, there were two ? both brilliant ? one taught me
Numerical Analysis, the other taught me programming.

[As it happens my initial practical programming was the numerical kind
because the Fortran compiler was more serviceable than the Pascal one.
But thats a different point]

The point is that the two of them disagreed strongly on what programming was
about.

The numerical analyst could see no earthly reason to use anything other than
Fortran.

The programmer had horror stories to tell about how Fortran damages the brain:
eg programs that inherently need a while-loop (eg binary search) seem to be
distinctly out of the reach of the Fortran programmer.  Recursion...
And much else.

The numerical analyst of course had no use for this philosophizing.

The view that strings and floats are more fundamental than containers and maps
reminds me of this view.

For me python is neat because I can write: [1,2,3]
when I want a list.

But it does not go nearly far enough.

I would like a set to be {1,2,3} or at worst ?1,2,3?
and a bag to be ?1,2,3?

Apart from the unicode niceness that Ive described here
http://blog.languager.org/2014/04/unicoded-python.html

Its a bit of a nuisance that we have to write set([1,2,3]) for the first

More irksome that for the second we've to preface with

from collections import Counter

And still more a PITA that a straightforward standard name like bag (or multiset)
is called by such an ungoogleable misleading name as counter.


From rosuav at gmail.com  Wed Jan 21 07:35:46 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 21 Jan 2015 23:35:46 +1100
Subject: Trees
In-Reply-To: <b37db482-1c2d-4b17-9b0b-0e37537482ef@googlegroups.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <87ppa9944t.fsf@elektro.pacujo.net>
 <mailman.17906.1421827045.18130.python-list@python.org>
 <b37db482-1c2d-4b17-9b0b-0e37537482ef@googlegroups.com>
Message-ID: <CAPTjJmqxKcMS-aquDsvMb60Mg26yAiB=oQsFXFJh2pbr6vPKWA@mail.gmail.com>

On Wed, Jan 21, 2015 at 11:09 PM, Rustom Mody <rustompmody at gmail.com> wrote:
> I would like a set to be {1,2,3} or at worst ?1,2,3?
> and a bag to be ?1,2,3?
>
> Apart from the unicode niceness that Ive described here
> http://blog.languager.org/2014/04/unicoded-python.html
>
> Its a bit of a nuisance that we have to write set([1,2,3]) for the first

Wait, what?

rosuav at sikorsky:~$ python
Python 2.7.3 (default, Mar 13 2014, 11:03:55)
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> type({1,2,3})
<type 'set'>
>>>
rosuav at sikorsky:~$ python3
Python 3.5.0a0 (default:4709290253e3, Jan 20 2015, 21:48:07)
[GCC 4.7.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> type({1,2,3})
<class 'set'>
>>>

Looks like {1,2,3} works for me.

ChrisA


From python.list at tim.thechases.com  Wed Jan 21 07:55:03 2015
From: python.list at tim.thechases.com (Tim Chase)
Date: Wed, 21 Jan 2015 06:55:03 -0600
Subject: Trees
In-Reply-To: <CAPTjJmqxKcMS-aquDsvMb60Mg26yAiB=oQsFXFJh2pbr6vPKWA@mail.gmail.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <87ppa9944t.fsf@elektro.pacujo.net>
 <mailman.17906.1421827045.18130.python-list@python.org>
 <b37db482-1c2d-4b17-9b0b-0e37537482ef@googlegroups.com>
 <CAPTjJmqxKcMS-aquDsvMb60Mg26yAiB=oQsFXFJh2pbr6vPKWA@mail.gmail.com>
Message-ID: <20150121065503.5555c910@bigbox.christie.dr>

On 2015-01-21 23:35, Chris Angelico wrote:
> On Wed, Jan 21, 2015 at 11:09 PM, Rustom Mody wrote
> > Its a bit of a nuisance that we have to write set([1,2,3]) for
> > the first
> 
> Wait, what?
> 
> rosuav at sikorsky:~$ python
> Python 2.7.3 (default, Mar 13 2014, 11:03:55)
> [GCC 4.7.2] on linux2
> Type "help", "copyright", "credits" or "license" for more
> information.
> >>> type({1,2,3})
> <type 'set'>
> >>>
> rosuav at sikorsky:~$ python3
> Python 3.5.0a0 (default:4709290253e3, Jan 20 2015, 21:48:07)
> [GCC 4.7.2] on linux
> Type "help", "copyright", "credits" or "license" for more
> information.
> >>> type({1,2,3})
> <class 'set'>
> >>>
> 
> Looks like {1,2,3} works for me.

That hasn't always worked:

tim at bigbox:~$ python2.5
Python 2.5.5 (r255:77872, Nov 28 2010, 16:43:48) 
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> type({1,2,3})
  File "<stdin>", line 1
    type({1,2,3})
           ^
SyntaxError: invalid syntax

tim at bigbox:~$ python2.6
Python 2.6.8 (unknown, Jan 26 2013, 14:35:25) 
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> type({1,2,3})
  File "<stdin>", line 1
    type({1,2,3})
           ^
SyntaxError: invalid syntax

And, prior to 2.4, you had to write

  from sets import Set as set

to even get sets.

  https://docs.python.org/2/whatsnew/2.4.html#pep-218-built-in-set-objects

-tkc














From rosuav at gmail.com  Wed Jan 21 08:01:04 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 00:01:04 +1100
Subject: Trees
In-Reply-To: <20150121065503.5555c910@bigbox.christie.dr>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <87ppa9944t.fsf@elektro.pacujo.net>
 <mailman.17906.1421827045.18130.python-list@python.org>
 <b37db482-1c2d-4b17-9b0b-0e37537482ef@googlegroups.com>
 <CAPTjJmqxKcMS-aquDsvMb60Mg26yAiB=oQsFXFJh2pbr6vPKWA@mail.gmail.com>
 <20150121065503.5555c910@bigbox.christie.dr>
Message-ID: <CAPTjJmp4sbmmTc9n98QO=TqU=RB4r5GbwVL7HhbFw8MjNrbXJA@mail.gmail.com>

On Wed, Jan 21, 2015 at 11:55 PM, Tim Chase
<python.list at tim.thechases.com> wrote:
> On 2015-01-21 23:35, Chris Angelico wrote:
>> On Wed, Jan 21, 2015 at 11:09 PM, Rustom Mody wrote
>> > Its a bit of a nuisance that we have to write set([1,2,3]) for
>> > the first
>>
>> Looks like {1,2,3} works for me.
>
> That hasn't always worked:

Sure, but "we have to write" implies current status; Python 2.7 was
released in 2010, so I would expect that anyone who's complaining
about set notation should have access to it. Even if it didn't work in
2.7 and you had to use 3.x, the argument's still fairly weak when it's
alongside a pipe-dream desire to use specific mathematical Unicode
characters in source code, because that's clearly a 3.x-only feature
(where source code is Unicode text rather than ASCII).

Nobody's going to moan "It's silly that we have to use 1 and 0 instead
of nice keywords True and False" on the basis that True and False
didn't exist in Python 2.0. At very least, use 2.7 before you
complain; preferably, use 3.4 (or 3.5).

ChrisA


From marfig at gmail.com  Wed Jan 21 09:05:48 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Wed, 21 Jan 2015 14:05:48 +0000 (UTC)
Subject: Trees
References: <mailman.17902.1421806760.18130.python-list@python.org>
Message-ID: <1a194e0a05c98d203a2df8bf9d3@nntp.aioe.org>

Hello Terry,

> It is not play with words. A tree is a recursive - nested -
> hierachical
> data structure with the restriction of no cycles or alternate
> pathways.
> Python collections whose members are general objects, including
> collections, can be nested.  The resulting structures *are* tree
> structures, if not more general directed graphs.  They are quite
> commonly used in Python.

Let's get somethig clear. Tree data structures have an associated logic that 
justifies their name as a de facto Tree Data Structure. If your low level 
description was how you described a tree to someone new to the concept, they 
would be none the wiser about what a Tree represents or what uses they could 
have for them. This logic is no different from the internal logic that diferentiates 
a dictionary from a list and helps carry their distinct operations. Despite 
a dictionary being nothing more than a glorified list.

Just as well, tree data structures only make sense along with their logic. 
Storage, traversal, insertion, random searches, retrieval, etc, all these 
algorithms are what in the end define a Tree data structure and what will 
help categorize it. Python standard library doesn't have any tree data structure 
implementation. It has lists, dictionaries, and other base structures that 
in the end will help define storage patterns for tree data structures. And 
that's it.

A simple binary tree needs to be implemented in Python as a binary tree, 
if it wants to be recognized as such. All your code examples illustrate exactly 
that. And if you care about code reuse, you will want to define a number 
of associated algorithms to take advantage of your storage model and answer 
your performance or memory requirements. Along with your list pattern for 
storage, you will probably also want to implement an insertion/search/update/traversal 
algorithms. That's when you have a tree.




From denismfmcmahon at gmail.com  Wed Jan 21 09:10:48 2015
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Wed, 21 Jan 2015 14:10:48 +0000 (UTC)
Subject: Concerning Dictionaries and += in Python 2.x
References: <bc9e302a-356c-4223-9c25-6a8003db48e6@googlegroups.com>
 <m9nbrj$i7h$1@dont-email.me>
 <mailman.17908.1421829827.18130.python-list@python.org>
Message-ID: <m9oc18$t3b$1@dont-email.me>

On Wed, 21 Jan 2015 09:43:31 +0100, Peter Otten wrote:

> There is also dict.from_keys()

See, I learned something too.

> The inner loop is not just inefficient for stock sold in large
> quantities,

Agreed, but as for:

> it will fail for stock sold by weight, volume etc.

I was trying to stay true to OPs original code and not introduce [too 
many] additional complications to his learning exercise.

-- 
Denis McMahon, denismfmcmahon at gmail.com


From python.list at tim.thechases.com  Wed Jan 21 09:26:00 2015
From: python.list at tim.thechases.com (Tim Chase)
Date: Wed, 21 Jan 2015 08:26:00 -0600
Subject: Trees
In-Reply-To: <CAPTjJmp4sbmmTc9n98QO=TqU=RB4r5GbwVL7HhbFw8MjNrbXJA@mail.gmail.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <87ppa9944t.fsf@elektro.pacujo.net>
 <mailman.17906.1421827045.18130.python-list@python.org>
 <b37db482-1c2d-4b17-9b0b-0e37537482ef@googlegroups.com>
 <CAPTjJmqxKcMS-aquDsvMb60Mg26yAiB=oQsFXFJh2pbr6vPKWA@mail.gmail.com>
 <20150121065503.5555c910@bigbox.christie.dr>
 <CAPTjJmp4sbmmTc9n98QO=TqU=RB4r5GbwVL7HhbFw8MjNrbXJA@mail.gmail.com>
Message-ID: <20150121082600.7142865d@bigbox.christie.dr>

On 2015-01-22 00:01, Chris Angelico wrote:
> On Wed, Jan 21, 2015 at 11:55 PM, Tim Chase
>>> Looks like {1,2,3} works for me.
>>
>> That hasn't always worked:
> 
> the argument's still fairly weak when it's alongside a pipe-dream
> desire to use specific mathematical Unicode characters in source
> code, because that's clearly a 3.x-only feature (where source code
> is Unicode text rather than ASCII).

I'm 100% in agreement that Unicode characters are a pipe-dream.  If I
wanted that, I'd use APL ;-)

> Nobody's going to moan "It's silly that we have to use 1 and 0
> instead of nice keywords True and False" on the basis that True and
> False didn't exist in Python 2.0. At very least, use 2.7 before you
> complain; preferably, use 3.4 (or 3.5).

While 2.0 is certainly antiquated, Red Hat Enterprise Linux (RHEL) is
often considered the best definition of what's considered "oldest
supported production environment".  RHEL v4 ships with Py2.3 and one
can still obtain extended support for this environment.  RHEL v5 is
actively supported (i.e., without the need for an extended-support
contract) and ships with Py2.4 so I generally try to at least support
2.4 when I'm writing code that could possibly end deploy on a server
such as RHEL5.   Some of us are stuck supporting code in such
antediluvian environments. :-/  Then again, if you're like me and
working in such environments, you already know to use set() instead
of {...} and to avoid the "with" statement, and the like. :)

Sources:
http://en.wikipedia.org/wiki/Red_Hat_Enterprise_Linux#Version_history

http://turbogears.org/1.0/docs/Install/Nix.html#centos-rhel RHEL=2.3

https://wiki.archlinux.org/index.php/python#Old_versions RHEL5=2.4

-tkc





From rosuav at gmail.com  Wed Jan 21 09:31:28 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 01:31:28 +1100
Subject: Trees
In-Reply-To: <20150121082600.7142865d@bigbox.christie.dr>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <87ppa9944t.fsf@elektro.pacujo.net>
 <mailman.17906.1421827045.18130.python-list@python.org>
 <b37db482-1c2d-4b17-9b0b-0e37537482ef@googlegroups.com>
 <CAPTjJmqxKcMS-aquDsvMb60Mg26yAiB=oQsFXFJh2pbr6vPKWA@mail.gmail.com>
 <20150121065503.5555c910@bigbox.christie.dr>
 <CAPTjJmp4sbmmTc9n98QO=TqU=RB4r5GbwVL7HhbFw8MjNrbXJA@mail.gmail.com>
 <20150121082600.7142865d@bigbox.christie.dr>
Message-ID: <CAPTjJmq2PYpgDZQP2HGLiFsBwOb+mp9n=5H9tQV3yyJR1ifK5g@mail.gmail.com>

On Thu, Jan 22, 2015 at 1:26 AM, Tim Chase
<python.list at tim.thechases.com> wrote:
> While 2.0 is certainly antiquated, Red Hat Enterprise Linux (RHEL) is
> often considered the best definition of what's considered "oldest
> supported production environment".  RHEL v4 ships with Py2.3 and one
> can still obtain extended support for this environment.  RHEL v5 is
> actively supported (i.e., without the need for an extended-support
> contract) and ships with Py2.4 so I generally try to at least support
> 2.4 when I'm writing code that could possibly end deploy on a server
> such as RHEL5.   Some of us are stuck supporting code in such
> antediluvian environments. :-/  Then again, if you're like me and
> working in such environments, you already know to use set() instead
> of {...} and to avoid the "with" statement, and the like. :)

I'm aware that there are reasons for wanting to support older versions
of things. I do it myself in several places (though not specifically
with Python pre-2.7). But there's still a difference between "Moan
moan, we have to use set([1,2,3]) when {1,2,3} would make *so* much
more sense" and "Sadly, I have to ensure that my code works on Python
2.4, so I can't take advantage of all the newer features". One is a
complaint about the language; the other is an acknowledgement of the
personal pain of having to support multiple versions (and is going to
get easier; as years go by, the oldest Python on a supported RHEL will
become newer).

ChrisA


From wrw at mac.com  Wed Jan 21 09:41:19 2015
From: wrw at mac.com (William Ray Wing)
Date: Wed, 21 Jan 2015 09:41:19 -0500
Subject: python traceroute
In-Reply-To: <m9nc4c$i7h$2@dont-email.me>
References: <dd1c4ee0-a65d-4d0b-915e-b7c306126685@googlegroups.com>
 <m9nc4c$i7h$2@dont-email.me>
Message-ID: <15F01788-718C-42F3-924E-CDFA38E18814@mac.com>


> On Jan 21, 2015, at 12:06 AM, Denis McMahon <denismfmcmahon at gmail.com> wrote:
> 
> On Tue, 20 Jan 2015 19:37:26 -0800, Chandrakant Tiwari wrote:
> 
>> in the program below i want it to make it work  the same way as TRACERT 
>> command.
> 
> As an observation, you're re-inventing a wheel that already works 
> perfectly well, in that any failings of tracert tend to be more down to 
> the way routers are configured to handle icmp than the tracert 
> application itself. Unless you're doing this purely as an exercise in 
> socket programming with python, it might be better to find a new problem 
> to solve.
> 
> -- 
> Denis McMahon, denismfmcmahon at gmail.com
> -- 
> https://mail.python.org/mailman/listinfo/python-list

I?d further add that as a security measure these days, many (soon to be most) hosts are configured to throw icmp packets away without acknowledging them in any way.

Bill

From steve+comp.lang.python at pearwood.info  Wed Jan 21 09:47:56 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 22 Jan 2015 01:47:56 +1100
Subject: Trees
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <87ppa9944t.fsf@elektro.pacujo.net>
 <mailman.17906.1421827045.18130.python-list@python.org>
 <b37db482-1c2d-4b17-9b0b-0e37537482ef@googlegroups.com>
Message-ID: <54bfbc1d$0$13007$c3e8da3$5496439d@news.astraweb.com>

Rustom Mody wrote:

> On Wednesday, January 21, 2015 at 1:27:39 PM UTC+5:30, Stephen Hansen
> wrote:
[...]
> Among my teachers of CS, there were two ? both brilliant ? one taught me
> Numerical Analysis, the other taught me programming.

I wonder just how brilliant the Numerical Analysis guy really was.


> The point is that the two of them disagreed strongly on what programming
> was about.
> 
> The numerical analyst could see no earthly reason to use anything other
> than Fortran.

Would you consider a cook who boiled everything "brilliant"? Somebody who
insisted that there was no earthly reason to have an oven, a frying pan, a
wok, or a steamer?

Or somebody who insisted that the *one and only* use for chemistry was to
set fire to wood and boil water?

Computers are used for vastly more than just numerical analysis.


> The programmer had horror stories to tell about how Fortran damages the
> brain: eg programs that inherently need a while-loop (eg binary search)
> seem to be
> distinctly out of the reach of the Fortran programmer.  Recursion...
> And much else.
> 
> The numerical analyst of course had no use for this philosophizing.

And how did this brilliant numerical analyst perform fast, efficient
searches of sorted data?


> The view that strings and floats are more fundamental than containers and
> maps reminds me of this view.

A strange comment to make.

I can insert a string or a float inside a container or map, but I cannot
insert a container or map inside a string or float.

Consider the computer hardware we use. Certain data structures are
fundamental to the architecture we use: bytes, pointers, ints, arrays are
very low-level. Floats are a little more complex -- they have a more
complex internal structure than ints. Hash tables are more complex still.

 
> For me python is neat because I can write: [1,2,3]
> when I want a list.

> But it does not go nearly far enough.
> 
> I would like a set to be {1,2,3} or at worst ?1,2,3?
> and a bag to be ?1,2,3?

In Python, you can write sets {1, 2, 3}.

Out of curiosity, what input method did you use to get those Unicode
characters? How many keystrokes or mouse clicks did it take to get this?

\N{LEFT S-SHAPED BAG DELIMITER} 1, 2, 3 \N{RIGHT S-SHAPED BAG DELIMITER}


"bag([1, 2, 3])" requires only 16 keypresses, and it is visible on virtually
every computer, while ? ? look like small boxes to me and probably most
people.

[...]
> More irksome that for the second we've to preface with
> 
> from collections import Counter
> 
> And still more a PITA that a straightforward standard name like bag (or
> multiset) is called by such an ungoogleable misleading name as counter.

It is not misleading. collections.Counter is a class for counting (i.e. a
counter), not a bag. It is merely *similar* to a bag, but the API is not
the same as the usual bag API because the motivating design is not the same
as for bags.

As for being "ungoogleable", that is just simply false. Perhaps you forgot
to push the enter key after typing in your search terms?

https://www.google.com.au/search?q=python+counter

The top three links are:

https://docs.python.org/2/library/collections.html?
https://docs.python.org/3.3/library/collections.html?
http://pymotw.com/2/collections/counter.html

and seven out of the ten links on the first page of results are about
Counter.

Your results may differ from mine, since Google bubbles your searches. But
Duck Duck Go doesn't:

https://duckduckgo.com/?q=python%20counter

Its results are not quite as good as Google's, but it finds the backported
Counter class on PyPI (which Google didn't) and it too links to the Python
Module Of The Week page. Adding "collections" to the search terms brings
the results up to Google quality.

So as you can see, it simply is not true that "Counter" is ungoogleable.



-- 
Steven



From ginolampascione at gmx.com  Wed Jan 21 09:53:07 2015
From: ginolampascione at gmx.com (CARMELO PIGNATRACOZZA DE ROSARIO ARGENTINA)
Date: Wed, 21 Jan 2015 06:53:07 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
References: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
Message-ID: <b596224c-b9f7-45e0-bdad-0dddd453620e@googlegroups.com>

-- redacted --


From ginolampascione at gmx.com  Wed Jan 21 09:58:17 2015
From: ginolampascione at gmx.com (CARMELO PIGNATRACOZZA DE ROSARIO ARGENTINA)
Date: Wed, 21 Jan 2015 06:58:17 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <68f91a40-933f-4c27-866f-ef432dd92fc5@googlegroups.com>
References: <68f91a40-933f-4c27-866f-ef432dd92fc5@googlegroups.com>
Message-ID: <6f9479ab-37de-43d4-8d40-d03f2b8f6392@googlegroups.com>

-- redacted --


From wxjmfauth at gmail.com  Wed Jan 21 10:15:02 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Wed, 21 Jan 2015 07:15:02 -0800 (PST)
Subject: How to "wow" someone new to Python
In-Reply-To: <mailman.17792.1421420646.18130.python-list@python.org>
References: <mailman.17792.1421420646.18130.python-list@python.org>
Message-ID: <b131566a-dd59-4500-8165-272070da6afb@googlegroups.com>

Le vendredi 16 janvier 2015 16:04:20 UTC+1, Chris Angelico a ?crit?:
> Scenario: You're introducing someone to Python for the first time.
> S/he may have some previous programming experience, or may be new to
> the whole idea of giving a computer instructions. You have a couple of
> minutes to show off how awesome Python is. What do you do?
> 
> I was thinking along the lines of a simple demo in the REPL, showing
> off some of Python's coolest features. But then I got stuck on the
> specifics. What are Python's best coolnesses? What makes for a good
> demo?
> 
> Ideally, this should be something that can be demo'd quickly and
> easily, and it should be impressive without going into great details
> of "and see, this is how it works on the inside". So, how would you
> brag about this language?
> 
> ChrisA

If you are smart enough, you can use a string.
On windows, with that string can make IDLE, tkinter,
and finally Python crash. No msg at all. The
main windows just desappears. It's quite clean,
not even a Python engine in the task manager.

For the record, I discovered this when toying
with my unicode plain text editor, I can now throw away,
an editor perfectly working with py32.

jmf


From rustompmody at gmail.com  Wed Jan 21 10:24:19 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Wed, 21 Jan 2015 07:24:19 -0800 (PST)
Subject: Trees
In-Reply-To: <mailman.17910.1421843755.18130.python-list@python.org>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <87ppa9944t.fsf@elektro.pacujo.net>
 <mailman.17906.1421827045.18130.python-list@python.org>
 <b37db482-1c2d-4b17-9b0b-0e37537482ef@googlegroups.com>
 <mailman.17910.1421843755.18130.python-list@python.org>
Message-ID: <1cf6ca5d-67f9-451a-b1da-62b3b8a3f0cf@googlegroups.com>

On Wednesday, January 21, 2015 at 6:06:06 PM UTC+5:30, Chris Angelico wrote:
> On Wed, Jan 21, 2015 at 11:09 PM, Rustom Mody  wrote:
> > I would like a set to be {1,2,3} or at worst ?1,2,3?
> > and a bag to be ?1,2,3?
> >
> > Apart from the unicode niceness that Ive described here
> > http://blog.languager.org/2014/04/unicoded-python.html
> >
> > Its a bit of a nuisance that we have to write set([1,2,3]) for the first
> 
> Wait, what?
> 
> rosuav at sikorsky:~$ python
> Python 2.7.3 (default, Mar 13 2014, 11:03:55)
> [GCC 4.7.2] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
> >>> type({1,2,3})
> <type 'set'>
> >>>
> rosuav at sikorsky:~$ python3
> Python 3.5.0a0 (default:4709290253e3, Jan 20 2015, 21:48:07)
> [GCC 4.7.2] on linux
> Type "help", "copyright", "credits" or "license" for more information.
> >>> type({1,2,3})
> <class 'set'>
> >>>
> 
> Looks like {1,2,3} works for me.
> 
> ChrisA

Ah thank you -- forgot -- mea culpa.


From ian.g.kelly at gmail.com  Wed Jan 21 11:15:25 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 21 Jan 2015 09:15:25 -0700
Subject: Trees
In-Reply-To: <54bfbc1d$0$13007$c3e8da3$5496439d@news.astraweb.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <87ppa9944t.fsf@elektro.pacujo.net>
 <mailman.17906.1421827045.18130.python-list@python.org>
 <b37db482-1c2d-4b17-9b0b-0e37537482ef@googlegroups.com>
 <54bfbc1d$0$13007$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CALwzid=hX6p5bAy29sH5jWXhBFi8ciWQhQiZnKPV+o0fh5a-Bw@mail.gmail.com>

On Wed, Jan 21, 2015 at 7:47 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
>> More irksome that for the second we've to preface with
>>
>> from collections import Counter
>>
>> And still more a PITA that a straightforward standard name like bag (or
>> multiset) is called by such an ungoogleable misleading name as counter.
>
> It is not misleading. collections.Counter is a class for counting (i.e. a
> counter), not a bag. It is merely *similar* to a bag, but the API is not
> the same as the usual bag API because the motivating design is not the same
> as for bags.

To expand on this, Counter does provide a few multiset operations like
union and intersection. But there are a number of cases where it falls
short or does not perform as expected. To name a few:

* There are no subset or superset comparison operations provided.
* len(counter) returns the number of keys, not the number of elements.
* Unlike a multiset, Counters can have negative or zero counts; one
curious consequence of this is that an "empty" Counter can have a
non-zero length and evaluate as true in boolean contexts.

A while back I fiddled around with creating a true MultiSet class
using a Counter as the underlying implementation. Here's what I came
up with:


from collections import Counter
from collections.abc import MutableSet, Set


__all__ = ['MultiSet']


class MultiSet(MutableSet):

  """Multiset class containing hashable items."""

  # Class invariants:
  #   * self._counter is a Counter s/t all values are positive ints denoting
  #     multiplicity.
  #   * set(self) == self._counter.keys()

  def __init__(self, iterable_or_mapping=()):
    """Create a new, empty MultiSet. If passed an iterable argument, initialize
    the MultiSet with items from the iterable. If passed a mapping argument,
    initialize the MultiSet with the keys of the mapping, each repeated a number
    of times equal to the associated value.
    """
    self._counter = +Counter(iterable_or_mapping)

  @classmethod
  def _from_counter(cls, counter):
    self = cls.__new__(cls)
    self._counter = counter
    return self

  def __contains__(self, item):
    return item in self._counter

  def __hash__(self):
    raise TypeError('unhashable type: %s' % type(self))

  def __iter__(self):
    return self._counter.elements()

  def __len__(self):
    # TODO: consider caching the length.
    return sum(self._counter.values())

  def __repr__(self):
    if self:
      return 'MultiSet(%r)' % list(self)
    return 'MultiSet()'

  def add(self, item):
    """Add an element to the MultiSet."""
    self._counter[item] += 1

  def clear(self):
    """Remove all elements from the MultiSet, leaving it empty."""
    self._counter.clear()

  def count(self, item):
    """Return the number of occurrences of the element."""
    return self._counter[item]

  def discard(self, item):
    """Remove an element from the MultiSet.

    If there are multiple occurrences, remove only one such occurrence. If the
    element is not a member, do nothing.
    """
    if item not in self._counter:
      return
    if self._counter[item] == 1:
      del self._counter[item]
    else:
      self._counter[item] -= 1

  def __or__(self, other):
    """Return the union of the MultiSet and another set."""
    if not isinstance(other, Set):
      return NotImplemented
    return self._from_counter(self._counter | _get_counter(other))

  __ror__ = __or__

  def __ior__(self, other):
    """Perform the in-place union of the MultiSet and another set."""
    if not isinstance(other, Set):
      return NotImplemented
    self._counter |= _get_counter(other)
    return self

  def __and__(self, other):
    """Return the intersection of the MultiSet and another set."""
    if not isinstance(other, Set):
      return NotImplemented
    return self._from_counter(self._counter & _get_counter(other))

  __rand__ = __and__

  def __iand__(self, other):
    """Perform the in-place intersection of the MultiSet and another set."""
    if not isinstance(other, Set):
      return NotImplemented
    self._counter &= _get_counter(other)
    return self

  def __sub__(self, other):
    """Return the difference of the MultiSet and another set."""
    if not isinstance(other, Set):
      return NotImplemented
    return self._from_counter(self._counter - _get_counter(other))

  def __rsub__(self, other):
    """Return the difference of another set and the MultiSet."""
    if not isinstance(other, Set):
      return NotImplemented
    return self._from_counter(_get_counter(other) - self._counter)

  def __isub__(self, other):
    """Perform the in-place set difference of the MultiSet and another set."""
    if not isinstance(other, Set):
      return NotImplemented
    self._counter -= _get_counter(other)
    return self

  def __xor__(self, other):
    """Return the symmetric difference of the MultiSet and another set."""
    if not isinstance(other, Set):
      return NotImplemented
    # X ^ Y == (X - Y) | (Y - X)
    other_counter = _get_counter(other)
    counter = (self._counter - other_counter) | (other_counter - self._counter)
    return self._from_counter(counter)

  __rxor__ = __xor__

  def __ixor__(self, other):
    "Perform the in-place symmetric difference of the MultiSet and another set."
    if not isinstance(other, Set):
      return NotImplemented
    # X ^ Y == (X - Y) | (Y - X)
    other_counter = _get_counter(other)
    other_diff = other_counter - self._counter
    self._counter -= other_counter
    self._counter |= other_diff
    return self

  def __eq__(self, other):
    """Return whether the MultiSet and the other set have the same contents."""
    if not isinstance(other, Set):
      return NotImplemented
    return self._counter == _get_counter(other)

  def __ne__(self, other):
    """Return whether the MultiSet and the other set have different contents."""
    if not isinstance(other, Set):
      return NotImplemented
    return self._counter != _get_counter(other)

  def __le__(self, other):
    """Return whether the MultiSet is a subset of the other set."""
    if not isinstance(other, Set):
      return NotImplemented
    other_counter = _get_counter(other)
    return all(self._counter[x] <= other_counter[x] for x in self._counter)

  def __lt__(self, other):
    """Return whether the MultiSet is a proper subset of the other set."""
    if not isinstance(other, Set):
      return NotImplemented
    return self.__le__(other) and not self.__eq__(other)

  def __ge__(self, other):
    """Return whether the MultiSet is a superset of the other set."""
    if not isinstance(other, Set):
      return NotImplemented
    other_counter = _get_counter(other)
    return all(self._counter[x] >= other_counter[x] for x in other_counter)

  def __gt__(self, other):
    """Return whether the MultiSet is a proper superset of the other set."""
    if not isinstance(other, Set):
      return NotImplemented
    return self.__ge__(other) and not self.__eq__(other)


def _get_counter(maybe_multiset):
  if isinstance(maybe_multiset, MultiSet):
    return maybe_multiset._counter
  else:
    return Counter(maybe_multiset)


From steve+comp.lang.python at pearwood.info  Wed Jan 21 11:34:26 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 22 Jan 2015 03:34:26 +1100
Subject: What killed Smalltalk could kill Python
Message-ID: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>

In 2009, Robert Martin gave a talk at RailsConf titled "What Killed
Smalltalk Could Kill Ruby". (No cheering, that sort of attitude is one of
the things that killed Smalltalk.) Although Martin discusses Ruby, the
lessons could also apply to Python.

Video is available here:

http://www.youtube.com/watch?v=YX3iRjKj7C0

Youngsters may not be aware of Smalltalk. It was the language which
popularised object oriented programming. Technically, Simula was the first
OOP language, but Smalltalk popularised it. For a decade or two in the 80s
and 90s, Smalltalk was *the* killer language, the one everybody wanted to
use if only their boss would let them. It was amazingly innovative:
Smalltalk introduced unit testing, test driven development, and it had
powerful refactoring IDEs back in the 1990s.

And now it's all but dead. Why did it die, and how can Python (or Ruby for
that matter) avoid the same fate?

Martin is a very entertaining speaker, funny and knowledgeable. It is a very
entertaining talk, and he covers not just Smalltalk and Ruby but the nature
of professionalism, how fear makes code worse, how to make code better,
Ward Cunningham, the hormonal characteristics of various languages, the
language wars of the 1990s, what is clean code, and more.



-- 
Steven



From ian.g.kelly at gmail.com  Wed Jan 21 12:27:21 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 21 Jan 2015 10:27:21 -0700
Subject: Trees
In-Reply-To: <CALwzid=hX6p5bAy29sH5jWXhBFi8ciWQhQiZnKPV+o0fh5a-Bw@mail.gmail.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <87ppa9944t.fsf@elektro.pacujo.net>
 <mailman.17906.1421827045.18130.python-list@python.org>
 <b37db482-1c2d-4b17-9b0b-0e37537482ef@googlegroups.com>
 <54bfbc1d$0$13007$c3e8da3$5496439d@news.astraweb.com>
 <CALwzid=hX6p5bAy29sH5jWXhBFi8ciWQhQiZnKPV+o0fh5a-Bw@mail.gmail.com>
Message-ID: <CALwzidkhp261c-zXxW64Kh3BcuTuvSBzqwEuudhqCKH8xhMSkg@mail.gmail.com>

On Wed, Jan 21, 2015 at 9:15 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> class MultiSet(MutableSet):

In retrospect this probably shouldn't derive from MutableSet, since
that carries the expectation that all elements are unique (much like
how bool shouldn't be subclassed). For instance, collections.Set
includes some operators that aren't compatible with the second operand
being a multiset.


From motoom at xs4all.nl  Wed Jan 21 12:45:05 2015
From: motoom at xs4all.nl (Michiel Overtoom)
Date: Wed, 21 Jan 2015 18:45:05 +0100
Subject: What killed Smalltalk could kill Python
In-Reply-To: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <282828DF-6AD7-4D05-9AA5-8F50FA3E63A3@xs4all.nl>


Hi Steven, you wrote:

> In 2009, Robert Martin gave a talk at RailsConf titled "What Killed
> Smalltalk Could Kill Ruby".

I've yet to watch the video, I'll do that later tonight, but I also remember what DHH said about Smalltalk in his FLOSS interview about Rails, with Randal Schwartz, in July 2009:

"""
[...] Smalltalk in itself... I tried a few times with some of the images, but it's too much of a different world. It's too idealistic for me in some senses. It's too much ?throw out everything you know and I will show you a new world?. I haven't been ready to take that red pill.

I really like that Ruby is sort of, lets extract 80, 90 percent of what awesome about that and inject it with some real-world pragmatic approaches, like: You can use the text editor you like; You can save files on the file system; You can all these things in tracks with the real world. You don't have to leave everything behind to jump into this Smalltalk world. To me the whole thing about the Smalltalk images which is always just too confusing to me. Why? There's all this different distributions, they're not really compatible, it just seems like a hassle. I just didn't have the patience to wade through all that. But I'm glad somebody else did. I'm glad that all that wisdom is available mostly to people using Ruby. So, yeah, again: Not really.
"""

Source: http://www.transcribed-interview.com/dhh-rails-david-heinemeier-hansson-interview-randal-schwartz-floss.html

Disclosure: I'm the one who made that transcription, and I recognized it from memory.

Greetings,

-- 
"You can't actually make computers run faster, you can only make them do less." - RiderOfGiraffes



From hayesstw at telkomsa.net  Wed Jan 21 12:59:42 2015
From: hayesstw at telkomsa.net (Steve Hayes)
Date: Wed, 21 Jan 2015 19:59:42 +0200
Subject: How to "wow" someone new to Python
References: <mailman.17792.1421420646.18130.python-list@python.org>
Message-ID: <82qvba51o427s4m63agk6ghekm0btg81on@4ax.com>

On Sat, 17 Jan 2015 02:03:57 +1100, Chris Angelico <rosuav at gmail.com> wrote:

>Scenario: You're introducing someone to Python for the first time.
>S/he may have some previous programming experience, or may be new to
>the whole idea of giving a computer instructions. You have a couple of
>minutes to show off how awesome Python is. What do you do?
>
>I was thinking along the lines of a simple demo in the REPL, showing
>off some of Python's coolest features. But then I got stuck on the
>specifics. What are Python's best coolnesses? What makes for a good
>demo?
>
>Ideally, this should be something that can be demo'd quickly and
>easily, and it should be impressive without going into great details
>of "and see, this is how it works on the inside". So, how would you
>brag about this language?

I can only say what made me sit up and take notice.

1. I found it already on my computer. 
2. It seemed to be used to run the Gramps genealogy program, which is quite
complex. I was impressed. 
3. When I started to look at it, I found that strings could be any length and
were not limited to swomething arbitrary, like 256 characters. 



-- 
Steve Hayes from Tshwane, South Africa
Web:  http://www.khanya.org.za/stevesig.htm
Blog: http://khanya.wordpress.com
E-mail - see web page, or parse: shayes at dunelm full stop org full stop uk


From irmen.NOSPAM at xs4all.nl  Wed Jan 21 13:20:37 2015
From: irmen.NOSPAM at xs4all.nl (Irmen de Jong)
Date: Wed, 21 Jan 2015 19:20:37 +0100
Subject: How to "wow" someone new to Python
In-Reply-To: <82qvba51o427s4m63agk6ghekm0btg81on@4ax.com>
References: <mailman.17792.1421420646.18130.python-list@python.org>
 <82qvba51o427s4m63agk6ghekm0btg81on@4ax.com>
Message-ID: <54bfedf5$0$2876$e4fe514c@news.xs4all.nl>

On 21-1-2015 18:59, Steve Hayes wrote:

> 3. When I started to look at it, I found that strings could be any length and
> were not limited to swomething arbitrary, like 256 characters. 

Even more fun is that Python's primitive integer type (longs for older Python versions)
has no arbitrary limitation either.

That amazed me at the time I discovered python :)

Irmen



From python.list at tim.thechases.com  Wed Jan 21 13:21:54 2015
From: python.list at tim.thechases.com (Tim Chase)
Date: Wed, 21 Jan 2015 12:21:54 -0600
Subject: What killed Smalltalk could kill Python
In-Reply-To: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <20150121122154.2f8904b5@bigbox.christie.dr>

On 2015-01-22 03:34, Steven D'Aprano wrote:
> In 2009, Robert Martin gave a talk at RailsConf titled "What Killed
> Smalltalk Could Kill Ruby". 

Holy pacing, Batman.  Watching it at 2x leaves me wondering how much
of the stage was worn off during the presentation.

> And now it's all but dead. Why did it die, and how can Python (or
> Ruby for that matter) avoid the same fate?

In my experience, most Python has a particularly low WTF-per-minute
score.

But mostly Michael's reply addresses my biggest pain points the last
couple times I tried Smalltalk: The whole "images" thing impeded me
from easily using my development preferred environment.

With Python, I can just install it and then either fire up the
REPL, or type some code into a file and run it (same I suppose would
go for Ruby).

I fought for over an hour trying to figure out how to just get
ANYTHING to run in Smalltalk.  I installed Squeak on Debian and yet I
couldn't get any code examples to run.  I had to go find some
environments on the web, download them, modify them, and eventually
something ran.  Eventually I just gave up and returned to a world
where everything made sense.

-tkc




From andre.roberge at gmail.com  Wed Jan 21 13:34:34 2015
From: andre.roberge at gmail.com (=?ISO-8859-1?Q?Andr=E9_Roberge?=)
Date: Wed, 21 Jan 2015 10:34:34 -0800 (PST)
Subject: How to "wow" someone new to Python
In-Reply-To: <mailman.17792.1421420646.18130.python-list@python.org>
References: <mailman.17792.1421420646.18130.python-list@python.org>
Message-ID: <5a29c139-9cec-4638-86af-353c1f2be447@googlegroups.com>

On Friday, 16 January 2015 11:04:20 UTC-4, Chris Angelico  wrote:
> Scenario: You're introducing someone to Python for the first time.
> S/he may have some previous programming experience, or may be new to
> the whole idea of giving a computer instructions. You have a couple of
> minutes to show off how awesome Python is. What do you do?
> 
> I was thinking along the lines of a simple demo in the REPL, showing
> off some of Python's coolest features. But then I got stuck on the
> specifics. What are Python's best coolnesses? What makes for a good
> demo?
> 
> Ideally, this should be something that can be demo'd quickly and
> easily, and it should be impressive without going into great details
> of "and see, this is how it works on the inside". So, how would you
> brag about this language?
> 
> ChrisA
If you are willing to install an older version of Python (because the program I am going to mention has not been updated in years ... but it *should* work with 2.6), I'm going to suggest an odd one:  Crunchy!  (ok, I'm biased :-).

The home page is at https://code.google.com/p/crunchy/ where you can find a link to some screencasts (based on an even older version ...)   So, before you install anything, just have a quick look at the screencast to see if it's worthwhile.

A demo using Crunchy seems to  be even more impressive if the person knows some programming.

(Here is what was said about an even older version of Crunchy by people at the Omaha Python group: " Jeff gave a presentation on Crunchy ([WWW]
http://crunchy.sourceforge.net/) Talk about a gee whiz app."  [https://mail.python.org/pipermail/omaha/2007-July/000065.html])

In a nutshell, I would open the official Python tutorial in my browser, showing the official Python tutorial.   (boring)

Then, I would open the exact same page using a browser tab served by Crunchy: "magically" some text-input boxes would have been inserted allowing you to try out the code in the REPL provided by Crunchy.  Then I'd use Crunchy to launch an external app (perhaps a tkinter program), etc.

As I said at the beginning, Crunchy has not been updated in *years* ... more or less since the IPython and Sage notebooks came along...

Andr?


From marfig at gmail.com  Wed Jan 21 14:05:10 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Wed, 21 Jan 2015 19:05:10 +0000 (UTC)
Subject: How to "wow" someone new to Python
References: <mailman.17792.1421420646.18130.python-list@python.org>
Message-ID: <bcb2d68705da8d203ccb1e735be@nntp.aioe.org>

 Chris,

> Scenario: You're introducing someone to Python for the first time.
> S/he may have some previous programming experience, or may be new to
> the whole idea of giving a computer instructions. You have a couple of
> minutes to show off how awesome Python is. What do you do?

Some ideas where given by others already. I especially liked the variable 
swap one liner by Emile van Sebille. That's a little simple gem that will 
impress any seasoned developer of other programming languages.

But speaking about impressing more experient programmers, I personally don't 
think Python has a wow factor in any of its features and syntax. At least 
in the way I understand the word "wow". Python shares its own brand of idiosyncracies 
with any other programming languages. Little gotchas and caveats that have 
you scratch your head and sometimes annoy you slightly. Python is it too 
cropped here and there with things worth criticizing.

Meanwhile some of its interesting language features, like Comprehensions 
and Generators, aren't really that impressive to a seasoned developer of 
functional programming languages or programming languages like C# with its 
highly powerful and expressive LINQ.

This means that, alone, Python won't really standout. But this is ok. No 
language does it on the merits of its syntax or feature set.

What does make Python standout in my opinion -- what gave me the wow -- is 
its interoperability. Here we have a general purpose scripting language with 
more hooks to other systems that any other programming language in existence. 
With just Python, I can build a modern GUI interface on any of the most popular 
operating systems, use it on PostgreSQL to build stored procedures and move 
most of my business rules to the database server and attach dynamic behavior 
to a system developed in some other programming language.

----
I apologize if my post was to long, but I lacked the time to make it shorter.




From rosuav at gmail.com  Wed Jan 21 14:06:10 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 06:06:10 +1100
Subject: How to "wow" someone new to Python
In-Reply-To: <54bfedf5$0$2876$e4fe514c@news.xs4all.nl>
References: <mailman.17792.1421420646.18130.python-list@python.org>
 <82qvba51o427s4m63agk6ghekm0btg81on@4ax.com>
 <54bfedf5$0$2876$e4fe514c@news.xs4all.nl>
Message-ID: <CAPTjJmrZ42_bVHiHy2pnGUOjkmuUCimkqSDDL7fmTg-u_vJxuQ@mail.gmail.com>

On Thu, Jan 22, 2015 at 5:20 AM, Irmen de Jong <irmen.NOSPAM at xs4all.nl> wrote:
> On 21-1-2015 18:59, Steve Hayes wrote:
>
>> 3. When I started to look at it, I found that strings could be any length and
>> were not limited to swomething arbitrary, like 256 characters.
>
> Even more fun is that Python's primitive integer type (longs for older Python versions)
> has no arbitrary limitation either.
>
> That amazed me at the time I discovered python :)

I hadn't worked with length-limited strings in basically forever
(technically BASIC has a length limit, but I never ran into it; and I
never did much with Pascal), but you're right, arbitrary-precision
integers would have impressed me a lot more if I hadn't first known
REXX. So... is there a way to show that off efficiently? Normally, any
calculation that goes beyond 2**32 has already gone way beyond most
humans' ability to hold the numbers in their heads.

ChrisA


From invalid at invalid.invalid  Wed Jan 21 14:18:41 2015
From: invalid at invalid.invalid (Grant Edwards)
Date: Wed, 21 Jan 2015 19:18:41 +0000 (UTC)
Subject: What killed Smalltalk could kill Python
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <m9ou2h$jvj$1@reader1.panix.com>

On 2015-01-21, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
> In 2009, Robert Martin gave a talk at RailsConf titled "What Killed
> Smalltalk Could Kill Ruby".

But does he answer the more important question "and can we use it to
kill PHP?".

-- 
Grant Edwards               grant.b.edwards        Yow! What UNIVERSE is this,
                                  at               please??
                              gmail.com            


From andre.roberge at gmail.com  Wed Jan 21 14:20:44 2015
From: andre.roberge at gmail.com (=?ISO-8859-1?Q?Andr=E9_Roberge?=)
Date: Wed, 21 Jan 2015 11:20:44 -0800 (PST)
Subject: How to "wow" someone new to Python
In-Reply-To: <mailman.17921.1421867178.18130.python-list@python.org>
References: <mailman.17792.1421420646.18130.python-list@python.org>
 <82qvba51o427s4m63agk6ghekm0btg81on@4ax.com>
 <54bfedf5$0$2876$e4fe514c@news.xs4all.nl>
 <mailman.17921.1421867178.18130.python-list@python.org>
Message-ID: <20425bf8-2862-432f-a6a9-cd7ea6d21853@googlegroups.com>

On Wednesday, 21 January 2015 15:06:33 UTC-4, Chris Angelico  wrote:
> On Thu, Jan 22, 2015 at 5:20 AM, Irmen de Jong  wrote:
> > On 21-1-2015 18:59, Steve Hayes wrote:
> >
> >> 3. When I started to look at it, I found that strings could be any length and
> >> were not limited to swomething arbitrary, like 256 characters.
> >
> > Even more fun is that Python's primitive integer type (longs for older Python versions)
> > has no arbitrary limitation either.
> >
> > That amazed me at the time I discovered python :)
> 
> I hadn't worked with length-limited strings in basically forever
> (technically BASIC has a length limit, but I never ran into it; and I
> never did much with Pascal), but you're right, arbitrary-precision
> integers would have impressed me a lot more if I hadn't first known
> REXX. So... is there a way to show that off efficiently? 

How about:

 >>> def fac(n):
 ...     ans = 1
 ...     while n > 1:
 ...         ans *= n
 ...         n -= 1
 ...     return ans
 ...
 >>> a = fac(100)
 >>> a
 93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000
 >>> b = fac(102)
 >>> b
 961446671503512660926865558697259548455355905059659464369444714048531715130254590603314961882364451384985595980362059157503710042865532928000000000000000000000000
 >>> b//a
 10302
 >>> b//a == 102 * 101
 True

Andr?


Normally, any
> calculation that goes beyond 2**32 has already gone way beyond most
> humans' ability to hold the numbers in their heads.
> 
> ChrisA


From mmr15 at case.edu  Wed Jan 21 16:20:02 2015
From: mmr15 at case.edu (Matthew Ruffalo)
Date: Wed, 21 Jan 2015 16:20:02 -0500
Subject: How to "wow" someone new to Python
In-Reply-To: <CAPTjJmrZ42_bVHiHy2pnGUOjkmuUCimkqSDDL7fmTg-u_vJxuQ@mail.gmail.com>
References: <mailman.17792.1421420646.18130.python-list@python.org>
 <82qvba51o427s4m63agk6ghekm0btg81on@4ax.com>
 <54bfedf5$0$2876$e4fe514c@news.xs4all.nl>
 <CAPTjJmrZ42_bVHiHy2pnGUOjkmuUCimkqSDDL7fmTg-u_vJxuQ@mail.gmail.com>
Message-ID: <54C01802.7020202@case.edu>

On 01/21/2015 02:06 PM, Chris Angelico wrote:
> On Thu, Jan 22, 2015 at 5:20 AM, Irmen de Jong <irmen.NOSPAM at xs4all.nl> wrote:
>> On 21-1-2015 18:59, Steve Hayes wrote:
>>
>>> 3. When I started to look at it, I found that strings could be any length and
>>> were not limited to swomething arbitrary, like 256 characters.
>> Even more fun is that Python's primitive integer type (longs for older Python versions)
>> has no arbitrary limitation either.
>>
>> That amazed me at the time I discovered python :)
> I hadn't worked with length-limited strings in basically forever
> (technically BASIC has a length limit, but I never ran into it; and I
> never did much with Pascal), but you're right, arbitrary-precision
> integers would have impressed me a lot more if I hadn't first known
> REXX. So... is there a way to show that off efficiently? Normally, any
> calculation that goes beyond 2**32 has already gone way beyond most
> humans' ability to hold the numbers in their heads.
>
> ChrisA
Yes, length-unlimited strings are *extremely* useful in some
applications. I remember bitterly cursing Java's string length limit of
2 ** 31 (maybe - 1) on multiple occasions. Python's strings seem to
behave like integers in that their size is limited only by available memory.

MMR...


From rosuav at gmail.com  Wed Jan 21 16:26:29 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 08:26:29 +1100
Subject: How to "wow" someone new to Python
In-Reply-To: <54C01802.7020202@case.edu>
References: <mailman.17792.1421420646.18130.python-list@python.org>
 <82qvba51o427s4m63agk6ghekm0btg81on@4ax.com>
 <54bfedf5$0$2876$e4fe514c@news.xs4all.nl>
 <CAPTjJmrZ42_bVHiHy2pnGUOjkmuUCimkqSDDL7fmTg-u_vJxuQ@mail.gmail.com>
 <54C01802.7020202@case.edu>
Message-ID: <CAPTjJmo-ZKpQzn7dodM9SnvJ_HcKMwNhP6rpXczkoB-qQoAJhw@mail.gmail.com>

On Thu, Jan 22, 2015 at 8:20 AM, Matthew Ruffalo <mmr15 at case.edu> wrote:
> Yes, length-unlimited strings are *extremely* useful in some
> applications. I remember bitterly cursing Java's string length limit of
> 2 ** 31 (maybe - 1) on multiple occasions. Python's strings seem to
> behave like integers in that their size is limited only by available memory.

Hmm, I don't know that you'll get much beyond 2**31 characters (even
all-ASCII characters in PEP 393) on a 32-bit Python, simply because
"available memory" is capped at 2**32 bytes minus other stuff. You'd
need a 64-bit Python to do that, and I would guess a 64-bit Java would
also raise the limit.

ChrisA


From alan at scooby-doo.csail.mit.edu  Wed Jan 21 16:44:19 2015
From: alan at scooby-doo.csail.mit.edu (Alan Bawden)
Date: Wed, 21 Jan 2015 16:44:19 -0500
Subject: How to "wow" someone new to Python
References: <mailman.17792.1421420646.18130.python-list@python.org>
 <82qvba51o427s4m63agk6ghekm0btg81on@4ax.com>
 <54bfedf5$0$2876$e4fe514c@news.xs4all.nl>
 <CAPTjJmrZ42_bVHiHy2pnGUOjkmuUCimkqSDDL7fmTg-u_vJxuQ@mail.gmail.com>
 <54C01802.7020202@case.edu>
 <mailman.17923.1421875592.18130.python-list@python.org>
Message-ID: <w2dsif33j2k.fsf@scooby-doo.csail.mit.edu>

Chris Angelico <rosuav at gmail.com> writes:
> ..., and I would guess a 64-bit Java would
> also raise the limit.

Even in a 64-bit Java, the _type_ returned by String.length() is 'int',
and is thus at most (2**31 - 1).  This isn't a problem for strings,
which never get that long in practice, but for some other Java datatypes
(e.g., Buffer) it is a real problem.  Score one for untyped languages.

-- 
Alan Bawden


From mmr15 at case.edu  Wed Jan 21 16:46:18 2015
From: mmr15 at case.edu (Matthew Ruffalo)
Date: Wed, 21 Jan 2015 16:46:18 -0500
Subject: How to "wow" someone new to Python
In-Reply-To: <CAPTjJmo-ZKpQzn7dodM9SnvJ_HcKMwNhP6rpXczkoB-qQoAJhw@mail.gmail.com>
References: <mailman.17792.1421420646.18130.python-list@python.org>
 <82qvba51o427s4m63agk6ghekm0btg81on@4ax.com>
 <54bfedf5$0$2876$e4fe514c@news.xs4all.nl>
 <CAPTjJmrZ42_bVHiHy2pnGUOjkmuUCimkqSDDL7fmTg-u_vJxuQ@mail.gmail.com>
 <54C01802.7020202@case.edu>
 <CAPTjJmo-ZKpQzn7dodM9SnvJ_HcKMwNhP6rpXczkoB-qQoAJhw@mail.gmail.com>
Message-ID: <54C01E2A.3040602@case.edu>

On 01/21/2015 04:26 PM, Chris Angelico wrote:
> On Thu, Jan 22, 2015 at 8:20 AM, Matthew Ruffalo <mmr15 at case.edu> wrote:
>> Yes, length-unlimited strings are *extremely* useful in some
>> applications. I remember bitterly cursing Java's string length limit of
>> 2 ** 31 (maybe - 1) on multiple occasions. Python's strings seem to
>> behave like integers in that their size is limited only by available memory.
> Hmm, I don't know that you'll get much beyond 2**31 characters (even
> all-ASCII characters in PEP 393) on a 32-bit Python, simply because
> "available memory" is capped at 2**32 bytes minus other stuff. You'd
> need a 64-bit Python to do that, and I would guess a 64-bit Java would
> also raise the limit.
>
> ChrisA
No, Java's String.length returns an int and Strings are limited to ~2 **
31 characters even in 64-bit Java.

I do seem to have encountered some strange behavior, though: creating
very large strings with str.__mul__ seems to enter an allocation loop in
Python 3.4. With a single-character string 's', I can create the
following new strings quickly:

s * 2 ** 33
s * 2 ** 34
s * 2 ** 35
s * 2 ** 36

but s * 2 ** 38 shows some odd memory usage. I'm watching the memory
usage of a Python process steadily increase to 256GB, drop to a few MB,
climb back to 256GB, drop to a few MB, and so on. It takes a half-dozen
cycles of allocation and deallocation before the interactive interpreter
gives me another prompt.

MMR...



From alan at scooby-doo.csail.mit.edu  Wed Jan 21 16:52:06 2015
From: alan at scooby-doo.csail.mit.edu (Alan Bawden)
Date: Wed, 21 Jan 2015 16:52:06 -0500
Subject: How to "wow" someone new to Python
References: <mailman.17792.1421420646.18130.python-list@python.org>
 <82qvba51o427s4m63agk6ghekm0btg81on@4ax.com>
 <54bfedf5$0$2876$e4fe514c@news.xs4all.nl>
 <CAPTjJmrZ42_bVHiHy2pnGUOjkmuUCimkqSDDL7fmTg-u_vJxuQ@mail.gmail.com>
 <54C01802.7020202@case.edu>
 <mailman.17923.1421875592.18130.python-list@python.org>
 <w2dsif33j2k.fsf@scooby-doo.csail.mit.edu>
Message-ID: <w2doapr3ipl.fsf@scooby-doo.csail.mit.edu>

Alan Bawden <alan at scooby-doo.csail.mit.edu> writes:
> ...  Score one for untyped languages.

Drat.  I should have writted "dynamically typed languages".

The language has changed.  When I was a novice Lisp hacker, we were
comfortable saying that Lisp was "untyped".  But nowadays we always say
that Lisp is "dynamically typed".  I could write an essay about why...

-- 
Alan Bawden


From marfig at gmail.com  Wed Jan 21 17:13:07 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Wed, 21 Jan 2015 23:13:07 +0100
Subject: How to "wow" someone new to Python
References: <mailman.17792.1421420646.18130.python-list@python.org>
 <82qvba51o427s4m63agk6ghekm0btg81on@4ax.com>
 <54bfedf5$0$2876$e4fe514c@news.xs4all.nl>
 <CAPTjJmrZ42_bVHiHy2pnGUOjkmuUCimkqSDDL7fmTg-u_vJxuQ@mail.gmail.com>
 <54C01802.7020202@case.edu>
 <mailman.17923.1421875592.18130.python-list@python.org>
 <w2dsif33j2k.fsf@scooby-doo.csail.mit.edu>
Message-ID: <MPG.2f2a42cc23059fe1989681@nntp.aioe.org>

In article <w2dsif33j2k.fsf at scooby-doo.csail.mit.edu>, alan at scooby-
doo.csail.mit.edu says...
> Even in a 64-bit Java, the _type_ returned by String.length() is
> 'int', and is thus at most (2**31 - 1).  This isn't a problem for
> strings, which never get that long in practice, but for some other
> Java datatypes (e.g., Buffer) it is a real problem.  Score one for
> untyped languages.

Still, assuming you have enough heap size, you can still create a 500 
million character string buffer. That's one of a heck large buffer. 
Nearly twice the online encyclopedia Britannica(1), and roughly 50 times 
the longest novel ever produced (2).

And considering you can always flush the buffer, I'm finding an hard 
time looking at unlimited string length in Python as wow factor. Even if 
we consider unicode strings. 


(1) 
http://en.wikipedia.org/wiki/Wikipedia:Size_comparisons#Comparison_of_en
cyclopedias

(2) http://en.wikipedia.org/wiki/List_of_longest_novels


From rosuav at gmail.com  Wed Jan 21 17:22:34 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 09:22:34 +1100
Subject: How to "wow" someone new to Python
In-Reply-To: <54C01E2A.3040602@case.edu>
References: <mailman.17792.1421420646.18130.python-list@python.org>
 <82qvba51o427s4m63agk6ghekm0btg81on@4ax.com>
 <54bfedf5$0$2876$e4fe514c@news.xs4all.nl>
 <CAPTjJmrZ42_bVHiHy2pnGUOjkmuUCimkqSDDL7fmTg-u_vJxuQ@mail.gmail.com>
 <54C01802.7020202@case.edu>
 <CAPTjJmo-ZKpQzn7dodM9SnvJ_HcKMwNhP6rpXczkoB-qQoAJhw@mail.gmail.com>
 <54C01E2A.3040602@case.edu>
Message-ID: <CAPTjJmoxdOSJ0QtdOvHUHFwiVDyPxGjZgGgNgfEZ4vUqyencww@mail.gmail.com>

On Thu, Jan 22, 2015 at 8:46 AM, Matthew Ruffalo <mmr15 at case.edu> wrote:
> No, Java's String.length returns an int and Strings are limited to ~2 **
> 31 characters even in 64-bit Java.

Huh, annoying. In Python, the length of a string (in characters) is
stored in a Py_ssize_t (if I recall correctly), which is, I believe, a
pointer-sized integer. So it'd be 64-bit on a 64-bit build.

> I do seem to have encountered some strange behavior, though: creating
> very large strings with str.__mul__ seems to enter an allocation loop in
> Python 3.4. With a single-character string 's', I can create the
> following new strings quickly:
>
> s * 2 ** 33
> s * 2 ** 34
> s * 2 ** 35
> s * 2 ** 36
>
> but s * 2 ** 38 shows some odd memory usage. I'm watching the memory
> usage of a Python process steadily increase to 256GB, drop to a few MB,
> climb back to 256GB, drop to a few MB, and so on. It takes a half-dozen
> cycles of allocation and deallocation before the interactive interpreter
> gives me another prompt.

That sounds like you're blooping through your page file. The exact
behaviour will depend on how much physical memory you have, how your
page file is implemented (which depends on your OS), the phase of the
moon, and what you had for breakfast three weeks ago.

ChrisA


From no.email at nospam.invalid  Wed Jan 21 17:27:37 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Wed, 21 Jan 2015 14:27:37 -0800
Subject: Trees
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
 <MPG.2f28eb55d73ef68c989680@nntp.aioe.org>
 <ba69cad8-68c0-421e-af79-e381ca179015@googlegroups.com>
 <87iog0aonw.fsf@jester.gateway.sonic.net>
 <c30a53ac-8709-44a0-b1da-78ed6e447b11@googlegroups.com>
Message-ID: <87egqnahwm.fsf@jester.gateway.sonic.net>

Rustom Mody <rustompmody at gmail.com> writes:
> Thats not bfs. That's inorder traversal

Oops, you're right.  How's this:

bfs x = go [x] where
  go [] = []
  go (L x:ts) = x:go ts
  go (B x lst rst:ts) = x : go (ts ++ [lst, rst])

*Main> bfs t
[6,2,8,1,4,7,9,3,5]


From rosuav at gmail.com  Wed Jan 21 17:35:45 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 09:35:45 +1100
Subject: What killed Smalltalk could kill Python
In-Reply-To: <m9ou2h$jvj$1@reader1.panix.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <m9ou2h$jvj$1@reader1.panix.com>
Message-ID: <CAPTjJmrOhgchuF4idomzMzzpZx7pq5-13HNqJ96T+NSVGhdA+g@mail.gmail.com>

On Thu, Jan 22, 2015 at 6:18 AM, Grant Edwards <invalid at invalid.invalid> wrote:
> On 2015-01-21, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
>> In 2009, Robert Martin gave a talk at RailsConf titled "What Killed
>> Smalltalk Could Kill Ruby".
>
> But does he answer the more important question "and can we use it to
> kill PHP?".

PHP won't die so long as there are people willing to apologize for its
every flaw and defend it on the basis that huge sites X, Y, and Z all
use it. But we don't need it to die. All we need is for Python to
live, and we can ignore PHP and write Unicode-aware web sites with
simple, trustworthy entry points, and not worry about the rest.

ChrisA


From no.email at nospam.invalid  Wed Jan 21 17:35:56 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Wed, 21 Jan 2015 14:35:56 -0800
Subject: How to "wow" someone new to Python
References: <mailman.17792.1421420646.18130.python-list@python.org>
 <82qvba51o427s4m63agk6ghekm0btg81on@4ax.com>
 <54bfedf5$0$2876$e4fe514c@news.xs4all.nl>
 <CAPTjJmrZ42_bVHiHy2pnGUOjkmuUCimkqSDDL7fmTg-u_vJxuQ@mail.gmail.com>
 <54C01802.7020202@case.edu>
 <mailman.17923.1421875592.18130.python-list@python.org>
 <w2dsif33j2k.fsf@scooby-doo.csail.mit.edu>
 <w2doapr3ipl.fsf@scooby-doo.csail.mit.edu>
Message-ID: <87a91bahir.fsf@jester.gateway.sonic.net>

Alan Bawden <alan at scooby-doo.csail.mit.edu> writes:
> The language has changed.  When I was a novice Lisp hacker, we were
> comfortable saying that Lisp was "untyped".  But nowadays we always say
> that Lisp is "dynamically typed".  I could write an essay about why...

I'd be interested in seeing that.  Lisp of course descends from Church's
untyped lambda calculus but I didn't realize Lisp terminology about its
(runtime) type system had changed historically.  PL theorists sometimes
like to refer to runtime types as "tags" rather than types.


From ian.g.kelly at gmail.com  Wed Jan 21 17:54:08 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 21 Jan 2015 15:54:08 -0700
Subject: Trees
In-Reply-To: <ba69cad8-68c0-421e-af79-e381ca179015@googlegroups.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
 <MPG.2f28eb55d73ef68c989680@nntp.aioe.org>
 <ba69cad8-68c0-421e-af79-e381ca179015@googlegroups.com>
Message-ID: <CALwzidnDP04rixTkaL+dmtVoVK6RstDM1E=E89izqMQr_Q6dSg@mail.gmail.com>

On Tue, Jan 20, 2015 at 6:23 PM, Rustom Mody <rustompmody at gmail.com> wrote:
> The Haskell is bullseye? in capturing the essense of a tree because
> conceptually a tree of type t is recursive in the sense that it can contain
> 2 subtrees -- (B x lst rst) -- or its a base case -- L x.

How do you create a tree containing an even number of elements under
this constraint?


From jbailey at emerytelcom.com  Wed Jan 21 18:06:17 2015
From: jbailey at emerytelcom.com (Jason Bailey)
Date: Wed, 21 Jan 2015 16:06:17 -0700
Subject: Check for running DHCP daemon?
Message-ID: <54C030E9.8010404@emerytelcom.com>

So I've got this python 3 script that needs to know if there is a 
running DHCP daemon (ISC DHCP server) on the local system. Is there a 
clean way to do this that (1) doesn't require me to do syscalls to local 
utilities (like ps, top, etc), and (2) doesn't require any custom 
modules (stock only)?

Thanks



From invalid at invalid.invalid  Wed Jan 21 18:10:25 2015
From: invalid at invalid.invalid (Grant Edwards)
Date: Wed, 21 Jan 2015 23:10:25 +0000 (UTC)
Subject: What killed Smalltalk could kill Python
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <m9ou2h$jvj$1@reader1.panix.com>
 <mailman.17926.1421879748.18130.python-list@python.org>
Message-ID: <m9pbl1$oan$1@reader1.panix.com>

On 2015-01-21, Chris Angelico <rosuav at gmail.com> wrote:
> On Thu, Jan 22, 2015 at 6:18 AM, Grant Edwards <invalid at invalid.invalid> wrote:
>> On 2015-01-21, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
>>> In 2009, Robert Martin gave a talk at RailsConf titled "What Killed
>>> Smalltalk Could Kill Ruby".
>>
>> But does he answer the more important question "and can we use it to
>> kill PHP?".
>
> PHP won't die so long as there are people willing to apologize for
> its every flaw and defend it on the basis that huge sites X, Y, and Z
> all use it. But we don't need it to die. All we need is for Python to
> live, and we can ignore PHP and write Unicode-aware web sites with
> simple, trustworthy entry points, and not worry about the rest.

I happily ignored PHP until a couple years back when we decided to use
PHP for the web site on a small embedded Linux system.  The reasoning
was that we didn't have any significant internal web site development
skills, and using PHP on Linux would make it easy to contract out the
web site design using an off-the-shelf light-weight framework.

[At the time, a couple of us could stumble around with HTML enough to
generate web pages that looked fresh out of 1995, but that was about
it. The web pages in our older devices looked rather "retro" and had
pretty limited functionality.]

At a certain point we couldn't afford the contractors any longer and
somebody had to take over maintenance and development of the web
stuff.  The JavaScript and jQuery part of it isn't bad.  Both have had
some thought put into them: they have their quirks but there's a
certain internal consistency and elegence.

PHP, on the other hand makes me want to scream.  It's all just a
random mess -- it's nothing _but_ quirks.  As one of the contractors
once said: PHP is like a combination of all the worst features of
bash, perl, and C.

I briefly considered trying to switch to Python, but the Python
footprint is just too big...

-- 
Grant Edwards               grant.b.edwards        Yow! RELATIVES!!
                                  at               
                              gmail.com            


From anthony at cajuntechie.org  Wed Jan 21 18:19:17 2015
From: anthony at cajuntechie.org (Anthony Papillion)
Date: Wed, 21 Jan 2015 17:19:17 -0600
Subject: What killed Smalltalk could kill Python
In-Reply-To: <CAPTjJmrOhgchuF4idomzMzzpZx7pq5-13HNqJ96T+NSVGhdA+g@mail.gmail.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <m9ou2h$jvj$1@reader1.panix.com>
 <CAPTjJmrOhgchuF4idomzMzzpZx7pq5-13HNqJ96T+NSVGhdA+g@mail.gmail.com>
Message-ID: <54C033F5.6080405@cajuntechie.org>

On 01/21/2015 04:35 PM, Chris Angelico wrote:
> On Thu, Jan 22, 2015 at 6:18 AM, Grant Edwards <invalid at invalid.invalid> wrote:
>> On 2015-01-21, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
>>> In 2009, Robert Martin gave a talk at RailsConf titled "What Killed
>>> Smalltalk Could Kill Ruby".
>>
>> But does he answer the more important question "and can we use it to
>> kill PHP?".
> 
> PHP won't die so long as there are people willing to apologize for its
> every flaw and defend it on the basis that huge sites X, Y, and Z all
> use it. But we don't need it to die. All we need is for Python to
> live, and we can ignore PHP and write Unicode-aware web sites with
> simple, trustworthy entry points, and not worry about the rest.

To be fair, PHP has come a long way in the last few years and, I hear,
there's movements within the community to make it better. Namespaces
were a bit deal as were a few other things. Personally, while I am
LOVING Python, I'd be sad to see PHP die. It's got a lot of potential if
the community can get its crap together and take off the ruby coloured
glasses.

Anthony


From rosuav at gmail.com  Wed Jan 21 18:30:22 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 10:30:22 +1100
Subject: Check for running DHCP daemon?
In-Reply-To: <54C030E9.8010404@emerytelcom.com>
References: <54C030E9.8010404@emerytelcom.com>
Message-ID: <CAPTjJmpJQrxf_0UQ+an0_G8GcXuDiu8rGcAOSN9q5iAGciQy9w@mail.gmail.com>

On Thu, Jan 22, 2015 at 10:06 AM, Jason Bailey <jbailey at emerytelcom.com> wrote:
> So I've got this python 3 script that needs to know if there is a running
> DHCP daemon (ISC DHCP server) on the local system. Is there a clean way to
> do this that (1) doesn't require me to do syscalls to local utilities (like
> ps, top, etc), and (2) doesn't require any custom modules (stock only)?

Not sure why you have these restrictions; normally I'd look at an
OS-provided status function (eg "/etc/init.d/isc-dhcp-server status",
which on my Debian system is implemented by looking for a PID file and
confirming with ps). But since DHCP uses port 67, you might be able to
use that; I don't know of a way, within your restrictions, to find out
if someone's bound to port 67, but you could send a DHCPDISCOVER
message to 127:0.0.1:67 and see if you get back an offer. That may not
be the best technique, but it could be done with just Python's
standard library. (Alternatively, if you're certain the DHCP server is
configured appropriately, you could send a DHCPREQUEST message with an
inappropriate IP and hope for a rejection.)

ChrisA


From tundra at tundraware.com  Wed Jan 21 18:37:00 2015
From: tundra at tundraware.com (Tim Daneliuk)
Date: Wed, 21 Jan 2015 17:37:00 -0600
Subject: What killed Smalltalk could kill Python
In-Reply-To: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <spp5pb-0tt1.ln1@ozzie.tundraware.com>

On 01/21/2015 10:34 AM, Steven D'Aprano wrote:
> In 2009, Robert Martin gave a talk at RailsConf titled "What Killed
> Smalltalk Could Kill Ruby". (No cheering, that sort of attitude is one of
> the things that killed Smalltalk.) Although Martin discusses Ruby, the
> lessons could also apply to Python.


I find these kinds of discussions sort of silly.  Once there is a critical
mass of installed base, no language EVER dies.

I suspect the real reason Smalltalk sort of got kicked to the curb is because
a) It clung to a kind of OO purity that simply is at odds with the practice
of programming at large scale  and   b) It thus never built the aforementioned
critical mass.

Language adoption at the scale needed to make a real dent doesn't happen
because of technical superiority (witness PHP as just one example).  It happens
because lots of people solve real problems faster than they used to.
In fact - outside the language cognoscenti and uber nerd community - I'd
argue that  Python adoption has little to do with functional programming,
lambda, OO, generators, or whatever happens to float your boat.  Python
got adopted because it made code production faster, and therefore cheaper.
Economics matters way more than technology here, I think.

I wrote some rambling disquisition on these matters some years ago ...

  http://www.tundraware.com/TechnicalNotes/Python-Is-Middleware

  http://www.tundraware.com/TechnicalNotes/How-To-Pick-A-Programming-Language
-- 
----------------------------------------------------------------------------
Tim Daneliuk     tundra at tundraware.com
PGP Key:         http://www.tundraware.com/PGP/



From rosuav at gmail.com  Wed Jan 21 18:41:19 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 10:41:19 +1100
Subject: What killed Smalltalk could kill Python
In-Reply-To: <54C033F5.6080405@cajuntechie.org>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <m9ou2h$jvj$1@reader1.panix.com>
 <CAPTjJmrOhgchuF4idomzMzzpZx7pq5-13HNqJ96T+NSVGhdA+g@mail.gmail.com>
 <54C033F5.6080405@cajuntechie.org>
Message-ID: <CAPTjJmqU8oa0ssdVqNs79LYLJPKgPquu_FCqSgpnRhQ3qzsH8g@mail.gmail.com>

On Thu, Jan 22, 2015 at 10:19 AM, Anthony Papillion
<anthony at cajuntechie.org> wrote:
> To be fair, PHP has come a long way in the last few years and, I hear,
> there's movements within the community to make it better. Namespaces
> were a bit deal as were a few other things. Personally, while I am
> LOVING Python, I'd be sad to see PHP die. It's got a lot of potential if
> the community can get its crap together and take off the ruby coloured
> glasses.

The huge advantage of PHP over other languages is that it comes free
with any cheap web host. That's also a huge *dis*advantage when it
comes to "movements... to make it better", because you can't know when
the new version will become sufficiently prevalent to depend on it.
I've seen PHP 4 compatibility code in current versions of some big
frameworks, although I've no idea whether that implies actual support
or just that nobody's removed it yet.

But there are a few fundamental problems with PHP, which are derived
directly from its philosophies. One of them is that any file in some
directory tree is automatically an entry point - specifically, an
*executable* entry point. PHP frameworks that accept file uploads have
to go to great lengths to ensure that malicious users can't upload
code and run it. Every web framework I've seen for Python, Ruby, Pike,
etc, has URL routing defined by the application, not the file system,
and if you define a readable uploads directory, all you're going to do
is allow people to re-download the same file. Even old CGI scripts,
where file system presence defined entry points, weren't as bad as PHP
- firstly because they were usually restricted to /cgi-bin/ (and you
simply wouldn't allow world writing to that directory), and secondly
because the scripts had to be marked executable, which PHP scripts
don't.

Maybe PHP will grow true Unicode support in a future version. Maybe
it'll gain a nice object model that compares well to Python's or
Ruby's or whichever other you want to look at. Maybe there'll be a
complete reworking of string comparisons so that "12e2" is no longer
equal to "1200". But I doubt it'll ever shift away from file-system
entry points.

And that's why I will continue to push people to Python+Flask rather than PHP.

ChrisA


From no.email at nospam.invalid  Wed Jan 21 18:46:34 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Wed, 21 Jan 2015 15:46:34 -0800
Subject: What killed Smalltalk could kill Python
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <873873ae91.fsf@jester.gateway.sonic.net>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:
> In 2009, Robert Martin gave a talk at RailsConf titled "What Killed
> Smalltalk Could Kill Ruby"...  http://www.youtube.com/watch?v=YX3iRjKj7C0

That's an hour-long video; could someone who's watched it give a brief
summary?

Meanwhile, there's this:  http://prog21.dadgum.com/203.html
"Retiring Python as a Teaching Language"

tl;dr: he's switched to recommending Javascript as a first language
instead of Python, since JS makes it easier to write graphics and games,
which is what lots of beginners are interested in now.


From irmen.NOSPAM at xs4all.nl  Wed Jan 21 18:46:52 2015
From: irmen.NOSPAM at xs4all.nl (Irmen de Jong)
Date: Thu, 22 Jan 2015 00:46:52 +0100
Subject: How to "wow" someone new to Python
In-Reply-To: <mailman.17921.1421867178.18130.python-list@python.org>
References: <mailman.17792.1421420646.18130.python-list@python.org>
 <82qvba51o427s4m63agk6ghekm0btg81on@4ax.com>
 <54bfedf5$0$2876$e4fe514c@news.xs4all.nl>
 <mailman.17921.1421867178.18130.python-list@python.org>
Message-ID: <54c03a6b$0$2893$e4fe514c@news.xs4all.nl>

On 21-1-2015 20:06, Chris Angelico wrote:
> On Thu, Jan 22, 2015 at 5:20 AM, Irmen de Jong <irmen.NOSPAM at xs4all.nl> wrote:
>> On 21-1-2015 18:59, Steve Hayes wrote:
>>
>>> 3. When I started to look at it, I found that strings could be any length and
>>> were not limited to swomething arbitrary, like 256 characters.
>>
>> Even more fun is that Python's primitive integer type (longs for older Python versions)
>> has no arbitrary limitation either.
>>
>> That amazed me at the time I discovered python :)
> 
> I hadn't worked with length-limited strings in basically forever
> (technically BASIC has a length limit, but I never ran into it; and I
> never did much with Pascal), but you're right, arbitrary-precision
> integers would have impressed me a lot more if I hadn't first known
> REXX. So... is there a way to show that off efficiently? Normally, any
> calculation that goes beyond 2**32 has already gone way beyond most
> humans' ability to hold the numbers in their heads.
> 
> ChrisA
> 

Something silly that I just thought about  (Python 3):


number = 2 * 3 * 5 * 103    # okay.
number = number * 3120937 * 6977407 * 8431103    # hmm...
number = number * 70546381234168412430433268433712277793053956898109255590133639943
print("I know a huge number, it is:", number)
secret_message = number.to_bytes(37, "big")
print(secret_message)


Or perhaps: (after pip install pyprimes)

>>> number = 1402811054100763300785480817886711606823329164566977593890  # wow?
>>> import pyprimes.factors
>>> print(pyprimes.factors.factorise(number))
[2, 3, 5, 557, 1559, 3413, 6991, 27799, 41333, 52999, 104681, 247001, 992441, 1111211,
1299689]
>>>



Irmen




From rosuav at gmail.com  Wed Jan 21 18:55:27 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 10:55:27 +1100
Subject: What killed Smalltalk could kill Python
In-Reply-To: <spp5pb-0tt1.ln1@ozzie.tundraware.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <spp5pb-0tt1.ln1@ozzie.tundraware.com>
Message-ID: <CAPTjJmoAehP2v+bVjdmqCpahNfAqpXoJu4-NHp+N9KJ=y9CnNw@mail.gmail.com>

On Thu, Jan 22, 2015 at 10:37 AM, Tim Daneliuk <tundra at tundraware.com> wrote:
> I find these kinds of discussions sort of silly.  Once there is a critical
> mass of installed base, no language EVER dies.

Not sure about that. Back in the 1990s, I wrote most of my code in
REXX, either command-line or using a GUI toolkit like VX-REXX. Where's
REXX today? Well, let's see. It's still the native-ish language of
OS/2. Where's OS/2 today? Left behind. REXX has no Unicode support (it
does, however, support DBCS - useful, no?), no inbuilt networking
support (there are third-party TCP/IP socket libraries for OS/2 REXX,
but I don't know that other REXX implementations have socket services;
and that's just basic BSD sockets, no higher-level protocol handling
at all), etc, etc. Sure, it's not technically dead... but is anyone
developing the language further? I don't think so. Is new REXX code
being written? Not a lot. Yet when OS/2 was more popular, REXX
definitely had its installed base. It was the one obvious scripting
language for any OS/2 program. Languages can definitely die, or at
least be so left behind that they may as well be dead.

ChrisA


From rosuav at gmail.com  Wed Jan 21 18:57:48 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 10:57:48 +1100
Subject: What killed Smalltalk could kill Python
In-Reply-To: <873873ae91.fsf@jester.gateway.sonic.net>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
Message-ID: <CAPTjJmrFA13RYvO9AiOQcfCK4e+we7rBAD0wg8uJVtNu0KsqJA@mail.gmail.com>

On Thu, Jan 22, 2015 at 10:46 AM, Paul Rubin <no.email at nospam.invalid> wrote:
> Meanwhile, there's this:  http://prog21.dadgum.com/203.html
> "Retiring Python as a Teaching Language"
>
> tl;dr: he's switched to recommending Javascript as a first language
> instead of Python, since JS makes it easier to write graphics and games,
> which is what lots of beginners are interested in now.

Bad idea. Better to pick a language that makes it easy to get things
right, and then work on the fun side with third-party libraries, than
to tempt people in with "hey look how easy it is to do X" and then
have them stuck with an inferior or flawed language. Too many people
already don't know the difference between UTF-16 and Unicode. Please,
educators, don't make it worse.

ChrisA


From torriem at gmail.com  Wed Jan 21 19:08:18 2015
From: torriem at gmail.com (Michael Torrie)
Date: Wed, 21 Jan 2015 17:08:18 -0700
Subject: What killed Smalltalk could kill Python
In-Reply-To: <spp5pb-0tt1.ln1@ozzie.tundraware.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <spp5pb-0tt1.ln1@ozzie.tundraware.com>
Message-ID: <54C03F72.4090500@gmail.com>

On 01/21/2015 04:37 PM, Tim Daneliuk wrote:
> On 01/21/2015 10:34 AM, Steven D'Aprano wrote:
>> In 2009, Robert Martin gave a talk at RailsConf titled "What Killed
>> Smalltalk Could Kill Ruby". (No cheering, that sort of attitude is one of
>> the things that killed Smalltalk.) Although Martin discusses Ruby, the
>> lessons could also apply to Python.
> 
> 
> I find these kinds of discussions sort of silly.  Once there is a critical
> mass of installed base, no language EVER dies.
> 
> I suspect the real reason Smalltalk sort of got kicked to the curb is because
> a) It clung to a kind of OO purity that simply is at odds with the practice
> of programming at large scale  and   b) It thus never built the aforementioned
> critical mass.

I suspect Smalltalk lost relevance mainly because it never integrated
very well into any computing system.  Everything ran in a virtual
machine in its own image in isolation as it were.  The IDE and the
runtime environment were inseparable, and as OS's developed their own
environments it just never tried to fit in.  It's almost as if Smalltalk
was the language, runtime, your program source code, *and* operating
system.  That's what he meant in his talk about the problem with
smalltalk being the "image."  The only way to distribute your smalltalk
programs was to distribute the image file, which was basically a memory
dump.  When you wanted to list out a smalltalk program you were
basically decompiling it to the editor widget.

So this integrated nature of smalltalk (source code, editor, live
objects, etc) was its most powerful feature, but ultimately its downfall
too in my opinion.  And at the same time we regularly pine for some of
those features.


From marfig at gmail.com  Wed Jan 21 19:09:51 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Thu, 22 Jan 2015 01:09:51 +0100
Subject: What killed Smalltalk could kill Python
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
 <mailman.17933.1421884677.18130.python-list@python.org>
Message-ID: <MPG.2f2a5e01b517d4db989682@nntp.aioe.org>

In article <mailman.17933.1421884677.18130.python-list at python.org>, 
rosuav at gmail.com says...
> 
> Bad idea. Better to pick a language that makes it easy to get things
> right, and then work on the fun side with third-party libraries, than
> to tempt people in with "hey look how easy it is to do X" and then
> have them stuck with an inferior or flawed language. Too many people
> already don't know the difference between UTF-16 and Unicode. Please,
> educators, don't make it worse.
> 
> ChrisA


Indeed. If games and funnies is what drive beginners into programming, 
that's fine. But the educational principles of programming shouldn't be 
trashed in the process. We need serious developers in today's complex 
application systems. Not uneducated programmers with nary a knowledge of 
Software Engineering. Besides if games and funnies are the only thing 
that can drive someone into programming, I'd rather not see that person 
become a developer.

"I want to become a programmer so I can make games" is, on the vast 
majority of cases, the quote of someone who will never become a 
programmer. Why should teachers reward that kind of thought?  


From marfig at gmail.com  Wed Jan 21 19:16:01 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Thu, 22 Jan 2015 01:16:01 +0100
Subject: What killed Smalltalk could kill Python
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
Message-ID: <MPG.2f2a5f9ab0001a82989683@nntp.aioe.org>

In article <873873ae91.fsf at jester.gateway.sonic.net>, 
no.email at nospam.invalid says...
> 
> Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:
> > In 2009, Robert Martin gave a talk at RailsConf titled "What Killed
> > Smalltalk Could Kill Ruby"...  http://www.youtube.com/watch?v=YX3iRjKj7C0
> 
> That's an hour-long video; could someone who's watched it give a brief
> summary?
> 

In a nutshell, he argues, along with Ward Cunningham, that what killed 
Smalltalk was how easy you could create unclean code with it. "Unclean" 
in this context means Smalltalk didn't punish bad software design 
decisions that would eventually lead into complex code and unmanageable 
systems with zero options of code maintenance.

I don't have an opinion. I didn't know Smalltalk. I started my 
programming carrer around the early nineties as a Dbase and later 
Clipper programmer.


From john_ladasky at sbcglobal.net  Wed Jan 21 19:22:07 2015
From: john_ladasky at sbcglobal.net (John Ladasky)
Date: Wed, 21 Jan 2015 16:22:07 -0800 (PST)
Subject: What killed Smalltalk could kill Python
In-Reply-To: <m9ou2h$jvj$1@reader1.panix.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <m9ou2h$jvj$1@reader1.panix.com>
Message-ID: <87195a31-991f-489a-a36f-3b1c0120793e@googlegroups.com>

On Wednesday, January 21, 2015 at 11:18:54 AM UTC-8, Grant Edwards wrote:
> On 2015-01-21, Steven D'Aprano <st... at pearwood.info> wrote:
> > In 2009, Robert Martin gave a talk at RailsConf titled "What Killed
> > Smalltalk Could Kill Ruby".
> 
> But does he answer the more important question "and can we use it to
> kill PHP?".

LOL!

Seriously, I did.



From marko at pacujo.net  Wed Jan 21 19:25:06 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 22 Jan 2015 02:25:06 +0200
Subject: What killed Smalltalk could kill Python
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <m9ou2h$jvj$1@reader1.panix.com>
 <mailman.17926.1421879748.18130.python-list@python.org>
 <m9pbl1$oan$1@reader1.panix.com>
Message-ID: <87fvb3hdb1.fsf@elektro.pacujo.net>

Grant Edwards <invalid at invalid.invalid>:

> [At the time, a couple of us could stumble around with HTML enough to
> generate web pages that looked fresh out of 1995, but that was about
> it. The web pages in our older devices looked rather "retro" and had
> pretty limited functionality.]

I miss that plain old look of web pages.


Marko


From sohcahtoa82 at gmail.com  Wed Jan 21 20:00:01 2015
From: sohcahtoa82 at gmail.com (sohcahtoa82 at gmail.com)
Date: Wed, 21 Jan 2015 17:00:01 -0800 (PST)
Subject: What killed Smalltalk could kill Python
In-Reply-To: <MPG.2f2a5e01b517d4db989682@nntp.aioe.org>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
 <mailman.17933.1421884677.18130.python-list@python.org>
 <MPG.2f2a5e01b517d4db989682@nntp.aioe.org>
Message-ID: <5d1c5dab-cb97-4845-85d3-76f2cde90d43@googlegroups.com>

On Wednesday, January 21, 2015 at 4:10:08 PM UTC-8, Mario Figueiredo wrote:
> In article <mailman.17933.1421884677.18130.python-list at python.org>, 
> rosuav at gmail.com says...
> > 
> > Bad idea. Better to pick a language that makes it easy to get things
> > right, and then work on the fun side with third-party libraries, than
> > to tempt people in with "hey look how easy it is to do X" and then
> > have them stuck with an inferior or flawed language. Too many people
> > already don't know the difference between UTF-16 and Unicode. Please,
> > educators, don't make it worse.
> > 
> > ChrisA
> 
> 
> Indeed. If games and funnies is what drive beginners into programming, 
> that's fine. But the educational principles of programming shouldn't be 
> trashed in the process. We need serious developers in today's complex 
> application systems. Not uneducated programmers with nary a knowledge of 
> Software Engineering. Besides if games and funnies are the only thing 
> that can drive someone into programming, I'd rather not see that person 
> become a developer.
> 
> "I want to become a programmer so I can make games" is, on the vast 
> majority of cases, the quote of someone who will never become a 
> programmer. Why should teachers reward that kind of thought?

I think one of the problems is that most of the people with the "I want to become a programmer so I can make games" mentality really have no clue at all how much work it takes to produce a game.  They just see that Minecraft was made started by just one guy and now he's a billionaire, and they think "I want that to happen to me!".  They think that just because the game has low-resolution graphics means they could produce something similar in just a couple days, ignoring complexities like rendering optimizations and interaction with the world.

Others will pick up Python because everyone tells them its an easy language to learn and then think they're going to make the next Call of Duty or World of Warcraft with it without any knowledge of basic algorithms.  They might learn a few from some tutorials, but they'll have no idea how to apply them.  They won't be able to make the jump from "Here's how to start a TCP server in one window while connecting to it from a client in another window and send chat messages back and forth" (essentially a basic implementation of netcat) to creating a game server that sends game state updates to the players.


From rosuav at gmail.com  Wed Jan 21 20:36:44 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 12:36:44 +1100
Subject: What killed Smalltalk could kill Python
In-Reply-To: <MPG.2f2a5e01b517d4db989682@nntp.aioe.org>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
 <mailman.17933.1421884677.18130.python-list@python.org>
 <MPG.2f2a5e01b517d4db989682@nntp.aioe.org>
Message-ID: <CAPTjJmphX4U630iV6VX7bSA_PuZEx3YJsDLo73sssaG77cV9fw@mail.gmail.com>

On Thu, Jan 22, 2015 at 11:09 AM, Mario Figueiredo <marfig at gmail.com> wrote:
> "I want to become a programmer so I can make games" is, on the vast
> majority of cases, the quote of someone who will never become a
> programmer. Why should teachers reward that kind of thought?

How about "I want to become a programmer so my brother, 2.5 years
older than me, won't be better than me any more"? Should that kind of
thinking be rewarded? Because that's how I got started. My brother was
being taught the basics of programming, I was jealous (being the
second child will tend to produce that), and so at six years old, I
started learning to code. And then a few years later, I wanted to
learn C because my brother didn't know it (we'd both learned BASIC),
and since I didn't have a C compiler, I learned 8086 Assembly Language
instead, using DEBUG.EXE. Largely out of jealousy.

I hope I've gained a little maturity since then...

ChrisA


From no.email at nospam.invalid  Wed Jan 21 20:38:24 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Wed, 21 Jan 2015 17:38:24 -0800
Subject: What killed Smalltalk could kill Python
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
 <mailman.17933.1421884677.18130.python-list@python.org>
 <MPG.2f2a5e01b517d4db989682@nntp.aioe.org>
Message-ID: <87vbjz8ui7.fsf@jester.gateway.sonic.net>

Mario Figueiredo <marfig at gmail.com> writes:
> "I want to become a programmer so I can make games" is, on the vast 
> majority of cases, the quote of someone who will never become a 
> programmer. Why should teachers reward that kind of thought?  

I don't see what the problem is.  Kids are interested in games and they
are into playing them, so of course they also want to program them.


From ethan at stoneleaf.us  Wed Jan 21 20:44:35 2015
From: ethan at stoneleaf.us (Ethan Furman)
Date: Wed, 21 Jan 2015 17:44:35 -0800
Subject: What killed Smalltalk could kill Python
In-Reply-To: <CAPTjJmphX4U630iV6VX7bSA_PuZEx3YJsDLo73sssaG77cV9fw@mail.gmail.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
 <mailman.17933.1421884677.18130.python-list@python.org>
 <MPG.2f2a5e01b517d4db989682@nntp.aioe.org>
 <CAPTjJmphX4U630iV6VX7bSA_PuZEx3YJsDLo73sssaG77cV9fw@mail.gmail.com>
Message-ID: <54C05603.1060007@stoneleaf.us>

On 01/21/2015 05:36 PM, Chris Angelico wrote:
> On Thu, Jan 22, 2015 at 11:09 AM, Mario Figueiredo <marfig at gmail.com> wrote:
>> "I want to become a programmer so I can make games" is, on the vast
>> majority of cases, the quote of someone who will never become a
>> programmer. Why should teachers reward that kind of thought?
> 
> How about "I want to become a programmer so my brother, 2.5 years
> older than me, won't be better than me any more"? Should that kind of
> thinking be rewarded? Because that's how I got started. My brother was
> being taught the basics of programming, I was jealous (being the
> second child will tend to produce that), and so at six years old, I
> started learning to code. And then a few years later, I wanted to
> learn C because my brother didn't know it (we'd both learned BASIC),
> and since I didn't have a C compiler, I learned 8086 Assembly Language
> instead, using DEBUG.EXE. Largely out of jealousy.

There is a difference between /your/ motivation to learn something, and teachers /pandering/ to such motivations.
There's nothing wrong with "I want to make games" as a personal driving factor, but the educational system should still
teach decent programming, not whatever piece of garbage will produce quick results at the expense of long-term productivity.

--
~Ethan~

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From rosuav at gmail.com  Wed Jan 21 20:45:32 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 12:45:32 +1100
Subject: What killed Smalltalk could kill Python
In-Reply-To: <87vbjz8ui7.fsf@jester.gateway.sonic.net>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
 <mailman.17933.1421884677.18130.python-list@python.org>
 <MPG.2f2a5e01b517d4db989682@nntp.aioe.org>
 <87vbjz8ui7.fsf@jester.gateway.sonic.net>
Message-ID: <CAPTjJmqaLbbr_Cy1PQsc1HCi+TMuBLUyQEX7fBPZQCrKeMqiHQ@mail.gmail.com>

On Thu, Jan 22, 2015 at 12:38 PM, Paul Rubin <no.email at nospam.invalid> wrote:
> Mario Figueiredo <marfig at gmail.com> writes:
>> "I want to become a programmer so I can make games" is, on the vast
>> majority of cases, the quote of someone who will never become a
>> programmer. Why should teachers reward that kind of thought?
>
> I don't see what the problem is.  Kids are interested in games and they
> are into playing them, so of course they also want to program them.

It's not a terrible justification for getting into programming. But
writing games is (almost always) a terrible way to start programming.
Either you pick up a super-restrictive "hey look, you can build a game
with just point and click" system, which isn't teaching programming at
all, or you end up getting bogged down in the massive details of what
it takes to write code.

If someone's unfazed by the "it'll take you years before you can
actually write a saleable game" consideration, then getting into
programming via toys (writing Fizz Buzz or a factorial calculator)
will put him/her on a much better footing for actual coding work.

ChrisA


From rantingrickjohnson at gmail.com  Wed Jan 21 21:11:31 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Wed, 21 Jan 2015 18:11:31 -0800 (PST)
Subject: What killed Smalltalk could kill Python
In-Reply-To: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <5f6034ce-fbb0-4257-b876-858e6e35e8ce@googlegroups.com>

On Wednesday, January 21, 2015 at 10:34:40 AM UTC-6, Steven D'Aprano wrote:
> In 2009, Robert Martin gave a talk at RailsConf titled
> "What Killed Smalltalk Could Kill Ruby". (No cheering,
> that sort of attitude is one of the things that killed
> Smalltalk.) Although Martin discusses Ruby, the lessons
> could also apply to Python.

Python is already headed towards obscurity. The fall began
with the release of Python3000 (from which we "might" have
recovered), but now it seems that GvR intends to drive the
final nail in python's coffin with this "type hinting" crap
that will convert Python syntax from a readable pseudo code
into a cryptic nightmare.

Type hinting violates the very *ESSENCE* of what Python was
meant to be, that is: a "clean and intuitive syntax". The
cleanness of Python is what attracts people to it, and the
hook is set when they discover the breadth of the stdlib.

If GvR brings this gawd awful type hinting idea to reality,
IT'S OVER! Python will be lost forever to history as just
another "interesting oddity". Time to call up the Robert 
Ripley estate and request some space in his museum!


From drsalists at gmail.com  Wed Jan 21 21:21:13 2015
From: drsalists at gmail.com (Dan Stromberg)
Date: Wed, 21 Jan 2015 18:21:13 -0800
Subject: Check for running DHCP daemon?
In-Reply-To: <54C030E9.8010404@emerytelcom.com>
References: <54C030E9.8010404@emerytelcom.com>
Message-ID: <CAGGBd_rbL21MZEh+6PoUYoM-OS-Mpd=sUpSTPiTGhwqJSrqNMw@mail.gmail.com>

On Wed, Jan 21, 2015 at 3:06 PM, Jason Bailey <jbailey at emerytelcom.com> wrote:
> So I've got this python 3 script that needs to know if there is a running
> DHCP daemon (ISC DHCP server) on the local system. Is there a clean way to
> do this that (1) doesn't require me to do syscalls to local utilities (like
> ps, top, etc), and (2) doesn't require any custom modules (stock only)?

The subprocess module is quite clean on *ix.  Don't let the subprocess
mess on Windows steer you away from it on *ix.  And don't let the
"subprocesses are bad" from the perl community misguide you either -
shell is fast today because it's highly parallel, because it's
unafraid of subprocesses.

You could open the files under /proc and look around, if you're on
Linux. But parsing "ps -eo whatever" would probably be cleaner.

A "syscall" is an interaction with a kernel.  I think you meant an
os.system() call.


From no.email at nospam.invalid  Wed Jan 21 21:53:33 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Wed, 21 Jan 2015 18:53:33 -0800
Subject: What killed Smalltalk could kill Python
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
 <mailman.17933.1421884677.18130.python-list@python.org>
 <MPG.2f2a5e01b517d4db989682@nntp.aioe.org>
 <87vbjz8ui7.fsf@jester.gateway.sonic.net>
 <mailman.17937.1421891140.18130.python-list@python.org>
Message-ID: <87r3un8r0y.fsf@jester.gateway.sonic.net>

Chris Angelico <rosuav at gmail.com> writes:
> Either you pick up a super-restrictive "hey look, you can build a game
> with just point and click" system, which isn't teaching programming at
> all, or you end up getting bogged down in the massive details of what
> it takes to write code.

Code Hero ran into various obstacles and never got finished, but it was
a game whose purpose was to teach the player how to write their own
games using Unity3D.  I saw some early versions and it seemed pretty
accessible.

https://en.wikipedia.org/wiki/Code_Hero

Heck, there's even a song about learning to program through wanting to
write games, and ending up treating programming as a type of
spirituality (there was an interview with the songwriter explaining
this, but it seems to have gone offline):

lyrics:
http://www.sccs.swarthmore.edu/users/01/bnewman/songs/lyrics/Code-Goddess.txt
mp3:
http://www.sccs.swarthmore.edu/users/01/bnewman/songs/music/Code-Goddess.mp3


> If someone's unfazed by the "it'll take you years before you can
> actually write a saleable game" consideration,

Wanting to write games is a completely different topic than wanting to
sell them.  It's just like any other creative outlet.  Most people who
teach themselves to juggle do it because juggling is fun, not because
they want to join the circus.  


From rosuav at gmail.com  Wed Jan 21 21:59:22 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 13:59:22 +1100
Subject: What killed Smalltalk could kill Python
In-Reply-To: <87r3un8r0y.fsf@jester.gateway.sonic.net>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
 <mailman.17933.1421884677.18130.python-list@python.org>
 <MPG.2f2a5e01b517d4db989682@nntp.aioe.org>
 <87vbjz8ui7.fsf@jester.gateway.sonic.net>
 <mailman.17937.1421891140.18130.python-list@python.org>
 <87r3un8r0y.fsf@jester.gateway.sonic.net>
Message-ID: <CAPTjJmo3fspAy5X21O2nPq7iFoPG=SOiGEbP=K5ETSxWFYBh8Q@mail.gmail.com>

On Thu, Jan 22, 2015 at 1:53 PM, Paul Rubin <no.email at nospam.invalid> wrote:
>> If someone's unfazed by the "it'll take you years before you can
>> actually write a saleable game" consideration,
>
> Wanting to write games is a completely different topic than wanting to
> sell them.  It's just like any other creative outlet.  Most people who
> teach themselves to juggle do it because juggling is fun, not because
> they want to join the circus.

True, but even a playable game is a long way beyond a first-day
programmer. (By "playable" I mean something that someone other than
its author would play and enjoy.) It's fine as a goal, but needs to be
viewed with a perspective of "that's where I'm trying to get to", not
"now I'm going to start writing games".

ChrisA


From rosuav at gmail.com  Wed Jan 21 22:08:53 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 14:08:53 +1100
Subject: What killed Smalltalk could kill Python
In-Reply-To: <0fp0cald824ke0bfphsghrfuf62nfhol2j@4ax.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <spp5pb-0tt1.ln1@ozzie.tundraware.com>
 <CAPTjJmoAehP2v+bVjdmqCpahNfAqpXoJu4-NHp+N9KJ=y9CnNw@mail.gmail.com>
 <0fp0cald824ke0bfphsghrfuf62nfhol2j@4ax.com>
Message-ID: <CAPTjJmp6WZjrAk6UBV0fGA5Y+-dL3BAuHn5L7Y1MS3U9xwg3GA@mail.gmail.com>

On Thu, Jan 22, 2015 at 1:59 PM, Dennis Lee Bieber
<wlfraed at ix.netcom.com> wrote:
>         To my mind, what killed REXX is that most operating systems just don't
> support its key feature well: ADDRESS targets!
>
>         When the only target turns ADDRESS into the equivalent of os.system()
> (or some variant of popen() ) it just loses too much. Besides the original
> mainframe implementation, I have a feeling only ARexx managed to maintain
> the spirit of REXX -- and that may have been as it was so easy to extend
> the native AmigaOS message passing IPC to create ARexx ports letting
> processes truly communicate interactively.

Very good point. I can count the instances where ADDRESS could be used
for something else on the fingers of one hand... and one of them was a
MUD server that I wrote myself, and which nobody else ever used. And
it would have done better to use SAY rather than ADDRESS; it's kinda
cute, but not very practical, to have something like this:

/* code file for implementing, say, the 'search' command */
if arg(1) = "haystack" then do
    "You find a needle in the haystack!"
    "It is long, sharp, and made of metal."
    call move_object create_object("needle"), caller
end
else "You find nothing of interest."

Each quoted string got sent to the client as a line of text. Yeah,
nice, but there are plenty of other ways to do it.

(The main coolness of this system was that I could update the REXX
code without restarting the server, which was pretty handy.)

Other than that, it's really not a well-used feature. Oh, what might
have been...

ChrisA


From python.list at tim.thechases.com  Wed Jan 21 22:22:31 2015
From: python.list at tim.thechases.com (Tim Chase)
Date: Wed, 21 Jan 2015 21:22:31 -0600
Subject: What killed Smalltalk could kill Python
In-Reply-To: <m9pbl1$oan$1@reader1.panix.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <m9ou2h$jvj$1@reader1.panix.com>
 <mailman.17926.1421879748.18130.python-list@python.org>
 <m9pbl1$oan$1@reader1.panix.com>
Message-ID: <20150121212231.3ecfe7e9@bigbox.christie.dr>

On 2015-01-21 23:10, Grant Edwards wrote:
> I happily ignored PHP until a couple years back when we decided to
> use PHP for the web site on a small embedded Linux system. 
[snip]
> I briefly considered trying to switch to Python, but the Python
> footprint is just too big...

Interesting that your experience swung that way.

I worked on a contract about a year ago where it involved deploying
web services & ZigBee communications on a Digi Connectport[1] which is
certainly a rather underpowered device (20MB of memory is tight).  My
biggest issue was the project-lead's choice of CherryPy and
SQLObject...neither has nearly the same quality of documentation as
I'd grown accustomed to in the Django world.  Yet I was able to run
an HTTPS CherryPy server talking to a local sqlite database with
minimal trouble, handling a modest (i.e., small business) load.

-tkc

[1]
http://www.digi.com/products/wireless-routers-gateways/gateways/xbee-gateway#specs







From steve+comp.lang.python at pearwood.info  Wed Jan 21 22:23:16 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 22 Jan 2015 14:23:16 +1100
Subject: What killed Smalltalk could kill Python
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
 <mailman.17933.1421884677.18130.python-list@python.org>
 <MPG.2f2a5e01b517d4db989682@nntp.aioe.org>
Message-ID: <54c06d26$0$12915$c3e8da3$5496439d@news.astraweb.com>

Mario Figueiredo wrote:

> In article <mailman.17933.1421884677.18130.python-list at python.org>,
> rosuav at gmail.com says...
>> 
>> Bad idea. Better to pick a language that makes it easy to get things
>> right, and then work on the fun side with third-party libraries, than
>> to tempt people in with "hey look how easy it is to do X" and then
>> have them stuck with an inferior or flawed language. Too many people
>> already don't know the difference between UTF-16 and Unicode. Please,
>> educators, don't make it worse.
>> 
>> ChrisA
> 
> 
> Indeed. If games and funnies is what drive beginners into programming,
> that's fine. But the educational principles of programming shouldn't be
> trashed in the process. We need serious developers in today's complex
> application systems.

Sure, but are they the *only* kinds of programmers that we need? Isn't there 
room in the world for an open-source developer who creates Firefox plug-ins, 
sys admins who write shell-scripts, cubical workers who write Excel 
worksheets, etc? Why shouldn't my Aunt Tilly write a mobile phone app to 
manage her cheesecake recipes just the way she likes?

http://livecode.com/

Programming games is hard. Arguably, it's *much* harder than most beginners 
can deal with, unless you start with a specialist language designed with 
game-related primitives:

http://scratch.mit.edu/

Even text based games are hard, and arguably need their own specialist 
language:

http://inform7.com/

Modern games *are* part of "today's complex application systems", and games 
developers may need the same skills used by "serious developers":

- project management
- testing
- change control
- release management
- documentation
- networking
- user authentication


etc. I'd further argue that many games developers have to know *more* that 
the typical developer. As a Python programmer, I don't have to manage 
memory, but many games devs are often programming down close to the metal 
and do need to care about the sort of low-level issues (memory, graphics, 
network latency) that I only have the fuzziest concept of. You don't write a 
high-performance 3D physics engine in Python. (At least not yet.)


> Not uneducated programmers with nary a knowledge of
> Software Engineering. Besides if games and funnies are the only thing
> that can drive someone into programming, I'd rather not see that person
> become a developer.

That's a terribly judgemental and rather arrogant statement. If people have 
a passion for mathematics, and that leads them to take up programming and 
invent Mathematica, would you say the world would have been better off if 
they never became a programmer?

What we need is more programmers with a passion for their job, and if that 
means learning to write games, then so be it. One of the problems with "9 to 
5 code monkeys" is that programming is just a job for them. They do the 
absolute minimum they need to keep their job. They don't program for fun, or 
to learn new skills, or to solve problems. They go to user groups and forums 
like here only when they have a question they want answered, they take and 
take and take and they never give back.

I'd rather teach somebody passionate about writing games than somebody 
apathetic about programming, and I'd rather the games person became a 
programmer.


-- 
Steven



From ouyanggh0815 at gmail.com  Wed Jan 21 22:38:22 2015
From: ouyanggh0815 at gmail.com (Guohua Ouyang)
Date: Thu, 22 Jan 2015 11:38:22 +0800
Subject: An improper change in httplib.py
Message-ID: <CAO0APJQtPjRQvisLSn1T2No402rDR8NPTD6sjMHjQPt6ihKWBw@mail.gmail.com>

This is my first post to the list, I apologies firstly if I made any mistake.

I was trying to get a package in golang behind the http or https
proxy, and it reports  an error "AttributeError: httpsconnection
instance has no attribute '_set_hostport'", details in the bottom.
After some trace work, I found it caused by the changes in the issue issue7776.

@@ -718,7 +734,7 @@
         else:
             self._tunnel_headers.clear()

-    def _set_hostport(self, host, port):
+    def _get_hostport(self, host, port):

First, it changes the method's name, doesn't it break the
compatibility for other packages, on my system,
mercurial-3.0-2.fc21.x86_64 still use "_set_hostport" as the error
shows.

Second, I found that line 1132 of [2] still use "
self._conn._set_hostport(host, port)", which should be
"_get_hostport", right?

[1] http://bugs.python.org/issue7776
[2] https://github.com/python/cpython/blob/2.7/Lib/httplib.py


$ go get code.google.com/p/go-uuid/uuid
# cd .; hg clone -U https://code.google.com/p/go-uuid
/home/guohua/go/src/code.google.com/p/go-uuid
** unknown exception encountered, please report by visiting
** http://mercurial.selenic.com/wiki/BugTracker
** Python 2.7.8 (default, Nov 10 2014, 08:19:18) [GCC 4.9.2 20141101
(Red Hat 4.9.2-1)]
** Mercurial Distributed SCM (version 3.0)
** Extensions loaded:
Traceback (most recent call last):
  File "/usr/bin/hg", line 38, in <module>
    mercurial.dispatch.run()
  File "/usr/lib64/python2.7/site-packages/mercurial/dispatch.py",
line 28, in run
    sys.exit((dispatch(request(sys.argv[1:])) or 0) & 255)
  File "/usr/lib64/python2.7/site-packages/mercurial/dispatch.py",
line 69, in dispatch
    ret = _runcatch(req)
  File "/usr/lib64/python2.7/site-packages/mercurial/dispatch.py",
line 138, in _runcatch
    return _dispatch(req)
  File "/usr/lib64/python2.7/site-packages/mercurial/dispatch.py",
line 810, in _dispatch
    cmdpats, cmdoptions)
  File "/usr/lib64/python2.7/site-packages/mercurial/dispatch.py",
line 590, in runcommand
    ret = _runcommand(ui, options, cmd, d)
  File "/usr/lib64/python2.7/site-packages/mercurial/dispatch.py",
line 901, in _runcommand
    return checkargs()
  File "/usr/lib64/python2.7/site-packages/mercurial/dispatch.py",
line 872, in checkargs
    return cmdfunc()
  File "/usr/lib64/python2.7/site-packages/mercurial/dispatch.py",
line 807, in <lambda>
    d = lambda: util.checksignature(func)(ui, *args, **cmdoptions)
  File "/usr/lib64/python2.7/site-packages/mercurial/util.py", line
518, in check
    return func(*args, **kwargs)
  File "/usr/lib64/python2.7/site-packages/mercurial/commands.py",
line 1298, in clone
    branch=opts.get('branch'))
  File "/usr/lib64/python2.7/site-packages/mercurial/hg.py", line 295, in clone
    srcpeer = peer(ui, peeropts, source)
  File "/usr/lib64/python2.7/site-packages/mercurial/hg.py", line 129, in peer
    return _peerorrepo(rui, path, create).peer()
  File "/usr/lib64/python2.7/site-packages/mercurial/hg.py", line 106,
in _peerorrepo
    obj = _peerlookup(path).instance(ui, path, create)
  File "/usr/lib64/python2.7/site-packages/mercurial/httppeer.py",
line 261, in instance
    inst._fetchcaps()
  File "/usr/lib64/python2.7/site-packages/mercurial/httppeer.py",
line 58, in _fetchcaps
    self.caps = set(self._call('capabilities').split())
  File "/usr/lib64/python2.7/site-packages/mercurial/httppeer.py",
line 172, in _call
    fp = self._callstream(cmd, **args)
  File "/usr/lib64/python2.7/site-packages/mercurial/httppeer.py",
line 119, in _callstream
    resp = self.urlopener.open(req)
  File "/usr/lib64/python2.7/urllib2.py", line 404, in open
    response = self._open(req, data)
  File "/usr/lib64/python2.7/urllib2.py", line 422, in _open
    '_open', req)
  File "/usr/lib64/python2.7/urllib2.py", line 382, in _call_chain
    result = func(*args)
  File "/usr/lib64/python2.7/site-packages/mercurial/url.py", line
372, in https_open
    return self.do_open(self._makeconnection, req)
  File "/usr/lib64/python2.7/site-packages/mercurial/keepalive.py",
line 254, in do_open
    self._start_transaction(h, req)
  File "/usr/lib64/python2.7/site-packages/mercurial/url.py", line
358, in _start_transaction
    return keepalive.KeepAliveHandler._start_transaction(self, h, req)
  File "/usr/lib64/python2.7/site-packages/mercurial/keepalive.py",
line 352, in _start_transaction
    h.endheaders()
  File "/usr/lib64/python2.7/httplib.py", line 991, in endheaders
    self._send_output(message_body)
  File "/usr/lib64/python2.7/httplib.py", line 844, in _send_output
    self.send(msg)
  File "/usr/lib64/python2.7/site-packages/mercurial/url.py", line
144, in _sendfile
    orgsend(self, data)
  File "/usr/lib64/python2.7/site-packages/mercurial/keepalive.py",
line 532, in safesend
    self.connect()
  File "/usr/lib64/python2.7/site-packages/mercurial/url.py", line
342, in connect
    _generic_proxytunnel(self)
  File "/usr/lib64/python2.7/site-packages/mercurial/url.py", line
228, in _generic_proxytunnel
    self._set_hostport(self.host, self.port)
AttributeError: httpsconnection instance has no attribute '_set_hostport'
package code.google.com/p/go-uuid/uuid: exit status 1


From JBailey at emerytelcom.com  Wed Jan 21 22:58:29 2015
From: JBailey at emerytelcom.com (Jason Bailey)
Date: Thu, 22 Jan 2015 03:58:29 +0000
Subject: Check for running DHCP daemon?
In-Reply-To: <CAGGBd_rbL21MZEh+6PoUYoM-OS-Mpd=sUpSTPiTGhwqJSrqNMw@mail.gmail.com>
References: <54C030E9.8010404@emerytelcom.com>,
 <CAGGBd_rbL21MZEh+6PoUYoM-OS-Mpd=sUpSTPiTGhwqJSrqNMw@mail.gmail.com>
Message-ID: <1e1a7b4bdcf1408799b7f95b5d24851a@ETEXCH2.corp.emerytelcom.com>

How would I get a list of running processes with the subprocess module? The documentation wasn't clear to me.

On Jan 21, 2015 7:21 PM, Dan Stromberg <drsalists at gmail.com> wrote:
On Wed, Jan 21, 2015 at 3:06 PM, Jason Bailey <jbailey at emerytelcom.com> wrote:
> So I've got this python 3 script that needs to know if there is a running
> DHCP daemon (ISC DHCP server) on the local system. Is there a clean way to
> do this that (1) doesn't require me to do syscalls to local utilities (like
> ps, top, etc), and (2) doesn't require any custom modules (stock only)?

The subprocess module is quite clean on *ix.  Don't let the subprocess
mess on Windows steer you away from it on *ix.  And don't let the
"subprocesses are bad" from the perl community misguide you either -
shell is fast today because it's highly parallel, because it's
unafraid of subprocesses.

You could open the files under /proc and look around, if you're on
Linux. But parsing "ps -eo whatever" would probably be cleaner.

A "syscall" is an interaction with a kernel.  I think you meant an
os.system() call.

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From steve+comp.lang.python at pearwood.info  Wed Jan 21 23:30:57 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 22 Jan 2015 15:30:57 +1100
Subject: Python is DOOMED! Again!
Message-ID: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>

Occasionally you find people spreading Fear, Uncertainty, Doubt about 
Python. Python is now over 20 years old and one of the most popular 
languages in the world no matter how you measure popularity:

http://import-that.dreamwidth.org/1388.html

so you don't often get FUD these days. When you do, it's usually about 
whitespace, or "Python is too slow", or occasionally "Python 3 is killing 
Python", but the latest FUD is about PEP 484 and type-hinting:

https://www.python.org/dev/peps/pep-0484/

Here's a typical example:

    Python is already headed towards obscurity. ... it seems that 
    GvR intends to drive the final nail in python's coffin with 
    this "type hinting" crap that will convert Python syntax from 
    a readable pseudo code into a cryptic nightmare.

    Type hinting violates the very ESSENCE of what Python was
    meant to be, that is: a "clean and intuitive syntax". 


(Google for it if you care for the source.)

So what is this unspeakable, nightmarish, cryptic abomination going to look 
like? Here's an example from PEP 484:

def greeting(name: str) -> str:
    return 'Hello ' + name


I don't know about you, but I think anyone who cannot read that and intuit 
that argument `name` is a string and the return result is also a string is 
probably going to have bigger troubles with Python than just type-hinting.

Remember too that type-hinting will *absolutely* remain *completely* 
optional for Python. Developers can choose to use it or not, they can mix 
hinted code with regular unhinted code, they can use type declarations 
purely as documentation or they can run an optional type-checker, as they 
choose.

Here's a potential real-world example, from the statistics module in Python 
3.4, before and after adding annotations:

def median_grouped(data, interval=1): ...

def median_grouped(data:Iterable[Real], interval:Real=1)->Real: ...


I say "potential" because the standard library doesn't use annotations yet, 
but it may in the future. 

So how does Python's proposed type-hints compared to that used by other 
languages?

Java:

  public double median_grouped(List<Double> data, double interval) {}

Pascal:

  function median_grouped(data: IterableOfReal; interval: Real): Real;

C:

  double
  median_grouped (IterableOfReal data, double interval)

Haskell:

  median_grouped               :: [Double] Double -> Double
  median_grouped data interval =  ...


(I may have taken some very slight liberties with the syntax, corrections or 
more idiomatic forms are very welcome.)


I think it is clear that Python's annotation syntax remains quite close to 
executable pseudo-code. Fears that type-hints will doom Python are not 
credible.


-- 
Steve



From rosuav at gmail.com  Wed Jan 21 23:34:54 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 15:34:54 +1100
Subject: What killed Smalltalk could kill Python
In-Reply-To: <54c06d26$0$12915$c3e8da3$5496439d@news.astraweb.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
 <mailman.17933.1421884677.18130.python-list@python.org>
 <MPG.2f2a5e01b517d4db989682@nntp.aioe.org>
 <54c06d26$0$12915$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmo4jXci9t9uz59GpjAx48ihKN0_mtHyms1ZBmsSeF_VEQ@mail.gmail.com>

On Thu, Jan 22, 2015 at 2:23 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> What we need is more programmers with a passion for their job, and if that
> means learning to write games, then so be it. One of the problems with "9 to
> 5 code monkeys" is that programming is just a job for them. They do the
> absolute minimum they need to keep their job. They don't program for fun, or
> to learn new skills, or to solve problems. They go to user groups and forums
> like here only when they have a question they want answered, they take and
> take and take and they never give back.

Absolutely agree... as long as that passion results in solid
competence. Whether someone comes into programming because s/he wants
to write games, organize recipes, automate some specific task, or
prove some mathematical point, non-trivial programming nearly always
requires non-trivial effort. That's the same as any other skill (you
wouldn't expect to be able to build a car in a day, even if you've
been driving them for *ages* - like, say, two whole years - and have
this brilliant idea for how you could improve on every car on the
roads), but for some reason a lot of people think that computers
should be easy.

ChrisA


From steve+comp.lang.python at pearwood.info  Wed Jan 21 23:39:09 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 22 Jan 2015 15:39:09 +1100
Subject: How to "wow" someone new to Python
References: <mailman.17792.1421420646.18130.python-list@python.org>
 <bcb2d68705da8d203ccb1e735be@nntp.aioe.org>
Message-ID: <54c07eed$0$13012$c3e8da3$5496439d@news.astraweb.com>

Mario Figueiredo wrote:

> But speaking about impressing more experient programmers, I personally
> don't think Python has a wow factor in any of its features and syntax. At
> least in the way I understand the word "wow".

Quote:

    I've seen Python criticized as "ugly" precisely because it doesn't 
    have a trick-based view of the world. In many ways, it's a dull
    language, borrowing solid old concepts from many other languages &
    styles: boring syntax, unsurprising semantics, few automatic 
    coercions, etc etc. But that's one of the things I like about it.
    - Tim Peters




-- 
Steve



From rosuav at gmail.com  Wed Jan 21 23:39:48 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 15:39:48 +1100
Subject: Check for running DHCP daemon?
In-Reply-To: <1e1a7b4bdcf1408799b7f95b5d24851a@ETEXCH2.corp.emerytelcom.com>
References: <54C030E9.8010404@emerytelcom.com>
 <CAGGBd_rbL21MZEh+6PoUYoM-OS-Mpd=sUpSTPiTGhwqJSrqNMw@mail.gmail.com>
 <1e1a7b4bdcf1408799b7f95b5d24851a@ETEXCH2.corp.emerytelcom.com>
Message-ID: <CAPTjJmrpjdNBf4C79gj2BB5S4+QhtDz0_LPcrn2J8-gVUY4T6g@mail.gmail.com>

On Thu, Jan 22, 2015 at 2:58 PM, Jason Bailey <JBailey at emerytelcom.com> wrote:
> How would I get a list of running processes with the subprocess module? The
> documentation wasn't clear to me.

Using the ps command. :)

rosuav at dewey:~$ python3
Python 3.4.2 (default, Oct  8 2014, 10:45:20)
[GCC 4.9.1] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import subprocess
>>> b" dhcpd\n" in subprocess.check_output(["ps","-A"])
False

rosuav at sikorsky:~$ python3
Python 3.5.0a0 (default:4709290253e3, Jan 20 2015, 21:48:07)
[GCC 4.7.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import subprocess
>>> b" dhcpd\n" in subprocess.check_output(["ps","-A"])
True

There's a DHCP server running on Sikorsky, but not on Dewey. :)

Of course, this can be faked. Any process can call itself 'dhcpd' and
pretend to be the DHCP server. It's up to you to decide how to deal
with that. (Probably by not caring, I would expect. Unless you
actually expect someone to maliciously try to confuse your script,
it's not worth the hassle of protecting yourself.)

ChrisA


From rosuav at gmail.com  Wed Jan 21 23:43:04 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 15:43:04 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmoBG7YhBiDpAP3qrsF_fSB7NKg5c6yBYtnsTDVmbqUqng@mail.gmail.com>

On Thu, Jan 22, 2015 at 3:30 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> C:
>
>   double
>   median_grouped (IterableOfReal data, double interval)
>
>
> (I may have taken some very slight liberties with the syntax, corrections or
> more idiomatic forms are very welcome.)

C doesn't really have iterables, so this is more likely to be passed
in as an array of doubles and a length:

double median_grouped(double *data, int datasize, double interval)

> I think it is clear that Python's annotation syntax remains quite close to
> executable pseudo-code. Fears that type-hints will doom Python are not
> credible.

Yep. If Py3K didn't kill Python, PEP 393 didn't kill Python, and the
lack of Python 2.8 didn't kill Python, then type hinting doesn't have
much chance.

ChrisA


From emil at fuse.pl  Wed Jan 21 23:46:09 2015
From: emil at fuse.pl (Emil Oppeln-Bronikowski)
Date: Thu, 22 Jan 2015 05:46:09 +0100
Subject: What killed Smalltalk could kill Python
In-Reply-To: <CAPTjJmoAehP2v+bVjdmqCpahNfAqpXoJu4-NHp+N9KJ=y9CnNw@mail.gmail.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <spp5pb-0tt1.ln1@ozzie.tundraware.com>
 <CAPTjJmoAehP2v+bVjdmqCpahNfAqpXoJu4-NHp+N9KJ=y9CnNw@mail.gmail.com>
Message-ID: <20150122044609.GA1948@mikrus>

On Thu, Jan 22, 2015 at 10:55:27AM +1100, Chris Angelico wrote:

> Where's REXX today?

Still (somehow) alive in neo-Amiga platforms like AmigaOS4.x, MorphOS and AROS. I know that's as good as dead but there are still people writing AREXX glue code.

-- 
vag?a?bond adjective \?va-g?-?b?nd\
 a :? of, relating to, or characteristic of a wanderer 
 b :? leading an unsettled, irresponsible, or disreputable life



From steve+comp.lang.python at pearwood.info  Wed Jan 21 23:51:13 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 22 Jan 2015 15:51:13 +1100
Subject: How to "wow" someone new to Python
References: <mailman.17792.1421420646.18130.python-list@python.org>
 <82qvba51o427s4m63agk6ghekm0btg81on@4ax.com>
 <54bfedf5$0$2876$e4fe514c@news.xs4all.nl>
 <CAPTjJmrZ42_bVHiHy2pnGUOjkmuUCimkqSDDL7fmTg-u_vJxuQ@mail.gmail.com>
 <54C01802.7020202@case.edu>
 <mailman.17923.1421875592.18130.python-list@python.org>
 <w2dsif33j2k.fsf@scooby-doo.csail.mit.edu>
 <w2doapr3ipl.fsf@scooby-doo.csail.mit.edu>
Message-ID: <54c081c3$0$2761$c3e8da3$76491128@news.astraweb.com>

Alan Bawden wrote:

> Alan Bawden <alan at scooby-doo.csail.mit.edu> writes:
>> ...  Score one for untyped languages.
> 
> Drat.  I should have writted "dynamically typed languages".
> 
> The language has changed.  When I was a novice Lisp hacker, we were
> comfortable saying that Lisp was "untyped".  But nowadays we always say
> that Lisp is "dynamically typed".  I could write an essay about why...

I've always understood that strictly speaking, "untyped" refers to low-level 
languages like assembly or Forth, where everything is a machine word.

In Forth, for example, all commands operate on single words on the stack, 
except for "double" variants which operate on two words at a time. E.g. you 
might have FOO to operate on the word at the top of the stack and FOOD to 
operate on the top two words. (Actually, given Forth's reputation for 
cryptic single-character line noise, it would probably be '^ and ''^ or 
something :-) In any case, there's a single stack, and double quantities 
aren't a separate data type, they're just two words.

(Some versions of Forth are arguably typed, in that they have a separate 
stack for floating point.)

I sometimes also use "untyped" to refer to languages like Hypertalk where 
everything is a string.



-- 
Steve



From rustompmody at gmail.com  Thu Jan 22 00:17:02 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Wed, 21 Jan 2015 21:17:02 -0800 (PST)
Subject: Trees
In-Reply-To: <87egqnahwm.fsf@jester.gateway.sonic.net>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
 <MPG.2f28eb55d73ef68c989680@nntp.aioe.org>
 <ba69cad8-68c0-421e-af79-e381ca179015@googlegroups.com>
 <87iog0aonw.fsf@jester.gateway.sonic.net>
 <c30a53ac-8709-44a0-b1da-78ed6e447b11@googlegroups.com>
 <87egqnahwm.fsf@jester.gateway.sonic.net>
Message-ID: <0f832000-4057-4142-89e7-05f57c8a200d@googlegroups.com>

On Thursday, January 22, 2015 at 3:57:50 AM UTC+5:30, Paul Rubin wrote:
> Rustom Mody  writes:
> > Thats not bfs. That's inorder traversal
> 
> Oops, you're right.  How's this:
> 
> bfs x = go [x] where
>   go [] = []
>   go (L x:ts) = x:go ts
>   go (B x lst rst:ts) = x : go (ts ++ [lst, rst])
> 
> *Main> bfs t
> [6,2,8,1,4,7,9,3,5]

Yeah thats right.
And now you can get the duality between dfs and bfs you were earlier after by
replacing the 
ts ++ [lst,rst]
with
[lst,rst] ++ ts

BTW this is just converting queue to stack;
And its neat; and out of reach of those who think only imperatively

PS
1. Ive not tried it
2. For n-ary trees its neater
3. In my imaginary language with first-class sets, bags, lists it would be neater still


From rustompmody at gmail.com  Thu Jan 22 00:20:10 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Wed, 21 Jan 2015 21:20:10 -0800 (PST)
Subject: Trees
In-Reply-To: <mailman.17927.1421880891.18130.python-list@python.org>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
 <MPG.2f28eb55d73ef68c989680@nntp.aioe.org>
 <ba69cad8-68c0-421e-af79-e381ca179015@googlegroups.com>
 <mailman.17927.1421880891.18130.python-list@python.org>
Message-ID: <f15dfb47-d16e-49dd-b3b9-5905c9004a78@googlegroups.com>

On Thursday, January 22, 2015 at 4:25:03 AM UTC+5:30, Ian wrote:
> On Tue, Jan 20, 2015 at 6:23 PM, Rustom Mody wrote:
> > The Haskell is bullseye? in capturing the essense of a tree because
> > conceptually a tree of type t is recursive in the sense that it can contain
> > 2 subtrees -- (B x lst rst) -- or its a base case -- L x.
> 
> How do you create a tree containing an even number of elements under
> this constraint?

Not sure what you are asking...

[And a text only group makes discussing pictur-esque things hard]
What do you mean by 'element'?
Leaf? Internal? Either?


From no.email at nospam.invalid  Thu Jan 22 00:35:05 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Wed, 21 Jan 2015 21:35:05 -0800
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <87mw5b8jjq.fsf@jester.gateway.sonic.net>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:
> def median_grouped(data:Iterable[Real], interval:Real=1)->Real: ...

Wow, that's really nice.  I had heard something about Python type hints
but hadn't seen them before.

> So how does Python's proposed type-hints compared to that used by other 
> languages?

The most closely comparable hinting system I can think of is the Erlang
Dialyzer:

    -spec median_grouped(iterable(real())) -> real().
    median_grouped(Data, Interval) -> ... 

Some more info at: 

http://learnyousomeerlang.com/types-or-lack-thereof#for-type-junkies
http://learnyousomeerlang.com/dialyzer#plt


From tjreedy at udel.edu  Thu Jan 22 00:45:23 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Thu, 22 Jan 2015 00:45:23 -0500
Subject: What killed Smalltalk could kill Python
In-Reply-To: <MPG.2f2a5f9ab0001a82989683@nntp.aioe.org>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
 <MPG.2f2a5f9ab0001a82989683@nntp.aioe.org>
Message-ID: <m9q2pk$p83$1@ger.gmane.org>

On 1/21/2015 7:16 PM, Mario Figueiredo wrote:
> In article <873873ae91.fsf at jester.gateway.sonic.net>,
> no.email at nospam.invalid says...
>>
>> Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:
>>> In 2009, Robert Martin gave a talk at RailsConf titled "What Killed
>>> Smalltalk Could Kill Ruby"...  http://www.youtube.com/watch?v=YX3iRjKj7C0
>>
>> That's an hour-long video; could someone who's watched it give a brief
>> summary?
>>
>
> In a nutshell, he argues, along with Ward Cunningham, that what killed
> Smalltalk was how easy you could create unclean code with it. "Unclean"
> in this context means Smalltalk didn't punish bad software design
> decisions that would eventually lead into complex code and unmanageable
> systems with zero options of code maintenance.

He followed that by saying that fine-grained test-driven development is 
the way to prevent unholy messes.  He noted that tdd started in 
smalltalk, but never really took there.

Reason 2: arrogance -- the walled garden and disdain for the messy 
problems of real enterprises. He did not seem as sure about how to 
counteract this.

-- 
Terry Jan Reedy



From nicholas.cole at gmail.com  Thu Jan 22 00:50:52 2015
From: nicholas.cole at gmail.com (Nicholas Cole)
Date: Thu, 22 Jan 2015 05:50:52 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAAu18heVKeV8AC1djHtus2FF_c_WiK1TgMNWm8ekpjST7tRBHA@mail.gmail.com>

I don't think that Python is doomed. I *do* think that type-hinting is
useful, and Python has borrowed a syntax that is similar to that used in
other languages, so that it is a familiar one to many developers.

It is a stretch to call it intuitive though, either to write or to
read. Personally, I would have favoured a doc string solution. The magic
comments that are part of the current proposal are genuinely intuitive, I
think. The function definition syntax is something to be learned and which
it takes me a little time to process even though I'm getting used to it. I
find that it's still a slight effort to remember which way around the name
of the argument and the type go. I'm sure I've seen one language that does
the oppoosite, and the fraction of a second it takes me to remember is a
tiny friction. There's no doubt, too, that long function definitions
(Python functions tend to have lots of arguments in the real world) are
going to look cluttered, and cluttered by lots of magic punctuation.

So useful, yes. Familiar already to those who use other languages, yes.
Intuitive, no. And there is a linguistic reason for that:

Consider this:

Define function add taking price1, price2, print_error equals true.

Yes, Python wouldn't understand that, but turning it in to a valid
definition requires only a tiny amount of effort.

Type definitions add a whole level of complexity:

Define function add taking the float price1, the float price2, print_error
equals the Boolean true. Make the function return a float.

Converting that into python simply requires more effort: in other words the
gap between what one might say in speech and what the code looks like is
bigger.

The reason for this is that a lot of information is being compressed in to
a small space. In English writing it is usually clearer to avoid long and
complicated sentences with lots of subclauses (even if they make perfect,
logical sense) in favour of shorter ones, and I think there is a parallel
here.

I would have preferred Python to mimic:

Define function add taking price1, the price2, print_error equals true.
Price1 is a float. Price2 is a float. The function returns a float.

But now this is sounding a little like something from Larry Wall, and so I
had better stop!  I wasn't trying to re-litigate the decisions that have
been taken, just to understand the friction.

Just my ?0.2

Nicholas.
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From no.email at nospam.invalid  Thu Jan 22 00:56:11 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Wed, 21 Jan 2015 21:56:11 -0800
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <87mw5b8jjq.fsf@jester.gateway.sonic.net>
Message-ID: <877fwf8ikk.fsf@jester.gateway.sonic.net>

Paul Rubin <no.email at nospam.invalid> writes:
>     -spec median_grouped(iterable(real())) -> real().

Oops:

     -spec median_grouped(iterable(real()), real()) -> real().


From rosuav at gmail.com  Thu Jan 22 00:56:38 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 16:56:38 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <CAAu18heVKeV8AC1djHtus2FF_c_WiK1TgMNWm8ekpjST7tRBHA@mail.gmail.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <CAAu18heVKeV8AC1djHtus2FF_c_WiK1TgMNWm8ekpjST7tRBHA@mail.gmail.com>
Message-ID: <CAPTjJmpaRgxdy_mmB47TR1RsvDkfnZpZL=3mvMMYvSt6tc6OCQ@mail.gmail.com>

On Thu, Jan 22, 2015 at 4:50 PM, Nicholas Cole <nicholas.cole at gmail.com> wrote:
> I would have preferred Python to mimic:
>
> Define function add taking price1, the price2, print_error equals true.
> Price1 is a float. Price2 is a float. The function returns a float.
>
> But now this is sounding a little like something from Larry Wall, and so I
> had better stop!

Actually, it sounds like pre-ANSI C. Something like this:

float add(price1, price2)
float price1;
float price2;
{
    ... body of function ...
}

Compare the more modern C style:

float add(float price1, float price2)
{
    ... body of function ...
}

(I omitted print_error from both as I don't know how pre-ANSI C did
default arguments, if at all. It's possible in the modern version but
I want the comparison to be fair.)

ChrisA


From ethan at stoneleaf.us  Thu Jan 22 01:02:11 2015
From: ethan at stoneleaf.us (Ethan Furman)
Date: Wed, 21 Jan 2015 22:02:11 -0800
Subject: Python is DOOMED! Again!
In-Reply-To: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <54C09263.6060306@stoneleaf.us>

On 01/21/2015 08:30 PM, Steven D'Aprano wrote:
> 
> So what is this unspeakable, nightmarish, cryptic abomination going to look 
> like? Here's an example from PEP 484:
> 
> def greeting(name: str) -> str:
>     return 'Hello ' + name
> 
> 
> I don't know about you, but I think anyone who cannot read that and intuit 
> that argument `name` is a string and the return result is also a string

There is nothing inherently intuitive about that syntax.  The : makes it look like a dictionary (but it isn't) and the
-> looks like a pointer to something (but it isn't).

> is probably going to have bigger troubles with Python than just type-hinting.

Yup, true -- I do find writing meta-classes takes extra work.  ;)

--
~Ethan~


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From breamoreboy at yahoo.co.uk  Thu Jan 22 01:12:18 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 22 Jan 2015 06:12:18 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <87mw5b8jjq.fsf@jester.gateway.sonic.net>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <87mw5b8jjq.fsf@jester.gateway.sonic.net>
Message-ID: <m9q4c8$eej$1@ger.gmane.org>

On 22/01/2015 05:35, Paul Rubin wrote:
> Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:
>> def median_grouped(data:Iterable[Real], interval:Real=1)->Real: ...
>
> Wow, that's really nice.  I had heard something about Python type hints
> but hadn't seen them before.
>

Currently flying here http://code.activestate.com/lists/python-ideas/30922/

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From breamoreboy at yahoo.co.uk  Thu Jan 22 01:22:30 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 22 Jan 2015 06:22:30 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <CAPTjJmpaRgxdy_mmB47TR1RsvDkfnZpZL=3mvMMYvSt6tc6OCQ@mail.gmail.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <CAAu18heVKeV8AC1djHtus2FF_c_WiK1TgMNWm8ekpjST7tRBHA@mail.gmail.com>
 <CAPTjJmpaRgxdy_mmB47TR1RsvDkfnZpZL=3mvMMYvSt6tc6OCQ@mail.gmail.com>
Message-ID: <m9q4vc$obk$1@ger.gmane.org>

On 22/01/2015 05:56, Chris Angelico wrote:
> On Thu, Jan 22, 2015 at 4:50 PM, Nicholas Cole <nicholas.cole at gmail.com> wrote:
>> I would have preferred Python to mimic:
>>
>> Define function add taking price1, the price2, print_error equals true.
>> Price1 is a float. Price2 is a float. The function returns a float.
>>
>> But now this is sounding a little like something from Larry Wall, and so I
>> had better stop!
>
> Actually, it sounds like pre-ANSI C.
>

*SCREAMS OUT LOUD* at the thought of the Whitesmith's compiler where 
IIRC printf was spelt format and the formatting codes weren't the same.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rantingrickjohnson at gmail.com  Thu Jan 22 01:25:00 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Wed, 21 Jan 2015 22:25:00 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <3fbbc664-ab4b-46e1-98a8-3859cb84fbb0@googlegroups.com>

On Wednesday, January 21, 2015 at 10:31:12 PM UTC-6, Steven D'Aprano wrote:
> Occasionally you find people spreading Fear, Uncertainty, Doubt about 
> Python. Python is now over 20 years old and one of the most popular 
> languages in the world no matter how you measure popularity:

What's next, are you going to drool over the TIOBE index
again? I can't help but giggle when folks put faith in crap
like that. You wanna know why python-list gets so much spam?
Because "Guido-bot" is attempting to improve Python's TIOBE
rating.

> so you don't often get FUD these days. When you do, it's
> usually about whitespace, or "Python is too slow", or
> occasionally "Python 3 is killing Python", but the latest
> FUD is about PEP 484 and type-hinting:

Yeah because people *NEVER* complain when they have *REAL*
problems, do they "Mr DeWaldo"?

> So what is this unspeakable, nightmarish, cryptic
> abomination going to look like? Here's an example from PEP
> 484:
> 
> def greeting(name: str) -> str:
>     return 'Hello ' + name
> 
> I don't know about you, but I think anyone who cannot read
> that and intuit that argument `name` is a string and the
> return result is also a string is probably going to have
> bigger troubles with Python than just type-hinting.
> 
> Remember too that type-hinting will *absolutely* remain
> *completely* optional for Python. Developers can choose to
> use it or not, 

But they cannot choose whether to *READ* it or not. Once
it's out there, it's out there, and everyone who has to
maintain code or read tutorials will have to suffer reading
noise they did not choose to write. This is not a "self-
inflicted" wound Steven, this is "assault with a noisy weapon"!

> they can mix hinted code with regular unhinted code, they
> can use type declarations purely as documentation or they
> can run an optional type-checker, as they choose.

The only thing worse than a bad idea is an inconsistent bad idea!

> Here's a potential real-world example, from the statistics
> module in Python 3.4, before and after adding annotations:

> 
> def median_grouped(data, interval=1): ...
> 
> def median_grouped(data:Iterable[Real], interval:Real=1)->Real: ...

Nice! I like how the first "toy example" was less noisy,
and then way down here you show us the real butt-uglyness of
this "feature from hell"!

> I think it is clear that Python's annotation syntax
> remains quite close to executable pseudo-code. 

Sure, for some perverted definition of "quite" and "close"!

> Fears that type-hints will doom Python are not credible.

Listen, there is a way that type hints can be introduced
*WITHOUT* forcing folks who don't care about them to read
them. If Mr Van Rossom would like my assistance, tell him to
send me a private email or ask me in this thread. 

However, if he refuses and continues down this "road to
perdition", i will be unable to help him save the Python
language, and all his work will have been for nothing. 

For the sake of this community and the many noobs who have
not found programming bliss via Python, i implore you to do
everything in your power to convince GvR that he is making a
grave mistake, for which no recovery will be possible.


From breamoreboy at yahoo.co.uk  Thu Jan 22 01:30:49 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 22 Jan 2015 06:30:49 +0000
Subject: What killed Smalltalk could kill Python
In-Reply-To: <5f6034ce-fbb0-4257-b876-858e6e35e8ce@googlegroups.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <5f6034ce-fbb0-4257-b876-858e6e35e8ce@googlegroups.com>
Message-ID: <m9q5ev$vp4$1@ger.gmane.org>

On 22/01/2015 02:11, Rick Johnson wrote:
> On Wednesday, January 21, 2015 at 10:34:40 AM UTC-6, Steven D'Aprano wrote:
>> In 2009, Robert Martin gave a talk at RailsConf titled
>> "What Killed Smalltalk Could Kill Ruby". (No cheering,
>> that sort of attitude is one of the things that killed
>> Smalltalk.) Although Martin discusses Ruby, the lessons
>> could also apply to Python.
>
> Python is already headed towards obscurity. The fall began
> with the release of Python3000 (from which we "might" have
> recovered), but now it seems that GvR intends to drive the
> final nail in python's coffin with this "type hinting" crap
> that will convert Python syntax from a readable pseudo code
> into a cryptic nightmare.
>
> Type hinting violates the very *ESSENCE* of what Python was
> meant to be, that is: a "clean and intuitive syntax". The
> cleanness of Python is what attracts people to it, and the
> hook is set when they discover the breadth of the stdlib.
>
> If GvR brings this gawd awful type hinting idea to reality,
> IT'S OVER! Python will be lost forever to history as just
> another "interesting oddity". Time to call up the Robert
> Ripley estate and request some space in his museum!
>

April 1st already?

Or will Python be saved by RickedPython3?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From no.email at nospam.invalid  Thu Jan 22 01:48:33 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Wed, 21 Jan 2015 22:48:33 -0800
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <3fbbc664-ab4b-46e1-98a8-3859cb84fbb0@googlegroups.com>
Message-ID: <8738738g5a.fsf@jester.gateway.sonic.net>

Rick Johnson <rantingrickjohnson at gmail.com> writes:
>> def median_grouped(data:Iterable[Real], interval:Real=1)->Real: ...
>
> Nice! I like how the first "toy example" was less noisy,
> and then way down here you show us the real butt-uglyness of
> this "feature from hell"!

It looks fine to me.  I'm still using Python 2.7 because I haven't found
a really compelling reason to migrate to Python 3, but this makes it
start looking worthwhile.

> Listen, there is a way that type hints can be introduced *WITHOUT*
> forcing folks who don't care about them to read them. 

You could write some IDE features to suppress visibility of the hints.
Or maybe it could be done with a decorator-like construct:

  @-spec(Iterable[Real], Real) -> Real

> For the sake of this community and the many noobs who have not found
> programming bliss via Python, i implore you to do everything in your
> power to convince GvR that he is making a grave mistake, for which no
> recovery will be possible.

I've always found Python 3 annoying because it broke compatibility with
Python 2, but only by a little bit, not enough to add real benefits.
This is a real benefit so IMHO it makes the language more attractive
rather than less.


From ian.g.kelly at gmail.com  Thu Jan 22 01:56:03 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 21 Jan 2015 23:56:03 -0700
Subject: Trees
In-Reply-To: <f15dfb47-d16e-49dd-b3b9-5905c9004a78@googlegroups.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
 <MPG.2f28eb55d73ef68c989680@nntp.aioe.org>
 <ba69cad8-68c0-421e-af79-e381ca179015@googlegroups.com>
 <mailman.17927.1421880891.18130.python-list@python.org>
 <f15dfb47-d16e-49dd-b3b9-5905c9004a78@googlegroups.com>
Message-ID: <CALwzid=pV4BzCkdMxy=0FpfBYep5qTEQx5A8MxhWGVi7aLN_6g@mail.gmail.com>

On Wed, Jan 21, 2015 at 10:20 PM, Rustom Mody <rustompmody at gmail.com> wrote:
> On Thursday, January 22, 2015 at 4:25:03 AM UTC+5:30, Ian wrote:
>> On Tue, Jan 20, 2015 at 6:23 PM, Rustom Mody wrote:
>> > The Haskell is bullseye? in capturing the essense of a tree because
>> > conceptually a tree of type t is recursive in the sense that it can contain
>> > 2 subtrees -- (B x lst rst) -- or its a base case -- L x.
>>
>> How do you create a tree containing an even number of elements under
>> this constraint?
>
> Not sure what you are asking...
>
> [And a text only group makes discussing pictur-esque things hard]
> What do you mean by 'element'?
> Leaf? Internal? Either?

By "element" I mean an individual datum contained in the tree.
Likewise the elements of a list are its contents.

Since each element is associated with a node, the question could
equally be phrased as "How do you create a tree containing an even
number of elements under this constraint?" The point I was driving at
is that the definition is incomplete -- in addition to being an
internal node or a leaf, a tree can also be empty. In fact I would
suggest that an empty tree should be the real base case, since what is
a leaf node but a node where both of its children are empty trees?


From ian.g.kelly at gmail.com  Thu Jan 22 02:01:25 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 22 Jan 2015 00:01:25 -0700
Subject: Trees
In-Reply-To: <CALwzid=pV4BzCkdMxy=0FpfBYep5qTEQx5A8MxhWGVi7aLN_6g@mail.gmail.com>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
 <MPG.2f28eb55d73ef68c989680@nntp.aioe.org>
 <ba69cad8-68c0-421e-af79-e381ca179015@googlegroups.com>
 <mailman.17927.1421880891.18130.python-list@python.org>
 <f15dfb47-d16e-49dd-b3b9-5905c9004a78@googlegroups.com>
 <CALwzid=pV4BzCkdMxy=0FpfBYep5qTEQx5A8MxhWGVi7aLN_6g@mail.gmail.com>
Message-ID: <CALwzidk4KR0DT3WNrtEPuJf5H08-KkbXa1C9P=CKuP2at6MsAQ@mail.gmail.com>

On Wed, Jan 21, 2015 at 11:56 PM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> Since each element is associated with a node, the question could
> equally be phrased as "How do you create a tree containing an even
> number of elements under this constraint?"

Of course I meant to write "nodes" there, not "elements".


From no.email at nospam.invalid  Thu Jan 22 02:16:11 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Wed, 21 Jan 2015 23:16:11 -0800
Subject: Trees
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
 <MPG.2f28eb55d73ef68c989680@nntp.aioe.org>
 <ba69cad8-68c0-421e-af79-e381ca179015@googlegroups.com>
 <mailman.17927.1421880891.18130.python-list@python.org>
Message-ID: <87y4ov70as.fsf@jester.gateway.sonic.net>

Ian Kelly <ian.g.kelly at gmail.com> writes:
> How do you create a tree containing an even number of elements under
> this constraint?

That's a good point, I've usually seen different definitions of trees,
e.g.

   data Tree a = Leaf | Branch a (Tree a) (Tree a)

so a Leaf node doesn't have a value associated with it.

  https://en.wikipedia.org/wiki/File:Red-black_tree_example.svg

has a picture of such a tree--don't worry about the node coloring for
this purpose.  Or the multi-way tree with arbitrary branching width:

   data RoseTree a = RoseTree a [RoseTree a]

Each node has a value and a list of zero or more subtrees.


From steve+comp.lang.python at pearwood.info  Thu Jan 22 02:23:25 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 22 Jan 2015 18:23:25 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
Message-ID: <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>

Ethan Furman wrote:

> On 01/21/2015 08:30 PM, Steven D'Aprano wrote:
>> 
>> So what is this unspeakable, nightmarish, cryptic abomination going to
>> look like? Here's an example from PEP 484:
>> 
>> def greeting(name: str) -> str:
>>     return 'Hello ' + name
>> 
>> 
>> I don't know about you, but I think anyone who cannot read that and
>> intuit that argument `name` is a string and the return result is also a
>> string
> 
> There is nothing inherently intuitive about that syntax.  

Strictly speaking, you are correct: the only truly intuitive interface is 
the nipple. Nevertheless, we often informally describe something as 
"intuitive" when we mean the meaning can be guessed or derived from context.


> The : makes it
> look like a dictionary (but it isn't) and the -> looks like a pointer to
> something (but it isn't).

I think you're over-thinking it from the perspective of a programmer with 
lots of experience. Think of it as pseudo-code seen from the perspective of 
somebody who doesn't know about dicts and pointers.

Arrows are common symbols for directions, flow of time, and results:

    Work hard --> Save $$$ --> Buy a new car!!!

It's not hard to jump to the conclusion that -> introduces the return 
result.

As for colons, don't think of "dict", think of "mapping". Colons in this 
case map argument name to argument type.

The point isn't that there are no other alternative interpretations 
possible, or that annotations are the only syntax imaginable, but that 
they're not hard to guess what they mean, and if you can't guess, they're 
not hard to learn and remember.


-- 
Steve



From nicholas.cole at gmail.com  Thu Jan 22 02:40:28 2015
From: nicholas.cole at gmail.com (Nicholas Cole)
Date: Thu, 22 Jan 2015 07:40:28 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <CAPTjJmpaRgxdy_mmB47TR1RsvDkfnZpZL=3mvMMYvSt6tc6OCQ@mail.gmail.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <CAAu18heVKeV8AC1djHtus2FF_c_WiK1TgMNWm8ekpjST7tRBHA@mail.gmail.com>
 <CAPTjJmpaRgxdy_mmB47TR1RsvDkfnZpZL=3mvMMYvSt6tc6OCQ@mail.gmail.com>
Message-ID: <CAAu18hfDGYkr-9O8kqCrZGmarUSEDRYcusGnJjFYQLiMH6prhQ@mail.gmail.com>

On Thu, Jan 22, 2015 at 5:56 AM, Chris Angelico <rosuav at gmail.com> wrote:
> On Thu, Jan 22, 2015 at 4:50 PM, Nicholas Cole <nicholas.cole at gmail.com> wrote:
>> I would have preferred Python to mimic:
>>
>> Define function add taking price1, the price2, print_error equals true.
>> Price1 is a float. Price2 is a float. The function returns a float.
>>
>> But now this is sounding a little like something from Larry Wall, and so I
>> had better stop!
>
> Actually, it sounds like pre-ANSI C. Something like this:
>
> float add(price1, price2)
> float price1;
> float price2;
> {
>     ... body of function ...
> }
>
> Compare the more modern C style:

I hadn't thought of that, but yes, you are quite right right.  I think
my point stands. I've ever programmed anything serious in any kind of
C, but the pre-ANSI C style is instantly readable to me (except maybe
that I had to look three times to find the return signature because my
eye glossed over the float at the start.

Far more intuitive than what is being proposed^W^W is part of Python 3. :-)


From ermanolillo at hotmail.com  Thu Jan 22 03:00:49 2015
From: ermanolillo at hotmail.com (ermanolillo)
Date: Thu, 22 Jan 2015 00:00:49 -0800 (PST)
Subject: Socket ICMP V6 error
Message-ID: <1421913649039-5083962.post@n6.nabble.com>



I've made a snniferr for a ICMP socket that works with IPv4. This is the
code:
	

import sys
import socket
import struct
import select
import time
import signal
import re

HOST = raw_input("Enter the interface to listen: ")

s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_ICMP)
s.bind((HOST, 0))
s.setsockopt(socket.IPPROTO_IP, socket.IP_HDRINCL, 1)

print "Server Started......"
for i in range(1,2000):

data = s.recvfrom(65565)
d1 = str(data[0])
data1 = re.search('@@(.*)', d1)

command = data1.group(0)
cmd = command[2:]
if i%2 == 0:
d = data[1]
d1 = str(d)
ip = d1[2:-5]

print cmd 
print ip

I have done a modification to adapt it to IPv6:

	

s = socket.socket(socket.AF_INET6, socket.SOCK_RAW, socket.IPPROTO_ICMPV6)

However I recive the next error:

	

File "server.py", line 16, in <module>
s.bind((HOST, 0))
File "/usr/lib/python2.7/socket.py", line 224, in meth
return getattr(self._sock,name)(*args)
socket.error: [Errno 22] Invalid argument

Could someone please help me?.

Thanks in advance



--
View this message in context: http://python.6.x6.nabble.com/Socket-ICMP-V6-error-tp5083962.html
Sent from the Python - python-list mailing list archive at Nabble.com.


From marfig at gmail.com  Thu Jan 22 03:10:34 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Thu, 22 Jan 2015 09:10:34 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <MPG.2f2aced5243efbfb989684@nntp.aioe.org>

In article <54c0a571$0$13002$c3e8da3$5496439d at news.astraweb.com>, 
steve+comp.lang.python at pearwood.info says...
> 
> The point isn't that there are no other alternative interpretations 
> possible, or that annotations are the only syntax imaginable, but that 
> they're not hard to guess what they mean, and if you can't guess, they're 
> not hard to learn and remember.

Possibly one common use case will be Unions. And that factory syntax is 
really awful and long when you look at a function definition with as 
little as 3 arguments. The one below has only 2 arguments.

def handle_employees(emp: Union[Employee, Sequence[Employee]], raise: 
Union[float, Sequence[float]]) -> Union[Employee, Sequence[Employee], 
None]:

That's for a generic list-like container. Have fun with the Mapping 
union.

Meanwhile there's quite a few more generics like the Sequence one above 
you may want to take a look at and try and remember. And that's just one 
factory (the generics support factory). You may also want to take a look 
at TypeVar and Callable for more syntactic hell.
 
Meanwhile, there's the strange decision to implement type hints for 
local variables # comment lines. I have an hard time wrapping my head 
around this one. Really, comments!?

Finally, remember all this is being added to your code just to 
facilitate static analysis. Strangely enough though I was taught from 
the early beginning that once I start to care about types in Python, I 
strayed from the pythonic way. I'm confused now... What is it then?


From fan.ding1 at kodak.com  Thu Jan 22 03:15:59 2015
From: fan.ding1 at kodak.com (fan.ding1 at kodak.com)
Date: Thu, 22 Jan 2015 16:15:59 +0800
Subject: python client call Java server by xmlrpc
Message-ID: <OF59D4DFCB.6AA85FAB-ON48257DD5.002C7812-48257DD5.002D68BE@knotes.kodak.com>

Hi all

I have xmlrpc server written in Java, and it has a method like

Fun( vector, vector), the vector is array of user-defined object, which is 
a class  extends HashMap.

And I call it like:

server = xmlrpclib.ServerProxy("http://myserver")

server.Fun( [ {"0.5":0.1}], [ ] )

It always fails with error

'No method matching arguments: , [Ljava.lang.Object;, [Ljava.lang.Object; 
'


Does anyone use this before? It troubles me some days.

Thanks a  lot.

Diana
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From rantingrickjohnson at gmail.com  Thu Jan 22 03:24:46 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 22 Jan 2015 00:24:46 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <8738738g5a.fsf@jester.gateway.sonic.net>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <3fbbc664-ab4b-46e1-98a8-3859cb84fbb0@googlegroups.com>
 <8738738g5a.fsf@jester.gateway.sonic.net>
Message-ID: <2d7880a5-9c2d-4a04-81f0-aa1e1d493e1a@googlegroups.com>

On Thursday, January 22, 2015 at 12:48:46 AM UTC-6, Paul Rubin wrote:
> Sir Richard Johnson writes:
> You could write some IDE features to suppress visibility
> of the hints. Or maybe it could be done with a decorator-
> like construct:
> 
>   @-spec(Iterable[Real], Real) -> Real

Yes, YES, *YES*!!!! That would be my first choice, or 
docstrings as a secondary. But to introduce new syntax 
into the method signatures is SUICIDE! What the hell is
this man thinking?

> > For the sake of this community and the many noobs who
> > have not found programming bliss via Python, i implore
> > you to do everything in your power to convince GvR that
> > he is making a grave mistake, for which no recovery will
> > be possible.
> 
> I've always found Python 3 annoying because it broke
> compatibility with Python 2, but only by a little bit, not
> enough to add real benefits. This is a real benefit so
> IMHO it makes the language more attractive rather than
> less.

Agreed. I'm not against the idea, heck, i want to see Python
improve just like anybody who loves this language, but the
implementation just plain sucks! Please convince GvR to move
this noisy syntax OUTSIDE of the signature! It's too noisy 
and its going to turn people off.


From breamoreboy at yahoo.co.uk  Thu Jan 22 03:40:47 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 22 Jan 2015 08:40:47 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <2d7880a5-9c2d-4a04-81f0-aa1e1d493e1a@googlegroups.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <3fbbc664-ab4b-46e1-98a8-3859cb84fbb0@googlegroups.com>
 <8738738g5a.fsf@jester.gateway.sonic.net>
 <2d7880a5-9c2d-4a04-81f0-aa1e1d493e1a@googlegroups.com>
Message-ID: <m9qd2m$lme$1@ger.gmane.org>

On 22/01/2015 08:24, Rick Johnson wrote:
>
> Yes, YES, *YES*!!!! That would be my first choice, or
> docstrings as a secondary. But to introduce new syntax
> into the method signatures is SUICIDE! What the hell is
> this man thinking?

I take it you mean these men Guido van Rossum <guido at python.org>, 
Jukka Lehtosalo <jukka.lehtosalo at iki.fi>, ?ukasz Langa <lukasz at 
langa.pl> as they are the authors of PEP484?

>
> Agreed. I'm not against the idea, heck, i want to see Python
> improve just like anybody who loves this language, but the
> implementation just plain sucks! Please convince GvR to move
> this noisy syntax OUTSIDE of the signature! It's too noisy
> and its going to turn people off.
>

What implementation?  The PEP is quite clearly marked as draft.  The 
Re-enactment of the Battle of Pearl Harbour is currently ongoing over on 
python-ideas regarding exactly what should be implemented.  There is 
also nothing to stop you writing another PEP with an alternative 
proposal, although I suspect there is as much chance of that ever 
happening as there is of ever seeing RickedPython(3).

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rantingrickjohnson at gmail.com  Thu Jan 22 03:42:09 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 22 Jan 2015 00:42:09 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <b631cc7a-2f2a-4269-9a0d-7228103f1852@googlegroups.com>

On Thursday, January 22, 2015 at 1:23:40 AM UTC-6, Steven D'Aprano wrote:

> The point isn't that there are no other alternative
> interpretations possible, or that annotations are the only
> syntax imaginable, but that they're not hard to guess what
> they mean, and if you can't guess, they're not hard to
> learn and remember.

That's highly subjective. Could you please stop licking
Guido's boots long enough to take a whiff of what the hell
you're shoveling? Is being teachers pet so important that
you're willing to turn off a vast majority of new Python
programmers? How much longer can this hemorrhaging go on
Steven?

Python is the only thing that is pure in the programming
world. The only language that offers the cleanest and most
intuit-able syntax, AND YOU"RE JUST GOING TO THROW IT ALL
AWAY SO YOU CAN BE A LAPDOG OF SATAN?

Everybody better listen up, and you'd better listen up good
folks. Because we've only got a short time to act before
this monstrosity is enacted. You need send Guido emails (and
lots of them) and tell him how destructive this is going to
be to our community. Stop being cowards, it's time to put
the big boy pants on. 

If you don't act now, then don't bother complaining later.
Python is dangling by a thin thread, and this is your last
chance to save everything we've worked for. All the lines of
code we've written won't mean spit if the language takes a
swan dive into obscurity!



From breamoreboy at yahoo.co.uk  Thu Jan 22 04:06:31 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 22 Jan 2015 09:06:31 +0000
Subject: An improper change in httplib.py
In-Reply-To: <CAO0APJQtPjRQvisLSn1T2No402rDR8NPTD6sjMHjQPt6ihKWBw@mail.gmail.com>
References: <CAO0APJQtPjRQvisLSn1T2No402rDR8NPTD6sjMHjQPt6ihKWBw@mail.gmail.com>
Message-ID: <m9qeit$en8$1@ger.gmane.org>

On 22/01/2015 03:38, Guohua Ouyang wrote:
> This is my first post to the list, I apologies firstly if I made any mistake.
>
> I was trying to get a package in golang behind the http or https
> proxy, and it reports  an error "AttributeError: httpsconnection
> instance has no attribute '_set_hostport'", details in the bottom.
> After some trace work, I found it caused by the changes in the issue issue7776.
>
> @@ -718,7 +734,7 @@
>           else:
>               self._tunnel_headers.clear()
>
> -    def _set_hostport(self, host, port):
> +    def _get_hostport(self, host, port):
>
> First, it changes the method's name, doesn't it break the
> compatibility for other packages, on my system,
> mercurial-3.0-2.fc21.x86_64 still use "_set_hostport" as the error
> shows.
>
> Second, I found that line 1132 of [2] still use "
> self._conn._set_hostport(host, port)", which should be
> "_get_hostport", right?
>
> [1] http://bugs.python.org/issue7776
> [2] https://github.com/python/cpython/blob/2.7/Lib/httplib.py

You've found a bug so please raise it on bugs.python.org :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From breamoreboy at yahoo.co.uk  Thu Jan 22 04:10:57 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 22 Jan 2015 09:10:57 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <m9qer7$j07$1@ger.gmane.org>

On 22/01/2015 04:30, Steven D'Aprano wrote:
> Occasionally you find people spreading Fear, Uncertainty, Doubt about
> Python. Python is now over 20 years old and one of the most popular
> languages in the world no matter how you measure popularity:
>
> http://import-that.dreamwidth.org/1388.html
>
> so you don't often get FUD these days. When you do, it's usually about
> whitespace, or "Python is too slow", or occasionally "Python 3 is killing
> Python", but the latest FUD is about PEP 484 and type-hinting:
>
> https://www.python.org/dev/peps/pep-0484/
>
> Here's a typical example:
>
>      Python is already headed towards obscurity. ... it seems that
>      GvR intends to drive the final nail in python's coffin with
>      this "type hinting" crap that will convert Python syntax from
>      a readable pseudo code into a cryptic nightmare.
>
>      Type hinting violates the very ESSENCE of what Python was
>      meant to be, that is: a "clean and intuitive syntax".
>
>
> (Google for it if you care for the source.)
>

So it's doomed again, big deal, it's the third time this week and the 
dustmen simply won't take it.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From nicholas.cole at gmail.com  Thu Jan 22 04:37:34 2015
From: nicholas.cole at gmail.com (Nicholas Cole)
Date: Thu, 22 Jan 2015 09:37:34 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
Message-ID: <CAAu18hd9t4O22xZs8huoUBQEqbpQFxu_h15SoC036FwzdYySpA@mail.gmail.com>

On Thu, Jan 22, 2015 at 8:10 AM, Mario Figueiredo <marfig at gmail.com> wrote:
> In article <54c0a571$0$13002$c3e8da3$5496439d at news.astraweb.com>,
> steve+comp.lang.python at pearwood.info says...
>>
>> The point isn't that there are no other alternative interpretations
>> possible, or that annotations are the only syntax imaginable, but that
>> they're not hard to guess what they mean, and if you can't guess, they're
>> not hard to learn and remember.
>
> Possibly one common use case will be Unions. And that factory syntax is
> really awful and long when you look at a function definition with as
> little as 3 arguments. The one below has only 2 arguments.
>
> def handle_employees(emp: Union[Employee, Sequence[Employee]], raise:
> Union[float, Sequence[float]]) -> Union[Employee, Sequence[Employee],
> None]:
>
> That's for a generic list-like container. Have fun with the Mapping
> union.

To be fair, is it clearer with some kind of formatting?

def handle_employees(
emp: Union[Employee, Sequence[Employee]],
raise: Union[float, Sequence[float]])
-> Union[Employee, Sequence[Employee], None]:

I still find that hard to read, but the line breaks help.  Just for
fun, I'd like to put out that without all of that noise the function
reads:

def handle_employees(employees, raise):
    .....
    return employees

And suddenly it looks like what most people who know anything about
programming recognise as Python again! With some kind of doc-string or
similar syntax it would read something like:

def handle_employees(employees, rasie):
    # employees: Union[Employee, Sequence[Employee]]
    # raise:  Union[float, Sequence[float]]
    # return: Union[Employee, Sequence[Employee], None]
    .....
    return employeees

There's a reasonable case that this is not all that dissimilar from
the function annotation syntax above, but the difference is surely
that in the one case you see immediately that there are two arguments,
and in the other you can't be sure without parsing some very cluttered
punctuation-heavy syntax.

Still, it would have been nicer to be able to write something like
this (where the Unions are implicit):

def handle_employees(employees, rasie):
    # employees: Employee, Sequence[Employee]
    # raise:  float, Sequence[float]
    # return: Employee, Sequence[Employee], None


Yes, I know that function annotations have been defined for a while,
and yes, I know that they are similar to a syntax used in other
languages, and yes, I know that they are optional.  All the same,
either they are going to become the norm or they are not. If they
become the norm (as I think they will because type hinting seems to
solve many problems that the community cares about) then I think we
have to accept that an important part of the language will become much
more cluttered, much less intuitive, and much more off-putting to
many.

I think the fact that the current proposals mix the annotation syntax
with an inline comment syntax is also horrible (though I don't see any
alternatives).  I would much rather have put all of the "magic" in to
comments or none.

N.


From marko at pacujo.net  Thu Jan 22 05:05:24 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 22 Jan 2015 12:05:24 +0200
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <b631cc7a-2f2a-4269-9a0d-7228103f1852@googlegroups.com>
Message-ID: <87h9vj6sgr.fsf@elektro.pacujo.net>

Rick Johnson <rantingrickjohnson at gmail.com>:

> Python is the only thing that is pure in the programming world. The
> only language that offers the cleanest and most intuit-able syntax,
> AND YOU"RE JUST GOING TO THROW IT ALL AWAY SO YOU CAN BE A LAPDOG OF
> SATAN?

I think the SATAN is in the optional type declarations, not in the
particular syntax chosen.


Marko


From rosuav at gmail.com  Thu Jan 22 05:09:19 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 21:09:19 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
Message-ID: <CAPTjJmrDNC=ESm5Vj4sOYdffb=UChzt2GmX5DxvpaBffHSzwMg@mail.gmail.com>

On Thu, Jan 22, 2015 at 7:10 PM, Mario Figueiredo <marfig at gmail.com> wrote:
> Possibly one common use case will be Unions. And that factory syntax is
> really awful and long when you look at a function definition with as
> little as 3 arguments. The one below has only 2 arguments.
>
> def handle_employees(emp: Union[Employee, Sequence[Employee]], raise:
> Union[float, Sequence[float]]) -> Union[Employee, Sequence[Employee],
> None]:

Hold on a moment, how often do you really do this kind of thing with
"might be one of them or a sequence"? Do you really have a function
that could take an Employee and a float, or a sequence of Employees
and a single float, or a single Employee and a sequence of floats, or
a sequence of both? Or do you, much more likely, actually have two
separate functions:

def handle_employee(emp: Employee, raise: float) -> Optional[Employee]:

def handle_employees(emp: Sequence[Employee], raise: Sequence[float])
-> List[Employee]:

The union in the return value seems particularly unlikely... and unhelpful.

ChrisA


From rosuav at gmail.com  Thu Jan 22 05:13:03 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 21:13:03 +1100
Subject: Socket ICMP V6 error
In-Reply-To: <1421913649039-5083962.post@n6.nabble.com>
References: <1421913649039-5083962.post@n6.nabble.com>
Message-ID: <CAPTjJmoC=MCzCGU0+d=T1HnjSpEooWYGzuofxC6w1Ado1rzSbw@mail.gmail.com>

On Thu, Jan 22, 2015 at 7:00 PM, ermanolillo <ermanolillo at hotmail.com> wrote:
> s = socket.socket(socket.AF_INET6, socket.SOCK_RAW, socket.IPPROTO_ICMPV6)
>
> However I recive the next error:
>
>
>
> File "server.py", line 16, in <module>
> s.bind((HOST, 0))
> File "/usr/lib/python2.7/socket.py", line 224, in meth
> return getattr(self._sock,name)(*args)
> socket.error: [Errno 22] Invalid argument
>
> Could someone please help me?.
>

For a start, what HOST are you using?

(Point of style: It's unusual to use an all-uppercase name like HOST
for something non-constant - in this case, it's coming from keyboard
input.)

ChrisA


From rosuav at gmail.com  Thu Jan 22 05:13:37 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 21:13:37 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <87h9vj6sgr.fsf@elektro.pacujo.net>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <b631cc7a-2f2a-4269-9a0d-7228103f1852@googlegroups.com>
 <87h9vj6sgr.fsf@elektro.pacujo.net>
Message-ID: <CAPTjJmrcWTatHqAvhQLdTmeqdW-XUSTd5PTbP8a7CYG3cuGd1A@mail.gmail.com>

On Thu, Jan 22, 2015 at 9:05 PM, Marko Rauhamaa <marko at pacujo.net> wrote:
> Rick Johnson <rantingrickjohnson at gmail.com>:
>
>> Python is the only thing that is pure in the programming world. The
>> only language that offers the cleanest and most intuit-able syntax,
>> AND YOU"RE JUST GOING TO THROW IT ALL AWAY SO YOU CAN BE A LAPDOG OF
>> SATAN?
>
> I think the SATAN is in the optional type declarations, not in the
> particular syntax chosen.

So optional type declarations are officially "the details" now? :)

ChrisA


From marfig at gmail.com  Thu Jan 22 05:31:51 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Thu, 22 Jan 2015 10:31:51 +0000 (UTC)
Subject: Python is DOOMED! Again!
References: <b631cc7a-2f2a-4269-9a0d-7228103f1852@googlegroups.com>
Message-ID: <1a194e0a09cf8d2044e268d5585@nntp.aioe.org>

 Rick,

> Python is the only thing that is pure in the programming world. The
> only language that offers the cleanest and most intuit-able syntax,
> AND YOU"RE JUST GOING TO THROW IT ALL AWAY SO YOU CAN BE A LAPDOG OF
> SATAN?

Nonsense. You are just used to it. I can read C with the same feeling of 
intuitiveness as you do Python. There's nothing inherently more intuitive 
about python and I just wished that meme died already. Besides it's all in 
the eye of the beholder. Some people, for intance, aren't all that comfortable 
about python white space as much as many die-hard pythonists would like to 
admit. It's not even a feature that gained traction on programming languages 
that came after python. 

> If you don't act now, then don't bother complaining later. Python is
> dangling by a thin thread, and this is your last chance to save
> everything we've worked for. All the lines of code we've written won't
> mean spit if the language takes a swan dive into obscurity!

PEP 484 just becomes silly when it comes to the section where it discusses 
whether type hints are pythonic. If that ridiculous paragraph reflects how 
we are looking today at the inclusion of new features, than I agree python 
is walking a dangerous road. But that also means Type Hints aren't the real 
problem here. We have a much bigger problem about the programming language 
principles and phylosophy.

In all honesty though, I never cared much about the ideals and zens in programming 
languages, especially ones want to want to adopt a batteries-included philosophy. 
Always seemed to me like nonsense talk. My experience taught me that you 
can't just have the latter without eventually breaking the former. 'import 
this' always read to me like wishful thinking.

Python isn't going anywhere towards obscurity. Not at least until a competiting 
language comes (it hasn't yet). I agree though that Python complexity has 
increased greatly over the years and this isn't showing any signs of stopping. 
And that is exactly the type of thing that promotes the birth of a new and 
better programming language. And, interestingly enough, that is always a 
good thing.




From marfig at gmail.com  Thu Jan 22 05:37:52 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Thu, 22 Jan 2015 10:37:52 +0000 (UTC)
Subject: Python is DOOMED! Again!
References: <mailman.17965.1421921362.18130.python-list@python.org>
Message-ID: <1a194e0a09d48d2044efdfe5477@nntp.aioe.org>

 Chris,

> Hold on a moment, how often do you really do this kind of thing with
> "might be one of them or a sequence"?

Is it really that important that I give a more real-life example, or can't 
you just get the problem from a ad-hoc example?

I could replace the variable names with spam, ham and eggs, if you wish.




From rosuav at gmail.com  Thu Jan 22 05:44:23 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 21:44:23 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <1a194e0a09d48d2044efdfe5477@nntp.aioe.org>
References: <mailman.17965.1421921362.18130.python-list@python.org>
 <1a194e0a09d48d2044efdfe5477@nntp.aioe.org>
Message-ID: <CAPTjJmo2=07-MqSD5HJEWNOZkhsS6-faifBBSdcKify26S3w3g@mail.gmail.com>

On Thu, Jan 22, 2015 at 9:37 PM, Mario Figueiredo <marfig at gmail.com> wrote:
> Chris,
>
>> Hold on a moment, how often do you really do this kind of thing with
>> "might be one of them or a sequence"?
>
>
> Is it really that important that I give a more real-life example, or can't
> you just get the problem from a ad-hoc example?
>
> I could replace the variable names with spam, ham and eggs, if you wish.

I'd rather see a real-world example that can't be solved with either
better design or some simple aliases. (And yes, the type hinting does
allow for aliases.)

ChrisA


From nicholas.cole at gmail.com  Thu Jan 22 05:46:18 2015
From: nicholas.cole at gmail.com (Nicholas Cole)
Date: Thu, 22 Jan 2015 10:46:18 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <CAPTjJmrDNC=ESm5Vj4sOYdffb=UChzt2GmX5DxvpaBffHSzwMg@mail.gmail.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <CAPTjJmrDNC=ESm5Vj4sOYdffb=UChzt2GmX5DxvpaBffHSzwMg@mail.gmail.com>
Message-ID: <CAAu18hekYw9G4O69NnUigKwUP+wB+U=WicnQ2Hpf2S5-BHMHbw@mail.gmail.com>

On Thursday, 22 January 2015, Chris Angelico <rosuav at gmail.com
<javascript:_e(%7B%7D,'cvml','rosuav at gmail.com');>> wrote:

> On Thu, Jan 22, 2015 at 7:10 PM, Mario Figueiredo <marfig at gmail.com>
> wrote:
> > Possibly one common use case will be Unions. And that factory syntax is
> > really awful and long when you look at a function definition with as
> > little as 3 arguments. The one below has only 2 arguments.
> >
> > def handle_employees(emp: Union[Employee, Sequence[Employee]], raise:
> > Union[float, Sequence[float]]) -> Union[Employee, Sequence[Employee],
> > None]:
>
> Hold on a moment, how often do you really do this kind of thing with
> "might be one of them or a sequence"? Do you really have a function
> that could take an Employee and a float, or a sequence of Employees
> and a single float, or a single Employee and a sequence of floats, or
> a sequence of both? Or do you, much more likely, actually have two
> separate functions:
>
> def handle_employee(emp: Employee, raise: float) -> Optional[Employee]:
>
> def handle_employees(emp: Sequence[Employee], raise: Sequence[float])
> -> List[Employee]:
>
> The union in the return value seems particularly unlikely... and unhelpful.
>

Hang on! The particular example may not make a lot of sense but there are
plenty of places in ordinary Python where functions can accept different
objects in arguments and return different things. The point here is that
that will become rapidly messy and hard to read.

Perhaps the new PEP will discourage this kind of thing and perhaps that is
to be welcomed not feared, but I don't think the example itself was
particularly contrived. I've seen it in plenty of code in the wild.
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From rosuav at gmail.com  Thu Jan 22 05:50:22 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 21:50:22 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <CAAu18hekYw9G4O69NnUigKwUP+wB+U=WicnQ2Hpf2S5-BHMHbw@mail.gmail.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <CAPTjJmrDNC=ESm5Vj4sOYdffb=UChzt2GmX5DxvpaBffHSzwMg@mail.gmail.com>
 <CAAu18hekYw9G4O69NnUigKwUP+wB+U=WicnQ2Hpf2S5-BHMHbw@mail.gmail.com>
Message-ID: <CAPTjJmqE7GjsMUh7fTMhgy3rGpV7mUNixe3uwBfyq9L0OPHOzg@mail.gmail.com>

On Thu, Jan 22, 2015 at 9:46 PM, Nicholas Cole <nicholas.cole at gmail.com> wrote:
> Hang on! The particular example may not make a lot of sense but there are
> plenty of places in ordinary Python where functions can accept different
> objects in arguments and return different things. The point here is that
> that will become rapidly messy and hard to read.

Yes; but with proper use of TypeVar can simplify things a lot - have a
read of the PEP.

ChrisA


From marfig at gmail.com  Thu Jan 22 06:06:33 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Thu, 22 Jan 2015 11:06:33 +0000 (UTC)
Subject: Python is DOOMED! Again!
References: <mailman.17970.1421923836.18130.python-list@python.org>
Message-ID: <1a194e0a09d98d20452ffdd8933@nntp.aioe.org>

 Chris,

> I'd rather see a real-world example that can't be solved with either
> better design or some simple aliases. (And yes, the type hinting does
> allow for aliases.)

Python is a duck-typing language, Chris. It is in its nature -- and we have 
been taught -- to ignore types and care only about operators. This means 
one of the most common design decisions in Python is exactly to code functions 
that are type ignorant. That is exactly why we need Type Hinting, because 
duck-typing complicates static analysis. And that is exactly why the Unions 
factory are a necessary part of the type hinting mechanism in PEP 484.

You will be seeing lots and lots of Unions in type annotated code once it 
gets implemented. And it's not because of the complexity of Unions syntax 
that I should now care about refactoring my code. That is a no-no.

If you don't know of any real-life example of python functions that will 
eventually force you into annotate them with unions syntax, look no further 
than your standard library. And also start questioning if you aren't complicating 
your own code with unnecessary function overloads.




From marfig at gmail.com  Thu Jan 22 06:12:55 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Thu, 22 Jan 2015 11:12:55 +0000 (UTC)
Subject: Python is DOOMED! Again!
References: <mailman.17969.1421923826.18130.python-list@python.org>
Message-ID: <1a194e0a09db8d20453e39394a3@nntp.aioe.org>

 Chris,

> On Thu, Jan 22, 2015 at 9:46 PM, Nicholas Cole
> <nicholas.cole at gmail.com> wrote:
> 
>> Hang on! The particular example may not make a lot of sense but there
>> are plenty of places in ordinary Python where functions can accept
>> different objects in arguments and return different things. The point
>> here is that that will become rapidly messy and hard to read.
>> 
> Yes; but with proper use of TypeVar can simplify things a lot - have a
> read of the PEP.
> 
> ChrisA
> 

I agree. TypeVar will help tremendously by removing the need for union in 
cases of object inheritance. But only on cases of object inheritance.




From rosuav at gmail.com  Thu Jan 22 07:14:59 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Jan 2015 23:14:59 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <1a194e0a09db8d20453e39394a3@nntp.aioe.org>
References: <mailman.17969.1421923826.18130.python-list@python.org>
 <1a194e0a09db8d20453e39394a3@nntp.aioe.org>
Message-ID: <CAPTjJmon_rohE5xrBCsWJuB34RAFwe+Yu_9rEnyxD-cAhMabOQ@mail.gmail.com>

On Thu, Jan 22, 2015 at 10:12 PM, Mario Figueiredo <marfig at gmail.com> wrote:
> I agree. TypeVar will help tremendously by removing the need for union in
> cases of object inheritance. But only on cases of object inheritance.

Why only inheritance? One of the examples is of str and bytes, which
don't have any inheritance relationship (they both just subclass
object), and it works just fine for that.

ChrisA


From gheskett at wdtv.com  Thu Jan 22 07:26:31 2015
From: gheskett at wdtv.com (Gene Heskett)
Date: Thu, 22 Jan 2015 07:26:31 -0500
Subject: What killed Smalltalk could kill Python
In-Reply-To: <20150122044609.GA1948@mikrus>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmoAehP2v+bVjdmqCpahNfAqpXoJu4-NHp+N9KJ=y9CnNw@mail.gmail.com>
 <20150122044609.GA1948@mikrus>
Message-ID: <201501220726.32008.gheskett@wdtv.com>

On Wednesday 21 January 2015 23:46:09 Emil Oppeln-Bronikowski did opine
And Gene did reply:
> On Thu, Jan 22, 2015 at 10:55:27AM +1100, Chris Angelico wrote:
> > Where's REXX today?
> 
> Still (somehow) alive in neo-Amiga platforms like AmigaOS4.x, MorphOS
> and AROS. I know that's as good as dead but there are still people
> writing AREXX glue code.

He asked about REXX, not AREXX. There is no comparison between the two as 
AREXX was a huge superset of REXX.

I have co-written some rather widely distributed amiga code in AREXX, then 
compiled it to standalone with RexxPlus.

When I switched platforms to linux in 1998, the first thing I did was to 
go find an AREXX for linux.  But had to settle for IBM's REXX/Regina, 
which wasn't capable of running any of our AREXX code.  AREXX hooked into 
the OS and there wasn't anything I ever wanted to do that could not be 
done in AREXX.

REXX/Regina is an extremely emasculated language that has zero connection 
into the os, and I found it completely useless when compared to AREXX.

If, when anyone here was using an amiga, and was using EzCron to schedule 
stuff, Jim Hines and I wrote it as there was no such scheduler for 
amigados.  Everything else we laid our hands on killed time by 
busywaiting, killing the machines performance. EzCron put itself to sleep 
intelligently by asking what time it was, and then sleeping until the 
first second of the next minute. That we published at the time, and then 
built on that for EzHome, which was a dumber version of what we call heyu 
today.

Trivia bit: William Hawes, who wrote AREXX and sold it thru the commode 
door sales channels, was never paid a dime for his work. But those 2 guys 
screwed everybody. He had an account on kernel.org in 1998, might still 
have, but it was empty then and the last time I looked, probably 5 years 
ago.

So I have no clue what a very talented programmer is doing for a living 
today. To me, that sad as hell.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>
US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS


From steve+comp.lang.python at pearwood.info  Thu Jan 22 09:16:27 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 23 Jan 2015 01:16:27 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
Message-ID: <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>

Mario Figueiredo wrote:

> In article <54c0a571$0$13002$c3e8da3$5496439d at news.astraweb.com>,
> steve+comp.lang.python at pearwood.info says...
>> 
>> The point isn't that there are no other alternative interpretations
>> possible, or that annotations are the only syntax imaginable, but that
>> they're not hard to guess what they mean, and if you can't guess, they're
>> not hard to learn and remember.
> 
> Possibly one common use case will be Unions. And that factory syntax is
> really awful and long when you look at a function definition with as
> little as 3 arguments. The one below has only 2 arguments.
> 
> def handle_employees(emp: Union[Employee, Sequence[Employee]], raise:
> Union[float, Sequence[float]]) -> Union[Employee, Sequence[Employee],
> None]:

You can't use "raise" as a parameter name, since that's a keyword. Using
floats for money is Just Wrong and anyone who does so should have their
licence to program taken away. And I really don't understand what this
function is supposed to do, that it returns None, a single Employee, or a
sequence of Employees. (If it's hard to declare what the return type is,
perhaps your function does too much or the wrong thing.)

But putting those aside, let's re-write that with something a little closer
to PEP-8 formatting:

def handle_employees(
            emp: Union[Employee, Sequence[Employee]],
            pay_raise: Union[int, Sequence[int]]
            ) -> Union[Employee, Sequence[Employee], None]:
    pass


That's quite nice and easy to follow. I can think of three improvements:

(1) Allow the return annotation to be on a line on its own rather than force
it to follow the closing bracket;

(2) Support | to make Unions of types;

(3) Have a shorter way to declare "Spam or Sequence (tuple?) of Spam". 


def handle_employees(
            emp: OneOrMore[Employee],
            pay_raise: OneOrMore[int])
            -> OneOrMore[Employee] | None:
    pass


(2) has been rejected by Guido, but he may change his mind. The name I've
chosen for (3) is just the first thing I've thought of.



> Meanwhile there's quite a few more generics like the Sequence one above
> you may want to take a look at and try and remember. And that's just one
> factory (the generics support factory). You may also want to take a look
> at TypeVar and Callable for more syntactic hell.

Exaggerate, much?

  
> Meanwhile, there's the strange decision to implement type hints for
> local variables # comment lines. I have an hard time wrapping my head
> around this one. Really, comments!?

Yes, really. There is plenty of prior art for machine-meaningful comments:

- mypy uses it, and it works fine
- Pascal uses {$ ...} compiler directives
- Unix uses a special hash-bang #! comment in the first line to 
  specify the executable that runs the script
- Python supports a special encoding declaration using #
- doctest uses comments for directives
- HTML puts code (Javascript usually) inside of comments
- JMSAssert for Java uses comments for design-by-contract assertions


But note that the type declarations have *no runtime effect*. They truly are
comments, aimed at the human reader and any compliant type-checker.


Guido has said that he isn't ruling out an explicit syntactic support for
type declarations in the future, but right now there are various
constraints:

- it must be backwards compatible, i.e. something that Python 3.4 and older
  will just ignore
- it must be available by lexical analysis, that is, from reading the 
  source code, which rules out anything that happens at runtime
- it must be human-readable
- and easily parsed by even simple tools



> Finally, remember all this is being added to your code just to
> facilitate static analysis. 

You say "just" to facilitate static analysis, but let me put it this way. It
is "just" to facilitate:

- improved correctness of programs
- to assist in finding bugs as early as possible
- reduced need to write tedious, boring unit tests to check things 
  that an automated type-checker can deal with instead
- to reduce the need for runtime type-checks and isinstance() calls
- to aid in producing documentation
- to give hints to IDEs, editors, linters, code browsers and 
  similar tools.



> Strangely enough though I was taught from 
> the early beginning that once I start to care about types in Python, I
> strayed from the pythonic way. I'm confused now... What is it then?

That's actually a really good question.

Good practice in Python will not change. If anything, explicitly checking
types with isinstance will become even less common: if you can use lexical
analysis to prove that the argument passed to a function is always a float,
there is no need to perform a runtime check that it is a float.

Notice that nearly all the examples in the PEP use abstract classes like
Sequence instead of concrete classes like list? This is a good thing, and
will encourage more flexible code. You don't need a specific type of
sequence, any type of sequence will do -- that's pretty much the definition
of duck-typing.

I've watched the evolution of typing in Python over the 15+ years. Back in
the old days of Python 1.4 and 1.5, the only way to type-check was to
compare two types for equality:

if type(x) == type(1.0):
    print "x is a float"


That was very restrictive. You couldn't check for subclasses. You couldn't
subclass built-in types like floats, but you could use delegation, but
there was no way to tell Python your float-proxy should be treated as if it
were a float. Being so restrictive, it was best avoided, hence the very
strong emphasis on duck-typing.

Python 2.2 introduced "new style classes", which meant that you could
subclass built-ins. Functions like str, float, int and list became type
objects (classes) instead of functions, so now you could write:

if type(x) == float: print "x is a float"

Python 2.2 also introduced issubclass and isinstance, which allowed you to
check for a specific type or sub-type. That's less restrictive than exact
type equality: if you want something that quacks like a float, chances are
that it probably is a float or a sub-class of a float.

Python 2.5 (I think?) introduced Abstract Base Classes, which takes it to
the next level. Now, if you want something that quacks like a float, you
don't even have to inherit from float! You can create your own classes
without inheriting from float at all, and then register it as a float, and
Python will treat it as if it were a float. Or you can inherit from
*abstract* classes which provide a lot of the basic functionality needed so
you're not forced to re-invent the wheel.

Duck-typing in the Python 1.5 sense has a number of issues that make it less
than a panacea:

- Sometimes you really must have an duck, not just something duck-like. 
  If you're trying to find a mate for Donald Duck, you want a duck, 
  not a goose.

- More practically, if you're interfacing with C or Java or Fortran code,
  you don't have the luxury of passing any old "duck like" object. If
  the C code requires a float, you have to be sure you give it a float.

- It is good programming practice to raise errors as close as possible 
  to the source as you can. If your function requires a float, it is 
  often better to raise an exception *immediately* if it receives a
  non-float, not deep inside the function's body.

- Duck-typing has its share of problems too. Consider a function that
  expects an Artist object, and calls the draw() method, but instead it
  received a Gunslinger object. Instead of getting a nice AttributeError,
  your code will now do the wrong thing. How do you prevent errors like
  this, if not by type-checking?


Since the "language wars" of the 1990s, dynamic languages have won. Even
static languages like Java contain dynamic features. But the victory isn't
all one way: dynamic languages are gaining static features too. Static
typing can improve performance and correctness, and it is silly to reject
that out of some misplaced idealism that there is One True Way to design a
language.




-- 
Steven



From jon+usenet at unequivocal.co.uk  Thu Jan 22 09:33:05 2015
From: jon+usenet at unequivocal.co.uk (Jon Ribbens)
Date: Thu, 22 Jan 2015 14:33:05 +0000 (UTC)
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <slrnmc22i1.uab.jon+usenet@frosty.unequivocal.co.uk>

On 2015-01-22, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
> You can't use "raise" as a parameter name, since that's a keyword. Using
> floats for money is Just Wrong and anyone who does so should have their
> licence to program taken away. And I really don't understand what this
> function is supposed to do, that it returns None, a single Employee, or a
> sequence of Employees. (If it's hard to declare what the return type is,
> perhaps your function does too much or the wrong thing.)

That makes me think - it seems odd to me that PEP 484 doesn't even
mention function overloading (even to say that it's outside the
scope).

I think overloading should certainly be considered, and unless the
consensus is that it is something that should never happen, it
should either be explicitly allowed or at least the type-hinting
syntax should be checked to ensure it is forward-compatible with it.


From steve+comp.lang.python at pearwood.info  Thu Jan 22 09:57:45 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 23 Jan 2015 01:57:45 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <mailman.17965.1421921362.18130.python-list@python.org>
Message-ID: <54c10fe9$0$12988$c3e8da3$5496439d@news.astraweb.com>

Chris Angelico wrote:

> Hold on a moment, how often do you really do this kind of thing with
> "might be one of them or a sequence"? 

isinstance(obj, one_class_or_tuple_of_classes)
issubclass(cls, one_class_or_tuple_of_classes)
mystr.startswith(prefix_or_tuple_of_prefixes)
mystr.endswith(suffix_or_tuple_of_suffixes)
template % one_string_or_tuple_of_strings  # or a dict :-)


I'm not suggesting that the specific example is a good one, but the
principle is sound.



-- 
Steven



From rosuav at gmail.com  Thu Jan 22 10:11:40 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 23 Jan 2015 02:11:40 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmrv4k6YNRvM8OXWkx5UNnuWR8eF-n3Xxn2JQ_=qbYxYMg@mail.gmail.com>

On Fri, Jan 23, 2015 at 1:16 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Mario Figueiredo wrote:
>
>> def handle_employees(emp: Union[Employee, Sequence[Employee]], raise:
>> Union[float, Sequence[float]]) -> Union[Employee, Sequence[Employee],
>> None]:
>
> Using
> floats for money is Just Wrong and anyone who does so should have their
> licence to program taken away.

But using a float to specify a percentage raise that an employee (or
class of employees) gets would be reasonable. You could "handle" all
your problem employees by giving them an across-the-board 3% raise to
try to stop them from going on strike (they have a Union, as we can
see there, so strikes are clearly possible).

Not that that matters to the typing question. If it really is a
monetary type, all you need to do is replace 'float' with 'Money'
which would be a superclass to USD, AUD, GBP, and RepublicCredits.
There's still the question of what it's doing.

My best guess about this function is that it has three modes:

1) handle_employee(emp: Employee, pay_raise: float)
Give one employee a percentage raise. (Note the different function name.)
2) handle_employees(emp: Sequence[Employee], pay_raise: float)
Give all these employees the same percentage raise.
3) handle_employees(emp: Sequence[Employee], pay_raise: Sequence[float])
Equivalent to [handle_employee(e, r) for e, r in zip(emp, pay_raise)]

I can't figure out any sane meaning for passing a single employee and
a sequence of floats, and I think the one-and-one case should have a
different name. That would mean that there's really only one Union
involved, and the plural function would look like this:

def handle_employees(emp: Sequence[Employee], pay_raise: Union[float,
Sequence[float]]):
    """Atomically give many employees raises.

    If pay_raise is a float, gives each employee that raise; otherwise, it
    should be a sequence of the same length as emp.
    """
    if isinstance(pay_raise, collections.Sequence):
        for e, r in zip(emp, pay_raise):
            handle_employee(e, r)
    else:
        for e in emp:
            handle_employee(e, pay_raise)

But I still have no clue what the return value of either the
one-and-one case or the multiple case should be.

> (3) Have a shorter way to declare "Spam or Sequence (tuple?) of Spam".
>
>
> def handle_employees(
>             emp: OneOrMore[Employee],
>             pay_raise: OneOrMore[int])
>             -> OneOrMore[Employee] | None:
>     pass

Yes, that would be a reasonable thing. It might even be possible to
implement it on top of TypeVar. That said, though, APIs that accept
"just one, or maybe more" have problems; for instance, you can't write
a "pretty-print" function that can take either an arbitrary object, or
a sequence of arbitrary objects. Fundamentally not possible. But when
you can guarantee that the thing you're getting OneOrMore of is not
itself iterable, it would be useful.

>> Meanwhile there's quite a few more generics like the Sequence one above
>> you may want to take a look at and try and remember. And that's just one
>> factory (the generics support factory). You may also want to take a look
>> at TypeVar and Callable for more syntactic hell.
>
> Exaggerate, much?

Maybe. Callable does get pretty hairy; specifying the arguments and
return values of a function is never pretty. Pike is no better:

> typeof(write);
(1) Result: function(array(string) | string, mixed ... : int)

That's a function which takes either a single string or an array of
strings, followed by any number of additional arguments, and returns
an integer.

> typeof(GTK2.setup_gtk);
(2) Result: function(void | array(string) | string, void | int : array(string))

Optional arguments: one or more strings, and maybe an integer. Returns
an array of strings.

> typeof(rm);
(3) Result: function(string : int)

This one's pretty simple. It takes a string (path name), and returns
an integer (success or failure flag). And deletes a file/directory.

> typeof(asin);
(4) Result: function(int | float : float)

Could take an integer or a float, and returns a float.

The PEP 484 equivalents would be, I think:

write = Callable[[Union[str, Sequence[str]], AnyArgs], int]
# I have no idea how to do optional args.
rm = Callable[[str], int]
asin = Callable[[Union[int, float]], float]

It's not too bad when the function signature is really simple. And
that's going to be the common case. But it is syntactically
complicated to type-check a callback's arguments. Imagine, for
instance, GUI toolkit callbacks; chances are you can stuff extra args
into them (so they need a *args equivalent at the end), and they'll
take a variety of different args. They will not be pretty... or else
they'll be type-hinted simply as Callable, with nothing else.

But ultimately, that's not a fault of the type hinting structure. It's
a natural consequence of the complexity of callbacks. You can't get
away from it.

ChrisA


From rosuav at gmail.com  Thu Jan 22 10:13:25 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 23 Jan 2015 02:13:25 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <54c10fe9$0$12988$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <mailman.17965.1421921362.18130.python-list@python.org>
 <54c10fe9$0$12988$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmrpwy4iio4OYev3S4Unpw4Vku7HSEcvaXxKmpq1DmQ5QA@mail.gmail.com>

On Fri, Jan 23, 2015 at 1:57 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Chris Angelico wrote:
>
>> Hold on a moment, how often do you really do this kind of thing with
>> "might be one of them or a sequence"?
>
> isinstance(obj, one_class_or_tuple_of_classes)
> issubclass(cls, one_class_or_tuple_of_classes)
> mystr.startswith(prefix_or_tuple_of_prefixes)
> mystr.endswith(suffix_or_tuple_of_suffixes)
> template % one_string_or_tuple_of_strings  # or a dict :-)
>
>
> I'm not suggesting that the specific example is a good one, but the
> principle is sound.

All of your examples are "might be one of them or a tuple". Not
"sequence", "tuple". That gets around the problem of recognition,
because in no case is a single tuple a valid argument.

I suspect it would be possible to use TypeVar to create a nice
"OneOrMore" like you suggested, but for reliability, it should
probably be "or tuple" rather than "or sequence".

ChrisA


From ermanolillo at hotmail.com  Thu Jan 22 10:24:41 2015
From: ermanolillo at hotmail.com (ermanolillo)
Date: Thu, 22 Jan 2015 07:24:41 -0800 (PST)
Subject: Socket ICMP V6 error
In-Reply-To: <1421913649039-5083962.post@n6.nabble.com>
References: <1421913649039-5083962.post@n6.nabble.com>
Message-ID: <1421940281496-5083982.post@n6.nabble.com>

HOST is  send by the keyboard. It?s the IPv6 address of my interface eth0.
For example, FE80::0202:B3FF:FE1E:8329.



Thanks



--
View this message in context: http://python.6.x6.nabble.com/Socket-ICMP-V6-error-tp5083962p5083982.html
Sent from the Python - python-list mailing list archive at Nabble.com.


From rosuav at gmail.com  Thu Jan 22 10:38:29 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 23 Jan 2015 02:38:29 +1100
Subject: Socket ICMP V6 error
In-Reply-To: <1421940281496-5083982.post@n6.nabble.com>
References: <1421913649039-5083962.post@n6.nabble.com>
 <1421940281496-5083982.post@n6.nabble.com>
Message-ID: <CAPTjJmp2onS1VTOb12HvhifLFK8_REN3O84NOm0aPrYTF7H6=g@mail.gmail.com>

On Fri, Jan 23, 2015 at 2:24 AM, ermanolillo <ermanolillo at hotmail.com> wrote:
> HOST is  send by the keyboard. It?s the IPv6 address of my interface eth0.
> For example, FE80::0202:B3FF:FE1E:8329.

I can't duplicate the problem. Are you certain that this is indeed an
appropriate address?

ChrisA


From emil at fuse.pl  Thu Jan 22 10:47:30 2015
From: emil at fuse.pl (Emil Oppeln-Bronikowski)
Date: Thu, 22 Jan 2015 16:47:30 +0100
Subject: What killed Smalltalk could kill Python
In-Reply-To: <201501220726.32008.gheskett@wdtv.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <CAPTjJmoAehP2v+bVjdmqCpahNfAqpXoJu4-NHp+N9KJ=y9CnNw@mail.gmail.com>
 <20150122044609.GA1948@mikrus>
 <201501220726.32008.gheskett@wdtv.com>
Message-ID: <20150122154730.GD1048@mikrus>

On Thu, Jan 22, 2015 at 07:26:31AM -0500, Gene Heskett wrote:

> > Still (somehow) alive in neo-Amiga platforms like AmigaOS4.x, MorphOS
> > and AROS. I know that's as good as dead but there are still people
> > writing AREXX glue code.
> He asked about REXX, not AREXX. There is no comparison between the two as 
> AREXX was a huge superset of REXX.

Never seeing a proper REXX I always assumed it's just Amiga port retrofitted to serve as OS' needs as IPC language.

You learn everyday.

> If, when anyone here was using an amiga, and was using EzCron to schedule 
> stuff, Jim Hines and I wrote it as there was no such scheduler for 
> amigados.

I used few cron-like daemons and the name rings a bell!

> Trivia bit: William Hawes, who wrote AREXX and sold it thru the commode 
> door sales channels, was never paid a dime for his work.

There are still problems with AREXX copyright/distribution, but as you can guess after few changes of hand Amiga's IP is mess.

AROS, begin FOSS reimplementation of AmigaOS API, uses Regina to replace AREXX

http://regina-rexx.sourceforge.net/
-- 
vag?a?bond adjective \?va-g?-?b?nd\
 a :? of, relating to, or characteristic of a wanderer 
 b :? leading an unsettled, irresponsible, or disreputable life



From alain at dpt-info.u-strasbg.fr  Thu Jan 22 11:21:52 2015
From: alain at dpt-info.u-strasbg.fr (Alain Ketterlin)
Date: Thu, 22 Jan 2015 17:21:52 +0100
Subject: Socket ICMP V6 error
References: <1421913649039-5083962.post@n6.nabble.com>
 <mailman.17975.1421940342.18130.python-list@python.org>
Message-ID: <878ugu4wgv.fsf@dpt-info.u-strasbg.fr>

ermanolillo <ermanolillo at hotmail.com> writes:

> HOST is  send by the keyboard. It?s the IPv6 address of my interface eth0.
> For example, FE80::0202:B3FF:FE1E:8329.

This is a link-local address, you can't use it just like that (you may
have several interfaces with the same link-local addr). Use getaddrinfo
on "FE80...%eth0" (change eth0 to the name of the interface you want to
use) to get a valid 4-tuple. Use that instead of your (HOST,0). You can
also try '::' (kind of inaddr6_any), I don't know if that's what you
want.

But I think you can't bind a raw socket in IPv6. (Not sure, try it and
see.)

-- Alain.


From rustompmody at gmail.com  Thu Jan 22 11:54:05 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Thu, 22 Jan 2015 08:54:05 -0800 (PST)
Subject: Trees
In-Reply-To: <87y4ov70as.fsf@jester.gateway.sonic.net>
References: <CAG=hEY1L-39EmuWpdEh_n-BNfs=qG9nL=MrMT0ar72yGBrkoUA@mail.gmail.com>
 <mailman.17884.1421734095.18130.python-list@python.org>
 <d34dbfbe-fe82-47dc-8bc3-c8773e2b70dd@googlegroups.com>
 <MPG.2f28eb55d73ef68c989680@nntp.aioe.org>
 <ba69cad8-68c0-421e-af79-e381ca179015@googlegroups.com>
 <mailman.17927.1421880891.18130.python-list@python.org>
 <87y4ov70as.fsf@jester.gateway.sonic.net>
Message-ID: <ead841db-2794-48cc-9c83-68836036f09f@googlegroups.com>

On Thursday, January 22, 2015 at 12:46:22 PM UTC+5:30, Paul Rubin wrote:
> Ian Kelly writes:
> > How do you create a tree containing an even number of elements under
> > this constraint?
> 
> That's a good point, I've usually seen different definitions of trees,
> e.g.
> 
>    data Tree a = Leaf | Branch a (Tree a) (Tree a)
> 
> so a Leaf node doesn't have a value associated with it.

Maybe you should call 'Leaf' instead as EmptyTree 

Then does it answer Ian's question?

Or Nil Null or some such then it is most obviously isomorphic to
the typical way of doing it in C.

The point is that these are frameworks for structural induction.
So choosing base-cases carefully is important.

This may seem harmless but is probably not a good idea

  data Tree a = Empty | Leaf a | Branch a (Tree a) (Tree a)

OTOH the classic S-exp of lisp would be modelled as

 data Sexp b = Cons (Sexp b) (Sexp b) | Leaf b

which captures the fact that the elements (b) are only at the leaves
and the conses provide pure branching without content

ie its not ... Cons b (Sexp b) (Sexp b)...


From automn at willow.org  Thu Jan 22 12:13:12 2015
From: automn at willow.org (Automn)
Date: 22 Jan 2015 17:13:12 GMT
Subject: kivy secret of mana game
Message-ID: <slrnmc2c3g.77n.automn@sigtrans.org>

Hello,

I am programming a "Secret of Mana" (Seiken Densetsu) game in kivy, it runs
on a phone with kivy launcher.

Features for now are : movement by swiping, polygon collision and image state
changes with resource handling.

The codebase can be found at : 
https://sourceforge.net/projects/kivypriestsoflore2

The graphics have been licensed for this.

Automn
-- 
my blog : http://thediaryofelvishhealer.blogspot.com/
Time heals.


From invalid at invalid.invalid  Thu Jan 22 12:52:12 2015
From: invalid at invalid.invalid (Grant Edwards)
Date: Thu, 22 Jan 2015 17:52:12 +0000 (UTC)
Subject: What killed Smalltalk could kill Python
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <m9ou2h$jvj$1@reader1.panix.com>
 <mailman.17926.1421879748.18130.python-list@python.org>
 <m9pbl1$oan$1@reader1.panix.com>
 <mailman.17942.1421896841.18130.python-list@python.org>
Message-ID: <m9rdcc$5e0$2@reader1.panix.com>

On 2015-01-22, Tim Chase <python.list at tim.thechases.com> wrote:
> On 2015-01-21 23:10, Grant Edwards wrote:
>> I happily ignored PHP until a couple years back when we decided to
>> use PHP for the web site on a small embedded Linux system. 
> [snip]
>> I briefly considered trying to switch to Python, but the Python
>> footprint is just too big...
>
> Interesting that your experience swung that way.
>
> I worked on a contract about a year ago where it involved deploying
> web services & ZigBee communications on a Digi Connectport[1] which is
> certainly a rather underpowered device (20MB of memory is tight).  My
> biggest issue was the project-lead's choice of CherryPy and
> SQLObject...neither has nearly the same quality of documentation as
> I'd grown accustomed to in the Django world.  Yet I was able to run
> an HTTPS CherryPy server talking to a local sqlite database with
> minimal trouble, handling a modest (i.e., small business) load.

Maybe I should look at Python again.

It's too late for this product, but maybe in the future...

-- 
Grant Edwards               grant.b.edwards        Yow! But was he mature
                                  at               enough last night at the
                              gmail.com            lesbian masquerade?


From sturla.molden at gmail.com  Thu Jan 22 13:03:33 2015
From: sturla.molden at gmail.com (Sturla Molden)
Date: Thu, 22 Jan 2015 18:03:33 +0000 (UTC)
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> Remember too that type-hinting will *absolutely* remain *completely* 
> optional for Python. Developers can choose to use it or not,

No! Developers have to do what managers and customers tell them to do. They
will start to require type hinting everywhere. And then the question is
what Python has to offer over Java or Swift.

Python will no longer be dynamic, it will just be a slow static language.

Yes, Python could still be used as a dynamic language, but nobody will
allow you to do it. Even packages in widespread use will be banned because
they don't typehint. And then there will be complaint about lack of such
packages.

And in 5 years every textbook read by new Python programmers will require
type hinting as a "best practice".

Forget about compatibility with Python 2.

People will upgrade from Python 2 to Swift.

And then goodbye.

Sturla



From sturla.molden at gmail.com  Thu Jan 22 13:11:36 2015
From: sturla.molden at gmail.com (Sturla Molden)
Date: Thu, 22 Jan 2015 18:11:36 +0000 (UTC)
Subject: Python is DOOMED! Again!
References: <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <b631cc7a-2f2a-4269-9a0d-7228103f1852@googlegroups.com>
 <87h9vj6sgr.fsf@elektro.pacujo.net>
Message-ID: <462177424443643069.422875sturla.molden-gmail.com@news.gmane.org>

Marko Rauhamaa <marko at pacujo.net> wrote:

> I think the SATAN is in the optional type declarations, not in the
> particular syntax chosen.

Yes.



From skip.montanaro at gmail.com  Thu Jan 22 13:14:51 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Thu, 22 Jan 2015 12:14:51 -0600
Subject: Python is DOOMED! Again!
In-Reply-To: <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
Message-ID: <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>

On Thu, Jan 22, 2015 at 12:03 PM, Sturla Molden <sturla.molden at gmail.com>
wrote:

> Python will no longer be dynamic, it will just be a slow static language.
>
> Yes, Python could still be used as a dynamic language, but nobody will
> allow you to do it. Even packages in widespread use will be banned because
> they don't typehint. And then there will be complaint about lack of such
> packages.
>

FUD? What evidence do you have that this will be the way things shake out?

Skip
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From sturla.molden at gmail.com  Thu Jan 22 13:23:37 2015
From: sturla.molden at gmail.com (Sturla Molden)
Date: Thu, 22 Jan 2015 18:23:37 +0000 (UTC)
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
Message-ID: <1193348871443643749.538222sturla.molden-gmail.com@news.gmane.org>

Skip Montanaro <skip.montanaro at gmail.com> wrote:

> FUD? What evidence do you have that this will be the way things shake out?

I don't underestimate the stupidity of those who are not writing the code
themselves.



From breamoreboy at yahoo.co.uk  Thu Jan 22 13:28:18 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 22 Jan 2015 18:28:18 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
Message-ID: <m9rfg8$vuv$1@ger.gmane.org>

On 22/01/2015 18:14, Skip Montanaro wrote:
>
> On Thu, Jan 22, 2015 at 12:03 PM, Sturla Molden <sturla.molden at gmail.com
> <mailto:sturla.molden at gmail.com>> wrote:
>
>     Python will no longer be dynamic, it will just be a slow static
>     language.
>
>     Yes, Python could still be used as a dynamic language, but nobody will
>     allow you to do it. Even packages in widespread use will be banned
>     because
>     they don't typehint. And then there will be complaint about lack of such
>     packages.
>
> FUD? What evidence do you have that this will be the way things shake out?
>

Evidence in completely the opposite direction if I'm reading this 
correctly https://www.python.org/dev/peps/pep-0484/#usage-patterns

"The main use case of type hinting is static analysis using an external 
tool without executing the analyzed program. Existing tools used for 
that purpose like pyflakes [pyflakes] or pylint [pylint] might be 
extended to support type checking. New tools, like mypy's mypy -S mode, 
can be adopted specifically for this purpose.

Type checking based on type hints is understood as a best-effort 
mechanism. In other words, whenever types are not annotated and cannot 
be inferred, the type checker considers such code valid. Type errors are 
only reported in case of explicit or inferred conflict. Moreover, as a 
mechanism that is not tied to execution of the code, it does not affect 
runtime behaviour. In other words, even in the case of a typing error, 
the program will continue running.

The implementation of a type checker, whether linting source files or 
enforcing type information during runtime, is out of scope for this PEP."

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rosuav at gmail.com  Thu Jan 22 13:33:00 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 23 Jan 2015 05:33:00 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
Message-ID: <CAPTjJmpgEdn_J5DRW-JAbfJV=f7qQFcZmuqBZHLANZ-viA6Nug@mail.gmail.com>

On Fri, Jan 23, 2015 at 5:03 AM, Sturla Molden <sturla.molden at gmail.com> wrote:
> Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
>
>> Remember too that type-hinting will *absolutely* remain *completely*
>> optional for Python. Developers can choose to use it or not,
>
> No! Developers have to do what managers and customers tell them to do. They
> will start to require type hinting everywhere. And then the question is
> what Python has to offer over Java or Swift.

Uhh... if your managers and customers are stipulating non-Pythonic
coding styles, then it's time to find new managers/customers. If
they're not writing the code, code quality shouldn't be their concern.

Of course, if you want to switch to Swift, sure, but I'm going to keep
working on Python. Just please don't FUD this list.

ChrisA


From random832 at fastmail.us  Thu Jan 22 13:41:29 2015
From: random832 at fastmail.us (random832 at fastmail.us)
Date: Thu, 22 Jan 2015 13:41:29 -0500
Subject: Python is DOOMED! Again!
In-Reply-To: <m9rfg8$vuv$1@ger.gmane.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
Message-ID: <1421952089.204892.217546113.4BE1C824@webmail.messagingengine.com>

On Thu, Jan 22, 2015, at 13:28, Mark Lawrence wrote:
> Evidence in completely the opposite direction if I'm reading this 
> correctly https://www.python.org/dev/peps/pep-0484/#usage-patterns
> 
> "The main use case of type hinting is static analysis using an external 
> tool without executing the analyzed program. Existing tools used for 
> that purpose like pyflakes [pyflakes] or pylint [pylint] might be 
> extended to support type checking. New tools, like mypy's mypy -S mode, 
> can be adopted specifically for this purpose.

How is that the opposite direction? It's a short jump from there to
"pylint [or whatever tool] will consider a lack of type hinting to be
something to warn for" and "managers/customers will consider this
warning to mean your program has failed and is unacceptable".


From breamoreboy at yahoo.co.uk  Thu Jan 22 14:05:16 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 22 Jan 2015 19:05:16 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <1421952089.204892.217546113.4BE1C824@webmail.messagingengine.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
 <1421952089.204892.217546113.4BE1C824@webmail.messagingengine.com>
Message-ID: <m9rhli$b37$1@ger.gmane.org>

On 22/01/2015 18:41, random832 at fastmail.us wrote:
> On Thu, Jan 22, 2015, at 13:28, Mark Lawrence wrote:
>> Evidence in completely the opposite direction if I'm reading this
>> correctly https://www.python.org/dev/peps/pep-0484/#usage-patterns
>>
>> "The main use case of type hinting is static analysis using an external
>> tool without executing the analyzed program. Existing tools used for
>> that purpose like pyflakes [pyflakes] or pylint [pylint] might be
>> extended to support type checking. New tools, like mypy's mypy -S mode,
>> can be adopted specifically for this purpose.
>
> How is that the opposite direction? It's a short jump from there to
> "pylint [or whatever tool] will consider a lack of type hinting to be
> something to warn for" and "managers/customers will consider this
> warning to mean your program has failed and is unacceptable".
>

You've snipped the other two paragraphs of the quote that I gave thus 
completely altering the context.  If they're too stupid to know the 
meaning of the word "hint" that's their problem.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From sturla.molden at gmail.com  Thu Jan 22 14:07:37 2015
From: sturla.molden at gmail.com (Sturla Molden)
Date: Thu, 22 Jan 2015 19:07:37 +0000 (UTC)
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CAPTjJmpgEdn_J5DRW-JAbfJV=f7qQFcZmuqBZHLANZ-viA6Nug@mail.gmail.com>
Message-ID: <1109172234443646336.064542sturla.molden-gmail.com@news.gmane.org>

Chris Angelico <rosuav at gmail.com> wrote:

> Uhh... if your managers and customers are stipulating non-Pythonic
> coding styles, then it's time to find new managers/customers. If
> they're not writing the code, code quality shouldn't be their concern.

I am saying the day someone requires me to write a type hint, I will no
longer be using Python or recommending it. Python is great, but not that
great.



From marko at pacujo.net  Thu Jan 22 14:08:12 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 22 Jan 2015 21:08:12 +0200
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17978.1421949825.18130.python-list@python.org>
Message-ID: <871tmmhbvn.fsf@elektro.pacujo.net>

Sturla Molden <sturla.molden at gmail.com>:

> No! Developers have to do what managers and customers tell them to do.
> They will start to require type hinting everywhere. And then the
> question is what Python has to offer over Java or Swift.

Yes, but that's what GvR is after, I'm guessing: have Python take over
the realms of Java and C#.

> Python will no longer be dynamic, it will just be a slow static language.

Defeating Java will be worth the loss! The business value of the
disillusioned early adopters is minuscule compared with the bounty of
enterprise computing.

Py3EE ? how cool is that!

> Yes, Python could still be used as a dynamic language, but nobody will
> allow you to do it. Even packages in widespread use will be banned
> because they don't typehint. And then there will be complaint about
> lack of such packages.

The managers want type checking, not to optimize, but to mechanically
guarantee the correctness of the code. Most people they hire aren't all
that skilled at coding and will fall in every trap they can. They'd like
automated tools to put straitjackets on their reports so they can do as
little damage as possible.

Then there will be the optimizers, enthusiastic hackers who just need to
tweak with nanoseconds, overclock and benchmark everything and add
liquid nitrogen cooling on top of that. They will sprinkle elaborate
type declarations anywhere they can and indirectly force applications
that interface with their code to declare types as well.


Marko


From sturla.molden at gmail.com  Thu Jan 22 14:09:28 2015
From: sturla.molden at gmail.com (Sturla Molden)
Date: Thu, 22 Jan 2015 19:09:28 +0000 (UTC)
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
 <1421952089.204892.217546113.4BE1C824@webmail.messagingengine.com>
 <m9rhli$b37$1@ger.gmane.org>
Message-ID: <925914839443646518.837194sturla.molden-gmail.com@news.gmane.org>

Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:

> If they're too stupid to know the 
> meaning of the word "hint" that's their problem.

It will also be Python's problem, because people are that stupid.



From marfig at gmail.com  Thu Jan 22 14:10:36 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Thu, 22 Jan 2015 20:10:36 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
 <mailman.17984.1421952098.18130.python-list@python.org>
Message-ID: <MPG.2f2b697d288c74b2989685@nntp.aioe.org>

In article <mailman.17984.1421952098.18130.python-list at python.org>, 
random832 at fastmail.us says...
> How is that the opposite direction? It's a short jump from there to
> "pylint [or whatever tool] will consider a lack of type hinting to be
> something to warn for" and "managers/customers will consider this
> warning to mean your program has failed and is unacceptable".

Customers don't have access to static analysis output and project 
managers should know better than to demand static analysis without 
properly contextualize it. I just don't see a project manager having no 
idea what static analysis means.

I think you are completely of the mark here, if you think type 
annotations will become some sort of obligatory feature.

The criticism is about the choices regarding its syntax and whether it 
should couple so tightly with our source code (as is suggested on the 
PEP) and whether it should be entirely moved to comment-like structures.

No one in their right mind looks at static analysis as an obligatory 
feature in Python, or any other programming language.


From marko at pacujo.net  Thu Jan 22 14:16:52 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 22 Jan 2015 21:16:52 +0200
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
Message-ID: <87wq4efwwr.fsf@elektro.pacujo.net>

Mark Lawrence <breamoreboy at yahoo.co.uk>:

> Evidence in completely the opposite direction if I'm reading this
> correctly https://www.python.org/dev/peps/pep-0484/#usage-patterns

That's not evidence, that's a prophecy.

What I'm seeing is a bad shift in the Python culture. What's next?
Unboxed objects? Unsafe objects? Micromanaged GC?

I'm afraid Python will lose its taste. Why not let Java handle its
niche? Maybe Go is the way to go for some applications? C++ might have
its uses. C is still the weapon of choice in many situations. Python is
perfect already. It doesn't need to get any faster.


Marko


From tjreedy at udel.edu  Thu Jan 22 14:20:04 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Thu, 22 Jan 2015 14:20:04 -0500
Subject: Python is DOOMED! Again!
In-Reply-To: <2d7880a5-9c2d-4a04-81f0-aa1e1d493e1a@googlegroups.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <3fbbc664-ab4b-46e1-98a8-3859cb84fbb0@googlegroups.com>
 <8738738g5a.fsf@jester.gateway.sonic.net>
 <2d7880a5-9c2d-4a04-81f0-aa1e1d493e1a@googlegroups.com>
Message-ID: <m9rih6$pr3$1@ger.gmane.org>

On 1/22/2015 3:24 AM, Rick Johnson wrote:

> Yes, YES, *YES*!!!! That would be my first choice, or
> docstrings as a secondary. But to introduce new syntax
> into the method signatures is SUICIDE! What the hell is
> this man thinking?

You are years late for complaining about new signature syntax.  The 
'new' annotation syntax was introduced 5+ years ago in 3.0 and is 
already being used for various purposes, but mostly for type hinting.

The current proposal is to introduce a new module that standardizes the 
type-hinting use.  It is true that it will likely make the use of 
annotation more common.

-- 
Terry Jan Reedy



From marko at pacujo.net  Thu Jan 22 14:22:59 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 22 Jan 2015 21:22:59 +0200
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <mailman.17983.1421951583.18130.python-list@python.org>
Message-ID: <87sif2fwmk.fsf@elektro.pacujo.net>

Chris Angelico <rosuav at gmail.com>:

> Uhh... if your managers and customers are stipulating non-Pythonic
> coding styles, then it's time to find new managers/customers.

Hah! What's considered Pythonic seems to be changing. Old-school
Pythonic will be heresy, and new-school Pythonic will be exalted to
dogma.

> Just please don't FUD this list.

Why do you think opinions on Python's future should be kept off this
list?


Marko


From no.email at nospam.invalid  Thu Jan 22 14:23:13 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Thu, 22 Jan 2015 11:23:13 -0800
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
Message-ID: <87iofy7h7i.fsf@jester.gateway.sonic.net>

Mario Figueiredo <marfig at gmail.com> writes:
> Strangely enough though I was taught from the early beginning that
> once I start to care about types in Python, I strayed from the
> pythonic way. 

That's a weird concept.  You always have to care about types.  It's just
that with a bit of discipline combined with unit tests to catch any
errors, you can keep the flow of types through the program simple enough
that you can get by without static analysis.  That frees your style in
some ways and cramps it in others.

https://cdsmith.wordpress.com/2011/01/09/an-old-article-i-wrote/
gets posted here now and then, and is still well worth reading.


From no.email at nospam.invalid  Thu Jan 22 14:25:41 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Thu, 22 Jan 2015 11:25:41 -0800
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <87egqm7h3e.fsf@jester.gateway.sonic.net>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:
> Since the "language wars" of the 1990s, dynamic languages have won. 

Are you kidding?  Nothing has won, the wars are still going on, and
dynamic and static typing both have their winning use cases and will be
around forever.


From no.email at nospam.invalid  Thu Jan 22 14:36:28 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Thu, 22 Jan 2015 11:36:28 -0800
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <87wq4efwwr.fsf@elektro.pacujo.net>
Message-ID: <87a91a7glf.fsf@jester.gateway.sonic.net>

>> correctly https://www.python.org/dev/peps/pep-0484/#usage-patterns
> That's not evidence, that's a prophecy.
> What I'm seeing is a bad shift in the Python culture. What's next?
> Unboxed objects? Unsafe objects? Micromanaged GC?

Why are you freaking out so much?  The "prophecy" is for something like
the Erlang Dialyzer, which has been very successful and useful in the
Erlang world.  Erlang is still dynamically typed (it's essentially Lisp
under the skin) but you can include some annotations that let external
tools (Dialyzer) check your program for type consistency.  Lots of bugs
in supposedly reliable production code were found after the Dialyzer was
deployed.  It would be great to have something like it for Python.


From skip.montanaro at gmail.com  Thu Jan 22 14:43:15 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Thu, 22 Jan 2015 13:43:15 -0600
Subject: Python is DOOMED! Again!
In-Reply-To: <87sif2fwmk.fsf@elektro.pacujo.net>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <mailman.17983.1421951583.18130.python-list@python.org>
 <87sif2fwmk.fsf@elektro.pacujo.net>
Message-ID: <CANc-5UwC5vMSAcUE07WkD2Wy8t36N5KXZCrzzmw9nxU-6dVNyw@mail.gmail.com>

On Thu, Jan 22, 2015 at 1:22 PM, Marko Rauhamaa <marko at pacujo.net> wrote:

> > Just please don't FUD this list.
>
> Why do you think opinions on Python's future should be kept off this
> list?


The way you couched your opinion as a certainty, as if you could see the
future, not as if you had an opinion stated like, "do you think this might
happen?"

Skip
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From sturla.molden at gmail.com  Thu Jan 22 14:53:46 2015
From: sturla.molden at gmail.com (Sturla Molden)
Date: Thu, 22 Jan 2015 20:53:46 +0100
Subject: Python is DOOMED! Again!
In-Reply-To: <MPG.2f2b697d288c74b2989685@nntp.aioe.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
 <mailman.17984.1421952098.18130.python-list@python.org>
 <MPG.2f2b697d288c74b2989685@nntp.aioe.org>
Message-ID: <m9rkga$rlj$1@ger.gmane.org>

On 22/01/15 20:10, Mario Figueiredo wrote:

> Customers don't have access to static analysis output and project
> managers should know better than to demand static analysis without
> properly contextualize it. I just don't see a project manager having no
> idea what static analysis means.

I don't know how it works in you country, but here projects managers are 
selected for having any kind of skill other than technical knowledge. I 
know of one who got the job because he was a professional hockey player. 
So yes, they can very well be unaware what static analysis means. But 
what they will do is pick up "buzzwords" from the kind of journals that 
project managers read. And then they want that buzzword implemented.

Sturla



From sturla.molden at gmail.com  Thu Jan 22 14:56:09 2015
From: sturla.molden at gmail.com (Sturla Molden)
Date: Thu, 22 Jan 2015 20:56:09 +0100
Subject: Python is DOOMED! Again!
In-Reply-To: <CANc-5UwC5vMSAcUE07WkD2Wy8t36N5KXZCrzzmw9nxU-6dVNyw@mail.gmail.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <mailman.17983.1421951583.18130.python-list@python.org>
 <87sif2fwmk.fsf@elektro.pacujo.net>
 <CANc-5UwC5vMSAcUE07WkD2Wy8t36N5KXZCrzzmw9nxU-6dVNyw@mail.gmail.com>
Message-ID: <m9rkkp$rlj$2@ger.gmane.org>

On 22/01/15 20:43, Skip Montanaro wrote:

> The way you couched your opinion as a certainty, as if you could see the
> future,

How do you know I cannot?






From breamoreboy at yahoo.co.uk  Thu Jan 22 14:56:47 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 22 Jan 2015 19:56:47 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <87egqm7h3e.fsf@jester.gateway.sonic.net>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <87egqm7h3e.fsf@jester.gateway.sonic.net>
Message-ID: <m9rkm6$upa$1@ger.gmane.org>

On 22/01/2015 19:25, Paul Rubin wrote:
> Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:
>> Since the "language wars" of the 1990s, dynamic languages have won.
>
> Are you kidding?  Nothing has won, the wars are still going on, and
> dynamic and static typing both have their winning use cases and will be
> around forever.
>

Unless you offer a new language that is absolutely guaranteed to have 
the best of both worlds, in which case there'd be major flame wars over 
whether you'd call it dynatically or stamically typed.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From marfig at gmail.com  Thu Jan 22 15:03:14 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Thu, 22 Jan 2015 21:03:14 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
 <mailman.17984.1421952098.18130.python-list@python.org>
 <MPG.2f2b697d288c74b2989685@nntp.aioe.org>
 <mailman.17990.1421956437.18130.python-list@python.org>
Message-ID: <MPG.2f2b75c814639267989686@nntp.aioe.org>

In article <mailman.17990.1421956437.18130.python-list at python.org>, 
sturla.molden at gmail.com says...
> 
> On 22/01/15 20:10, Mario Figueiredo wrote:
> 
> > Customers don't have access to static analysis output and project
> > managers should know better than to demand static analysis without
> > properly contextualize it. I just don't see a project manager having no
> > idea what static analysis means.
> 
> I don't know how it works in you country, but here projects managers are 
> selected for having any kind of skill other than technical knowledge. I 
> know of one who got the job because he was a professional hockey player. 
> So yes, they can very well be unaware what static analysis means. But 
> what they will do is pick up "buzzwords" from the kind of journals that 
> project managers read. And then they want that buzzword implemented.
> 
> Sturla

That is fine. But then the problem isn't type hinting, is it? Neither I 
think you are suggesting we don't introduce language because there are 
bad project managers out there.

The problem is then bad project managers. That has nothing to do with 
type hinting, or Python for that matter.


From ian.g.kelly at gmail.com  Thu Jan 22 15:06:09 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 22 Jan 2015 13:06:09 -0700
Subject: kivy secret of mana game
In-Reply-To: <slrnmc2c3g.77n.automn@sigtrans.org>
References: <slrnmc2c3g.77n.automn@sigtrans.org>
Message-ID: <CALwzidnGBoMd=fdWc=q3jvfBGFbW81EJfjgO1aaixUZtauT-7A@mail.gmail.com>

On Thu, Jan 22, 2015 at 10:13 AM, Automn <automn at willow.org> wrote:
> The graphics have been licensed for this.

Really? I'm surprised Square-Enix would even give consideration to
licensing something like this.


From rantingrickjohnson at gmail.com  Thu Jan 22 15:23:15 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 22 Jan 2015 12:23:15 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <1a194e0a09cf8d2044e268d5585@nntp.aioe.org>
References: <b631cc7a-2f2a-4269-9a0d-7228103f1852@googlegroups.com>
 <1a194e0a09cf8d2044e268d5585@nntp.aioe.org>
Message-ID: <df42ff5a-e4fe-4129-9278-1a5eaa6993b3@googlegroups.com>

On Thursday, January 22, 2015 at 4:32:04 AM UTC-6, Mario Figueiredo wrote:
> Rick,
> 
> > Python is the only thing that is pure in the programming
> > world. The only language that offers the cleanest and
> > most intuit-able syntax, AND YOU"RE JUST GOING TO THROW
> > IT ALL AWAY [...] ?
> 
> Nonsense. You are just used to it. I can read C with the
> same feeling of intuitiveness as you do Python. There's
> nothing inherently more intuitive about python and I just
> wished that meme died already. Besides it's all in the eye
> of the beholder.

And is *YOUR* eye the only eye in this universe? A concert
pianist could say the same about a piece of music that only
a handful of people in the world could play!

    YOU'RE IGNORING WHAT PYTHON WAS, AND IS MEANT TO BE!

Python was not created to be some esoteric language that
sadistic professors could drop on students heads like a
grand piano from a third story window, *NO*, python was
meant to be a gateway to intuitive programming bliss. 

Python was meant to be the "lingua franca" of the
Programming world. The idea was to cut out the noisy syn
taxes that plagued other language and thereby allow the
programmer to focus on solving problems and writing
algorithms.

As the complexity of a syntax increases, so too does the
work required to comprehend it. If you like C so much then
go back to writing C code, Python fills a niche, and we must
remain committed to our founding goals.

  THIS "TYPE HINTING" IDEA HAS TO BE THE SINGLE WORSE CASE
  OF FEATURE CREEP I'VE EVER HEARD OF!

> PEP 484 just becomes silly when it comes to the section
> where it discusses whether type hints are pythonic. If
> that ridiculous paragraph reflects how we are looking
> today at the inclusion of new features, than I agree
> python is walking a dangerous road. 

  "IF THE IMPLEMENTATION IS HARD TO EXPLAIN, IT'S A BAD
  IDEA."
  
> But that also means Type Hints aren't the real problem
> here. We have a much bigger problem about the programming
> language principles and philosophy.

I don't understand??? 

Now it seems you are agreeing with me?

Are you sure you've given this issue it's due consideration?
And have you weighed that consideration from an objective
perspective? I think any rational person would agree that
Python is more important than our personal needs, wants, or
desires.

> In all honesty though, I never cared much about the ideals
> and zens in programming languages, especially ones want to
> want to adopt a batteries-included philosophy.

And yet you're here, using the Python language who's
*SECOND-PHILOSOPHICAL-GOAL* was to provide a large stdlib.

Why are you torturing yourself by using a language you
obviously don't like? But more importantly, why are you
attempting to torture everyone else by encouraging the
demise of this fine language? At best this idea will violate
Python's founding philosophy, at worst it will be the end of
something that brought light into a dark world.

> Always seemed to me like nonsense talk. My experience
> taught me that you can't just have the latter without
> eventually breaking the former. 'import this' always read
> to me like wishful thinking.

The "python zen" will always be under attack because it's a
difficult set of rules to follow, but despite the practical
application of the rules, the philosphy they describe is
*SOUND*!

Many times killing an opponent may be easier than attempting
to compromise with him, but we don't sacrifice logical
foundations just to appease every Python programmer who
wants Python to be more like X, Y, or Z! (or REXX!)

What's next? Are we going to cow-tow to the lispers and
adopt "nesting to infinity" just so we can go around
blabbing about how easy a lisp interpreter is to write,
never mind that writing any *REAL* lisp code is an exercise
in *EYEBALL-PARSING-ASININITY*!

How about taking after the Perl philosophy of peppering the
syntax with punctuation until the very sight of it causes an
intellectual sneeze fest! 

Not enough for you? Heck, why allow Dijkstra to rest-in-
peace in an upward facing position when we could resurrect
GOTO!

Need more examples?


> Python isn't going anywhere towards obscurity. Not at
> least until a competiting language comes (it hasn't yet).
> I agree though that Python complexity has increased
> greatly over the years and this isn't showing any signs of
> stopping. And that is exactly the type of thing that
> promotes the birth of a new and better programming
> language. And, interestingly enough, that is always a good
> thing.

I agree. The birth of new languages is always a good thing,
(i'm a huge fan of evolution if you have not noticed!), and
i am fully aware that Python is not going to live forever.

Sooner or later someone will see the deficiencies of Python
and think: "Hey, i can do better!", but that time is not
now. Python still has a firm grip on the niche of
"intuitive syntax with batteries included" and we have a
*DUTY* to every potential programmer to ensure that Python
will be available for them when they need it. 

 YOU CANNOT BENEFIT EVOLUTION BY COMMITTING SUICIDE!

============================================================
 SUMMARY
============================================================
You argue that readability is a relative construct, and you
are correct, but what you fail to acknowledge is that while
the ability to read noisy syntaxes improves with practice,
the comprehensive abilities of neophytes will always remain
constant. Python was built for the sake of the neophytes, 
not to suffer the whims of the guru!


From rantingrickjohnson at gmail.com  Thu Jan 22 15:24:58 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 22 Jan 2015 12:24:58 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <1a194e0a09d48d2044efdfe5477@nntp.aioe.org>
References: <mailman.17965.1421921362.18130.python-list@python.org>
 <1a194e0a09d48d2044efdfe5477@nntp.aioe.org>
Message-ID: <372dd8be-6910-4c55-a1e8-1a1f1466dcaa@googlegroups.com>

On Thursday, January 22, 2015 at 4:37:49 AM UTC-6, Mario Figueiredo wrote:

> I could replace the variable names with spam, ham and eggs, if you wish.

ROTF!


From skip.montanaro at gmail.com  Thu Jan 22 15:31:30 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Thu, 22 Jan 2015 14:31:30 -0600
Subject: Python is DOOMED! Again!
In-Reply-To: <m9rkkp$rlj$2@ger.gmane.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <mailman.17983.1421951583.18130.python-list@python.org>
 <87sif2fwmk.fsf@elektro.pacujo.net>
 <CANc-5UwC5vMSAcUE07WkD2Wy8t36N5KXZCrzzmw9nxU-6dVNyw@mail.gmail.com>
 <m9rkkp$rlj$2@ger.gmane.org>
Message-ID: <CANc-5UzWLA-t8C-zHygEfofi1Ysb_VryqtJ--Y_aJLg3EO0wdQ@mail.gmail.com>

On Thu, Jan 22, 2015 at 1:56 PM, Sturla Molden <sturla.molden at gmail.com>
wrote:

> On 22/01/15 20:43, Skip Montanaro wrote:
>
>  The way you couched your opinion as a certainty, as if you could see the
>> future,
>>
>
> How do you know I cannot?


Perhaps you can, but then your statements are opinions, then are they?

Skip
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From skip.montanaro at gmail.com  Thu Jan 22 15:32:42 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Thu, 22 Jan 2015 14:32:42 -0600
Subject: Python is DOOMED! Again!
In-Reply-To: <CANc-5UzWLA-t8C-zHygEfofi1Ysb_VryqtJ--Y_aJLg3EO0wdQ@mail.gmail.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <mailman.17983.1421951583.18130.python-list@python.org>
 <87sif2fwmk.fsf@elektro.pacujo.net>
 <CANc-5UwC5vMSAcUE07WkD2Wy8t36N5KXZCrzzmw9nxU-6dVNyw@mail.gmail.com>
 <m9rkkp$rlj$2@ger.gmane.org>
 <CANc-5UzWLA-t8C-zHygEfofi1Ysb_VryqtJ--Y_aJLg3EO0wdQ@mail.gmail.com>
Message-ID: <CANc-5UzR-4wWJiTHyCfQM42nKMZ+B18KUKAcRG5_57Fn4ojC5g@mail.gmail.com>

On Thu, Jan 22, 2015 at 2:31 PM, Skip Montanaro <skip.montanaro at gmail.com>
wrote:

> Perhaps you can, but then your statements are opinions, then are they?


Crap. I meant:

"... then your statements aren't opinions ..."

S
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From rantingrickjohnson at gmail.com  Thu Jan 22 15:38:58 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 22 Jan 2015 12:38:58 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <mailman.17980.1421950499.18130.python-list@python.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <mailman.17980.1421950499.18130.python-list@python.org>
Message-ID: <bdccca3a-3793-446f-bf50-2fe49b7bba5d@googlegroups.com>

On Thursday, January 22, 2015 at 12:15:11 PM UTC-6, Skip Montanaro wrote:
> On Thu, Jan 22, 2015 at 12:03 PM, Sturla Molden <sturla... at gmail.com> wrote:
>
> > Python will no longer be dynamic, it will just be a slow
> > static language. Yes, Python could still be used as a
> > dynamic language, but nobody will allow you to do it.
> > Even packages in widespread use will be banned because
> > they don't typehint. And then there will be complaint
> > about lack of such packages.
> 
> FUD? What evidence do you have that this will be the way
> things shake out?

And what evidence do *YOU* have that supports your argument?
You cannot invalidate an unproven argument by juxtaposing
it with another unproven argument.



From rantingrickjohnson at gmail.com  Thu Jan 22 15:44:33 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 22 Jan 2015 12:44:33 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <mailman.17982.1421951313.18130.python-list@python.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
Message-ID: <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>

On Thursday, January 22, 2015 at 12:28:47 PM UTC-6, Mark Lawrence wrote:
> Evidence in completely the opposite direction if I'm
> reading this correctly [snip link]
> 
> "The main use case of type hinting is static analysis
> using an external tool without executing the analyzed
> program. Existing tools used for that purpose like
> pyflakes [pyflakes] or pylint [pylint] might be extended
> to support type checking. New tools, like mypy's mypy -S
> mode, can be adopted specifically for this purpose.

So if the purpose is "static analysis", what is the
justification for injecting new syntax into function sigs?
I'm not *TOTALLY* against the idea of "type hints", but i am
*TOTALLY* against their proposed location.


From python at mrabarnett.plus.com  Thu Jan 22 15:46:58 2015
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 22 Jan 2015 20:46:58 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <df42ff5a-e4fe-4129-9278-1a5eaa6993b3@googlegroups.com>
References: <b631cc7a-2f2a-4269-9a0d-7228103f1852@googlegroups.com>
 <1a194e0a09cf8d2044e268d5585@nntp.aioe.org>
 <df42ff5a-e4fe-4129-9278-1a5eaa6993b3@googlegroups.com>
Message-ID: <54C161C2.7070905@mrabarnett.plus.com>

On 2015-01-22 20:23, Rick Johnson wrote:
> On Thursday, January 22, 2015 at 4:32:04 AM UTC-6, Mario Figueiredo wrote:
>> Rick,
>>
>> > Python is the only thing that is pure in the programming
>> > world. The only language that offers the cleanest and
>> > most intuit-able syntax, AND YOU"RE JUST GOING TO THROW
>> > IT ALL AWAY [...] ?
>>
>> Nonsense. You are just used to it. I can read C with the
>> same feeling of intuitiveness as you do Python. There's
>> nothing inherently more intuitive about python and I just
>> wished that meme died already. Besides it's all in the eye
>> of the beholder.
>
> And is *YOUR* eye the only eye in this universe? A concert
> pianist could say the same about a piece of music that only
> a handful of people in the world could play!
>
>      YOU'RE IGNORING WHAT PYTHON WAS, AND IS MEANT TO BE!
>
> Python was not created to be some esoteric language that
> sadistic professors could drop on students heads like a
> grand piano from a third story window, *NO*, python was
> meant to be a gateway to intuitive programming bliss.
>
> Python was meant to be the "lingua franca" of the
> Programming world. The idea was to cut out the noisy syn
> taxes that plagued other language and thereby allow the
> programmer to focus on solving problems and writing
> algorithms.
>
If you want to know why Python was created, ask its creator:

"""My original motivation for creating Python was the perceived need
for a higher level language in the Amoeba project. I realized that the
development of system administration utilities in C was taking too
long. ... So there was a need for a language that would "bridge the gap
between C and the shell." For a long time, this was Python?s main
catchphrase."""

http://python-history.blogspot.co.uk/2009/01/personal-history-part-1-cwi.html



From breamoreboy at yahoo.co.uk  Thu Jan 22 15:50:18 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 22 Jan 2015 20:50:18 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
Message-ID: <m9rnqg$fri$1@ger.gmane.org>

On 22/01/2015 20:44, Rick Johnson wrote:
> On Thursday, January 22, 2015 at 12:28:47 PM UTC-6, Mark Lawrence wrote:
>> Evidence in completely the opposite direction if I'm
>> reading this correctly [snip link]
>>
>> "The main use case of type hinting is static analysis
>> using an external tool without executing the analyzed
>> program. Existing tools used for that purpose like
>> pyflakes [pyflakes] or pylint [pylint] might be extended
>> to support type checking. New tools, like mypy's mypy -S
>> mode, can be adopted specifically for this purpose.
>
> So if the purpose is "static analysis", what is the
> justification for injecting new syntax into function sigs?
> I'm not *TOTALLY* against the idea of "type hints", but i am
> *TOTALLY* against their proposed location.
>

Fine, just write an alternative PEP.

Personally I couldn't give one hoot let alone two whether or not this 
proposal ever sees the light of day.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From marfig at gmail.com  Thu Jan 22 16:06:02 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Thu, 22 Jan 2015 22:06:02 +0100
Subject: Python is DOOMED! Again!
References: <b631cc7a-2f2a-4269-9a0d-7228103f1852@googlegroups.com>
 <1a194e0a09cf8d2044e268d5585@nntp.aioe.org>
 <df42ff5a-e4fe-4129-9278-1a5eaa6993b3@googlegroups.com>
Message-ID: <MPG.2f2b84a3b2318e2e989687@nntp.aioe.org>

In article <df42ff5a-e4fe-4129-9278-1a5eaa6993b3 at googlegroups.com>, 
rantingrickjohnson at gmail.com says...

> python was meant to be a gateway to intuitive programming bliss. 
> Python was meant to be the "lingua franca" of the Programming world.

And it failed miserably on both instances. Like any other programming 
language before and after it which pretended to be the one stop solution 
to world hunger.
 
No. Python most important goal is to solve software requirements, like 
any programming language should. Intuitiveness, simplicity, easy of use, 
expressiveness, and all the other waiving flags you like to carry, are 
secondary-only goals. You sacrifice them for the first goal if they get 
in the way. It's the way of any evolving language.

> You argue that readability is a relative construct, and you
> are correct, but what you fail to acknowledge is that while
> the ability to read noisy syntaxes improves with practice,
> the comprehensive abilities of neophytes will always remain
> constant. Python was built for the sake of the neophytes, 
> not to suffer the whims of the guru!

I couldn't give a rat's arse about neophytes and I consider myself a 
beginner in the world of python. I'm more interested in having a 
language that can solve my problems.

Expressiveness, simplicity, intuitiveness, all are lofty goals. But they 
are always going to be limited by the feature set of your language. And 
as it grows, as it tries to incorporate more and more features in order 
to become more and more capable of handling all types of modern software 
requirements, it will loose some of that expressivness, some of that 
simplicity and some of that intuitiveness. It's just how it is with any 
programming language.


From rantingrickjohnson at gmail.com  Thu Jan 22 16:08:28 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 22 Jan 2015 13:08:28 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <87sif2fwmk.fsf@elektro.pacujo.net>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <mailman.17983.1421951583.18130.python-list@python.org>
 <87sif2fwmk.fsf@elektro.pacujo.net>
Message-ID: <07b43d77-aee3-41de-b3eb-61719061226a@googlegroups.com>

On Thursday, January 22, 2015 at 1:23:11 PM UTC-6, Marko Rauhamaa wrote:
> Chris Angelico:
>
> > Just please don't FUD this list.
> 
> Why do you think opinions on Python's future should be
> kept off this list?
 
Because he's one of the more prevalent boot licking rabbid
fanboys of GvR. If you don't believe me then Google this 
thread:

  [Python-ideas] Need help converting HTML doc to ReST
  
He replied within 15 mins with great enthusiasm to do his
"master's bidding". How pathetic!

Python is not as "open" as the PSF policy statements would
have you believe. You either agree with GvR (and his
minions), or you don't exist. It's that simple.



From ian.g.kelly at gmail.com  Thu Jan 22 16:24:36 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 22 Jan 2015 14:24:36 -0700
Subject: Python is DOOMED! Again!
In-Reply-To: <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CALwzid=EX=nV=_bzPoFCCqzRNb_BMr21Rdc502013oTSPpnoKw@mail.gmail.com>

On Thu, Jan 22, 2015 at 7:16 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
>> Meanwhile, there's the strange decision to implement type hints for
>> local variables # comment lines. I have an hard time wrapping my head
>> around this one. Really, comments!?
>
> Yes, really. There is plenty of prior art for machine-meaningful comments:
>
> - mypy uses it, and it works fine
> - Pascal uses {$ ...} compiler directives
> - Unix uses a special hash-bang #! comment in the first line to
>   specify the executable that runs the script
> - Python supports a special encoding declaration using #
> - doctest uses comments for directives
> - HTML puts code (Javascript usually) inside of comments
> - JMSAssert for Java uses comments for design-by-contract assertions

Perhaps even more relevant to PEP 484:

- The Closure compiler for Javascript uses JSDoc tags in comments for
static typing and analysis.


From marko at pacujo.net  Thu Jan 22 16:25:08 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Thu, 22 Jan 2015 23:25:08 +0200
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <mailman.17983.1421951583.18130.python-list@python.org>
 <87sif2fwmk.fsf@elektro.pacujo.net>
 <07b43d77-aee3-41de-b3eb-61719061226a@googlegroups.com>
Message-ID: <87h9vifqyz.fsf@elektro.pacujo.net>

Rick Johnson <rantingrickjohnson at gmail.com>:

> On Thursday, January 22, 2015 at 1:23:11 PM UTC-6, Marko Rauhamaa wrote:
> Because he's one of the more prevalent boot licking rabbid
> fanboys of GvR.

You are out of line, but then, you never pretended otherwise.


Marko


From emile at fenx.com  Thu Jan 22 16:56:58 2015
From: emile at fenx.com (Emile van Sebille)
Date: Thu, 22 Jan 2015 13:56:58 -0800
Subject: Python is DOOMED! Again!
In-Reply-To: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <m9rrnd$l8h$1@ger.gmane.org>

On 1/21/2015 8:30 PM, Steven D'Aprano wrote:

<snip>

> Here's an example from PEP 484:
>
> def greeting(name: str) -> str:
>      return 'Hello ' + name

I've been lightly scanning and following the PEP 484 discussion, and one 
point I don't think I've seen mentioned is how you might hint a function 
that accepts different types, eg:

def adder(a,b): return a+b

This is one of the pythonic idioms that help with polymorphic functions. 
  Is there a proposal for providing hinting for these?

Thanks,

Emile




From ian.g.kelly at gmail.com  Thu Jan 22 17:08:14 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 22 Jan 2015 15:08:14 -0700
Subject: Python is DOOMED! Again!
In-Reply-To: <m9rrnd$l8h$1@ger.gmane.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <m9rrnd$l8h$1@ger.gmane.org>
Message-ID: <CALwzidmZzogxZqLgC8qYHXhseGBEpoFN5cQgL14N_rwyiRU=Jw@mail.gmail.com>

On Thu, Jan 22, 2015 at 2:56 PM, Emile van Sebille <emile at fenx.com> wrote:
> I've been lightly scanning and following the PEP 484 discussion, and one
> point I don't think I've seen mentioned is how you might hint a function
> that accepts different types, eg:
>
> def adder(a,b): return a+b
>
> This is one of the pythonic idioms that help with polymorphic functions.  Is
> there a proposal for providing hinting for these?

You can use TypeVar for that.

T = TypeVar('T')

def adder(a: T, b: T) -> T:
    return a + b

I'm not thrilled about having to actually declare T in this sort of
situation, but I don't have a better proposal.


From ian.g.kelly at gmail.com  Thu Jan 22 17:12:30 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 22 Jan 2015 15:12:30 -0700
Subject: Python is DOOMED! Again!
In-Reply-To: <CALwzidmZzogxZqLgC8qYHXhseGBEpoFN5cQgL14N_rwyiRU=Jw@mail.gmail.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <m9rrnd$l8h$1@ger.gmane.org>
 <CALwzidmZzogxZqLgC8qYHXhseGBEpoFN5cQgL14N_rwyiRU=Jw@mail.gmail.com>
Message-ID: <CALwzidmW-8YQYBAB5+tbUFY0iB3PVHjyXL2eqL1g43WPVWiETA@mail.gmail.com>

On Thu, Jan 22, 2015 at 3:08 PM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> On Thu, Jan 22, 2015 at 2:56 PM, Emile van Sebille <emile at fenx.com> wrote:
>> I've been lightly scanning and following the PEP 484 discussion, and one
>> point I don't think I've seen mentioned is how you might hint a function
>> that accepts different types, eg:
>>
>> def adder(a,b): return a+b
>>
>> This is one of the pythonic idioms that help with polymorphic functions.  Is
>> there a proposal for providing hinting for these?
>
> You can use TypeVar for that.
>
> T = TypeVar('T')
>
> def adder(a: T, b: T) -> T:
>     return a + b
>
> I'm not thrilled about having to actually declare T in this sort of
> situation, but I don't have a better proposal.

Hmm, but also that hinting doesn't cover cases like adder(12, 37.5)
where two different types can be passed, and the return type could be
either. I think for full generality you would just have to forgo
hinting on this function.


From marfig at gmail.com  Thu Jan 22 17:25:19 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Thu, 22 Jan 2015 23:25:19 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
Message-ID: <MPG.2f2b9739d70d7220989688@nntp.aioe.org>

In article <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb at googlegroups.com>, 
rantingrickjohnson at gmail.com says...
> 
> So if the purpose is "static analysis", what is the
> justification for injecting new syntax into function sigs?

1. Annotations where created exactly for this purpose. So there's some 
preassure to put them to work on what they were always meant to be used 
for.

2. Docstrings are meant as source of code documentation and to fill the 
object's __doc__ attribute, as per PEP 257. As such they aren't good 
consistent candidates for type hinting for purposes of static analysis 
tools.

3. Decorators are meant as function transformation tools, as per PEP 318 
and, as such, are them too not suitable to include type annotations for 
the purpose of static analysis.

4. There is no other formal annotation mechanism, other than these 
potential three.

Arguably, you can make a case against 1. And that's my own issue with 
type hinting as it is being proposed on PEP 484. The real problem is 
annotations as they were defined are a really bad idea. To couple type 
annotations so tightly with code, just results in plain ugly and hard to 
read code.

Personally I would love to see the present annotations just go away and 
a new docstring-like structure to emerge in their place. But that's 
probably not going to happen.

What I agree can't be done though, is to use docstrings or decorators as 
a source for type annotations.


From auriocus at gmx.de  Thu Jan 22 17:26:15 2015
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Thu, 22 Jan 2015 23:26:15 +0100
Subject: apostrophe not considered with tkinter's wordstart and wordend
In-Reply-To: <f1bcb866-b07f-478d-83a4-dcf4b2b096e5@googlegroups.com>
References: <e6143cd5-3475-431a-b2cf-17fd9659681c@googlegroups.com>
 <655cce0d-2db3-4a0d-ab3d-64d5db5e1634@googlegroups.com>
 <714d9211-9b50-4e62-a7dd-25ff94a32d8a@googlegroups.com>
 <f1bcb866-b07f-478d-83a4-dcf4b2b096e5@googlegroups.com>
Message-ID: <m9rtd8$15e$1@dont-email.me>

Am 05.01.15 um 14:20 schrieb Rick Johnson:
> *GASP*! Of course all this could be avoided if those short-
> sighted TK folks would have allowed the programmer to define
> the pattern!
>
> ?_?

Well, it turns out you actually can. We don't have Guido's time machine, 
but still there is a configuration option in Tk, albeit a very obscure 
one: you have to set the global Tcl variables tcl_wordchars and 
tcl_nonwordchars after loading Tk to a regexp which defines the word 
boundaries:

	http://wiki.tcl.tk/1655

Strangely, there is a different preset for Windows and X11. The Windows 
preset - consider everything besides space as part of the word - makes 
more sense to me than the Unix default, which only counts letters, 
numbers and underscores as part of the word. To set the Windows preset, 
do this:

tk.eval('set tcl_wordchars {\S}');
tk.eval('set tcl_nonwordchars {\s}');

(untested in Python, only tested directly from a wish shell)


	Christian


From ckaynor at zindagigames.com  Thu Jan 22 17:27:26 2015
From: ckaynor at zindagigames.com (Chris Kaynor)
Date: Thu, 22 Jan 2015 14:27:26 -0800
Subject: Python is DOOMED! Again!
In-Reply-To: <CALwzidmW-8YQYBAB5+tbUFY0iB3PVHjyXL2eqL1g43WPVWiETA@mail.gmail.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <m9rrnd$l8h$1@ger.gmane.org>
 <CALwzidmZzogxZqLgC8qYHXhseGBEpoFN5cQgL14N_rwyiRU=Jw@mail.gmail.com>
 <CALwzidmW-8YQYBAB5+tbUFY0iB3PVHjyXL2eqL1g43WPVWiETA@mail.gmail.com>
Message-ID: <CALvWhxsaokixX2GtFcjX-6tjVuULoy3hF7emxAfBQqAcaMPQqw@mail.gmail.com>

On Thu, Jan 22, 2015 at 2:12 PM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
>>> def adder(a,b): return a+b
>>>
>>> This is one of the pythonic idioms that help with polymorphic functions.  Is
>>> there a proposal for providing hinting for these?
>>
>> You can use TypeVar for that.
>>
>> T = TypeVar('T')
>>
>> def adder(a: T, b: T) -> T:
>>     return a + b
>>
>> I'm not thrilled about having to actually declare T in this sort of
>> situation, but I don't have a better proposal.
>
> Hmm, but also that hinting doesn't cover cases like adder(12, 37.5)
> where two different types can be passed, and the return type could be
> either. I think for full generality you would just have to forgo
> hinting on this function.

Or use Any, which is basically the same thing:

def adder(a: Any, b: Any) -> Any:
    return a + b

Chris


From ouyanggh0815 at gmail.com  Thu Jan 22 17:35:52 2015
From: ouyanggh0815 at gmail.com (Guohua Ouyang)
Date: Fri, 23 Jan 2015 06:35:52 +0800
Subject: An improper change in httplib.py
In-Reply-To: <112947510.5511972.1421928291463.JavaMail.yahoo@jws11124.mail.ir2.yahoo.com>
References: <CAO0APJRm0PzV5Vu5HNztNPc5UUeFuN+UoHkZaWdA5Cfw6omHXA@mail.gmail.com>
 <112947510.5511972.1421928291463.JavaMail.yahoo@jws11124.mail.ir2.yahoo.com>
Message-ID: <CAO0APJST78M76f4iRhkSZ8Dtb_F9NjVuk5+PRPCYJS7+DoJ5ng@mail.gmail.com>

Have reported an issue http://bugs.python.org/issue23300.

"That leading underscore in the method name means it is not a public
API and thus changes are allowed without any backwards-compatibility
guarantees. Mercurial will need to update their code to handle this if
they want to continue to use the method."

I checked the official mercurial repo, it does not use the method
anymore, so I filed a bug to fedora. [1]

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1185105

On Thu, Jan 22, 2015 at 8:04 PM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> No problem, but out of courtesy could you please reply to the list and not
> just me.
>
> Kindest regards.
>
> Mark Lawrence.
>
>
> On Thursday, 22 January 2015, 11:51, Guohua Ouyang <ouyanggh0815 at gmail.com>
> wrote:
>
>
>
> thanks, file the issue 23300
>
> On Thu, Jan 22, 2015 at 5:06 PM, Mark Lawrence <breamoreboy at yahoo.co.uk>
> wrote:
>> On 22/01/2015 03:38, Guohua Ouyang wrote:
>>>
>>> This is my first post to the list, I apologies firstly if I made any
>>> mistake.
>>>
>>> I was trying to get a package in golang behind the http or https
>>> proxy, and it reports  an error "AttributeError: httpsconnection
>>> instance has no attribute '_set_hostport'", details in the bottom.
>>> After some trace work, I found it caused by the changes in the issue
>>> issue7776.
>>>
>>> @@ -718,7 +734,7 @@
>>>          else:
>>>              self._tunnel_headers.clear()
>>>
>>> -    def _set_hostport(self, host, port):
>>> +    def _get_hostport(self, host, port):
>>>
>>> First, it changes the method's name, doesn't it break the
>>> compatibility for other packages, on my system,
>>> mercurial-3.0-2.fc21.x86_64 still use "_set_hostport" as the error
>>> shows.
>>>
>>> Second, I found that line 1132 of [2] still use "
>>> self._conn._set_hostport(host, port)", which should be
>>> "_get_hostport", right?
>>>
>>> [1] http://bugs.python.org/issue7776
>>> [2] https://github.com/python/cpython/blob/2.7/Lib/httplib.py
>>
>>
>> You've found a bug so please raise it on bugs.python.org :)
>>
>> --
>> My fellow Pythonistas, ask not what our language can do for you, ask
>> what you can do for our language.
>>
>> Mark Lawrence
>>
>> --
>> https://mail.python.org/mailman/listinfo/python-list
>
>


From ian.g.kelly at gmail.com  Thu Jan 22 17:47:35 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 22 Jan 2015 15:47:35 -0700
Subject: Python is DOOMED! Again!
In-Reply-To: <CALvWhxsaokixX2GtFcjX-6tjVuULoy3hF7emxAfBQqAcaMPQqw@mail.gmail.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <m9rrnd$l8h$1@ger.gmane.org>
 <CALwzidmZzogxZqLgC8qYHXhseGBEpoFN5cQgL14N_rwyiRU=Jw@mail.gmail.com>
 <CALwzidmW-8YQYBAB5+tbUFY0iB3PVHjyXL2eqL1g43WPVWiETA@mail.gmail.com>
 <CALvWhxsaokixX2GtFcjX-6tjVuULoy3hF7emxAfBQqAcaMPQqw@mail.gmail.com>
Message-ID: <CALwzidngr-MLeFCZFam_WeUaqs2A306qamCthVN6Jn-MYkUOPA@mail.gmail.com>

On Thu, Jan 22, 2015 at 3:27 PM, Chris Kaynor <ckaynor at zindagigames.com> wrote:
> Or use Any, which is basically the same thing:
>
> def adder(a: Any, b: Any) -> Any:
>     return a + b

Yeah, but this just seems like extra noise since it's not going to
help the type checker at all.


From marfig at gmail.com  Thu Jan 22 17:54:33 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Thu, 22 Jan 2015 23:54:33 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <m9rrnd$l8h$1@ger.gmane.org>
 <CALwzidmZzogxZqLgC8qYHXhseGBEpoFN5cQgL14N_rwyiRU=Jw@mail.gmail.com>
 <CALwzidmW-8YQYBAB5+tbUFY0iB3PVHjyXL2eqL1g43WPVWiETA@mail.gmail.com>
 <CALvWhxsaokixX2GtFcjX-6tjVuULoy3hF7emxAfBQqAcaMPQqw@mail.gmail.com>
 <mailman.18004.1421966906.18130.python-list@python.org>
Message-ID: <MPG.2f2b9dfa912e55e1989689@nntp.aioe.org>

In article <mailman.18004.1421966906.18130.python-list at python.org>, 
ian.g.kelly at gmail.com says...
> 
> On Thu, Jan 22, 2015 at 3:27 PM, Chris Kaynor <ckaynor at zindagigames.com> wrote:
> > Or use Any, which is basically the same thing:
> >
> > def adder(a: Any, b: Any) -> Any:
> >     return a + b
> 
> Yeah, but this just seems like extra noise since it's not going to
> help the type checker at all.


I agree. It's after all a fully polymorphic function. There is no reason 
to pass it through a static analyzer.


From ben+python at benfinney.id.au  Thu Jan 22 18:22:47 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Fri, 23 Jan 2015 10:22:47 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CAPTjJmpgEdn_J5DRW-JAbfJV=f7qQFcZmuqBZHLANZ-viA6Nug@mail.gmail.com>
 <1109172234443646336.064542sturla.molden-gmail.com@news.gmane.org>
Message-ID: <85mw5ao0xk.fsf@benfinney.id.au>

Sturla Molden <sturla.molden at gmail.com> writes:

> Chris Angelico <rosuav at gmail.com> wrote:
>
> > Uhh... if your managers and customers are stipulating non-Pythonic
> > coding styles, then it's time to find new managers/customers. If
> > they're not writing the code, code quality shouldn't be their
> > concern.
>
> I am saying the day someone requires me to write a type hint, I will
> no longer be using Python or recommending it.

Surely a more appropriate response would be to stop taking orders from
that person, and continue writing Python.

-- 
 \        ?The problem with television is that the people must sit and |
  `\    keep their eyes glued on a screen: the average American family |
_o__)                 hasn't time for it.? ?_The New York Times_, 1939 |
Ben Finney



From no.email at nospam.invalid  Thu Jan 22 18:24:01 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Thu, 22 Jan 2015 15:24:01 -0800
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <m9rrnd$l8h$1@ger.gmane.org>
 <mailman.18000.1421964545.18130.python-list@python.org>
Message-ID: <8738727626.fsf@jester.gateway.sonic.net>

Ian Kelly <ian.g.kelly at gmail.com> writes:
> T = TypeVar('T')
> def adder(a: T, b: T) -> T:  ...
> I'm not thrilled about having to actually declare T in this sort of
> situation, but I don't have a better proposal.

Oh man, that's ugly.  Maybe a decorator would be a bit less awful:

    @-typevar T
    def adder(a: T, b: T) -> T: ...

I'm using @- for a hypothetical decorator that receives the AST for the
stuff on the rest of the line, instead of being evaluated as a function.

The above looks sort of like C++, which would say

  template <typename T>
  T addr (T a, T b) { ... }



From invalid at invalid.invalid  Thu Jan 22 19:09:42 2015
From: invalid at invalid.invalid (Grant Edwards)
Date: Fri, 23 Jan 2015 00:09:42 +0000 (UTC)
Subject: How to "wow" someone new to Python
References: <mailman.17792.1421420646.18130.python-list@python.org>
 <bcb2d68705da8d203ccb1e735be@nntp.aioe.org>
 <54c07eed$0$13012$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <m9s3g6$7jv$1@reader1.panix.com>

On 2015-01-22, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
> Mario Figueiredo wrote:
>
>> But speaking about impressing more experient programmers, I personally
>> don't think Python has a wow factor in any of its features and syntax. At
>> least in the way I understand the word "wow".
>
> Quote:
>
>     I've seen Python criticized as "ugly" precisely because it doesn't 
>     have a trick-based view of the world. In many ways, it's a dull
>     language, borrowing solid old concepts from many other languages &
>     styles: boring syntax, unsurprising semantics, few automatic 
>     coercions, etc etc. But that's one of the things I like about it.
>     - Tim Peters

Well, you know the ancient Chinese programmer's curse:

  "May you program in an interesting language".

-- 
Grant Edwards               grant.b.edwards        Yow! Pardon me, but do you
                                  at               know what it means to be
                              gmail.com            TRULY ONE with your BOOTH!


From steve+comp.lang.python at pearwood.info  Thu Jan 22 19:16:19 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 23 Jan 2015 11:16:19 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <87wq4efwwr.fsf@elektro.pacujo.net>
Message-ID: <54c192d4$0$13006$c3e8da3$5496439d@news.astraweb.com>

Marko Rauhamaa wrote:

> Python is perfect already.

I have no words.



-- 
Steven



From sturla.molden at gmail.com  Thu Jan 22 19:40:33 2015
From: sturla.molden at gmail.com (Sturla Molden)
Date: Fri, 23 Jan 2015 01:40:33 +0100
Subject: Python is DOOMED! Again!
In-Reply-To: <MPG.2f2b75c814639267989686@nntp.aioe.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
 <mailman.17984.1421952098.18130.python-list@python.org>
 <MPG.2f2b697d288c74b2989685@nntp.aioe.org>
 <mailman.17990.1421956437.18130.python-list@python.org>
 <MPG.2f2b75c814639267989686@nntp.aioe.org>
Message-ID: <m9s59v$bh6$1@ger.gmane.org>

On 22/01/15 21:03, Mario Figueiredo wrote:

> That is fine. But then the problem isn't type hinting, is it? Neither I
> think you are suggesting we don't introduce language because there are
> bad project managers out there.
>
> The problem is then bad project managers. That has nothing to do with
> type hinting, or Python for that matter.

It has everything to do with Python if we facilitate them.

Type hinting will be mandatory because of bad managers. But then someone 
is going to ask what benefit Python has to offer:

Readabiliy? No ... down the drain.

Dynamic typing? No ... down the drain.

Speed? No ... still 200x slower than Swift.

Why go for Python? There is no benefit to it any longer.


Sturla
















From sturla.molden at gmail.com  Thu Jan 22 19:44:05 2015
From: sturla.molden at gmail.com (Sturla Molden)
Date: Fri, 23 Jan 2015 01:44:05 +0100
Subject: Python is DOOMED! Again!
In-Reply-To: <CALwzidmZzogxZqLgC8qYHXhseGBEpoFN5cQgL14N_rwyiRU=Jw@mail.gmail.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <m9rrnd$l8h$1@ger.gmane.org>
 <CALwzidmZzogxZqLgC8qYHXhseGBEpoFN5cQgL14N_rwyiRU=Jw@mail.gmail.com>
Message-ID: <m9s5gl$eoj$1@ger.gmane.org>

On 22/01/15 23:08, Ian Kelly wrote:

> T = TypeVar('T')
>
> def adder(a: T, b: T) -> T:
>      return a + b
>
> I'm not thrilled about having to actually declare T in this sort of
> situation, but I don't have a better proposal.

Here is a better proposal:

def adder(a, b):
     return a + b



Sturla




From rosuav at gmail.com  Thu Jan 22 20:00:10 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 23 Jan 2015 12:00:10 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <m9s59v$bh6$1@ger.gmane.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
 <mailman.17984.1421952098.18130.python-list@python.org>
 <MPG.2f2b697d288c74b2989685@nntp.aioe.org>
 <mailman.17990.1421956437.18130.python-list@python.org>
 <MPG.2f2b75c814639267989686@nntp.aioe.org>
 <m9s59v$bh6$1@ger.gmane.org>
Message-ID: <CAPTjJmpnxfxYPJT5ocRF=r69by0dWTFKYDY4O64LYd5bzShHFQ@mail.gmail.com>

On Fri, Jan 23, 2015 at 11:40 AM, Sturla Molden <sturla.molden at gmail.com> wrote:
> Type hinting will be mandatory because of bad managers. But then someone is
> going to ask what benefit Python has to offer:

Type hinting will never be mandatory, because bad managers are not in
charge. You can't blame the language because you're *choosing* to
continue to work for someone who demands the unreasonable. Yes, I
understand that there are reasons for not immediately quitting a job
when someone insists on something you disagree with (yaknow, reasons
like "got bills to pay", little trivialities like that); but it's
still your choice. You have to weigh up the value of the job against
the value of the philosophy. And Python's philosophy isn't changed by
that.

ChrisA


From rantingrickjohnson at gmail.com  Thu Jan 22 20:06:20 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 22 Jan 2015 17:06:20 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
Message-ID: <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>

On Thursday, January 22, 2015 at 4:25:37 PM UTC-6, Mario Figueiredo wrote:
> 1. Annotations where created exactly for this purpose. So
> there's some preassure to put them to work on what they
> were always meant to be used for.
> 
> 2. Docstrings are meant as source of code documentation
> and to fill the object's __doc__ attribute, as per PEP
> 257. As such they aren't good consistent candidates for
> type hinting for purposes of static analysis tools.
> 
> 3. Decorators are meant as function transformation tools,
> as per PEP 318 and, as such, are them too not suitable to
> include type annotations for the purpose of static
> analysis.
> 
> 4. There is no other formal annotation mechanism, other
> than these potential three.
> 
> Arguably, you can make a case against 1. And that's my own
> issue with type hinting as it is being proposed on PEP
> 484. The real problem is annotations as they were defined
> are a really bad idea. To couple type annotations so
> tightly with code, just results in plain ugly and hard to
> read code.

Yes, i whole heartily agree!

> Personally I would love to see the present annotations
> just go away and a new docstring-like structure to emerge
> in their place. But that's probably not going to happen.
> 
> What I agree can't be done though, is to use docstrings or
> decorators as a source for type annotations.

I have a completely different idea. 

============================================================
 Python Sanity Proposal: "Type Hinting Sanity"
============================================================
Note: This is the closest you're going to get to a PEP from me!

Okay, i have found a solution to the type hinting problem
that will appease both sides. On one side we have those who
are proposing type hinting annotations within function sigs,
and on the other side, we have those who oppose the
implementation of type hinting via this method because of
the readability concerns. The solution is move the type
hinting syntax completely out of the source file and into
another file -- think of it as a "Python Type Hinting Header
File".

============================================================
 Summary
============================================================
  
(1) Agree on a file extension that python will recognize
as containing "type hint specs". Unfortunately we cannot
use ".pth", which would be the perfect acronym for "Python
Type Hints", so choose something else. :-(

(2) Define a spec for writing annotations that will map to
funcs/methods of the same name. I would argue to keep the
spec compact, but i really don't care about the spec at
this point.

      
============================================================
 Simplistic Example Code utilizing two files:
============================================================

  #
  # scriptA.py
  #
  def greeting(name): 
      return 'Hello ' + name 
      
  #    
  # scriptA.typehints
  #
  greeting{name:str} -> str


============================================================
 Benefits:
============================================================

(1) Removes the noisy syntax from the source file. Python
code will remain as clean tomorrow as it is today.
  
(2) Puts the onerous on the author *NOT* on the reader.
This system utilizes a concept known as "Level Of Detail"
(or LOD). LOD means that i should not need to see a type
hint unless i *WANT* to see a type hint. You can think of
it as akin to "Java @string resources".  

(3) If i decide i don't want type hints in my code, all i
have to do is delete or rename a file, which is much less
error prone then editing source code. 

(4) Has the added benefit of aiding when debugging type hints.
  
--
  
My suggestion is the only way to implement type hints
without destroying Python! I just hope that GvR will give it
serious objective consideration.



From emile at fenx.com  Thu Jan 22 20:14:54 2015
From: emile at fenx.com (Emile van Sebille)
Date: Thu, 22 Jan 2015 17:14:54 -0800
Subject: Python is DOOMED! Again!
In-Reply-To: <CAPTjJmpnxfxYPJT5ocRF=r69by0dWTFKYDY4O64LYd5bzShHFQ@mail.gmail.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
 <mailman.17984.1421952098.18130.python-list@python.org>
 <MPG.2f2b697d288c74b2989685@nntp.aioe.org>
 <mailman.17990.1421956437.18130.python-list@python.org>
 <MPG.2f2b75c814639267989686@nntp.aioe.org> <m9s59v$bh6$1@ger.gmane.org>
 <CAPTjJmpnxfxYPJT5ocRF=r69by0dWTFKYDY4O64LYd5bzShHFQ@mail.gmail.com>
Message-ID: <m9s7ah$9dh$1@ger.gmane.org>

On 1/22/2015 5:00 PM, Chris Angelico wrote:
> On Fri, Jan 23, 2015 at 11:40 AM, Sturla Molden <sturla.molden at gmail.com> wrote:
>> Type hinting will be mandatory because of bad managers. But then someone is
>> going to ask what benefit Python has to offer:
>
> Type hinting will never be mandatory,

I'm sure it will be in some places, if only to the extent that PEP8 
compliance is enforced.

> because bad managers are not in charge.

But coding standards may be, and in certain sized shops, should be.  So 
as tools come of age, standards will be updated, and hinting will be 
added and hence become required.

> You can't blame the language because you're *choosing* to

 >sigh< It's good to have choices.

Bottom line is that the decisions being made today about type hinting 
will live on, so it's good to consider eventualities that are real.

Emile




From rantingrickjohnson at gmail.com  Thu Jan 22 20:15:28 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 22 Jan 2015 17:15:28 -0800 (PST)
Subject: Python Sanity Proposal: Type Hinting Solution
Message-ID: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>


Note: This is the closest you're going to get to a PEP from me! 

Okay, i have found a solution to the type hinting problem 
that will appease both sides. On one side we have those who 
are proposing type hinting annotations within function sigs, 
and on the other side, we have those who oppose the 
implementation of type hinting via this method because of 
the readability concerns. The solution is move the type 
hinting syntax completely out of the source file and into 
another file -- think of it as a "Python Type Hinting Header 
File". 

============================================================ 
 Summary 
============================================================ 
  
(1) Agree on a file extension that python will recognize 
as containing "type hint specs". Unfortunately we cannot 
use ".pth", which would be the perfect acronym for "Python 
Type Hints", so choose something else. :-( 

(2) Define a spec for writing annotations that will map to 
funcs/methods of the same name. I would argue to keep the 
spec compact, but i really don't care about the spec at 
this point. 

      
============================================================ 
 Simplistic Example Code utilizing two files: 
============================================================ 

  # 
  # scriptA.py 
  # 
  def greeting(name): 
      return 'Hello ' + name 
      
  #     
  # scriptA.typehints 
  # 
  greeting{name:str} -> str 


============================================================ 
 Benefits: 
============================================================ 

(1) Removes the noisy syntax from the source file. Python 
code will remain as clean tomorrow as it is today. 
  
(2) Puts the onerous on the author *NOT* on the reader. 
This system utilizes a concept known as "Level Of Detail" 
(or LOD). LOD means that i should not need to see a type 
hint unless i *WANT* to see a type hint. You can think of 
it as akin to "Java @string resources".   

(3) If i decide i don't want type hints in my code, all i 
have to do is delete or rename a file, which is much less 
error prone then editing source code. 

(4) Has the added benefit of aiding when debugging type hints. 
  
-- 
  
My suggestion is the only way to implement type hints 
without destroying Python! I just hope that GvR will give it 
serious objective consideration. 


From no.email at nospam.invalid  Thu Jan 22 20:31:17 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Thu, 22 Jan 2015 17:31:17 -0800
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
 <mailman.17984.1421952098.18130.python-list@python.org>
 <MPG.2f2b697d288c74b2989685@nntp.aioe.org>
 <mailman.17990.1421956437.18130.python-list@python.org>
 <MPG.2f2b75c814639267989686@nntp.aioe.org>
 <mailman.18006.1421973642.18130.python-list@python.org>
Message-ID: <87sif25llm.fsf@jester.gateway.sonic.net>

Sturla Molden <sturla.molden at gmail.com> writes:
> Type hinting will be mandatory because of bad managers.

That's a pretty weird concept: I've worked for good managers and bad
ones, but so far never one who imposed any low-level code style
decisions without also being involved in writing the code.  That was
always left to project leads.  Upper management (i.e. the CTO) sometimes
made high level decisions like "the production apps will be in Java not
Python" but that's different.

> But then someone is going to ask what benefit Python has to offer:
>
> Readabiliy? No ... down the drain.

The type hints don't impair readability as far as I can tell.  Rather,
they help it, since they indicate concisely what the function does.

> Dynamic typing? No ... down the drain.

It's still dynamic in the sense of having a universal type, and the
hints can also let the compiler specialize.

> Speed? No ... still 200x slower than Swift.

I don't think it's anything like 200x now, especially with pypy.  The
type hints will allow more optimization though the language semantics
will always keep it a slower than C/C++ (dunno about Swift).  

> Why go for Python? There is no benefit to it any longer.

The type hints look like an improvement to me.  I'd use them if they
were available.  I wouldn't have any problem with a project lead
mandating them, just like they currently mandate use of specific unit
test packages, etc.  I could imagine mandating them in a project that I
was leading.  The "bad management" thing only applies when someone
mandates coding practices that they themselves don't have to follow.

I think you're imagining some terrible scenario that's not close to
reality.  Erlang has a similar feature that I've already mentioned a few
times in this thread.  I've used it and it's a good feature.  It helps
keep the code organized and it doesn't get in the way too much.  You
don't have to put a signature on every function: it's optional so you
can put them in just the important places and let the tool figure out
the rest.

If you use a seriously typeful language like Haskell, you have to design
your whole program around the static types.  But with Erlang you can
code pretty much the same way you would in Python, add a few signatures
here and there, and that's enough for the analysis tool to do some quite
useful checks.

I remember in one of the endless static-vs-dynamic debates on
comp.lang.lisp, someone mentioned a code instrumentation experiment that
found that even in dynamic languages, most functions were monomorphic in
practice.  I think that's mostly because experienced programmers
unconsciously follow an ML-like type discipline most of the time, even
when the compiler isn't enforcing it.  So having some compile-time
checking will mostly do good.


From steve+comp.lang.python at pearwood.info  Thu Jan 22 20:41:59 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 23 Jan 2015 12:41:59 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <87egqm7h3e.fsf@jester.gateway.sonic.net>
Message-ID: <54c1a6e8$0$12996$c3e8da3$5496439d@news.astraweb.com>

Paul Rubin wrote:

> Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:
>> Since the "language wars" of the 1990s, dynamic languages have won.
> 
> Are you kidding?  Nothing has won, the wars are still going on, and
> dynamic and static typing both have their winning use cases and will be
> around forever.

No, I stand by my statement, on the basis that Bob Martin said it and he's
smarter than me and he actually was a participant so he knows what he's
talking about *wink*

In one sense, "language wars" still go on. Conflict never really ends, it
just shifts from place to place, and there will always be "brush wars",
like Pascal versus PL/P, Pascal versus C, C versus Java, Perl versus
Python, Python versus Ruby, etc.

But the 1990s idea was that there ought to be One Language To Rule Them All,
that there should be a single language which is the optimal language for
every programming task. The 90s brought that to a head, with Smalltalk,
Java, C, and Lisp all contenders.

Today the nature of the wars has tended to change. Naturally there are still
clueless n00bs who insist that there must be One True Language for
everything but the wars today are more about the full technology stack
(e.g. C#/.NET/IIS/Windows versus Java/J2EE/Apache/Solaris) rather than
specifically about the language.

So in the sense that people still argue about languages, you are correct
that "language wars" continue, but Martin's specific claim was that dynamic
languages *as a group* won the war in the sense that all popular static
languages now include dynamic features, while dynamic languages don't
include static features:

Popular dynamic languages include:
- Python
- PHP
- Javascript

None of them can really be characterised as having "static" features in any
meaningful sense. (The introduction of type-hints to Python won't change
that, any more than documenting the types in a docstring has changed it.)

Popular static languages include:
- Java has reflection and runtime generics
- C# has the "dynamic" keyword which is based on .Net's reflection
- C++ has dynamic dispatch and virtual functions


Go is an interesting (counter-?) example: it is a static language almost
entirely lacking in dynamic features. From the Go FAQs:

"The only way to have dynamically dispatched methods is through an
interface. Methods on a struct or any other concrete type are always
resolved statically."

http://golang.org/doc/faq#How_do_I_get_dynamic_dispatch_of_methods

(Go may have other dynamic features, but I am unaware of them.) But Go is
lacking many other features (exceptions, generics, variant types, even
basic numeric coercions. Go is either going to revolutionise programming or
it will end up just another niche language. I suspect the latter.

The point is, despite maverick languages like Go, mainstream static
languages have developed dynamic features, while dynamic languages have not
reduced their dynamicism to become more static. Instead, dynamic languages
are developing Just In Time compilers to use *runtime* type information for
efficiency (e.g. Mercury, PHP, Python, Javascript all do this).




-- 
Steven



From ben+python at benfinney.id.au  Thu Jan 22 21:05:56 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Fri, 23 Jan 2015 13:05:56 +1100
Subject: [RELEASE] =?utf-8?Q?=E2=80=98python-daemon?= =?utf-8?B?4oCZ?=
 version 2.0.4 released
Message-ID: <20150123020555.GB3566@benfinney.id.au>

Howdy all,

I am pleased to announce the release of version 2.0.4 of the
?python-daemon? library.

The current release is always available at
<URL:https://pypi.python.org/pypi/python-daemon/>.

The project's forums and VCS are hosted at Alioth
<URL:https://alioth.debian.org/projects/python-daemon/>.


Significant changes since the previous version
==============================================

This is a bug fix release, addressing packaging bugs:

* Remove custom Setuptools entry points.

  This addresses a bug reported by many people (thanks!) who found
  subsequent Setuptools actions impacted by these entry points.

* Write version info metadata using Setuptools ?egg_info? command.


What is the ?python-daemon? library?
====================================

?python-daemon? is a Python library to implement a well-behaved Unix
daemon process.

-- 
 \      ?The way to build large Python applications is to componentize |
  `\             and loosely-couple the hell out of everything.? ?Aahz |
_o__)                                                                  |
Ben Finney <ben at benfinney.id.au>


From rustompmody at gmail.com  Thu Jan 22 21:59:50 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Thu, 22 Jan 2015 18:59:50 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <mailman.17998.1421961926.18130.python-list@python.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17998.1421961926.18130.python-list@python.org>
Message-ID: <a14188d8-84c1-496a-b0f3-cce0935ab4b8@googlegroups.com>

On Friday, January 23, 2015 at 2:55:38 AM UTC+5:30, Ian wrote:
> On Thu, Jan 22, 2015 at 7:16 AM, Steven D'Aprano wrote:
> >> Meanwhile, there's the strange decision to implement type hints for
> >> local variables # comment lines. I have an hard time wrapping my head
> >> around this one. Really, comments!?
> >
> > Yes, really. There is plenty of prior art for machine-meaningful comments:
> >
> > - mypy uses it, and it works fine
> > - Pascal uses {$ ...} compiler directives
> > - Unix uses a special hash-bang #! comment in the first line to
> >   specify the executable that runs the script
> > - Python supports a special encoding declaration using #
> > - doctest uses comments for directives
> > - HTML puts code (Javascript usually) inside of comments
> > - JMSAssert for Java uses comments for design-by-contract assertions
> 
> Perhaps even more relevant to PEP 484:
> 
> - The Closure compiler for Javascript uses JSDoc tags in comments for
> static typing and analysis.

I have not studied this carefully... so no opinion
However Peyton Jones is known to have said that for Haskell,
Haskell is on a Damas-Milner cusp -- basically if haskell's type system
becomes any more sophisticated, then automatic type inference becomes undecidable
http://repository.upenn.edu/cgi/viewcontent.cgi?article=1336&context=cis_papers

Personally I find the predecessor of Haskell, gofer, prettier than Haskell
precisely because Haskell's type system has become too 'clever':

See my answer
http://stackoverflow.com/questions/25855507/are-typeclasses-essential

What has all this to do with python?? Dunno
Just that the 'optionality' of type-hinting may not be quite straightforward

================
PS Ian for a hot thread like this its good to put quotes carefully
You are quoting Steven quoting somebody -- dunno who that somebody is


From rustompmody at gmail.com  Thu Jan 22 22:11:11 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Thu, 22 Jan 2015 19:11:11 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <mailman.18001.1421965225.18130.python-list@python.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <m9rrnd$l8h$1@ger.gmane.org>
 <CALwzidmZzogxZqLgC8qYHXhseGBEpoFN5cQgL14N_rwyiRU=Jw@mail.gmail.com>
 <mailman.18001.1421965225.18130.python-list@python.org>
Message-ID: <12a0f55b-c6d8-4eab-8736-ec9dc46151a6@googlegroups.com>

On Friday, January 23, 2015 at 3:50:38 AM UTC+5:30, Ian wrote:
> On Thu, Jan 22, 2015 at 3:08 PM, Ian Kelly  wrote:
> > On Thu, Jan 22, 2015 at 2:56 PM, Emile van Sebille  wrote:
> >> I've been lightly scanning and following the PEP 484 discussion, and one
> >> point I don't think I've seen mentioned is how you might hint a function
> >> that accepts different types, eg:
> >>
> >> def adder(a,b): return a+b
> >>
> >> This is one of the pythonic idioms that help with polymorphic functions.  Is
> >> there a proposal for providing hinting for these?
> >
> > You can use TypeVar for that.
> >
> > T = TypeVar('T')
> >
> > def adder(a: T, b: T) -> T:
> >     return a + b
> >
> > I'm not thrilled about having to actually declare T in this sort of
> > situation, but I don't have a better proposal.
> 
> Hmm, but also that hinting doesn't cover cases like adder(12, 37.5)
> where two different types can be passed, and the return type could be
> either. I think for full generality you would just have to forgo
> hinting on this function.

You are 'discovering' two bugs in python's design:
1. [1,2,3] + [4,5,6]
uses the same symbol for an unrelated operation 
1 + 4

2. 1 + 2.14
has an implicit conversion

The second is present in almost all languages so its best called 'feature' not bug

The first I expect will incur costs that are way out of proportion to the benefits


From python at mrabarnett.plus.com  Thu Jan 22 22:22:14 2015
From: python at mrabarnett.plus.com (MRAB)
Date: Fri, 23 Jan 2015 03:22:14 +0000
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
Message-ID: <54C1BE66.9070501@mrabarnett.plus.com>

On 2015-01-23 01:15, Rick Johnson wrote:
>
> Note: This is the closest you're going to get to a PEP from me!
>
> Okay, i have found a solution to the type hinting problem
> that will appease both sides. On one side we have those who
> are proposing type hinting annotations within function sigs,
> and on the other side, we have those who oppose the
> implementation of type hinting via this method because of
> the readability concerns. The solution is move the type
> hinting syntax completely out of the source file and into
> another file -- think of it as a "Python Type Hinting Header
> File".
>
> ============================================================
>   Summary
> ============================================================
>
> (1) Agree on a file extension that python will recognize
> as containing "type hint specs". Unfortunately we cannot
> use ".pth", which would be the perfect acronym for "Python
> Type Hints", so choose something else. :-(
>
> (2) Define a spec for writing annotations that will map to
> funcs/methods of the same name. I would argue to keep the
> spec compact, but i really don't care about the spec at
> this point.
>
>
> ============================================================
>   Simplistic Example Code utilizing two files:
> ============================================================
>
>    #
>    # scriptA.py
>    #
>    def greeting(name):
>        return 'Hello ' + name
>
>    #
>    # scriptA.typehints
>    #
>    greeting{name:str} -> str
>
>
> ============================================================
>   Benefits:
> ============================================================
>
> (1) Removes the noisy syntax from the source file. Python
> code will remain as clean tomorrow as it is today.
>
> (2) Puts the onerous on the author *NOT* on the reader.
> This system utilizes a concept known as "Level Of Detail"
> (or LOD). LOD means that i should not need to see a type
> hint unless i *WANT* to see a type hint. You can think of
> it as akin to "Java @string resources".
>
> (3) If i decide i don't want type hints in my code, all i
> have to do is delete or rename a file, which is much less
> error prone then editing source code.
>
> (4) Has the added benefit of aiding when debugging type hints.
>
>
You also need to handle methods.

A simple way would be to use indentation:

# scriptA.py
class Greeter:
     def __init__(self, name):
         self.name = name

     def greet(self):
         print('Hello,', self.name)

def greeting(name):
     return 'Hello ' + name

# scriptA.typehints
Greeter:
     __init__(self, name: str)
greeting{name: str} -> str


I'm not sure about the best format for functions within functions. This
repeats the function name:

# scriptB.py
def greet(name):
     def make_message():
         return 'Hello,' + name
     print(make_message())

# scriptB.typehints
greet(name: str)
greet:
     make_message() -> str


But a shorter version might not be clear:

# scriptB.typehints
greet(name: str):
     make_message() -> str


especially when the outer function has a hint for its return type!



From tjreedy at udel.edu  Thu Jan 22 22:22:15 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Thu, 22 Jan 2015 22:22:15 -0500
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
Message-ID: <m9sep8$p53$1@ger.gmane.org>

On 1/22/2015 8:15 PM, Rick Johnson wrote:

> Okay, i have found a solution to the type hinting problem
> that will appease both sides. On one side we have those who
> are proposing type hinting annotations within function sigs,
> and on the other side, we have those who oppose the
> implementation of type hinting via this method because of
> the readability concerns. The solution is move the type
> hinting syntax completely out of the source file and into
> another file -- think of it as a "Python Type Hinting Header
> File".

This idea is so brilliant that it is already an option in mypy and is 
part of the new type-hint proposal.  The separate type-hint files are 
called 'stub files'.  I don't know what the extension is.  These will be 
used for the stdlib, which will not have annotations in the .py files

> (2) Define a spec for writing annotations that will map to
> funcs/methods of the same name. I would argue to keep the
> spec compact, but i really don't care about the spec at
> this point.

It will use the one  proposed, with whatever modification still to come.
I believe stub files can also be used for functions defined in C.

>   Simplistic Example Code utilizing two files:

>    # scriptA.py
>    def greeting(name):
>        return 'Hello ' + name

>    # scriptA.typehints
>    greeting{name:str} -> str

I believe stub files can also be used for functions defined in C.


>   Benefits:

> (1) Removes the noisy syntax from the source file. Python
> code will remain as clean tomorrow as it is today.

This will at least be an option.  You are and will be free to advocate 
that people always use stub files.

> (2) Puts the onerous on the author *NOT* on the reader.
> This system utilizes a concept known as "Level Of Detail"
> (or LOD). LOD means that i should not need to see a type
> hint unless i *WANT* to see a type hint.

One thing not discussed here (but was in the earlier python-ideas thread 
some months ago) is that some groups have standards for using some 
functions that is stricter than the function's full duck-typing 
generality.  A stub file allows a group to specify a restrictive use 
annotation for their static checker without putting lies into the code 
or doc of the function itself.

> (3) If i decide i don't want type hints in my code, all i
> have to do is delete or rename a file, which is much less
> error prone then editing source code.

If the annotations are in a separate file, deleting will hardly be 
necessary since the file will be ignored until one runs software that 
uses it.

> (4) Has the added benefit of aiding when debugging type hints.

I am not sure what you mean here.   It will be easier to temporarily 
comment out an incorrect annotation for a function, pending correction, 
when in a separate file.


-- 
Terry Jan Reedy



From rustompmody at gmail.com  Thu Jan 22 22:23:50 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Thu, 22 Jan 2015 19:23:50 -0800 (PST)
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
Message-ID: <ab558381-d9d7-435e-82fd-1496597d4e6a@googlegroups.com>

On Friday, January 23, 2015 at 6:45:39 AM UTC+5:30, Rick Johnson wrote:
> Note: This is the closest you're going to get to a PEP from me! 
> 
> Okay, i have found a solution to the type hinting problem 
> that will appease both sides. On one side we have those who 
> are proposing type hinting annotations within function sigs, 
> and on the other side, we have those who oppose the 
> implementation of type hinting via this method because of 
> the readability concerns. The solution is move the type 
> hinting syntax completely out of the source file and into 
> another file -- think of it as a "Python Type Hinting Header 
> File". 
> 
> ============================================================ 
>  Summary 
> ============================================================ 
>   
> (1) Agree on a file extension that python will recognize 
> as containing "type hint specs". Unfortunately we cannot 
> use ".pth", which would be the perfect acronym for "Python 
> Type Hints", so choose something else. :-( 
> 
> (2) Define a spec for writing annotations that will map to 
> funcs/methods of the same name. I would argue to keep the 
> spec compact, but i really don't care about the spec at 
> this point. 
> 
>       
> ============================================================ 
>  Simplistic Example Code utilizing two files: 
> ============================================================ 
> 
>   # 
>   # scriptA.py 
>   # 
>   def greeting(name): 
>       return 'Hello ' + name 
>       
>   #     
>   # scriptA.typehints 
>   # 
>   greeting{name:str} -> str 
> 

1. Allow in same file
2. Chage syntax slightly to
type greeting : str -> str

[type is the keyword equivalent to your other typehint file ]
 and you have essentially the Haskell solution.

The catch I expect is that haskell is strongly committed to simultaneous
definitions:

x = 1
y = x+2

is the same as
y = x+2
x = 1

and so definitions can generally be permuted around

Python is committed to the opposite extreme:
even def and class are not declarative but imperative



From tjreedy at udel.edu  Thu Jan 22 22:34:55 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Thu, 22 Jan 2015 22:34:55 -0500
Subject: Python is DOOMED! Again!
In-Reply-To: <m9s59v$bh6$1@ger.gmane.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
 <mailman.17984.1421952098.18130.python-list@python.org>
 <MPG.2f2b697d288c74b2989685@nntp.aioe.org>
 <mailman.17990.1421956437.18130.python-list@python.org>
 <MPG.2f2b75c814639267989686@nntp.aioe.org> <m9s59v$bh6$1@ger.gmane.org>
Message-ID: <m9sfh1$47c$1@ger.gmane.org>

On 1/22/2015 7:40 PM, Sturla Molden wrote:
> On 22/01/15 21:03, Mario Figueiredo wrote:
>
>> That is fine. But then the problem isn't type hinting, is it? Neither I
>> think you are suggesting we don't introduce language because there are
>> bad project managers out there.
>>
>> The problem is then bad project managers. That has nothing to do with
>> type hinting, or Python for that matter.
>
> It has everything to do with Python if we facilitate them.
>
> Type hinting will be mandatory because of bad managers. But then someone
> is going to ask what benefit Python has to offer:
>
> Readabiliy? No ... down the drain.

Type hints can be put in separate stub files and will be put in separate 
files for the stdlib.  If a client want to pay you to write type stubs, 
and you cannot stand to do it for even for pay, I am sure you will be 
able to subcontract the work.  I am sure someone will write python 
probrams to make the process easier.

Many Pythonistas would be glad to see more work, not bitch about it.

Readability?  Unchanged (at least for your own code and much of the rest).

> Dynamic typing? No ... down the drain.

??? Python objects will still be dynamically typed.  For the present, 
compilation will be completely uneffected.

Dynamic typing? unchanged.

> Speed? No ... still 200x slower than Swift.

Sturla, I *know* you must have heard of numpy?  cython?


-- 
Terry Jan Reedy



From invalid at invalid.invalid  Thu Jan 22 22:40:32 2015
From: invalid at invalid.invalid (Grant Edwards)
Date: Fri, 23 Jan 2015 03:40:32 +0000 (UTC)
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <3fbbc664-ab4b-46e1-98a8-3859cb84fbb0@googlegroups.com>
 <8738738g5a.fsf@jester.gateway.sonic.net>
 <2d7880a5-9c2d-4a04-81f0-aa1e1d493e1a@googlegroups.com>
 <mailman.17961.1421916074.18130.python-list@python.org>
Message-ID: <m9sfrg$kvs$1@reader1.panix.com>

On 2015-01-22, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:

> What implementation?  The PEP is quite clearly marked as draft.  The
> Re-enactment of the Battle of Pearl Harbour is currently ongoing
> over on python-ideas regarding exactly what should be implemented.

I, for one, shall certainly sleep easier knowing the Batley
Townswomens' Guild is looking out for our interestes.

--
Grant




From rosuav at gmail.com  Thu Jan 22 22:52:51 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 23 Jan 2015 14:52:51 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <12a0f55b-c6d8-4eab-8736-ec9dc46151a6@googlegroups.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <m9rrnd$l8h$1@ger.gmane.org>
 <CALwzidmZzogxZqLgC8qYHXhseGBEpoFN5cQgL14N_rwyiRU=Jw@mail.gmail.com>
 <mailman.18001.1421965225.18130.python-list@python.org>
 <12a0f55b-c6d8-4eab-8736-ec9dc46151a6@googlegroups.com>
Message-ID: <CAPTjJmpMOcFGooUaayiHjYA0qzYtVLSMaaVCGM_tHVgALbp+=Q@mail.gmail.com>

On Fri, Jan 23, 2015 at 2:11 PM, Rustom Mody <rustompmody at gmail.com> wrote:
> 1. [1,2,3] + [4,5,6]
> uses the same symbol for an unrelated operation
> 1 + 4

They're not unrelated operations. Maybe in the purity of mathematics
they're distinct, but in the practical world of "getting-stuff-done
programming", they're the same operation, as is string concatenation.
It makes perfect sense to use the same symbol for all of them.

ChrisA


From steve+comp.lang.python at pearwood.info  Thu Jan 22 22:53:36 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 23 Jan 2015 14:53:36 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
 <mailman.17984.1421952098.18130.python-list@python.org>
 <MPG.2f2b697d288c74b2989685@nntp.aioe.org>
 <mailman.17990.1421956437.18130.python-list@python.org>
 <MPG.2f2b75c814639267989686@nntp.aioe.org>
 <mailman.18006.1421973642.18130.python-list@python.org>
Message-ID: <54c1c5c1$0$13001$c3e8da3$5496439d@news.astraweb.com>

Sturla Molden wrote:

> On 22/01/15 21:03, Mario Figueiredo wrote:
> 
>> That is fine. But then the problem isn't type hinting, is it? Neither I
>> think you are suggesting we don't introduce language because there are
>> bad project managers out there.
>>
>> The problem is then bad project managers. That has nothing to do with
>> type hinting, or Python for that matter.
> 
> It has everything to do with Python if we facilitate them.
> 
> Type hinting will be mandatory because of bad managers. 

Oh come on, that's ridiculous.

If your manager is so bad, why isn't he insisting that you program in PHP or
Java or Algol 68 [insert name of some language you dislike] instead of
Python? Is your bad manager forcing you to write Java-style code in Python,
or insisting on Hungarian Notation?

And how does *your* bad manager force *me* to change my coding style?

This is especially ridiculous given how much Python code is open-source and
beholden to nobody except the author.


> But then someone 
> is going to ask what benefit Python has to offer:
> 
> Readabiliy? No ... down the drain.

A ridiculous overreaction to a minor syntactic change which has been
available in Python 3.x for about five years.


> Dynamic typing? No ... down the drain.

That's just completely untrue. The presence of a type-checker doesn't
prevent dynamic typing. If you think it does, I'm afraid you don't
understand the difference between static and dynamic typing, you don't
understand the proposal for type-hinting as already demonstrated by Mypy,
or both.

This proposal is not based on a theoretical hope that it will help Python,
it has already been working for a number of years. The difference is that
now Guido is taken *proven technology* from a third-party implementation,
Mypy, and standardising the language so that other implementations, IDEs,
text editors, linters and other tools can make use of it.


> Speed? No ... still 200x slower than Swift.

That would make Swift 20x faster than C. Even PyPy doesn't claim to be ten
times faster than C across the board.



-- 
Steven



From tjreedy at udel.edu  Thu Jan 22 22:57:49 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Thu, 22 Jan 2015 22:57:49 -0500
Subject: Python is DOOMED! Again!
In-Reply-To: <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
Message-ID: <m9sgrv$mof$1@ger.gmane.org>

On 1/22/2015 3:44 PM, Rick Johnson wrote:
> On Thursday, January 22, 2015 at 12:28:47 PM UTC-6, Mark Lawrence wrote:
>> Evidence in completely the opposite direction if I'm
>> reading this correctly [snip link]
>>
>> "The main use case of type hinting is static analysis
>> using an external tool without executing the analyzed
>> program. Existing tools used for that purpose like
>> pyflakes [pyflakes] or pylint [pylint] might be extended
>> to support type checking. New tools, like mypy's mypy -S
>> mode, can be adopted specifically for this purpose.
>
> So if the purpose is "static analysis", what is the
> justification for injecting new syntax into function sigs?

The syntax was put there years ago.

> I'm not *TOTALLY* against the idea of "type hints", but i am
> *TOTALLY* against their proposed location.

Unlike other annotations, type annotations can be put in a separate stub 
file.

-- 
Terry Jan Reedy



From rosuav at gmail.com  Thu Jan 22 22:59:00 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 23 Jan 2015 14:59:00 +1100
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <m9sep8$p53$1@ger.gmane.org>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
Message-ID: <CAPTjJmqXLWEkz-KzxWWD4KRkHs4cdC3Z0DKZ8otjqTkytydsmQ@mail.gmail.com>

On Fri, Jan 23, 2015 at 2:22 PM, Terry Reedy <tjreedy at udel.edu> wrote:
> This idea is so brilliant that it is already an option in mypy and is part
> of the new type-hint proposal.  The separate type-hint files are called
> 'stub files'.

It's worth pointing out, too, that the idea isn't panaceaic - it's
just another tool in the box. Any time you break related things into
separate places, especially separate files, the tendency for them to
get out of sync grows dramatically. Use of stub files for something
that's only occasionally run (the type-checking linter) increases the
potential time delay between the error and the fix. Unless you make a
git/hg hook that runs type checks, chances are you'll have those
issues in your code.

Stub files are useful, but they aren't going to magically solve
everyone's complaints.

ChrisA


From tjreedy at udel.edu  Thu Jan 22 22:59:16 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Thu, 22 Jan 2015 22:59:16 -0500
Subject: Python is DOOMED! Again!
In-Reply-To: <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
Message-ID: <m9sgul$mof$2@ger.gmane.org>

On 1/22/2015 8:06 PM, Rick Johnson wrote:
> On Thursday, January 22, 2015 at 4:25:37 PM UTC-6, Mario Figueiredo wrote:
>> 1. Annotations where created exactly for this purpose. So
>> there's some preassure to put them to work on what they
>> were always meant to be used for.

> Yes, i whole heartily agree!

> I have a completely different idea.

See my response to this where is was posted in a new thread.

-- 
Terry Jan Reedy



From steve+comp.lang.python at pearwood.info  Thu Jan 22 23:23:36 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 23 Jan 2015 15:23:36 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
Message-ID: <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>

Rick Johnson wrote:

> The solution is move the type
> hinting syntax completely out of the source file and into
> another file -- think of it as a "Python Type Hinting Header
> File".

The 1970s called, they want their bad ideas back.

I can do no better than to quote from the Go FAQs:

    Dependency management is a big part of software development 
    today but the ?header files? of languages in the C tradition 
    are antithetical to clean dependency analysis?and fast 
    compilation.

http://golang.org/doc/faq#What_is_the_purpose_of_the_project


Things that go together should appear together. Imagine a language where you
declared the function name in one file, the function parameters in a second
file, any default values in a third file, and the function body in a fourth
file. Ridiculous. Ideally, all these things should be found together,
preferably close enough for the reader to take it all in at a glance
(although some function bodies may be too large).

There may be times where splitting related things are unavoidable, but they
should be a last resort, only to be used when any other solution is
unacceptable.

We know from Pascal and other languages that declaring types in the
parameter list works well and is very readable:

function calc(a: Real, b: Real): Integer;
  ...


We also know from Pascal that separating the declaration from the value
doesn't work so well:

function calc(a: Real, b: Real): Integer;
  var
    x: Integer;
    y: Real;
    z: array[1...100] of Something;
  begin
    {code goes here}
    {possibly a lot of it}
    {and finally we get to this}
    x = some_function(a, 2*b+1);  {what's the type of x again?}
  end;




-- 
Steven



From steve+comp.lang.python at pearwood.info  Thu Jan 22 23:51:28 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 23 Jan 2015 15:51:28 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CAPTjJmpgEdn_J5DRW-JAbfJV=f7qQFcZmuqBZHLANZ-viA6Nug@mail.gmail.com>
 <mailman.17986.1421953669.18130.python-list@python.org>
Message-ID: <54c1d351$0$12990$c3e8da3$5496439d@news.astraweb.com>

Sturla Molden wrote:

> Chris Angelico <rosuav at gmail.com> wrote:
> 
>> Uhh... if your managers and customers are stipulating non-Pythonic
>> coding styles, then it's time to find new managers/customers. If
>> they're not writing the code, code quality shouldn't be their concern.
> 
> I am saying the day someone requires me to write a type hint, I will no
> longer be using Python or recommending it. Python is great, but not that
> great.


You probably already write type checks, only you might do it like this:


def my_func(x, index=0):
    if not isinstance(index, int):
        raise TypeError("index must be an integer")
    do_stuff()


or perhaps like this:


def my_func(x, index=0):
    try:
        if index == int(index):
            do_stuff()
    except TypeError:
        raise
    else:
        raise TypeError("index must be an integer, not a float")


And then you write tests to confirm that my_func fails correctly when given
an index which is not an integer. Most of that is monkey-work, so simple
that even the compiler can do it.


How about writing this instead?

def my_func(x, index:int=0): 
    do_stuff()


Is that really such an unspeakable burden? *Always* a burden? You cannot
imagine any circumstances where you would gain some advantage by having an
automated type-checker identify type-related bugs?

Well okay then. Keep working the way you do right now.



-- 
Steven



From tjreedy at udel.edu  Fri Jan 23 00:03:26 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Fri, 23 Jan 2015 00:03:26 -0500
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <CAPTjJmqXLWEkz-KzxWWD4KRkHs4cdC3Z0DKZ8otjqTkytydsmQ@mail.gmail.com>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <CAPTjJmqXLWEkz-KzxWWD4KRkHs4cdC3Z0DKZ8otjqTkytydsmQ@mail.gmail.com>
Message-ID: <m9skn0$dok$1@ger.gmane.org>

On 1/22/2015 10:59 PM, Chris Angelico wrote:
> On Fri, Jan 23, 2015 at 2:22 PM, Terry Reedy <tjreedy at udel.edu> wrote:
>> This idea is so brilliant that it is already an option in mypy and is part
>> of the new type-hint proposal.  The separate type-hint files are called
>> 'stub files'.
>
> It's worth pointing out, too, that the idea isn't panaceaic - it's
> just another tool in the box. Any time you break related things into
> separate places, especially separate files, the tendency for them to
> get out of sync grows dramatically.

The same could be said of putting tests in a separate file.

 > Use of stub files for something
> that's only occasionally run (the type-checking linter) increases the
> potential time delay between the error and the fix.

Projects that view type-checks as tests that must pass will probably run 
them much more often.

-- 
Terry Jan Reedy



From rustompmody at gmail.com  Fri Jan 23 00:06:52 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Thu, 22 Jan 2015 21:06:52 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <mailman.18014.1421985178.18130.python-list@python.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <m9rrnd$l8h$1@ger.gmane.org>
 <CALwzidmZzogxZqLgC8qYHXhseGBEpoFN5cQgL14N_rwyiRU=Jw@mail.gmail.com>
 <mailman.18001.1421965225.18130.python-list@python.org>
 <12a0f55b-c6d8-4eab-8736-ec9dc46151a6@googlegroups.com>
 <mailman.18014.1421985178.18130.python-list@python.org>
Message-ID: <1b65206c-6a38-4157-8d9a-98512ebf5557@googlegroups.com>

On Friday, January 23, 2015 at 9:23:11 AM UTC+5:30, Chris Angelico wrote:
> On Fri, Jan 23, 2015 at 2:11 PM, Rustom Mody wrote:
> > 1. [1,2,3] + [4,5,6]
> > uses the same symbol for an unrelated operation
> > 1 + 4
> 
> They're not unrelated operations. Maybe in the purity of mathematics
> they're distinct, but in the practical world of "getting-stuff-done
> programming", they're the same operation, as is string concatenation.
> It makes perfect sense to use the same symbol for all of them.
> 
> ChrisA

You are conflating 3 things of which two are logically related --
string, list, number

String and list are the same
In python they are both iterable
In classic Haskell they were literally the same
"abc" is equivlent to ['a', 'b', 'c']
[Modern Haskell has confused the issue by adding a menagerie of types
for efficiency reasons]

As for string and number how is
"1" + "2" == "12"
related to
1+2 == 3
??


From rosuav at gmail.com  Fri Jan 23 00:31:55 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 23 Jan 2015 16:31:55 +1100
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <m9skn0$dok$1@ger.gmane.org>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <CAPTjJmqXLWEkz-KzxWWD4KRkHs4cdC3Z0DKZ8otjqTkytydsmQ@mail.gmail.com>
 <m9skn0$dok$1@ger.gmane.org>
Message-ID: <CAPTjJmrxP18o69KOJ2vP0fX0dBRm=dBQNvByx7r7bQvK3pyH=w@mail.gmail.com>

On Fri, Jan 23, 2015 at 4:03 PM, Terry Reedy <tjreedy at udel.edu> wrote:
> On 1/22/2015 10:59 PM, Chris Angelico wrote:
>>
>> On Fri, Jan 23, 2015 at 2:22 PM, Terry Reedy <tjreedy at udel.edu> wrote:
>>>
>>> This idea is so brilliant that it is already an option in mypy and is
>>> part
>>> of the new type-hint proposal.  The separate type-hint files are called
>>> 'stub files'.
>>
>>
>> It's worth pointing out, too, that the idea isn't panaceaic - it's
>> just another tool in the box. Any time you break related things into
>> separate places, especially separate files, the tendency for them to
>> get out of sync grows dramatically.
>
>
> The same could be said of putting tests in a separate file.

Yep. It's not a killer, but it does have a cost. That's one reason for
doctests - to put the tests in with the code. Everything's a
trade-off; with tests it's often better to put them in another file,
but type hints are short and compact, and can be briefly stated.
Unlike the complicated ones this thread has given us, most real-world
ones will be short. So we have the option to put them in-line or out
of line, and the two options have competing costs (readability vs code
disconnect).

ChrisA


From rosuav at gmail.com  Fri Jan 23 00:33:54 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 23 Jan 2015 16:33:54 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <1b65206c-6a38-4157-8d9a-98512ebf5557@googlegroups.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <m9rrnd$l8h$1@ger.gmane.org>
 <CALwzidmZzogxZqLgC8qYHXhseGBEpoFN5cQgL14N_rwyiRU=Jw@mail.gmail.com>
 <mailman.18001.1421965225.18130.python-list@python.org>
 <12a0f55b-c6d8-4eab-8736-ec9dc46151a6@googlegroups.com>
 <mailman.18014.1421985178.18130.python-list@python.org>
 <1b65206c-6a38-4157-8d9a-98512ebf5557@googlegroups.com>
Message-ID: <CAPTjJmrVcSQF660_e0J1mMG7+qH5rXKiSpOOYf8rnOWA09A26A@mail.gmail.com>

On Fri, Jan 23, 2015 at 4:06 PM, Rustom Mody <rustompmody at gmail.com> wrote:
> As for string and number how is
> "1" + "2" == "12"
> related to
> 1+2 == 3
> ??

They're both adding stuff together. Makes good sense.

Personally, I'd like str+int -> str, eg "1"+2 == "12", but Python
decided otherwise. We definitely agree on str+str though.

ChrisA


From steve+comp.lang.python at pearwood.info  Fri Jan 23 00:34:14 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 23 Jan 2015 16:34:14 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17978.1421949825.18130.python-list@python.org>
Message-ID: <54c1dd57$0$13000$c3e8da3$5496439d@news.astraweb.com>

Sturla Molden wrote:

> Python will no longer be dynamic, it will just be a slow static language.

It is worth explaining why this is wrong.

First, we need some definitions.

A *statically typed language* is one where variables have a type known to
the compiler at compile-time. That may be because the programmer declares
the type like in C:

    int n = 23;

or because the compiler can logically derive the type, like in Haskell:

    n = 23

(the compiler knows that 23 is an int, not a string or a Widget or a list,
and therefore on the assumption that you know what you are doing, n must be
an int too). Later, when you go to do an operation on n:

    n.append('foo')

the compiler knows that this must be an error, because n is an int, and ints
don't have an append method. And when you go to do an assignment:

    n = 'foo'

the compiler will prevent it because n is an int variable, not a string
variable.


In *dynamically typed languages*, variables don't have types, but *values*
do. Since variables don't have types, the compiler won't prevent you from
re-assigning a string to the same name that once held an int:

    n = 23
    n = 'foo'

but nor can it tell at compile time that n is an int and doesn't have an
append method. The way it tells is to wait until runtime and then attempt
to call the append method and see if it fails.

But... that's not a law of physics. Just because dumb compilers are dumb
doesn't mean that you can't have smarter compiles. 30 years ago the state
of the art for dynamic languages like Lisp and Smalltalk was good enough to
reason about type errors just as well as we human beings can. If we see:

    n = 23
    n.append('foo')

we know that this is going to fail. We don't need to run the code because we
can reason that at the time n.append is called, n is bound to an int and
ints don't have append methods. That's not very hard. Even Barry the intern
can do that, why can't Python?

Why can't Python tell me that 1+"1" will fail ahead of time?

Even in languages like C, the type-checking is done during a separate phase
of compilation, before code generation. So we can split the code-checker
out from the compiler, and make it a separate program which analyses the
source code, and stick it in your editor or IDE. Now when you start to
type:

   L = []
   L.appe

the IDE can guess that L is a list, and offer to auto-complete "append". But
given

   n.appe

it can predict that n isn't a list, and flag the word in red or beep or
something, depending on how annoying it wants to be. Or you can run the
type-checker as a separate program, like a linter or PEP-8 checker, and it
will analyse the source code and point out that on page 2 you assign n=23
and then on page 4 you call n.append but nowhere in the intermediate code
was n reassigned to a list.

If this was Java, the compiler would refuse to generate code while there are
any compile-time errors. But this is Python, and the type-checker is a
separate tool, so you can ignore it and run your script and sure enough you
will get an AttributeError when it tries to call n.append. Because maybe
you wanted an AttributeError.

This doesn't remove the dynamicism from the language. It's still dynamically
typed, it still has powerful runtime features. You won't even have to
declare types for everything if you don't want to.



-- 
Steven



From wuwei23 at gmail.com  Fri Jan 23 00:35:17 2015
From: wuwei23 at gmail.com (alex23)
Date: Fri, 23 Jan 2015 15:35:17 +1000
Subject: What killed Smalltalk could kill Python
In-Reply-To: <mailman.17937.1421891140.18130.python-list@python.org>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
 <mailman.17933.1421884677.18130.python-list@python.org>
 <MPG.2f2a5e01b517d4db989682@nntp.aioe.org>
 <87vbjz8ui7.fsf@jester.gateway.sonic.net>
 <mailman.17937.1421891140.18130.python-list@python.org>
Message-ID: <m9smik$3or$1@dont-email.me>

On 22/01/2015 11:45 AM, Chris Angelico wrote:
> It's not a terrible justification for getting into programming. But
> writing games is (almost always) a terrible way to start programming.

However, modifying games, I would argue, is a great way. The 
ComputerCraft mod for Minecraft, for example, added Lua-based control of 
in-game entities. It allows new developers to focus on internal game 
logic without being overwhelmed by the set up required to make it work.

An extreme example is DoubleFine's Hack'n'Slash, wihch exposes its 
underlying logic in-game (also in Lua) and provides the user with tools 
to modify them: http://www.hacknslashthegame.com/

Initially the player starts off by modifying globals (to, say, add or 
remove entities from a room, or change their movement direction), and 
ends with them having full access to the game (but not engine) code.


From steve+comp.lang.python at pearwood.info  Fri Jan 23 00:37:24 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 23 Jan 2015 16:37:24 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17998.1421961926.18130.python-list@python.org>
Message-ID: <54c1de14$0$13000$c3e8da3$5496439d@news.astraweb.com>

Ian Kelly wrote:

> Perhaps even more relevant to PEP 484:
> 
> - The Closure compiler for Javascript uses JSDoc tags in comments for
> static typing and analysis.


Nice!



-- 
Steven



From wuwei23 at gmail.com  Fri Jan 23 00:39:12 2015
From: wuwei23 at gmail.com (alex23)
Date: Fri, 23 Jan 2015 15:39:12 +1000
Subject: What killed Smalltalk could kill Python
In-Reply-To: <54c06d26$0$12915$c3e8da3$5496439d@news.astraweb.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
 <mailman.17933.1421884677.18130.python-list@python.org>
 <MPG.2f2a5e01b517d4db989682@nntp.aioe.org>
 <54c06d26$0$12915$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <m9smpv$48q$1@dont-email.me>

On 22/01/2015 1:23 PM, Steven D'Aprano wrote:
> Modern games *are* part of "today's complex application systems", and games
> developers may need the same skills used by "serious developers"

I wish more game developers would understand this. I've lost count of 
the number of games that have failed during development because all of 
the source code was stolen or destroyed. I've had arguments with game 
devs (some who've worked at some of the bigger studios) because they're 
convinced that nothing outside of game development has anything to teach 
them...when their (for eg) revision control entails zipping up their 
daily changes and emailing them to the rest of the team...



From steve+comp.lang.python at pearwood.info  Fri Jan 23 00:59:36 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 23 Jan 2015 16:59:36 +1100
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <CAPTjJmqXLWEkz-KzxWWD4KRkHs4cdC3Z0DKZ8otjqTkytydsmQ@mail.gmail.com>
 <mailman.18018.1421989508.18130.python-list@python.org>
Message-ID: <54c1e349$0$12975$c3e8da3$5496439d@news.astraweb.com>

Terry Reedy wrote:

> On 1/22/2015 10:59 PM, Chris Angelico wrote:
>> On Fri, Jan 23, 2015 at 2:22 PM, Terry Reedy <tjreedy at udel.edu> wrote:
>>> This idea is so brilliant that it is already an option in mypy and is
>>> part
>>> of the new type-hint proposal.  The separate type-hint files are called
>>> 'stub files'.
>>
>> It's worth pointing out, too, that the idea isn't panaceaic - it's
>> just another tool in the box. Any time you break related things into
>> separate places, especially separate files, the tendency for them to
>> get out of sync grows dramatically.
> 
> The same could be said of putting tests in a separate file.

I agree!

Python has doctests, which live right there with the function. It also has
assertions, which can be considered a form of continuous testing.

Eiffel has syntax for design-by-contract (testing pre-conditions,
post-conditions and invariants) there in the body of the function or
method:

https://docs.eiffel.com/book/method/et-design-contract-tm-assertions-and-exceptions#Expressing_assertions


Contracts are a form of testing, since they are designed to be disabled in
production. Other languages with syntactic support for Design By Contract
include Clojure, Cobra, D, Mercury, Perl6 and Racket.

Cobra is especially close to Python-like syntax, and supports unit tests as
well:


    def sqroot(i as int) as float
        require 
           i > 0
        ensure
           result > 0
        tests
           assert sqroot(25) == 5.0
        body
            ...


It would be nice to be able to include at least *some* tests right there in
the code rather than in a separate file.


-- 
Steven



From rosuav at gmail.com  Fri Jan 23 01:07:29 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 23 Jan 2015 17:07:29 +1100
Subject: What killed Smalltalk could kill Python
In-Reply-To: <m9smik$3or$1@dont-email.me>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
 <mailman.17933.1421884677.18130.python-list@python.org>
 <MPG.2f2a5e01b517d4db989682@nntp.aioe.org>
 <87vbjz8ui7.fsf@jester.gateway.sonic.net>
 <mailman.17937.1421891140.18130.python-list@python.org>
 <m9smik$3or$1@dont-email.me>
Message-ID: <CAPTjJmpv=sASHNTS-6K1SSaGDC8-guVSenxfjpmyKz0rYHZAow@mail.gmail.com>

On Fri, Jan 23, 2015 at 4:35 PM, alex23 <wuwei23 at gmail.com> wrote:
> On 22/01/2015 11:45 AM, Chris Angelico wrote:
>>
>> It's not a terrible justification for getting into programming. But
>> writing games is (almost always) a terrible way to start programming.
>
>
> However, modifying games, I would argue, is a great way. The ComputerCraft
> mod for Minecraft, for example, added Lua-based control of in-game entities.
> It allows new developers to focus on internal game logic without being
> overwhelmed by the set up required to make it work.
>

Yes, as long as you have the right structure. I wouldn't just say to
someone "here, have at it, you'll learn to program", but as part of a
properly-designed course, it could be a great way to teach coding.

There's a gentle spectrum from tweaking edit files ("I'm going to make
the shotgun deal ten times the damage") through those kinds of script
files up to actual full programming, and I think it can be a fine way
for someone to get started.

ChrisA


From breamoreboy at yahoo.co.uk  Fri Jan 23 01:20:54 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Fri, 23 Jan 2015 06:20:54 +0000
Subject: An improper change in httplib.py
In-Reply-To: <CAO0APJST78M76f4iRhkSZ8Dtb_F9NjVuk5+PRPCYJS7+DoJ5ng@mail.gmail.com>
References: <CAO0APJRm0PzV5Vu5HNztNPc5UUeFuN+UoHkZaWdA5Cfw6omHXA@mail.gmail.com>
 <112947510.5511972.1421928291463.JavaMail.yahoo@jws11124.mail.ir2.yahoo.com>
 <CAO0APJST78M76f4iRhkSZ8Dtb_F9NjVuk5+PRPCYJS7+DoJ5ng@mail.gmail.com>
Message-ID: <m9sp8d$jsg$1@ger.gmane.org>

On 22/01/2015 22:35, Guohua Ouyang wrote:
> Have reported an issue http://bugs.python.org/issue23300.
>
> "That leading underscore in the method name means it is not a public
> API and thus changes are allowed without any backwards-compatibility
> guarantees. Mercurial will need to update their code to handle this if
> they want to continue to use the method."
>
> I checked the official mercurial repo, it does not use the method
> anymore, so I filed a bug to fedora. [1]
>
> [1] https://bugzilla.redhat.com/show_bug.cgi?id=1185105
>

That comment on the issue is just wrong.  The issue has been re-opened.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From breamoreboy at yahoo.co.uk  Fri Jan 23 01:29:26 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Fri, 23 Jan 2015 06:29:26 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <54c192d4$0$13006$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <87wq4efwwr.fsf@elektro.pacujo.net>
 <54c192d4$0$13006$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <m9spod$rt3$1@ger.gmane.org>

On 23/01/2015 00:16, Steven D'Aprano wrote:
> Marko Rauhamaa wrote:
>
>> Python is perfect already.
>
> I have no words.
>

https://mail.python.org/pipermail/python-list/2002-November/154258.html

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From breamoreboy at yahoo.co.uk  Fri Jan 23 01:33:40 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Fri, 23 Jan 2015 06:33:40 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <m9s5gl$eoj$1@ger.gmane.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <m9rrnd$l8h$1@ger.gmane.org>
 <CALwzidmZzogxZqLgC8qYHXhseGBEpoFN5cQgL14N_rwyiRU=Jw@mail.gmail.com>
 <m9s5gl$eoj$1@ger.gmane.org>
Message-ID: <m9sq0a$vdg$1@ger.gmane.org>

On 23/01/2015 00:44, Sturla Molden wrote:
> On 22/01/15 23:08, Ian Kelly wrote:
>
>> T = TypeVar('T')
>>
>> def adder(a: T, b: T) -> T:
>>      return a + b
>>
>> I'm not thrilled about having to actually declare T in this sort of
>> situation, but I don't have a better proposal.
>
> Here is a better proposal:
>
> def adder(a, b):
>      return a + b
>

All those wasted characters?

What is wrong with:-

def adder(a, b): return a + b ? :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From breamoreboy at yahoo.co.uk  Fri Jan 23 01:38:32 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Fri, 23 Jan 2015 06:38:32 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <54c1c5c1$0$13001$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
 <mailman.17984.1421952098.18130.python-list@python.org>
 <MPG.2f2b697d288c74b2989685@nntp.aioe.org>
 <mailman.17990.1421956437.18130.python-list@python.org>
 <MPG.2f2b75c814639267989686@nntp.aioe.org>
 <mailman.18006.1421973642.18130.python-list@python.org>
 <54c1c5c1$0$13001$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <m9sq9e$3gb$1@ger.gmane.org>

On 23/01/2015 03:53, Steven D'Aprano wrote:
>
> If your manager is so bad, why isn't he insisting that you program in PHP or
> Java or Algol 68 [insert name of some language you dislike] instead of
> Python? Is your bad manager forcing you to write Java-style code in Python,
> or insisting on Hungarian Notation?
>

Seems like a good excuse to mention CORAL 66 for the first time in 
years, even if it wasn't *that* bad :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From dieter at handshake.de  Fri Jan 23 02:26:08 2015
From: dieter at handshake.de (dieter)
Date: Fri, 23 Jan 2015 08:26:08 +0100
Subject: python client call Java server by xmlrpc
References: <OF59D4DFCB.6AA85FAB-ON48257DD5.002C7812-48257DD5.002D68BE@knotes.kodak.com>
Message-ID: <878uguklf3.fsf@handshake.de>

fan.ding1 at kodak.com writes:

> I have xmlrpc server written in Java, and it has a method like
>
> Fun( vector, vector), the vector is array of user-defined object, which is 
> a class  extends HashMap.
>
> And I call it like:
>
> server = xmlrpclib.ServerProxy("http://myserver")
>
> server.Fun( [ {"0.5":0.1}], [ ] )
>
> It always fails with error
>
> 'No method matching arguments: , [Ljava.lang.Object;, [Ljava.lang.Object; 
> '
> Does anyone use this before? It troubles me some days.

The standard XML-RPC protocol knows only about a very small set
of types. Extensions are required to pass on more type information.

The (slightly confusing) error message (you got) indicates
that the XML-RPC framework on the server side has
not correctly recognized the types of the incoming parameters:
it should recognize the "[]" (as this is a standard type)
(and maybe the open "[" indicates that it has indeed)
but apparently, it got the content elements only as
generalized "Object"s not something specific (extending "HashMap").


The "xmlrpclib" in the Python runtime libary does not support
extensions to pass on additional type information (as far as I know).
This might indicate that you cannot use Python's "xmlrpclib" out
of the box to interact with your Java implemented XML-RPC service.


I would approach the problem as follows.

Implement a Java based XML-RPC client for your service. Should this
fail, then your service implementation has too complex types for
XML-RPC (and you must simplify them).

Should you succeed, you can use a tcp logger (or maybe debugging
tools of the Java libary implementing XML-RPC) to determine
the exact messages exchanged between client and server.
This way, you can learn how your Java libraries pass on non standard
type information. You can then derive a new class from Python's "xmlrpclib"
and implement there this type information passing extension (apparently
used by your Java libaries).



From no.email at nospam.invalid  Fri Jan 23 03:11:18 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Fri, 23 Jan 2015 00:11:18 -0800
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17998.1421961926.18130.python-list@python.org>
 <a14188d8-84c1-496a-b0f3-cce0935ab4b8@googlegroups.com>
Message-ID: <87oapp6hnd.fsf@jester.gateway.sonic.net>

Rustom Mody <rustompmody at gmail.com> writes:
> However Peyton Jones is known to have said that for Haskell,
> Haskell is on a Damas-Milner cusp

He's talking about the hairy recent stuff that edge Haskell towards
dependent types.  E.g. type families (type-level functions) plus
type-level numbers, etc.  I don't think anyone has suggested pressing
Python type hints to anywhere near such lengths.

Really, I think the examples to look to are Erlang (Dialyzer) and Racket
(Typed Racket), not Haskell.  Clojure's static types are adapted from
Racket's and should work in about the same way.  These (unlike Haskell)
are all examples of optional static types, where you can mix static and
dynamic code or leave out all the annotations if you want.  

I have to say that my personal experience with the Erlang dialyzer
wasn't all that great, but I was new to it and I think it's probably
more effective when used the "right" way, i.e. by people who are more
used to it than I was.


From wxjmfauth at gmail.com  Fri Jan 23 04:07:20 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Fri, 23 Jan 2015 01:07:20 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <c44c9497-fe91-4c46-a751-a53e515fa0d1@googlegroups.com>

Le jeudi 22 janvier 2015 05:31:12 UTC+1, Steven D'Aprano a ?crit?:
> Occasionally you find people spreading Fear, Uncertainty, Doubt about 
> Python. Python is now over 20 years old and one of the most popular 
> languages in the world no matter how you measure popularity:
> 
> http://import-that.dreamwidth.org/1388.html
> 
> so you don't often get FUD these days. When you do, it's usually about 
> whitespace, or "Python is too slow", or occasionally "Python 3 is killing 
> Python", but the latest FUD is about PEP 484 and type-hinting:
> 
> https://www.python.org/dev/peps/pep-0484/
> 
> Here's a typical example:
> 
>     Python is already headed towards obscurity. ... it seems that 
>     GvR intends to drive the final nail in python's coffin with 
>     this "type hinting" crap that will convert Python syntax from 
>     a readable pseudo code into a cryptic nightmare.
> 
>     Type hinting violates the very ESSENCE of what Python was
>     meant to be, that is: a "clean and intuitive syntax". 
> 
> 
> (Google for it if you care for the source.)
> 
> So what is this unspeakable, nightmarish, cryptic abomination going to look 
> like? Here's an example from PEP 484:
> 
> def greeting(name: str) -> str:
>     return 'Hello ' + name
> 
> 
> I don't know about you, but I think anyone who cannot read that and intuit 
> that argument `name` is a string and the return result is also a string is 
> probably going to have bigger troubles with Python than just type-hinting.
> 
> Remember too that type-hinting will *absolutely* remain *completely* 
> optional for Python. Developers can choose to use it or not, they can mix 
> hinted code with regular unhinted code, they can use type declarations 
> purely as documentation or they can run an optional type-checker, as they 
> choose.
> 
> Here's a potential real-world example, from the statistics module in Python 
> 3.4, before and after adding annotations:
> 
> def median_grouped(data, interval=1): ...
> 
> def median_grouped(data:Iterable[Real], interval:Real=1)->Real: ...
> 
> 
> I say "potential" because the standard library doesn't use annotations yet, 
> but it may in the future. 
> 
> So how does Python's proposed type-hints compared to that used by other 
> languages?
> 
> Java:
> 
>   public double median_grouped(List<Double> data, double interval) {}
> 
> Pascal:
> 
>   function median_grouped(data: IterableOfReal; interval: Real): Real;
> 
> C:
> 
>   double
>   median_grouped (IterableOfReal data, double interval)
> 
> Haskell:
> 
>   median_grouped               :: [Double] Double -> Double
>   median_grouped data interval =  ...
> 
> 
> (I may have taken some very slight liberties with the syntax, corrections or 
> more idiomatic forms are very welcome.)
> 
> 
> I think it is clear that Python's annotation syntax remains quite close to 
> executable pseudo-code. Fears that type-hints will doom Python are not 
> credible.
> 
> 
> -- 
> Steve

Hey, two days ago, I found a new way to make Python crash
with non ascii characters.
Good news for potential users. No?

jmf


From wxjmfauth at gmail.com  Fri Jan 23 04:19:57 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Fri, 23 Jan 2015 01:19:57 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <871tmmhbvn.fsf@elektro.pacujo.net>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17978.1421949825.18130.python-list@python.org>
 <871tmmhbvn.fsf@elektro.pacujo.net>
Message-ID: <c74d87a2-751b-4be7-bc08-780bab304dac@googlegroups.com>

Le jeudi 22 janvier 2015 20:08:25 UTC+1, Marko Rauhamaa a ?crit?:
> Sturla Molden <sturla.molden at gmail.com>:
> 
> > No! Developers have to do what managers and customers tell them to do.
> > They will start to require type hinting everywhere. And then the
> > question is what Python has to offer over Java or Swift.
> 
> Yes, but that's what GvR is after, I'm guessing: have Python take over
> the realms of Java and C#.
> 
With such a unicode handling. I doubt.

jmf


From wuwei23 at gmail.com  Fri Jan 23 05:10:07 2015
From: wuwei23 at gmail.com (alex23)
Date: Fri, 23 Jan 2015 20:10:07 +1000
Subject: Python is DOOMED! Again!
In-Reply-To: <mailman.17964.1421919464.18130.python-list@python.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <mailman.17964.1421919464.18130.python-list@python.org>
Message-ID: <m9t6l0$gom$1@dont-email.me>

On 22/01/2015 7:37 PM, Nicholas Cole wrote:
> Still, it would have been nicer to be able to write something like
> this (where the Unions are implicit):

Coincidentally, you also demonstrate what makes this a lesser idea :)

> def handle_employees(employees, rasie):
                                   ^^^^^
>      # raise:  float, Sequence[float]
          ^^^^^

There is a distinct advantage in not repeating yourself.


From morillas at gmail.com  Fri Jan 23 05:54:15 2015
From: morillas at gmail.com (Luis Miguel Morillas)
Date: Fri, 23 Jan 2015 11:54:15 +0100
Subject: ANN: Python Events Calendar - Please submit your 2015 events
In-Reply-To: <54B58B91.9000204@python.org>
References: <54B58B91.9000204@python.org>
Message-ID: <CAFQDTO1Aj9m3AndD-TEMDXNsGCHg=dGNiBM4H2S0nTGP85QS3g@mail.gmail.com>

Hi all

I wrote this script that can read the Python Calendars and shows the
geolocated info on a map and on a timeline.

http://lmorillas.github.io/python_events/


Enjoy

Saludos,

-- luismiguel  (@lmorillas)


2015-01-13 22:18 GMT+01:00 M.-A. Lemburg <mal at python.org>:
> [Please help spread the word by forwarding to other relevant mailing lists,
>  user groups, etc. world-wide; thanks :-)]
>
> ________________________________________________________________________
> ANNOUNCING
>
>          Python Events Calendars - Please submit your 2015 events
>
>            maintained by the Python Software Foundation (PSF)
>                     and a group of volunteers
>
> ________________________________________________________________________
> INTRODUCTION
>
> As some of you may know, the PSF has a team of volunteers who are
> maintaining a set of central Python event calendars. We currently have
> two calendars in place:
>
>  * Python Events Calendar - meant for conferences and larger gatherings
>    focusing on Python or a related technology (in whole or in part)
>
>  * Python User Group Calendar - meant for user group events and other
>    smaller local events
>
> The calendars are displayed on http://pycon.org/ and also on the new
> https://python.org/ website at https://www.python.org/events/python-events/
> and https://www.python.org/events/python-user-group/.
>
> You can subscribe to the calendars using iCal and RSS feeds and also
> embed the calendar widgets on your sites. We have also added a
> Twitter feed @PythonEvents to get immediate updates whenever a new
> event is added. Please see our wiki page for details:
>
>    https://wiki.python.org/moin/PythonEventsCalendar
>
> The calendars are open to the world-wide Python community, so you
> can have local user group events, as well as regional and
> international conference events added to the calendars.
>
> ________________________________________________________________________
> NEWS
>
> Looking back on 2014, the calendars have proven to be a great tool
> for the Python community to connect, with more than 60 conferences
> and more than a hundred of user group events listed.
>
> We would therefore like to encourage everyone to submit their
> 2015 events, so that the Python community can get a better overview
> over what's happening in Python land.
>
> ________________________________________________________________________
> ADDING EVENTS
>
> Please see the instructions at https://wiki.python.org/moin/PythonEventsCalendar#Available_Calendars
> for details on how to
> submit an event. We've made it really easy for you: just need to send
> an email to our team address using the email template we
> provide for this. Thanks.
>
> ________________________________________________________________________
> MORE INFORMATION
>
> More information on the calendars, the URLs, feed links, IDs, embedding,
> etc. is available on the wiki:
>
>     https://wiki.python.org/moin/PythonEventsCalendar
>
> Enjoy,
> --
> Marc-Andre Lemburg
> Director
> Python Software Foundation
> http://www.python.org/psf/
>
> --
> https://mail.python.org/mailman/listinfo/python-announce-list
>
>         Support the Python Software Foundation:
>         http://www.python.org/psf/donations/


From steve+comp.lang.python at pearwood.info  Fri Jan 23 05:59:40 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 23 Jan 2015 21:59:40 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17973.1421939508.18130.python-list@python.org>
Message-ID: <54c2299d$0$13005$c3e8da3$5496439d@news.astraweb.com>

Chris Angelico wrote:

> On Fri, Jan 23, 2015 at 1:16 AM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> Mario Figueiredo wrote:
>>
>>> def handle_employees(emp: Union[Employee, Sequence[Employee]], raise:
>>> Union[float, Sequence[float]]) -> Union[Employee, Sequence[Employee],
>>> None]:
>>
>> Using
>> floats for money is Just Wrong and anyone who does so should have their
>> licence to program taken away.
> 
> But using a float to specify a percentage raise that an employee (or
> class of employees) gets would be reasonable. 

I don't think that a raise of 0.10000000000000001 (10%),
0.035000000000000003 (3.5%) or 0.070000000000000007 (7%) is quite what
people intended.

:-)

(Don't use binary floating point numbers for anything related to money. Just
don't.)


-- 
Steven



From mal at python.org  Fri Jan 23 06:02:38 2015
From: mal at python.org (M.-A. Lemburg)
Date: Fri, 23 Jan 2015 12:02:38 +0100
Subject: ANN: Python Events Calendar - Please submit your 2015 events
In-Reply-To: <CAFQDTO1Aj9m3AndD-TEMDXNsGCHg=dGNiBM4H2S0nTGP85QS3g@mail.gmail.com>
References: <54B58B91.9000204@python.org>
 <CAFQDTO1Aj9m3AndD-TEMDXNsGCHg=dGNiBM4H2S0nTGP85QS3g@mail.gmail.com>
Message-ID: <54C22A4E.3080407@python.org>

On 23.01.2015 11:54, Luis Miguel Morillas wrote:
> Hi all
> 
> I wrote this script that can read the Python Calendars and shows the
> geolocated info on a map and on a timeline.
> 
> http://lmorillas.github.io/python_events/

Very cool :-) Thanks.

I'll add a link to our wiki page.

> Enjoy
> 
> Saludos,
> 
> -- luismiguel  (@lmorillas)
> 
> 
> 2015-01-13 22:18 GMT+01:00 M.-A. Lemburg <mal at python.org>:
>> [Please help spread the word by forwarding to other relevant mailing lists,
>>  user groups, etc. world-wide; thanks :-)]
>>
>> ________________________________________________________________________
>> ANNOUNCING
>>
>>          Python Events Calendars - Please submit your 2015 events
>>
>>            maintained by the Python Software Foundation (PSF)
>>                     and a group of volunteers
>>
>> ________________________________________________________________________
>> INTRODUCTION
>>
>> As some of you may know, the PSF has a team of volunteers who are
>> maintaining a set of central Python event calendars. We currently have
>> two calendars in place:
>>
>>  * Python Events Calendar - meant for conferences and larger gatherings
>>    focusing on Python or a related technology (in whole or in part)
>>
>>  * Python User Group Calendar - meant for user group events and other
>>    smaller local events
>>
>> The calendars are displayed on http://pycon.org/ and also on the new
>> https://python.org/ website at https://www.python.org/events/python-events/
>> and https://www.python.org/events/python-user-group/.
>>
>> You can subscribe to the calendars using iCal and RSS feeds and also
>> embed the calendar widgets on your sites. We have also added a
>> Twitter feed @PythonEvents to get immediate updates whenever a new
>> event is added. Please see our wiki page for details:
>>
>>    https://wiki.python.org/moin/PythonEventsCalendar
>>
>> The calendars are open to the world-wide Python community, so you
>> can have local user group events, as well as regional and
>> international conference events added to the calendars.
>>
>> ________________________________________________________________________
>> NEWS
>>
>> Looking back on 2014, the calendars have proven to be a great tool
>> for the Python community to connect, with more than 60 conferences
>> and more than a hundred of user group events listed.
>>
>> We would therefore like to encourage everyone to submit their
>> 2015 events, so that the Python community can get a better overview
>> over what's happening in Python land.
>>
>> ________________________________________________________________________
>> ADDING EVENTS
>>
>> Please see the instructions at https://wiki.python.org/moin/PythonEventsCalendar#Available_Calendars
>> for details on how to
>> submit an event. We've made it really easy for you: just need to send
>> an email to our team address using the email template we
>> provide for this. Thanks.
>>
>> ________________________________________________________________________
>> MORE INFORMATION
>>
>> More information on the calendars, the URLs, feed links, IDs, embedding,
>> etc. is available on the wiki:
>>
>>     https://wiki.python.org/moin/PythonEventsCalendar
>>
>> Enjoy,
>> --
>> Marc-Andre Lemburg
>> Director
>> Python Software Foundation
>> http://www.python.org/psf/
>>
>> --
>> https://mail.python.org/mailman/listinfo/python-announce-list
>>
>>         Support the Python Software Foundation:
>>         http://www.python.org/psf/donations/

-- 
Marc-Andre Lemburg
Director
Python Software Foundation
http://www.python.org/psf/


From rosuav at gmail.com  Fri Jan 23 06:38:17 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 23 Jan 2015 22:38:17 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <54c2299d$0$13005$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17973.1421939508.18130.python-list@python.org>
 <54c2299d$0$13005$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmoh_BbF6xXmukp+r+OjO9KW-BDdDr6EX=fKnDDVbCtY0A@mail.gmail.com>

On Fri, Jan 23, 2015 at 9:59 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> I don't think that a raise of 0.10000000000000001 (10%),
> 0.035000000000000003 (3.5%) or 0.070000000000000007 (7%) is quite what
> people intended.
>
> :-)

I also don't think it'll make any appreciable difference, especially
if the actual salary is stored as an integer :-)

> (Don't use binary floating point numbers for anything related to money. Just
> don't.)

While I generally agree, it's not quite as hard-and-fast as that. It's
just important to know that binary floating point can't accurately
represent many commonly-used real numbers... the same consideration
that they always need.

ChrisA


From andrew3 at r3dsolutions.com  Fri Jan 23 06:46:03 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Fri, 23 Jan 2015 03:46:03 -0800
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
 <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
Message-ID: <54C2347B.1000405@r3dsolutions.com>


On 01/15/2015 09:05 AM, Ian Kelly wrote:
> On Thu, Jan 15, 2015 at 12:23 AM, Andrew Robinson
> <andrew3 at r3dsolutions.com> wrote:
>> Can you name any other language that *does* allow subclassing of
>> booleans or creation of new boolean values?
>>
>> Yes. Several off the top of my head -- and I have mentioned these before.
>> They generally come with the extra subclasses pre-created and the user
>> doesn't get to create the classes, but only use them; none the less -- they
>> have more than two values with which to do logic equations with.
>>
>> VHDL, Verilog, HDL, Silos III, and there are IEEE variants also.
>> C/C++ historically allowed you to do it with instances included, although I
>> am not sure it still does.
> Sorry, let me rehprase my question. Of course there will be
> special-purpose languages that allow you to do interesting things with
> the logic values and operators. Can you name any other
> *general-purpose* language that allows subclassing of booleans or
> creation of new boolean values? If not, it seems rather unfair to
> single out Python and marvel that this isn't allowed when it's
> actually quite normal to disallow it. Unless you care to provide an
> example, I am fairly sure your claim of C/C++ is wrong. The bool type
> in C++ is a primitive type, none of which can be inherited from. C
> doesn't even have a bool type; at most you have macros for true and
> false to 1 and 0, so the "booleans" there are just ordinary integers.
Ian,
I agree with you mostly; there is good reason to pick on other 
languages, too, with respect to what a bool is.

Although, I have to laugh -- Verilog can syntheze a CPU -- implement 
memory -- and then load a program and run python on the virtual 
machine.   When the pentium was first developed, I watched as Intel 
actually booted up MS-DOS under using Xilinx chips to run the verilog 
program's output they could physically run anything a pentium processor 
could run.  That's *IS* what I consider "general purpose".

But you're sort of confounding my need for type information in my new 
class as a way to advertise compatability with bool, with subclassing -- 
which is only one way that I was exploring to get the 'type' name 
attached to the new object;  That's a mistake that D'Aprano seems to be 
repetitively making as well.
But please note: Type checking for 'bool' is only needed for 
legacy/compatability reasons -- but new code can use any type; so 
subtyping is not strictly necessary if there is another way to get the 
'bool' type attached to my return object for advertising purposes; for 
what I am interested in is an object who presents as bool for legacy 
code, but new code can convert it to anything at all..

C++ *DOES* allow the necessary kind of type checking and subclassing for 
what I need to do in spite of not having a subclass mechanism built into 
the language for base types; eg: C++ allows a semantic subclass to be 
constructed which can be typecast to a bool for compatibility, but 
otherwise presents extra data and the type the enhanced object reports 
is irrelevant.  As I've mentioned before, people can do object oriented 
programming in C,  So, to satisfy your curiosity -- I'll show you a 
mixed C/C++ example, where I make a semantic subclass that has five 
values AllFalse, PartFalse, Uncertain, PartTrue, True ; and these five 
values will have a typeid() of bool and be 100% compatible with legacy 
C++ bool; but upon request, they these 'bool' types will re-cast into a 
semantic subtype that provides additional certainty data.

See the program at end of e-mail.  It compiles with gcc 4.8.2 with no 
warnings;  g++ filename.cc ; ./a.out

But let me explain a bit more why I'm picking on Python:  For even if we 
set the electronic engineering concerns aside that I've raised (and they 
are valid, as OOP is supposed to model reality, not reality be bent to 
match OOP) -- People's facile explanations about why Python's version of 
bool is the way it is -- still bothers me here in the python mail list 
-- because people seem to have a very wrong idea about bool's nature as 
a dualton being somehow justified solely by the fact that there are only 
two values in Boolean logic; For, singletons style programming is not 
justified by the number of values an object has in reality -- And I know 
Charles bool didn't use singletons in his algebra,  -- just read his 
work and you'll see he never mentions them or describes them, but he 
does actually use dozens of *instances* of the True and False objects he 
was talking about -- for the obvious reason that he would have needed 
special mirrors, dichroic or partially silvered, to be even able to 
attempt to make one instance of True written on paper show up in 
multiple places; And that's silly to do when there's no compelling 
reason to do it.

Yet -- people here seem to want to insist that the bool type with only 
two *instances* is some kind of pure re-creation of what Charles Bool 
did -- when clearly it isn't.  It's a amalgamation of enhancements such 
as binary words instead of just True/False and many other things 
(operators that work on words rather than single bits.).  So -- I don't 
see that Python's implementation of Bool is justified by either a purist 
appeal to Charles bool, or by ignoring pragmatic concerns that have been 
attached to Bool's work for years by Electrical Engineers in order to 
make it more useful for *practical* computer problems.  Yet these two 
things are what this python list has sort of harped on.

That brings me to your point about other languages;  I think following 
other languages restrictions arbitrarily is potentially a lemmings 
approach, eg: just because 'everyone' is doing it statistically does not 
mean that it is good to do it that way; If many languages do something, 
there is excellent cause to examine and look for reasons 'why' they do 
that (and I'd love to hear your opinions) but Python has a different set 
of constraints as an interpreter, as opposed to a compiler, and many 
other differences which cause unintended side effects when mimicking 
other programming languages. It's the unintended side effects and 
surprises when a hasty decision is made that's the issue here.

Where python is different from other languages regarding bool -- and 
deserves a little extra picking on, is that Guido has imposed four 
constraints *simultaneously* to bool which together cause a conflict 
that I don't think (offhand) I've ever encountered in another language;  
Definitely not in C/C++!

The four things are: 1 -- he cut off subtyping and created no alternate 
method of doing type checking of duck-types,  2 -- he does not allow 
multiple instances,  3 -- he himself did not implement bool using the 
standard alternative methodology to subclassing -- eg: as a composite 
structure with delegation. 4.  and he has made bool into the default 
return type for base type comparison operators; which means that general 
programmers expect a bool for base types and may check for it, even if 
Python's built in functions do not.

If any one of these four things had not been done, I would not have 
reason to complain about bool in Python; because there would be a way 
for me to easily work with people expecting a bool as a return type from 
comparison operators, using standard OOP techniques and a little 
creativity to make something perfectly compatible; rather than having to 
dig through manuals endlessly with conflicting notions, pep's, and 
subtleties that make for an extremely steep learning curve and lots of 
time spent making only slight progress when there's not much *reasoning* 
behind what Guido did which is consistent and useable as a guideline...

As far a subtyping goes; The very fact that Guido used subtyping to 
create bool in the first place (subtype of int), precludes any real 
claim that bool should not itself be subclassable just because bools 
only have two values;  I mean, seriously --  Guido's 'strict' Bool is 
already an impure form of OOP that is borderline hypocrisy, as it can 
'+' to 2 or 3... and many other things;  and worse I've just come across 
a couple of papers which suggest that Guido doesn't like subclassing 
when Composite object structures could be used instead to replace the 
subclass 'is' relationship with a 'has a' relationship.  So -- if that's 
the case, why isn't bool a composite to begin with ?  eg: Guido's 
programming guides must be read with a caveat 'do what Guido says and 
not what Guido does' ?!

Now to your last point -- I need to point out that  C++ does not have 
all four restrictions I've mentioned so it doesn't have the problem 
Python does;  In C++, there are instances of bool, and therefore I can 
easily encode extra information in a bool object without changing the 
object itself.

Here's a skeleton example, where I only implement one operator '<' on 
the semantic subclass, but the example shows the principle of how to 
extend the bool type via typecasting to bool.  There are better ways of 
doing this, and there are some problems with how I implemented esp. as 
many use cases are not properly covered -- but it serves to show that 
C/C++ CAN encode new subtypes (semantic subtypes only not C++ subtypes) 
while using only the base type itself to transmit data in a perfectly 
backwards compatible way.  In Python, however, it's pretty close to 
hopeless...

#include <iostream>
#include <typeinfo>
using namespace std;

// Create a new super-bool type which is semantically a subtype of bool,
// But have it masquerade as a bool for compatability, unless new code
// explicity typecasts it and access its subtype members.

struct _SBool {
     bool basebool;
     int certainty;
};

class SBool: public _SBool {
public:
     SBool( const bool& );
     bool operator < (const SBool &);
};

// Create all 4 of the statistical uncertainty values as penta-ton.
const _SBool bools[5] = {{false,0},{false,1},{false,2},{false,3},{true,4}};

// Create 4 global alias bool names having full compatability with bool
// for legacy code, but useable in mixed or advanced compares.

const bool & AllFalse  = bools[0].basebool; // uncertainty 0
const bool & PartFalse = bools[1].basebool; // uncertainty 1
const bool & Uncertain = bools[2].basebool; // uncertainty 2
const bool & PartTrue  = bools[3].basebool; // uncertainty 3
const bool & True      = bools[4].basebool; // uncertainty 4

// Create the typecast method.
SBool::SBool( const bool &b ) {
     const void* that = &b;
     if ((that >= bools) && (that < bools+5)) *this=*(const SBool*)that;
     else *this=*(const SBool*)(const void*) &(b?True:AllFalse);

bool SBool::operator < (const SBool &other ) {
     return this->certainty < other.certainty;
}

// ------------------------------------  Test harness.
int main(void) {
     cout << "type match=" <<  (typeid(bool) == typeid(AllFalse)) << endl;
     cout << "testing as bool "       << AllFalse << PartFalse << 
Uncertain << PartTrue << True << endl;
     cout << "testing as SBool "      << SBool(PartFalse).certainty << 
endl;
     cout << "testing up-cast false " << SBool(false).certainty << endl;
     cout << "testing up-cast true "  << SBool(true).certainty << endl;
     cout << "testing advanced compare (should be true)" << 
(SBool(AllFalse) < PartFalse) << endl;
     cout << "testing legacy compare (should be false) " << (AllFalse < 
PartFalse) << endl;
     return 0;
}

//------------------------------------ End of program, Test output 
follows -------------------

type match=1
testing as bool 00001
testing as SBool 1
testing up-cast false 0
testing up-cast true 4
testing advanced compare (should be true)1
testing legacy compare (should be false) 0bash-4.2$















From steve+comp.lang.python at pearwood.info  Fri Jan 23 06:50:09 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 23 Jan 2015 22:50:09 +1100
Subject: Random ALL CAPS posts on this group
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
 <38b9177e-e947-4a62-9823-554e5e266c4e@googlegroups.com>
 <CAPTjJmqMF7SDhwbSO28n_NzJsoxZjA0Aj9D=Nq3NZyX3rO2VDA@mail.gmail.com>
 <mailman.17877.1421720150.18130.python-list@python.org>
Message-ID: <54c23572$0$12977$c3e8da3$5496439d@news.astraweb.com>

Ben Finney wrote:

> Chris Angelico <rosuav at gmail.com> writes:
> 
>> On Tue, Jan 20, 2015 at 11:38 AM, Rick Johnson
>> <rantingrickjohnson at gmail.com> wrote:
>> > That's the beauty of free speech: "We have right to be annoyed, and
>> > the author has the right not to give a damn". The only alternative
>> > is fascist censorship, and I'll happily endure these annoyances to
>> > prevent that!
>>
>> Free speech also gives the freedom to not listen.
> 
> Freedom of expression entails an obligation on the state to not quash
> anyone's expression. It does not affect anyone who is not the state; it
> imposes no obligation on the PSF.

By this reasoning, you would be perfectly comfortable with a state of
affairs where a media monopoly suppressed any and all dissenting
viewpoints, provided that it was a *privately owned* monopoly and not the
government. To quote Bill Cole:

    Here in the US, we are so schizoid and deeply opposed to 
    government censorship that we insist on having unaccountable
    private parties to do it instead.


Since I am pretty sure that you don't actually consider private censorship
to be a good thing, perhaps we can agree that the question of free speech
is a little more complicated than just the state versus non-state.



-- 
Steven



From rosuav at gmail.com  Fri Jan 23 06:58:03 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 23 Jan 2015 22:58:03 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54C2347B.1000405@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
 <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
 <54C2347B.1000405@r3dsolutions.com>
Message-ID: <CAPTjJmoFpxE+B1_=cSMq6hytnY3807XrHK5TKc+Cx81HF_3D+w@mail.gmail.com>

On Fri, Jan 23, 2015 at 10:46 PM, Andrew Robinson
<andrew3 at r3dsolutions.com> wrote:
> 4.  and he has made bool into the default return type for base type
> comparison operators; which means that general programmers expect a bool for
> base types and may check for it, even if Python's built in functions do not.

I don't get this. They're specifically documented as NOT being
required to return a bool, so if any code is type-checking the return
values, that code is buggy.

ChrisA


From rosuav at gmail.com  Fri Jan 23 07:03:27 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 23 Jan 2015 23:03:27 +1100
Subject: Random ALL CAPS posts on this group
In-Reply-To: <54c23572$0$12977$c3e8da3$5496439d@news.astraweb.com>
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
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On Fri, Jan 23, 2015 at 10:50 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
>> Freedom of expression entails an obligation on the state to not quash
>> anyone's expression. It does not affect anyone who is not the state; it
>> imposes no obligation on the PSF.
>
> By this reasoning, you would be perfectly comfortable with a state of
> affairs where a media monopoly suppressed any and all dissenting
> viewpoints, provided that it was a *privately owned* monopoly and not the
> government. To quote Bill Cole:
>
>     Here in the US, we are so schizoid and deeply opposed to
>     government censorship that we insist on having unaccountable
>     private parties to do it instead.
>
>
> Since I am pretty sure that you don't actually consider private censorship
> to be a good thing, perhaps we can agree that the question of free speech
> is a little more complicated than just the state versus non-state.

It's definitely not "state vs non-state". Freedom of expression should
allow me to say anything I like in my own home, but it doesn't
guarantee that I can walk into someone else's place of business and
start insulting the customers. Or, more strictly, he has the right to
throw me out, and I can't hide behind "freedom of speech" as a right
to say whatever I like.

But he has that right because I'm in his place of business. I'm fully
allowed to leave, and say my piece somewhere else. It's even more
obvious when he has to expend resources to allow my voice to be heard;
not every letter to the editor will be published in the newspaper, for
instance, and nobody would expect them all to be. Yes, the newspaper
is quite possibly biased in its selection of which to print; that's
just something you have to accept.

ChrisA


From breamoreboy at yahoo.co.uk  Fri Jan 23 07:07:28 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Fri, 23 Jan 2015 12:07:28 +0000
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54C2347B.1000405@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
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Message-ID: <m9tdi6$qic$1@ger.gmane.org>

On 23/01/2015 11:46, Andrew Robinson wrote:
>

Unless I've missed something all you've done is show that you haven't 
got the faintest idea what you're talking about.  Would you either 
please go away before I die laughing, or tell me where you get the stuff 
that you're taking.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From fetchinson at googlemail.com  Fri Jan 23 08:23:17 2015
From: fetchinson at googlemail.com (Fetchinson .)
Date: Fri, 23 Jan 2015 14:23:17 +0100
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <54c1e349$0$12975$c3e8da3$5496439d@news.astraweb.com>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
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Message-ID: <CADjSo4REHKArf0fr+3E1wm-Gu4472JQN720e0jLVTRjBgSX5Hw@mail.gmail.com>

On 1/23/15, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
> Terry Reedy wrote:
>
>> On 1/22/2015 10:59 PM, Chris Angelico wrote:
>>> On Fri, Jan 23, 2015 at 2:22 PM, Terry Reedy <tjreedy at udel.edu> wrote:
>>>> This idea is so brilliant that it is already an option in mypy and is
>>>> part
>>>> of the new type-hint proposal.  The separate type-hint files are called
>>>> 'stub files'.
>>>
>>> It's worth pointing out, too, that the idea isn't panaceaic - it's
>>> just another tool in the box. Any time you break related things into
>>> separate places, especially separate files, the tendency for them to
>>> get out of sync grows dramatically.
>>
>> The same could be said of putting tests in a separate file.
>
> I agree!
>
> Python has doctests, which live right there with the function. It also has
> assertions, which can be considered a form of continuous testing.
>
> Eiffel has syntax for design-by-contract (testing pre-conditions,
> post-conditions and invariants) there in the body of the function or
> method:
>
> https://docs.eiffel.com/book/method/et-design-contract-tm-assertions-and-exceptions#Expressing_assertions
>
>
> Contracts are a form of testing, since they are designed to be disabled in
> production. Other languages with syntactic support for Design By Contract
> include Clojure, Cobra, D, Mercury, Perl6 and Racket.
>
> Cobra is especially close to Python-like syntax, and supports unit tests as
> well:
>
>
>     def sqroot(i as int) as float
>         require
>            i > 0
>         ensure
>            result > 0
>         tests
>            assert sqroot(25) == 5.0
>         body
>             ...
>
> It would be nice to be able to include at least *some* tests right there in
> the code rather than in a separate file.

I completely agree. A cobra-style type hinting implementation would
satisfy everyone who doesn't want to make function signatures noisy
(including me) and would also satisfy those who advocate for the
actual feature (type hinting) without worrying much about the
implementation detail. These two groups are overlapping by the way :)

In any case, I'm pretty sure it was said before, but I can't really
find it anywhere, can someone tell me what the rationale is for
*function signature* type hinting?

I totally get type hinting in general, but why does it have to be in
the function signature? Any reason for that specifically?

Are there lots of folks who actually insist on the type hints being in
the function signature and definitely want to see it there and not
somewhere else?

I'd say cobra-style type hinting would be great, but also something
which is property looking:

@official_type_hinting_by_the_psf( arg1: str, arg2: int, returns: bool )
def myfunction( arg1, arg2 ):
    return True

I really like the idea that in python I don't have lots of choices in
many areas, certain things are dictated. The big advantage is that
when I read other people's code I know what to expect so me being
restricted is a small price to pay that is totally worth it. So I'd
come down on the side of the complainers in this case, the type
hinting pep introduces noisy and not so readable features (I
understand these are optional) which if used will make readability
suffer. If there is a pep for it, people will use it, so the fact that
it is optional is irrelevant, it will be used, so people will be faced
with it when reading other people's code, whether they like it or not.

Cheers,
Daniel




-- 
Psss, psss, put it down! - http://www.cafepress.com/putitdown


From invalid at invalid.invalid  Fri Jan 23 09:47:04 2015
From: invalid at invalid.invalid (Grant Edwards)
Date: Fri, 23 Jan 2015 14:47:04 +0000 (UTC)
Subject: [OT] absolute vs. relative URI
Message-ID: <m9tmt8$hbn$1@reader1.panix.com>

I'm maintaining a web app were the original author(s) went to a little
bit of trouble to always use absolute URIs in links in the pages.

First, the code checks the port number the server is listening on and
extrapolates the protocol being used (http or https).  Then it grabs
the server value from the request and sets a more-or-less global
variable 'wwwroot' something like this:

   if port in (443,8433)
     proto = 'https'
   else
     proto = 'http'
     
   wwwroot = "%s://%s/"  % (proto,server)

If the user orignally entered a URL with the literal IP address
10.0.0.99, then wwwroot ends up with a value of "http://10.0.0.99/"

Then, throughout the rest of the code that variable is used so that
all links are absolute (including protocol, host, and absolute path):

  "<a src='%sWhatever>Whatever</a>" % wwwroot

Why do they go to the extra work of constructing the value for wwwroot
and then inserting it later?
  
I'm not an HTLM/HTTP guru, but I've tinkered with web pages for 20+
years, and for links within sites, I've always used links either
relative to the current location or an absolute _path_ relative to the
current server:

  <a src='/Whatever'>Whatever</a>

I've never had any problems with links like that.  Is there some case
where that doesn't work right and I've just been stupidly lucky?
  
-- 
Grant Edwards               grant.b.edwards        Yow! It don't mean a
                                  at               THING if you ain't got
                              gmail.com            that SWING!!


From marko at pacujo.net  Fri Jan 23 10:18:05 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Fri, 23 Jan 2015 17:18:05 +0200
Subject: [OT] absolute vs. relative URI
References: <m9tmt8$hbn$1@reader1.panix.com>
Message-ID: <87twzh34r6.fsf@elektro.pacujo.net>

Grant Edwards <invalid at invalid.invalid>:

> I'm not an HTLM/HTTP guru, but I've tinkered with web pages for 20+
> years, and for links within sites, I've always used links either
> relative to the current location or an absolute _path_ relative to the
> current server:
>
>   <a src='/Whatever'>Whatever</a>
>
> I've never had any problems with links like that.  Is there some case
> where that doesn't work right and I've just been stupidly lucky?

An ancient HTML spec (<URL: https://tools.ietf.org/html/rfc1866>)
specifies:

    HREF
        gives the URI of the head anchor of a hyperlink.

It refers to the URI spec (<URL: https://tools.ietf.org/html/rfc1630>):

    Partial (relative) form
       Within a object whose URI is well defined, the URI of another
       object may be given in abbreviated form, where parts of the two
       URIs are the same. This allows objects within a group to refer to
       each other without requiring the space for a complete reference,
       and it incidentally allows the group of objects to be moved
       without changing any references.

       [...]

       The rules for the use of a partial name relative to the URI of
       the context are: [...]

Bottom line: you are safe.


Marko


From rustompmody at gmail.com  Fri Jan 23 10:31:29 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 23 Jan 2015 07:31:29 -0800 (PST)
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <mailman.18030.1422013652.18130.python-list@python.org>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
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Message-ID: <bad017ab-490f-4daa-a552-33591c559398@googlegroups.com>

On Friday, January 23, 2015 at 5:18:32 PM UTC+5:30, Andrew Robinson wrote:
> On 01/15/2015 09:05 AM, Ian Kelly wrote:
> > On Thu, Jan 15, 2015 at 12:23 AM, Andrew Robinson wrote:
> >> Can you name any other language that *does* allow subclassing of
> >> booleans or creation of new boolean values?
> >>
> >> Yes. Several off the top of my head -- and I have mentioned these before.
> >> They generally come with the extra subclasses pre-created and the user
> >> doesn't get to create the classes, but only use them; none the less -- they
> >> have more than two values with which to do logic equations with.
> >>
> >> VHDL, Verilog, HDL, Silos III, and there are IEEE variants also.
> >> C/C++ historically allowed you to do it with instances included, although I
> >> am not sure it still does.
> > Sorry, let me rehprase my question. Of course there will be
> > special-purpose languages that allow you to do interesting things with
> > the logic values and operators. Can you name any other
> > *general-purpose* language that allows subclassing of booleans or
> > creation of new boolean values? If not, it seems rather unfair to
> > single out Python and marvel that this isn't allowed when it's
> > actually quite normal to disallow it. Unless you care to provide an
> > example, I am fairly sure your claim of C/C++ is wrong. The bool type
> > in C++ is a primitive type, none of which can be inherited from. C
> > doesn't even have a bool type; at most you have macros for true and
> > false to 1 and 0, so the "booleans" there are just ordinary integers.
> Ian,
> I agree with you mostly; there is good reason to pick on other 
> languages, too, with respect to what a bool is.
> 
> Although, I have to laugh -- Verilog can syntheze a CPU -- implement 
> memory -- and then load a program and run python on the virtual 
> machine.   When the pentium was first developed, I watched as Intel 
> actually booted up MS-DOS under using Xilinx chips to run the verilog 
> program's output they could physically run anything a pentium processor 
> could run.  That's *IS* what I consider "general purpose".
> 
> But you're sort of confounding my need for type information in my new 
> class as a way to advertise compatability with bool, with subclassing -- 
> which is only one way that I was exploring to get the 'type' name 
> attached to the new object;  That's a mistake that D'Aprano seems to be 
> repetitively making as well.
> But please note: Type checking for 'bool' is only needed for 
> legacy/compatability reasons -- but new code can use any type; so 
> subtyping is not strictly necessary if there is another way to get the 
> 'bool' type attached to my return object for advertising purposes; for 
> what I am interested in is an object who presents as bool for legacy 
> code, but new code can convert it to anything at all..
> 
> C++ *DOES* allow the necessary kind of type checking and subclassing for 
> what I need to do in spite of not having a subclass mechanism built into 
> the language for base types; eg: C++ allows a semantic subclass to be 
> constructed which can be typecast to a bool for compatibility, but 
> otherwise presents extra data and the type the enhanced object reports 
> is irrelevant.  As I've mentioned before, people can do object oriented 
> programming in C,  So, to satisfy your curiosity -- I'll show you a 
> mixed C/C++ example, where I make a semantic subclass that has five 
> values AllFalse, PartFalse, Uncertain, PartTrue, True ; and these five 
> values will have a typeid() of bool and be 100% compatible with legacy 
> C++ bool; but upon request, they these 'bool' types will re-cast into a 
> semantic subtype that provides additional certainty data.
> 
> See the program at end of e-mail.  It compiles with gcc 4.8.2 with no 
> warnings;  g++ filename.cc ; ./a.out
> 
> But let me explain a bit more why I'm picking on Python:  For even if we 
> set the electronic engineering concerns aside that I've raised (and they 
> are valid, as OOP is supposed to model reality, not reality be bent to 
> match OOP) -- People's facile explanations about why Python's version of 
> bool is the way it is -- still bothers me here in the python mail list 
> -- because people seem to have a very wrong idea about bool's nature as 
> a dualton being somehow justified solely by the fact that there are only 
> two values in Boolean logic; For, singletons style programming is not 
> justified by the number of values an object has in reality -- And I know 
> Charles bool didn't use singletons in his algebra,  -- just read his 
> work and you'll see he never mentions them or describes them, but he 
> does actually use dozens of *instances* of the True and False objects he 
> was talking about -- for the obvious reason that he would have needed 
> special mirrors, dichroic or partially silvered, to be even able to 
> attempt to make one instance of True written on paper show up in 
> multiple places; And that's silly to do when there's no compelling 
> reason to do it.
> 
> Yet -- people here seem to want to insist that the bool type with only 
> two *instances* is some kind of pure re-creation of what Charles Bool 
> did -- when clearly it isn't.  It's a amalgamation of enhancements such 
> as binary words instead of just True/False and many other things 
> (operators that work on words rather than single bits.).  So -- I don't 
> see that Python's implementation of Bool is justified by either a purist 
> appeal to Charles bool, or by ignoring pragmatic concerns that have been 
> attached to Bool's work for years by Electrical Engineers in order to 
> make it more useful for *practical* computer problems.  Yet these two 
> things are what this python list has sort of harped on.
> 
> That brings me to your point about other languages;  I think following 
> other languages restrictions arbitrarily is potentially a lemmings 
> approach, eg: just because 'everyone' is doing it statistically does not 
> mean that it is good to do it that way; If many languages do something, 
> there is excellent cause to examine and look for reasons 'why' they do 
> that (and I'd love to hear your opinions) but Python has a different set 
> of constraints as an interpreter, as opposed to a compiler, and many 
> other differences which cause unintended side effects when mimicking 
> other programming languages. It's the unintended side effects and 
> surprises when a hasty decision is made that's the issue here.
> 
> Where python is different from other languages regarding bool -- and 
> deserves a little extra picking on, is that Guido has imposed four 
> constraints *simultaneously* to bool which together cause a conflict 
> that I don't think (offhand) I've ever encountered in another language;  
> Definitely not in C/C++!
> 
> The four things are: 1 -- he cut off subtyping and created no alternate 
> method of doing type checking of duck-types,  2 -- he does not allow 
> multiple instances,  3 -- he himself did not implement bool using the 
> standard alternative methodology to subclassing -- eg: as a composite 
> structure with delegation. 4.  and he has made bool into the default 
> return type for base type comparison operators; which means that general 
> programmers expect a bool for base types and may check for it, even if 
> Python's built in functions do not.
> 
> If any one of these four things had not been done, I would not have 
> reason to complain about bool in Python; because there would be a way 
> for me to easily work with people expecting a bool as a return type from 
> comparison operators, using standard OOP techniques and a little 
> creativity to make something perfectly compatible; rather than having to 
> dig through manuals endlessly with conflicting notions, pep's, and 
> subtleties that make for an extremely steep learning curve and lots of 
> time spent making only slight progress when there's not much *reasoning* 
> behind what Guido did which is consistent and useable as a guideline...
> 
> As far a subtyping goes; The very fact that Guido used subtyping to 
> create bool in the first place (subtype of int), precludes any real 
> claim that bool should not itself be subclassable just because bools 
> only have two values;  I mean, seriously --  Guido's 'strict' Bool is 
> already an impure form of OOP that is borderline hypocrisy, as it can 
> '+' to 2 or 3... and many other things;  and worse I've just come across 
> a couple of papers which suggest that Guido doesn't like subclassing 
> when Composite object structures could be used instead to replace the 
> subclass 'is' relationship with a 'has a' relationship.  So -- if that's 
> the case, why isn't bool a composite to begin with ?  eg: Guido's 
> programming guides must be read with a caveat 'do what Guido says and 
> not what Guido does' ?!
> 
> Now to your last point -- I need to point out that  C++ does not have 
> all four restrictions I've mentioned so it doesn't have the problem 
> Python does;  In C++, there are instances of bool, and therefore I can 
> easily encode extra information in a bool object without changing the 
> object itself.
> 
> Here's a skeleton example, where I only implement one operator '<' on 
> the semantic subclass, but the example shows the principle of how to 
> extend the bool type via typecasting to bool.  There are better ways of 
> doing this, and there are some problems with how I implemented esp. as 
> many use cases are not properly covered -- but it serves to show that 
> C/C++ CAN encode new subtypes (semantic subtypes only not C++ subtypes) 
> while using only the base type itself to transmit data in a perfectly 
> backwards compatible way.  In Python, however, it's pretty close to 
> hopeless...
> 
> #include <iostream>
> #include <typeinfo>
> using namespace std;
> 
> // Create a new super-bool type which is semantically a subtype of bool,
> // But have it masquerade as a bool for compatability, unless new code
> // explicity typecasts it and access its subtype members.
> 
> struct _SBool {
>      bool basebool;
>      int certainty;
> };
> 
> class SBool: public _SBool {
> public:
>      SBool( const bool& );
>      bool operator < (const SBool &);
> };
> 
> // Create all 4 of the statistical uncertainty values as penta-ton.
> const _SBool bools[5] = {{false,0},{false,1},{false,2},{false,3},{true,4}};
> 
> // Create 4 global alias bool names having full compatability with bool
> // for legacy code, but useable in mixed or advanced compares.
> 
> const bool & AllFalse  = bools[0].basebool; // uncertainty 0
> const bool & PartFalse = bools[1].basebool; // uncertainty 1
> const bool & Uncertain = bools[2].basebool; // uncertainty 2
> const bool & PartTrue  = bools[3].basebool; // uncertainty 3
> const bool & True      = bools[4].basebool; // uncertainty 4
> 
> // Create the typecast method.
> SBool::SBool( const bool &b ) {
>      const void* that = &b;
>      if ((that >= bools) && (that < bools+5)) *this=*(const SBool*)that;
>      else *this=*(const SBool*)(const void*) &(b?True:AllFalse);
> 
> bool SBool::operator < (const SBool &other ) {
>      return this->certainty < other.certainty;
> }
> 
> // ------------------------------------  Test harness.
> int main(void) {
>      cout << "type match=" <<  (typeid(bool) == typeid(AllFalse)) << endl;
>      cout << "testing as bool "       << AllFalse << PartFalse << 
> Uncertain << PartTrue << True << endl;
>      cout << "testing as SBool "      << SBool(PartFalse).certainty << 
> endl;
>      cout << "testing up-cast false " << SBool(false).certainty << endl;
>      cout << "testing up-cast true "  << SBool(true).certainty << endl;
>      cout << "testing advanced compare (should be true)" << 
> (SBool(AllFalse) < PartFalse) << endl;
>      cout << "testing legacy compare (should be false) " << (AllFalse < 
> PartFalse) << endl;
>      return 0;
> }
> 
> //------------------------------------ End of program, Test output 
> follows -------------------
> 
> type match=1
> testing as bool 00001
> testing as SBool 1
> testing up-cast false 0
> testing up-cast true 4
> testing advanced compare (should be true)1
> testing legacy compare (should be false) 0bash-4.2$

Can you tell me what of the following code does not satisfy your requirements?
[Needs python 3.4]


>>> from enum import IntEnum
>>> class B4(IntEnum):
	F1 = 0
	F2 = 0
	F3 = 0
	T  = 1

In words:
Thats a type of 4-valued boolean
Of which F1/2/3 behave falsey in standard python bool-expecting contexts
T behaves truey (or truish)
[Check with bool(B4.F1) for example]

If you get fed up with typing B4.blah make global variables (actually constants)
F2 = B4.F2

If you need to distinguish the falsey ones, its a bit of a headache
dict(B4.__members__)
should contain all the info you need to make these distinctions


From invalid at invalid.invalid  Fri Jan 23 10:40:52 2015
From: invalid at invalid.invalid (Grant Edwards)
Date: Fri, 23 Jan 2015 15:40:52 +0000 (UTC)
Subject: [OT] absolute vs. relative URI
References: <m9tmt8$hbn$1@reader1.panix.com>
 <87twzh34r6.fsf@elektro.pacujo.net>
Message-ID: <m9tq24$1pu$1@reader1.panix.com>

On 2015-01-23, Marko Rauhamaa <marko at pacujo.net> wrote:
> Grant Edwards <invalid at invalid.invalid>:
>
>> I'm not an HTLM/HTTP guru, but I've tinkered with web pages for 20+
>> years, and for links within sites, I've always used links either
>> relative to the current location or an absolute _path_ relative to the
>> current server:
>>
>>   <a src='/Whatever'>Whatever</a>
>>
>> I've never had any problems with links like that.  Is there some case
>> where that doesn't work right and I've just been stupidly lucky?
>
> An ancient HTML spec (<URL: https://tools.ietf.org/html/rfc1866>)
> specifies:
[...]
> It refers to the URI spec (<URL: https://tools.ietf.org/html/rfc1630>):
[...]
>
> Bottom line: you are safe.

Thanks, I was pretty sure that was the case. But, I'm still baffled
why the original author(s) went to the extra work to always generate
absolute URIs.  The pages were originally developed by a web
development company we contracted to do the initial design for us. We
were _assuming_ they knew more about that sort of thing than we
old-school EE types.

[I must admit that I have learned a lot from their code about how to
use CSS to avoid putting layout/presentation info directly in the HTML
tags the way we did in days of yore.]

-- 
Grant Edwards               grant.b.edwards        Yow! I have a TINY BOWL in
                                  at               my HEAD
                              gmail.com            


From automn at willow.org  Fri Jan 23 10:58:34 2015
From: automn at willow.org (Automn)
Date: 23 Jan 2015 15:58:34 GMT
Subject: kivy secret of mana game
References: <slrnmc2c3g.77n.automn@sigtrans.org>
 <mailman.17993.1421957212.18130.python-list@python.org>
Message-ID: <slrnmc4s3j.ok3.automn@sigtrans.org>

On 2015-01-22, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> On Thu, Jan 22, 2015 at 10:13 AM, Automn <automn at willow.org> wrote:
>> The graphics have been licensed for this.
>
> Really? I'm surprised Square-Enix would even give consideration to
> licensing something like this.

The graphics have all been purchased. I forgot to tell that the game and its
codebase are GPL version 2 and PFL 2.0.

-- 
my blog : http://thediaryofelvishhealer.blogspot.com/
Time heals.


From kwpolska at gmail.com  Fri Jan 23 11:00:15 2015
From: kwpolska at gmail.com (Chris Warrick)
Date: Fri, 23 Jan 2015 17:00:15 +0100
Subject: [OT] absolute vs. relative URI
In-Reply-To: <m9tq24$1pu$1@reader1.panix.com>
References: <m9tmt8$hbn$1@reader1.panix.com>
 <87twzh34r6.fsf@elektro.pacujo.net>
 <m9tq24$1pu$1@reader1.panix.com>
Message-ID: <CAMw+j7+EWX+K_c1a368fA5b6BERv0Ah0SxOd-=HkPiVqdt970g@mail.gmail.com>

On Fri, Jan 23, 2015 at 4:40 PM, Grant Edwards <invalid at invalid.invalid> wrote:
> On 2015-01-23, Marko Rauhamaa <marko at pacujo.net> wrote:
>> Grant Edwards <invalid at invalid.invalid>:
>>
>>> I'm not an HTLM/HTTP guru, but I've tinkered with web pages for 20+
>>> years, and for links within sites, I've always used links either
>>> relative to the current location or an absolute _path_ relative to the
>>> current server:
>>>
>>>   <a src='/Whatever'>Whatever</a>
>>>
>>> I've never had any problems with links like that.  Is there some case
>>> where that doesn't work right and I've just been stupidly lucky?
>>
>> An ancient HTML spec (<URL: https://tools.ietf.org/html/rfc1866>)
>> specifies:
> [...]
>> It refers to the URI spec (<URL: https://tools.ietf.org/html/rfc1630>):
> [...]
>>
>> Bottom line: you are safe.

Technically, there is one way to break things:
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base

However, nobody really uses that.  Determining the protocol and server
URL is a lot of effort, but it does not give any advantages over plain
"/Whatever".  Moreover, it would be safer and more future-proof to use
a protocol-relative "//example.com/Whatever" URL instead of
determining the protocol by ports (why 8433?  I can serve (insecure)
HTTP there; hell: I can be a complete jerk and swap ports 80 and
443!).

But, this webapp completely ignores a pitfall in the process: it
assumes the app lives in the web server root.  You can easily change
this via your favorite HTTP daemon.

> Thanks, I was pretty sure that was the case. But, I'm still baffled
> why the original author(s) went to the extra work to always generate
> absolute URIs.  The pages were originally developed by a web
> development company we contracted to do the initial design for us. We
> were _assuming_ they knew more about that sort of thing than we
> old-school EE types.

Hah!  Those people certainly don?t look ?experienced?.

   "<a src='%sWhatever>Whatever</a>" % wwwroot

0. This should be href=, but this is probably an error with retyping.
(use copy-paste next time.)
1. "double" quotes should be used,
2. and on both sides of the URL.
3. This should be handled in (Jinja2) templates,
4. which should not involve string formatting;
5. especially old-style %-based string formatting!

-- 
Chris Warrick <https://chriswarrick.com/>
PGP: 5EAAEA16


From jbailey at emerytelcom.com  Fri Jan 23 11:02:32 2015
From: jbailey at emerytelcom.com (Jason Bailey)
Date: Fri, 23 Jan 2015 09:02:32 -0700
Subject: Check for running DHCP daemon?
In-Reply-To: <CAPTjJmrpjdNBf4C79gj2BB5S4+QhtDz0_LPcrn2J8-gVUY4T6g@mail.gmail.com>
References: <54C030E9.8010404@emerytelcom.com>
 <CAGGBd_rbL21MZEh+6PoUYoM-OS-Mpd=sUpSTPiTGhwqJSrqNMw@mail.gmail.com>
 <1e1a7b4bdcf1408799b7f95b5d24851a@ETEXCH2.corp.emerytelcom.com>
 <CAPTjJmrpjdNBf4C79gj2BB5S4+QhtDz0_LPcrn2J8-gVUY4T6g@mail.gmail.com>
Message-ID: <54C27098.8020708@emerytelcom.com>

Hmm, okay. What you are saying makes sense.

I'm actually wondering if it might be more beneficial for me to check if 
the local DHCP port (udp 67) is bound and in use. I had tried to do this 
some time ago, and couldn't get it working right (it would always test 
true, even when it shouldn't have). Can anyone steer me in the right 
direction on port status?

Jason Bailey
Network Technician
Emery Telcom
Office: (435) 636-0052
JBailey at emerytelcom.com

On 01/21/2015 09:39 PM, Chris Angelico wrote:
> On Thu, Jan 22, 2015 at 2:58 PM, Jason Bailey <JBailey at emerytelcom.com> wrote:
>> How would I get a list of running processes with the subprocess module? The
>> documentation wasn't clear to me.
> Using the ps command. :)
>
> rosuav at dewey:~$ python3
> Python 3.4.2 (default, Oct  8 2014, 10:45:20)
> [GCC 4.9.1] on linux
> Type "help", "copyright", "credits" or "license" for more information.
>>>> import subprocess
>>>> b" dhcpd\n" in subprocess.check_output(["ps","-A"])
> False
>
> rosuav at sikorsky:~$ python3
> Python 3.5.0a0 (default:4709290253e3, Jan 20 2015, 21:48:07)
> [GCC 4.7.2] on linux
> Type "help", "copyright", "credits" or "license" for more information.
>>>> import subprocess
>>>> b" dhcpd\n" in subprocess.check_output(["ps","-A"])
> True
>
> There's a DHCP server running on Sikorsky, but not on Dewey. :)
>
> Of course, this can be faked. Any process can call itself 'dhcpd' and
> pretend to be the DHCP server. It's up to you to decide how to deal
> with that. (Probably by not caring, I would expect. Unless you
> actually expect someone to maliciously try to confuse your script,
> it's not worth the hassle of protecting yourself.)
>
> ChrisA

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From tjreedy at udel.edu  Fri Jan 23 11:17:52 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Fri, 23 Jan 2015 11:17:52 -0500
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54C2347B.1000405@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
 <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
 <54C2347B.1000405@r3dsolutions.com>
Message-ID: <m9ts7h$t5n$1@ger.gmane.org>

On 1/23/2015 6:46 AM, Andrew Robinson wrote:

> -- because people seem to have a very wrong idea about bool's nature as
> a dualton being somehow justified solely by the fact that there are only
> two values in Boolean logic; For, singletons style programming is not
> justified by the number of values an object has in reality -- And I know
> Charles bool didn't use singletons in his algebra,  -- just read his
> work and you'll see he never mentions them or describes them, but he
> does actually use dozens of *instances* of the True and False objects he

In mathematics, as conceived by most mathematicians, there is only one 
instance of each immutable value.  Value is identity. There is only one 
immutable empty set. (This, without the assumed 'immutable' added, is a 
quote from beginning set theory texts written to counteract the beginner 
mistake, here repeated by you, of thinking that there might be more than 
one.)  There is only one 0, one 1, one (immutable) set {0, 1}, and one 
one symbol 'a'.  The notion of identity separate from value is only 
needed for mutable objects, which generally do not appear in math.  So 
unless Boole was an oddball among mathematicians, he considered multiple 
instances of the word 'True' to be multiple references to the one and 
only logical value True.

In Python, any immutable instance *could be* a singleton.  In current 
CPython, the ints -10 to 256 *are* singletons.  In 'x = 1 + 1', the two 
1s are the same 1.  Other ints are not made to be singletons only 
because the cost would be greater than the benefit.  Similarly, ascii 
chars are singletons and some other strings are interned to make them 
singletons.  Also, the empty tuple is a singleton.  Empty lists cannot 
be because they are mutable and each instance must be separately mutable.

 >>> x = 'a'; y = 'a'; x is y
True
 >>> x = (); y = (); x is y
True

> was talking about -- for the obvious reason that he would have needed
> special mirrors, dichroic or partially silvered, to be even able to
> attempt to make one instance of True written on paper show up in
> multiple places;

This is engineer talk.  From a mathematical point of view, the above is 
nonsense.  Math values are generally seen as timeless spaceless platonic 
values.

-- 
Terry Jan Reedy



From ian.g.kelly at gmail.com  Fri Jan 23 11:28:29 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 23 Jan 2015 09:28:29 -0700
Subject: Python is DOOMED! Again!
In-Reply-To: <a14188d8-84c1-496a-b0f3-cce0935ab4b8@googlegroups.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17998.1421961926.18130.python-list@python.org>
 <a14188d8-84c1-496a-b0f3-cce0935ab4b8@googlegroups.com>
Message-ID: <CALwzidns9vM_0_soGbFKtD4CxHpumzKL4uuTHjhc8hkq07efnQ@mail.gmail.com>

On Thu, Jan 22, 2015 at 7:59 PM, Rustom Mody <rustompmody at gmail.com> wrote:
> PS Ian for a hot thread like this its good to put quotes carefully
> You are quoting Steven quoting somebody -- dunno who that somebody is

I include quote that only for context to Steven's quote. Since I'm not
replying to it, I don't care who wrote it, and if I don't care, then
why should the reader? So I'm sorry, but I'm more likely to simply
delete that context than mess around with multiple levels of
attribution.


From ian.g.kelly at gmail.com  Fri Jan 23 11:50:54 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 23 Jan 2015 09:50:54 -0700
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <bad017ab-490f-4daa-a552-33591c559398@googlegroups.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
 <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
 <mailman.18030.1422013652.18130.python-list@python.org>
 <bad017ab-490f-4daa-a552-33591c559398@googlegroups.com>
Message-ID: <CALwzidm6ydZQ99_eNqLn5r2DWU7OPVbkvxg9yjFo-xdiNU0DwA@mail.gmail.com>

On Fri, Jan 23, 2015 at 8:31 AM, Rustom Mody <rustompmody at gmail.com> wrote:
> Can you tell me what of the following code does not satisfy your requirements?
> [Needs python 3.4]
>
>
>>>> from enum import IntEnum
>>>> class B4(IntEnum):
>         F1 = 0
>         F2 = 0
>         F3 = 0
>         T  = 1

This strikes me as a potential problem:

>>> B4.F1 is B4.F2 is B4.F3
True
>>> list(B4)
[<B4.F1: 0>, <B4.T: 1>]

Enum members with the same values are just aliases for one another,
not distinct entities.


From jrs.idx at ntlworld.com  Fri Jan 23 12:00:03 2015
From: jrs.idx at ntlworld.com (John Sampson)
Date: Fri, 23 Jan 2015 17:00:03 +0000
Subject: Case-insensitive sorting of strings (Python newbie)
Message-ID: <54C27E13.5090808@ntlworld.com>

I notice that the string method 'lower' seems to convert some strings 
(input from a text file) to Unicode but not others.
This messes up sorting if it is used on arguments of 'sorted' since 
Unicode strings come before ordinary ones.

Is there a better way of case-insensitive sorting of strings in a list? 
Is it necessary to convert strings read from a plaintext file
to Unicode? If so, how? This is Python 2.7.8.

Regards

John Sampson


From rustompmody at gmail.com  Fri Jan 23 12:03:38 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 23 Jan 2015 09:03:38 -0800 (PST)
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <mailman.18039.1422031903.18130.python-list@python.org>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
 <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
 <mailman.18030.1422013652.18130.python-list@python.org>
 <bad017ab-490f-4daa-a552-33591c559398@googlegroups.com>
 <mailman.18039.1422031903.18130.python-list@python.org>
Message-ID: <5a785a32-3855-457f-be3f-76066dfb20c8@googlegroups.com>

On Friday, January 23, 2015 at 10:22:06 PM UTC+5:30, Ian wrote:
> On Fri, Jan 23, 2015 at 8:31 AM, Rustom Mody wrote:
> > Can you tell me what of the following code does not satisfy your requirements?
> > [Needs python 3.4]
> >
> >
> >>>> from enum import IntEnum
> >>>> class B4(IntEnum):
> >         F1 = 0
> >         F2 = 0
> >         F3 = 0
> >         T  = 1
> 
> This strikes me as a potential problem:
> 
> >>> B4.F1 is B4.F2 is B4.F3
> True
> >>> list(B4)
> [<B4.F1: 0>, <B4.T: 1>]
> 
> Enum members with the same values are just aliases for one another,
> not distinct entities.

Yeah....

The only workaround I have been able to come up with is:

class B4(IntEnum):
>         F1 = 0
>         F2 = ""
>         F3 = None
>         T  = 1 

which is not bad; its ridiculous
[Like going around with a broken broom searching for falsey objects :-) ]


From rosuav at gmail.com  Fri Jan 23 12:04:24 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 04:04:24 +1100
Subject: Check for running DHCP daemon?
In-Reply-To: <54C27098.8020708@emerytelcom.com>
References: <54C030E9.8010404@emerytelcom.com>
 <CAGGBd_rbL21MZEh+6PoUYoM-OS-Mpd=sUpSTPiTGhwqJSrqNMw@mail.gmail.com>
 <1e1a7b4bdcf1408799b7f95b5d24851a@ETEXCH2.corp.emerytelcom.com>
 <CAPTjJmrpjdNBf4C79gj2BB5S4+QhtDz0_LPcrn2J8-gVUY4T6g@mail.gmail.com>
 <54C27098.8020708@emerytelcom.com>
Message-ID: <CAPTjJmrh2gZLhw6YktCPV5bw1K7VVnSx+Pz1nGO7G6Y8fqpvGA@mail.gmail.com>

On Sat, Jan 24, 2015 at 3:02 AM, Jason Bailey <jbailey at emerytelcom.com> wrote:
> I'm actually wondering if it might be more beneficial for me to check if the
> local DHCP port (udp 67) is bound and in use. I had tried to do this some
> time ago, and couldn't get it working right (it would always test true, even
> when it shouldn't have). Can anyone steer me in the right direction on port
> status?

You can check with netstat:

$ sudo netstat -n4lp|grep ':67 '
udp        0      0 0.0.0.0:67              0.0.0.0:*
         22466/dhcpd

On my system, there's a /proc/net/udp which carries this information.
Everything's in hex, so port 67 is shown as 0043:

$ grep :0043 /proc/net/udp
 5755: 00000000:0043 00000000:0000 07 00000000:00000000 00:00000000
00000000     0        0 8334454 2 ffff880403e60b40 0

You'd have to check your own system to know what's truly reliable and
worth using.

ChrisA


From michael at stroeder.com  Fri Jan 23 12:10:03 2015
From: michael at stroeder.com (=?UTF-8?Q?Michael_Str=c3=b6der?=)
Date: Fri, 23 Jan 2015 18:10:03 +0100
Subject: Case-insensitive sorting of strings (Python newbie)
In-Reply-To: <mailman.18040.1422032384.18130.python-list@python.org>
References: <mailman.18040.1422032384.18130.python-list@python.org>
Message-ID: <m9tv8d$nbj$1@dont-email.me>

John Sampson wrote:
> I notice that the string method 'lower' seems to convert some strings (input
> from a text file) to Unicode but not others.
> This messes up sorting if it is used on arguments of 'sorted' since Unicode
> strings come before ordinary ones.

I doubt that. Can you provide a short example?

> Is there a better way of case-insensitive sorting of strings in a list? Is it
> necessary to convert strings read from a plaintext file
> to Unicode? If so, how? This is Python 2.7.8.

Well, if you have non-ASCII chars for many Unicode characters str.lower()
won't give reasonable results. So binary strings containing an encoding of
Unicode character entities should be decoded to Unicode strings first.

Ciao, Michael.



From invalid at invalid.invalid  Fri Jan 23 12:10:48 2015
From: invalid at invalid.invalid (Grant Edwards)
Date: Fri, 23 Jan 2015 17:10:48 +0000 (UTC)
Subject: [OT] absolute vs. relative URI
References: <m9tmt8$hbn$1@reader1.panix.com>
 <87twzh34r6.fsf@elektro.pacujo.net> <m9tq24$1pu$1@reader1.panix.com>
 <mailman.18035.1422028823.18130.python-list@python.org>
Message-ID: <m9tvao$gn9$1@reader1.panix.com>

On 2015-01-23, Chris Warrick <kwpolska at gmail.com> wrote:
>
> Hah!  Those people certainly don?t look ?experienced?.
>
>    "<a src='%sWhatever>Whatever</a>" % wwwroot
>
> 0. This should be href=, but this is probably an error with retyping.
> (use copy-paste next time.)
> 1. "double" quotes should be used,
> 2. and on both sides of the URL.

My bad. Those three were typos in my example.  Real examples that I
could cut/paste all had way to much other cruft involved to serve as
useful illustrations of my quesiton.

> 3. This should be handled in (Jinja2) templates,
> 4. which should not involve string formatting;
> 5. especially old-style %-based string formatting!

The code I posted wasn't from the actual project -- it was just an
illustration to show what they were doing rather than exactly how they
were doing it.

-- 
Grant Edwards               grant.b.edwards        Yow! All this time I've
                                  at               been VIEWING a RUSSIAN
                              gmail.com            MIDGET SODOMIZE a HOUSECAT!


From rosuav at gmail.com  Fri Jan 23 12:11:18 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 04:11:18 +1100
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <CADjSo4REHKArf0fr+3E1wm-Gu4472JQN720e0jLVTRjBgSX5Hw@mail.gmail.com>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <CAPTjJmqXLWEkz-KzxWWD4KRkHs4cdC3Z0DKZ8otjqTkytydsmQ@mail.gmail.com>
 <mailman.18018.1421989508.18130.python-list@python.org>
 <54c1e349$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <CADjSo4REHKArf0fr+3E1wm-Gu4472JQN720e0jLVTRjBgSX5Hw@mail.gmail.com>
Message-ID: <CAPTjJmq0H_Mad3MG_tOW7k0HxCCgOaCHChV3zDw-xHK5KX5oBg@mail.gmail.com>

On Sat, Jan 24, 2015 at 12:23 AM, Fetchinson .
<fetchinson at googlemail.com> wrote:
> In any case, I'm pretty sure it was said before, but I can't really
> find it anywhere, can someone tell me what the rationale is for
> *function signature* type hinting?
>
> I totally get type hinting in general, but why does it have to be in
> the function signature? Any reason for that specifically?

Is there any particular reason for the number of arguments to be part
of the function signature? I totally get the notion of declaring how
many arguments a function takes, but why does it have to be in the
function signature?

Data types are just as much a part of that signature as argument count
is. You could argue that the function's return type isn't part of
that, but that's about it.

> If there is a pep for it, people will use it, so the fact that
> it is optional is irrelevant...

Function annotations were introduced in 2006 (Python 3.0) with PEP 3107:

https://www.python.org/dev/peps/pep-3107/

They were optional then, they are still optional now. Have you been
overrun with them for the past decade? If not, why do you expect now
to be?

ChrisA


From ginolampascione at gmx.com  Fri Jan 23 12:20:26 2015
From: ginolampascione at gmx.com (CARMELO PIGNATRACOZZA DE ROSARIO ARGENTINA)
Date: Fri, 23 Jan 2015 09:20:26 -0800 (PST)
Subject: -- redacted --
Message-ID: <932064e4-d5b5-410a-990c-15a20def69a5@googlegroups.com>

-- redacted --


From rustompmody at gmail.com  Fri Jan 23 12:22:14 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 23 Jan 2015 09:22:14 -0800 (PST)
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <mailman.18039.1422031903.18130.python-list@python.org>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
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Message-ID: <bb5f6854-5ae9-48e5-bb89-4870a552a00f@googlegroups.com>

On Friday, January 23, 2015 at 10:22:06 PM UTC+5:30, Ian wrote:
> On Fri, Jan 23, 2015 at 8:31 AM, Rustom Mody  wrote:
> > Can you tell me what of the following code does not satisfy your requirements?
> > [Needs python 3.4]
> >
> >
> >>>> from enum import IntEnum
> >>>> class B4(IntEnum):
> >         F1 = 0
> >         F2 = 0
> >         F3 = 0
> >         T  = 1
> 
> This strikes me as a potential problem:
> 
> >>> B4.F1 is B4.F2 is B4.F3
> True

Thanks for pointing that out
I saw the problem but not where/why/how

Strikes me that making enumerations is-equal rather than just
=-equal is a bit heavy-handed and unnecessary
What do you think?
[BTW Changing IntEnum to (plain) Enum does not help]


From rosuav at gmail.com  Fri Jan 23 12:23:44 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 04:23:44 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <5a785a32-3855-457f-be3f-76066dfb20c8@googlegroups.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
 <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
 <mailman.18030.1422013652.18130.python-list@python.org>
 <bad017ab-490f-4daa-a552-33591c559398@googlegroups.com>
 <mailman.18039.1422031903.18130.python-list@python.org>
 <5a785a32-3855-457f-be3f-76066dfb20c8@googlegroups.com>
Message-ID: <CAPTjJmo-aTTZvE1C57kj1hadM4jP+HE5At3VuPtL8k9BzvMWFA@mail.gmail.com>

On Sat, Jan 24, 2015 at 4:03 AM, Rustom Mody <rustompmody at gmail.com> wrote:
> The only workaround I have been able to come up with is:
>
> class B4(IntEnum):
>>         F1 = 0
>>         F2 = ""
>>         F3 = None
>>         T  = 1
>
> which is not bad; its ridiculous

It's ridiculous because you declared an IntEnum and then started using
non-integer values that boolify to the same value (and don't intify).
If that even works, it's a total hack, and it might stop working in a
future version... for example, it doesn't seem to work on my Python
3.5:

>>> class B4(IntEnum):
...  F1=0
...  F2=""
...  F3=None
...  T=1
...
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.5/enum.py", line 152, in __new__
    enum_member = __new__(enum_class, *args)
ValueError: invalid literal for int() with base 10: ''

Using Enum instead of IntEnum does work, but it's still hardly a
normal use of an enumeration.

ChrisA


From rustompmody at gmail.com  Fri Jan 23 12:29:59 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 23 Jan 2015 09:29:59 -0800 (PST)
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <mailman.18043.1422033834.18130.python-list@python.org>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
 <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
 <mailman.18030.1422013652.18130.python-list@python.org>
 <bad017ab-490f-4daa-a552-33591c559398@googlegroups.com>
 <mailman.18039.1422031903.18130.python-list@python.org>
 <5a785a32-3855-457f-be3f-76066dfb20c8@googlegroups.com>
 <mailman.18043.1422033834.18130.python-list@python.org>
Message-ID: <4f8bb3c3-212a-4fe4-83fa-87c27939550e@googlegroups.com>

On Friday, January 23, 2015 at 10:54:06 PM UTC+5:30, Chris Angelico wrote:
> On Sat, Jan 24, 2015 at 4:03 AM, Rustom Mody wrote:
> > The only workaround I have been able to come up with is:
> >
> > class B4(IntEnum):
> >>         F1 = 0
> >>         F2 = ""
> >>         F3 = None
> >>         T  = 1
> >
> > which is not bad; its ridiculous
> 
> It's ridiculous because you declared an IntEnum and then started using
> non-integer values that boolify to the same value (and don't intify).
> If that even works, it's a total hack, and it might stop working in a
> future version... for example, it doesn't seem to work on my Python
> 3.5:
> 
> >>> class B4(IntEnum):
> ...  F1=0
> ...  F2=""
> ...  F3=None
> ...  T=1
> ...
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
>   File "/usr/local/lib/python3.5/enum.py", line 152, in __new__
>     enum_member = __new__(enum_class, *args)
> ValueError: invalid literal for int() with base 10: ''
> 
> Using Enum instead of IntEnum does work, but it's still hardly a
> normal use of an enumeration.
> 
> ChrisA

I mis-cut-n-pasted.
Should have been Enum not IntEnum


From rosuav at gmail.com  Fri Jan 23 12:37:33 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 04:37:33 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <bb5f6854-5ae9-48e5-bb89-4870a552a00f@googlegroups.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
 <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
 <mailman.18030.1422013652.18130.python-list@python.org>
 <bad017ab-490f-4daa-a552-33591c559398@googlegroups.com>
 <mailman.18039.1422031903.18130.python-list@python.org>
 <bb5f6854-5ae9-48e5-bb89-4870a552a00f@googlegroups.com>
Message-ID: <CAPTjJmohgVUPT4QXRf-e1B1Wt1insL4NMbJqj6a0pT1wt=8N9A@mail.gmail.com>

On Sat, Jan 24, 2015 at 4:22 AM, Rustom Mody <rustompmody at gmail.com> wrote:
> Strikes me that making enumerations is-equal rather than just
> =-equal is a bit heavy-handed and unnecessary
> What do you think?

*Normal* use of an enumeration does make sense for them to be
identical. Classic use would be like this:

class AnsiColor(IntEnum):
    black = 0
    red = 1
    green = 2
    orange = 3
    # ... blue, magenta, cyan, white
    bold_black = 8
    bold_red = 9
    # etc etc etc
    bold_orange = 11
    yellow = 11 # On many screens, bold orange looks more yellow

There is absolutely no difference between the ANSI color "bold orange"
and the ANSI color "yellow". So you would expect them to be identical:

>>> AnsiColor.yellow
<AnsiColor.bold_orange: 11>
>>> AnsiColor.yellow is AnsiColor.bold_orange
True

And they are. There's simply no use-case for equal-but-distinct
tokens, when you're primarily using this to give names to numbers. For
another example, you could localize all the color names, or use
"bright" instead of "bold", or drop the underscores; but ultimately,
if you send "\e[11m" to the console, you're going to get the same
color, whether that 11 was called "bold_orange" or "jaune".

What you're trying to do here is a hack, so it's no surprise that the
system doesn't properly support it.

ChrisA


From rustompmody at gmail.com  Fri Jan 23 12:45:31 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 23 Jan 2015 09:45:31 -0800 (PST)
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <mailman.18044.1422034655.18130.python-list@python.org>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
 <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
 <mailman.18030.1422013652.18130.python-list@python.org>
 <bad017ab-490f-4daa-a552-33591c559398@googlegroups.com>
 <mailman.18039.1422031903.18130.python-list@python.org>
 <bb5f6854-5ae9-48e5-bb89-4870a552a00f@googlegroups.com>
 <mailman.18044.1422034655.18130.python-list@python.org>
Message-ID: <80e55765-89c8-4431-9723-7ea4d2d16d50@googlegroups.com>

On Friday, January 23, 2015 at 11:07:48 PM UTC+5:30, Chris Angelico wrote:
> On Sat, Jan 24, 2015 at 4:22 AM, Rustom Mody  wrote:
> > Strikes me that making enumerations is-equal rather than just
> > =-equal is a bit heavy-handed and unnecessary
> > What do you think?
> 
> *Normal* use of an enumeration does make sense for them to be
> identical. Classic use would be like this:
> 
> class AnsiColor(IntEnum):
>     black = 0
>     red = 1
>     green = 2
>     orange = 3
>     # ... blue, magenta, cyan, white
>     bold_black = 8
>     bold_red = 9
>     # etc etc etc
>     bold_orange = 11
>     yellow = 11 # On many screens, bold orange looks more yellow
> 
> There is absolutely no difference between the ANSI color "bold orange"
> and the ANSI color "yellow". So you would expect them to be identical:
> 
> >>> AnsiColor.yellow
> <AnsiColor.bold_orange: 11>
> >>> AnsiColor.yellow is AnsiColor.bold_orange
> True
> 
> And they are. There's simply no use-case for equal-but-distinct
> tokens, when you're primarily using this to give names to numbers. For
> another example, you could localize all the color names, or use
> "bright" instead of "bold", or drop the underscores; but ultimately,
> if you send "\e[11m" to the console, you're going to get the same
> color, whether that 11 was called "bold_orange" or "jaune".
> 
> What you're trying to do here is a hack, so it's no surprise that the
> system doesn't properly support it.
> 
> ChrisA

No disagreement with the 'hack'
As for "no use case for equal but distinct tokens" - thats a strange
view given this thread


From rosuav at gmail.com  Fri Jan 23 12:48:45 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 04:48:45 +1100
Subject: [OT] absolute vs. relative URI
In-Reply-To: <CAMw+j7+EWX+K_c1a368fA5b6BERv0Ah0SxOd-=HkPiVqdt970g@mail.gmail.com>
References: <m9tmt8$hbn$1@reader1.panix.com>
 <87twzh34r6.fsf@elektro.pacujo.net>
 <m9tq24$1pu$1@reader1.panix.com>
 <CAMw+j7+EWX+K_c1a368fA5b6BERv0Ah0SxOd-=HkPiVqdt970g@mail.gmail.com>
Message-ID: <CAPTjJmocM=8OcKQcyjh9xzvK33BQerifBHzr7sjtjZaMWDS-2g@mail.gmail.com>

On Sat, Jan 24, 2015 at 3:00 AM, Chris Warrick <kwpolska at gmail.com> wrote:
> 5. especially old-style %-based string formatting!

Please. There's nothing wrong with %-style formatting. It's not
deprecated, and never will be; and it has the advantage of being
cross-language compatible. I was speaking with a Python student
yesterday who didn't understand the {} notation, but grokked "%d + %d
= %d" % (x, y, x+y) instantly, thanks to experience with other
languages.

Use of % formatting is not a bug.

ChrisA


From __peter__ at web.de  Fri Jan 23 12:53:03 2015
From: __peter__ at web.de (Peter Otten)
Date: Fri, 23 Jan 2015 18:53:03 +0100
Subject: Case-insensitive sorting of strings (Python newbie)
References: <54C27E13.5090808@ntlworld.com>
Message-ID: <m9u1pv$a0o$1@ger.gmane.org>

John Sampson wrote:

> I notice that the string method 'lower' seems to convert some strings
> (input from a text file) to Unicode but not others.
> This messes up sorting if it is used on arguments of 'sorted' since
> Unicode strings come before ordinary ones.
> 
> Is there a better way of case-insensitive sorting of strings in a list?
> Is it necessary to convert strings read from a plaintext file
> to Unicode? If so, how? This is Python 2.7.8.

The standard recommendation is to convert bytes to unicode as early as 
possible and only manipulate unicode. This is more likely to give correct 
results when slicing or converting a string.

$ cat tmp.txt
?hnlich
?blich
n?tig
m?glich
Ma?
Ma?e
Masse
?HNLICH
$ python
Python 2.7.6 (default, Mar 22 2014, 22:59:56) 
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> for line in open("tmp.txt"):
...     line = line.strip()
...     print line, line.lower()
... 
?hnlich ?hnlich
?blich ?blich
n?tig n?tig
m?glich m?glich
Ma? ma?
Ma?e ma?e
Masse masse
?HNLICH ?hnlich

Now the same with unicode. To read text with a specific encoding use either 
codecs.open() or io.open() instead of the built-in (replace utf-8 with your 
actual encoding):

>>> import io
>>> for line in io.open("tmp.txt", encoding="utf-8"): 
...     line = line.strip()
...     print line, line.lower()
... 
?hnlich ?hnlich
?blich ?blich
n?tig n?tig
m?glich m?glich
Ma? ma?
Ma?e ma?e
Masse masse
?HNLICH ?hnlich

Unfortunately this will not give the order that you (or a german speaker in 
the example below) will probably expect:

>>> print "".join(sorted(io.open("tmp.txt"), key=unicode.lower))
Masse
Ma?
Ma?e
m?glich
n?tig
?hnlich
?HNLICH
?blich

For case-insensitive sorting you get better results with locale.strxfrm() -- 
but this doesn't accept unicode:

>>> import locale
>>> locale.setlocale(locale.LC_ALL, "")
'de_DE.UTF-8'
>>> print "".join(sorted(io.open("tmp.txt"), key=locale.strxfrm))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeEncodeError: 'ascii' codec can't encode character u'\xe4' in position 
0: ordinal not in range(128)

As a workaround you can sort first:

>>> print "".join(sorted(open("tmp.txt"), key=locale.strxfrm))
?hnlich
?HNLICH
Ma?
Masse
Ma?e
m?glich
n?tig
?blich

You should still convert the result to unicode if you want to do further 
processing in Python.



From rosuav at gmail.com  Fri Jan 23 12:55:37 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 04:55:37 +1100
Subject: [OT] absolute vs. relative URI
In-Reply-To: <m9tmt8$hbn$1@reader1.panix.com>
References: <m9tmt8$hbn$1@reader1.panix.com>
Message-ID: <CAPTjJmptjaf7QKScdKyV0DFLRTuCnuza79kGs9UzU5u3N4O8VA@mail.gmail.com>

On Sat, Jan 24, 2015 at 1:47 AM, Grant Edwards <invalid at invalid.invalid> wrote:
> I'm maintaining a web app were the original author(s) went to a little
> bit of trouble to always use absolute URIs in links in the pages.

The advantage is that someone who downloads the bare page will still
be referencing images, CSS, other links, etc, from the original
server. The disadvantage is... exactly the same. These days, it's MUCH
better to use relative links, and then let something like wget rewrite
them as necessary. In fact, if all your links are relative (not even
the leading slash - use ../../../ as many times as is necessary), they
don't even need rewriting, and you can test your web site by just
pointing your browser at the file system.

The original code seems rather fragile. The port number isn't
incorporated, so incoming requests on 8443 will end up going through
to https:// with the default port of 443. Any other port will be sent
back through 80. Strongly recommend not doing this.

ChrisA


From ginobusciarello at outlook.com  Fri Jan 23 12:56:12 2015
From: ginobusciarello at outlook.com (Dieffe)
Date: Fri, 23 Jan 2015 09:56:12 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
References: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
Message-ID: <71a9fd22-14ac-4ed9-a33d-d012e3e06718@googlegroups.com>

-- redacted --


From ginobusciarello at outlook.com  Fri Jan 23 12:56:45 2015
From: ginobusciarello at outlook.com (Dieffe)
Date: Fri, 23 Jan 2015 09:56:45 -0800 (PST)
Subject: -- redacted --
Message-ID: <f1473cf5-cc0e-46bf-aea6-b1404014d925@googlegroups.com>

-- redacted --


From steve+comp.lang.python at pearwood.info  Fri Jan 23 12:56:53 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 24 Jan 2015 04:56:53 +1100
Subject: Case-insensitive sorting of strings (Python newbie)
References: <mailman.18040.1422032384.18130.python-list@python.org>
Message-ID: <54c28b66$0$12998$c3e8da3$5496439d@news.astraweb.com>

John Sampson wrote:

> I notice that the string method 'lower' seems to convert some strings
> (input from a text file) to Unicode but not others.

I don't think so. You're going to have to show an example.

I *think* what you might be running into is an artifact of printing to a
terminal, which may (or may not) interpret some byte sequences as UTF-8
characters, but I can't replicate it. So I'll have to see an example.
Please state what OS you are running on, and what encoding your terminal is
set to. Also, are you opening the file in text mode or binary mode?


> This messes up sorting if it is used on arguments of 'sorted' since
> Unicode strings come before ordinary ones.
> 
> Is there a better way of case-insensitive sorting of strings in a list?
> Is it necessary to convert strings read from a plaintext file
> to Unicode? If so, how? This is Python 2.7.8.

Best practice is to always convert to Unicode, even if you know your text is
pure ASCII. You *may* be able to get away with not doing so if you know you
have ASCII, but that's still the lazy way. And of course you need to know
what encoding has been used.

There is some overhead with decoding to Unicode, so if performance really is
critical, *and* your needs are quite low, you may be able to get away with
just treating the strings as ASCII byte strings:

with open("my file.txt") as f:
    for line in f:
        print line.lower()


will correctly lowercase ASCII strings. It won't lowercase non-ASCII
letters, and there's a good chance that they may display as raw bytes in
some encoding. Otherwise, I think the best way to approach this may be:


import io
with io.open("my file.txt", encoding='utf-8') as f:
    for line in f:
        print line.lower()


Assuming the file actually is encoded with UTF-8, that ought to work
perfectly.

But to really know what is going on we will need more information.


-- 
Steven



From rosuav at gmail.com  Fri Jan 23 12:58:54 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 04:58:54 +1100
Subject: Case-insensitive sorting of strings (Python newbie)
In-Reply-To: <m9u1pv$a0o$1@ger.gmane.org>
References: <54C27E13.5090808@ntlworld.com>
	<m9u1pv$a0o$1@ger.gmane.org>
Message-ID: <CAPTjJmrDierT4rBuz5McJO67t+LLd3vW-4N8KS2LZg7k6Ptfyg@mail.gmail.com>

On Sat, Jan 24, 2015 at 4:53 AM, Peter Otten <__peter__ at web.de> wrote:
> Now the same with unicode. To read text with a specific encoding use either
> codecs.open() or io.open() instead of the built-in (replace utf-8 with your
> actual encoding):
>
>>>> import io
>>>> for line in io.open("tmp.txt", encoding="utf-8"):
> ...     line = line.strip()
> ...     print line, line.lower()

In Python 3, the built-in open() function sports a fancy encoding=
parameter like that.

for line in open("tmp.txt", encoding="utf-8"):

If you can, I would recommend using Python 3 for all this kind of
thing. The difference may not be huge, but there are all sorts of
little differences here and there that mean that Unicode support is
generally better; most of it stems from the fact that the default
quoted string literal is a Unicode string rather than a byte string,
which means that basically every function ever written for Py3 has
been written to be Unicode-compatible.

ChrisA


From ian.g.kelly at gmail.com  Fri Jan 23 13:00:26 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 23 Jan 2015 11:00:26 -0700
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54C2347B.1000405@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
 <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
 <54C2347B.1000405@r3dsolutions.com>
Message-ID: <CALwzidnh_um7rKqmQYNWb6LYuoHVvzUVc6L6nhoApfRwpNHzMg@mail.gmail.com>

On Fri, Jan 23, 2015 at 4:46 AM, Andrew Robinson
<andrew3 at r3dsolutions.com> wrote:
> Although, I have to laugh -- Verilog can syntheze a CPU -- implement memory
> -- and then load a program and run python on the virtual machine.   When the
> pentium was first developed, I watched as Intel actually booted up MS-DOS
> under using Xilinx chips to run the verilog program's output they could
> physically run anything a pentium processor could run.  That's *IS* what I
> consider "general purpose".

Turing-complete and "general purpose" are not the same. Would you
write a web application or a banking system in Verilog? Using Verilog
to host a virtual machine that runs such a program written in some
other language doesn't count; the actual application is still written
in that other language. You could implement the same Pentium virtual
machine in Brainf*** if you chose, but it will still be an esoteric
language, not a general-purpose one.

> But you're sort of confounding my need for type information in my new class
> as a way to advertise compatability with bool, with subclassing -- which is
> only one way that I was exploring to get the 'type' name attached to the new
> object;  That's a mistake that D'Aprano seems to be repetitively making as
> well.

No, I'm just responding specifically to the complaint you've been
making about not being able to subclass bool.

> C++ *DOES* allow the necessary kind of type checking and subclassing for
> what I need to do in spite of not having a subclass mechanism built into the
> language for base types; eg: C++ allows a semantic subclass to be
> constructed which can be typecast to a bool for compatibility, but otherwise
> presents extra data and the type the enhanced object reports is irrelevant.
> As I've mentioned before, people can do object oriented programming in C,
> So, to satisfy your curiosity -- I'll show you a mixed C/C++ example, where
> I make a semantic subclass that has five values AllFalse, PartFalse,
> Uncertain, PartTrue, True ; and these five values will have a typeid() of
> bool and be 100% compatible with legacy C++ bool; but upon request, they
> these 'bool' types will re-cast into a semantic subtype that provides
> additional certainty data.
>
> See the program at end of e-mail.  It compiles with gcc 4.8.2 with no
> warnings;  g++ filename.cc ; ./a.out

I'm not convinced this is generally safe. Unaware client code that
uses these values will lose the certainty values, even if the values
are later passed back into aware code.

const bool& is_p_equal_np() {
    return Uncertain;
}

void some_other_sbool_aware_code(const SBool& value) {
    if (SBool(PartFalse) < value) {
        cout << "Success: value is greater than PartFalse" << endl;
    } else {
        cout << "Failure: value is not greater than PartFalse" << endl;
    }
}

void some_sbool_unaware_code() {
    bool uncertainty = is_p_equal_np();
    some_other_sbool_aware_code(uncertainty);
}

Calling some_sbool_unaware_code() prints the Failure message because
the bool reference gets lost, and the typecast to SBool in
some_other_sbool_aware_code consequently results in AllFalse.

To the extent that this does work, it seems to be based on pointer
arithmetic, which is intentionally and explicitly something that
Python doesn't support. If Python had the means to distinguish name
bindings, then I see no other reason the same approach couldn't work.

> But let me explain a bit more why I'm picking on Python:  For even if we set
> the electronic engineering concerns aside that I've raised (and they are
> valid, as OOP is supposed to model reality, not reality be bent to match
> OOP) -- People's facile explanations about why Python's version of bool is
> the way it is -- still bothers me here in the python mail list -- because
> people seem to have a very wrong idea about bool's nature as a dualton being
> somehow justified solely by the fact that there are only two values in
> Boolean logic; For, singletons style programming is not justified by the
> number of values an object has in reality -- And I know Charles bool didn't
> use singletons in his algebra,  -- just read his work and you'll see he
> never mentions them or describes them, but he does actually use dozens of
> *instances* of the True and False objects he was talking about -- for the
> obvious reason that he would have needed special mirrors, dichroic or
> partially silvered, to be even able to attempt to make one instance of True
> written on paper show up in multiple places; And that's silly to do when
> there's no compelling reason to do it.

Writing down the word true multiple times doesn't create multiple
"instances" of the mathematical true. Mathematically, they're all the
same platonic object.

> As far a subtyping goes; The very fact that Guido used subtyping to create
> bool in the first place (subtype of int), precludes any real claim that bool
> should not itself be subclassable just because bools only have two values;
> I mean, seriously --  Guido's 'strict' Bool is already an impure form of OOP
> that is borderline hypocrisy, as it can '+' to 2 or 3... and many other
> things;  and worse I've just come across a couple of papers which suggest
> that Guido doesn't like subclassing when Composite object structures could
> be used instead to replace the subclass 'is' relationship with a 'has a'
> relationship.  So -- if that's the case, why isn't bool a composite to begin
> with ?  eg: Guido's programming guides must be read with a caveat 'do what
> Guido says and not what Guido does' ?!

bool is a subclass of int for backward compatibility. The bool type
wasn't added to Python until version 2.3. Before that, Python used 0
and 1 (hence why the __bool__ method is named __nonzero__ in 2.x).
Because bool subclasses int, it still does; it just has a more
specific type and names for them as well.


From rosuav at gmail.com  Fri Jan 23 13:03:48 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 05:03:48 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <80e55765-89c8-4431-9723-7ea4d2d16d50@googlegroups.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
 <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
 <mailman.18030.1422013652.18130.python-list@python.org>
 <bad017ab-490f-4daa-a552-33591c559398@googlegroups.com>
 <mailman.18039.1422031903.18130.python-list@python.org>
 <bb5f6854-5ae9-48e5-bb89-4870a552a00f@googlegroups.com>
 <mailman.18044.1422034655.18130.python-list@python.org>
 <80e55765-89c8-4431-9723-7ea4d2d16d50@googlegroups.com>
Message-ID: <CAPTjJmpk6Ox=QOMwJmNSTPkPGUPMDV5tR=8BkTrw8XAgjCm9cg@mail.gmail.com>

On Sat, Jan 24, 2015 at 4:45 AM, Rustom Mody <rustompmody at gmail.com> wrote:
> No disagreement with the 'hack'
> As for "no use case for equal but distinct tokens" - thats a strange
> view given this thread

Look at it this way: A classic enumeration has no use-case for
equal-but-distinct; this thread doesn't disagree with that, because
this thread is not about classic enumerations. In the same way,
integers don't have use-cases for equal-but-distinct either, but in
practice, you can distinguish between exact literals and the results
of computation:

rosuav at sikorsky:~$ cat unique_numbers.py
x = 100000
y = 100000
z = 99999+1
print(x is y, x is z, y is z)
rosuav at sikorsky:~$ python3 unique_numbers.py
True False False

This is still not good code, though. If you really need to distinguish
those, your code is majorly fragile.

ChrisA


From ian.g.kelly at gmail.com  Fri Jan 23 13:04:18 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 23 Jan 2015 11:04:18 -0700
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <5a785a32-3855-457f-be3f-76066dfb20c8@googlegroups.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
 <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
 <mailman.18030.1422013652.18130.python-list@python.org>
 <bad017ab-490f-4daa-a552-33591c559398@googlegroups.com>
 <mailman.18039.1422031903.18130.python-list@python.org>
 <5a785a32-3855-457f-be3f-76066dfb20c8@googlegroups.com>
Message-ID: <CALwzid=Q2XyOs5V7WD1imaqghq=N66wE4nrjSZjrFw_fZxS9NQ@mail.gmail.com>

On Fri, Jan 23, 2015 at 10:03 AM, Rustom Mody <rustompmody at gmail.com> wrote:
> On Friday, January 23, 2015 at 10:22:06 PM UTC+5:30, Ian wrote:
>> On Fri, Jan 23, 2015 at 8:31 AM, Rustom Mody wrote:
>> > Can you tell me what of the following code does not satisfy your requirements?
>> > [Needs python 3.4]
>> >
>> >
>> >>>> from enum import IntEnum
>> >>>> class B4(IntEnum):
>> >         F1 = 0
>> >         F2 = 0
>> >         F3 = 0
>> >         T  = 1
>>
>> This strikes me as a potential problem:
>>
>> >>> B4.F1 is B4.F2 is B4.F3
>> True
>> >>> list(B4)
>> [<B4.F1: 0>, <B4.T: 1>]
>>
>> Enum members with the same values are just aliases for one another,
>> not distinct entities.
>
> Yeah....
>
> The only workaround I have been able to come up with is:
>
> class B4(IntEnum):
>>         F1 = 0
>>         F2 = ""
>>         F3 = None
>>         T  = 1
>
> which is not bad; its ridiculous
> [Like going around with a broken broom searching for falsey objects :-) ]

How about something like this:

>>> from enum import Enum
>>> class B4(Enum):
...     F1 = (False, 1)
...     F2 = (False, 2)
...     F3 = (False, 3)
...     T = (True, 4)
...     def __bool__(self):
...         return self.value[0]
...
>>> B4.F1 is B4.F2
False
>>> bool(B4.F1)
False
>>> bool(B4.T)
True


From ian.g.kelly at gmail.com  Fri Jan 23 13:13:26 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 23 Jan 2015 11:13:26 -0700
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <80e55765-89c8-4431-9723-7ea4d2d16d50@googlegroups.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
 <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
 <mailman.18030.1422013652.18130.python-list@python.org>
 <bad017ab-490f-4daa-a552-33591c559398@googlegroups.com>
 <mailman.18039.1422031903.18130.python-list@python.org>
 <bb5f6854-5ae9-48e5-bb89-4870a552a00f@googlegroups.com>
 <mailman.18044.1422034655.18130.python-list@python.org>
 <80e55765-89c8-4431-9723-7ea4d2d16d50@googlegroups.com>
Message-ID: <CALwzidmjBc2QFdBYGv1KEswaK5ZJ-irru7VzG8x0_HAaJ4f5+g@mail.gmail.com>

On Fri, Jan 23, 2015 at 10:45 AM, Rustom Mody <rustompmody at gmail.com> wrote:
> No disagreement with the 'hack'
> As for "no use case for equal but distinct tokens" - thats a strange
> view given this thread

If you want equal but distinct, you can give them distinct values and
define an __eq__ method that compares them as equal. Because of this
though I do take some issue with the Planet example in the docs:

https://docs.python.org/3/library/enum.html#planet

If any planets happened to have the same mass and radius (which I
realize would be unlikely in this case), the example would fail. Using
the value of the enum for both identity and data conflates the two
concepts and leads to pitfalls.


From automn at willow.org  Fri Jan 23 13:23:36 2015
From: automn at willow.org (Automn)
Date: 23 Jan 2015 18:23:36 GMT
Subject: Loading a module from a subdirectory
References: <mailman.8020.1394485253.18130.python-list@python.org>
Message-ID: <slrnmc54jh.uif.automn@sigtrans.org>

On 2014-03-10, Virgil Stokes <vs at it.uu.se> wrote:
> This is a multi-part message in MIME format.
> --------------030903060901020503030004
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> Content-Transfer-Encoding: 7bit
>
> I have the following folder-file structure:
>
>   C:/PythonCode/VideoPlayerSimulator/
>                                   +--  __init__.py   (empty file)
>                                   +--  GlbVars.py (contains the single 
> class Glb)
>
>   C:/PythonCode/VideoPlayerSimulator/RubberBanding/
>                                           +--  __init__.py
>                                           +--  ImportDemo.py
>
>   where, ImportDemo.py contains the following code (a single line):
>
> from VideoPlayerSimulator.GlbVars import Glb as G
>
>   gives the following error when I execute it:
>
> *ImportError: No module named VideoPlayerSimulator.GlbVars*
>
>   Note:
>    1. My sys.path contains:
>       ['C:\\PythonCode\\VideoPlayerSimulator', ...]
>    2. Python 2.7.5 on a Window 7 platform
>    3. The same ImportDemo.py file when executed on my Window Vista platform
>       with the same folder-file structure, *DOES NOT* give an error and 
> works
>       as expected.
>
> Why does the error occur, and why does it not occur on the Windows Vista 
> platform?
>

I don't think you understand what Mr. Otten said, it is not undefined behaviour,
maybe you could demangle your import statement.

Automn


From rosuav at gmail.com  Fri Jan 23 13:25:25 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 05:25:25 +1100
Subject: kivy secret of mana game
In-Reply-To: <U7www.319380$Um.61244@fx22.am4>
References: <slrnmc2c3g.77n.automn@sigtrans.org>
 <U7www.319380$Um.61244@fx22.am4>
Message-ID: <CAPTjJmpAmrNB20vHYbc1j6-WMhZfv0F5gxrnZ9odBo8-x4VGQw@mail.gmail.com>

On Sat, Jan 24, 2015 at 5:09 AM, Tony the Tiger <tony at tiger.invalid> wrote:
> On Thu, 22 Jan 2015 17:13:12 +0000, Automn wrote:
>
>> game
>
> No interest, at all, nada, zilch. zero, nothing.
>
>  /Grrr

Then don't bother responding, just skip the thread and move on.

The rest of us, who don't have this unnatural aversion to games, can
still help out (although the OP didn't have any specific questions or
anything, so this looked like just an announcement).

ChrisA


From ethan at stoneleaf.us  Fri Jan 23 13:36:22 2015
From: ethan at stoneleaf.us (Ethan Furman)
Date: Fri, 23 Jan 2015 10:36:22 -0800
Subject: kivy secret of mana game
In-Reply-To: <slrnmc2c3g.77n.automn@sigtrans.org>
References: <slrnmc2c3g.77n.automn@sigtrans.org>
Message-ID: <54C294A6.7030907@stoneleaf.us>

On 01/22/2015 09:13 AM, Automn wrote:
> 
> I am programming a "Secret of Mana" (Seiken Densetsu) game in kivy, it runs
> on a phone with kivy launcher.

AWESOME!!!!

That was a totally fabulous game -- one of the very few I actually played to the end.  :)

--
~Ethan~

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From ian.g.kelly at gmail.com  Fri Jan 23 13:58:54 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 23 Jan 2015 11:58:54 -0700
Subject: Loading a module from a subdirectory
In-Reply-To: <slrnmc54jh.uif.automn@sigtrans.org>
References: <mailman.8020.1394485253.18130.python-list@python.org>
 <slrnmc54jh.uif.automn@sigtrans.org>
Message-ID: <CALwzidkv9qH+AR6qeXFNGpZhq0jXPZBNr6JW91mAEFEJ7sp9GQ@mail.gmail.com>

On Fri, Jan 23, 2015 at 11:23 AM, Automn <automn at willow.org> wrote:
> On 2014-03-10, Virgil Stokes <vs at it.uu.se> wrote:
>> [SNIP]
>
> I don't think you understand what Mr. Otten said, it is not undefined behaviour,
> maybe you could demangle your import statement.

The post you're replying to is 10 months old. One way or another, the
OP has probably resolved the problem by now.


From rantingrickjohnson at gmail.com  Fri Jan 23 14:02:00 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Fri, 23 Jan 2015 11:02:00 -0800 (PST)
Subject: [OT] absolute vs. relative URI
In-Reply-To: <mailman.18045.1422035333.18130.python-list@python.org>
References: <m9tmt8$hbn$1@reader1.panix.com>
 <87twzh34r6.fsf@elektro.pacujo.net>
 <m9tq24$1pu$1@reader1.panix.com>
 <CAMw+j7+EWX+K_c1a368fA5b6BERv0Ah0SxOd-=HkPiVqdt970g@mail.gmail.com>
 <mailman.18045.1422035333.18130.python-list@python.org>
Message-ID: <53547444-2dd1-4b50-a5ad-0fd162a51ab1@googlegroups.com>

On Friday, January 23, 2015 at 11:49:05 AM UTC-6, Chris Angelico wrote:
> On Sat, Jan 24, 2015 at 3:00 AM, Chris Warrick  wrote:
> > 5. especially old-style %-based string formatting!
> 
> Please. There's nothing wrong with %-style formatting. 

*BALD-FACED-PARTISAN-LIE*! 

If there is *NOTHING* wrong with %formatting then why did we
violate our philosophy of "there should be one way to do
it..." and introduce the string.format() method?

The new string.format() method is not merely *ANOTHER* way
to do the same thing Chris, it's first and foremost a bug-
fix for the limited capabilities of the legacy %formatting.

But string.format() is so much more than a mere bug-fix,
Chris, since it not only offers a richer set of tools, you
can even create your own custom extension of the formatter:
    
    https://docs.python.org/2/library/string.html#string-formatting
    
...try to do all that with %formatting! And lets not forget
that a *FORMAT-METHOD* aligns itself nicely with the wise
philosophy of OOP! (oh boy, i'm going flac for that one from
the OOP hating religious nutters!)

> It's not deprecated, and never will be;

Chris, what do you call a statement that is based on an
un-provable premise? Oh and, GvR told me to tell you that he
wants his time machine back, and if it has even one dent
you're going to be in some serious trouble!

> and it has the advantage of being cross-language
> compatible. I was speaking with a Python student yesterday
> who didn't understand the {} notation, but grokked "%d +
> %d = %d" % (x, y, x+y) instantly, thanks to experience
> with other languages.

So now you finally admit to us that you base your decisions
on emotion and ignore facts. This was something that i had
suspected for some time and i'm glad that you can finally
admit the truth.

So even though string.format() is highly superior to the
legacy %format crap, you will happily ignore the
advancements and cling to your instinctual emotions like the
religious nutters clinging to a bible.

> Use of % formatting is not a bug.

"not a bug"? Another ridiculous judgment! I believe the
description you're looking for is: "is a foolish
consistency".



From marko at pacujo.net  Fri Jan 23 14:14:15 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Fri, 23 Jan 2015 21:14:15 +0200
Subject: Case-insensitive sorting of strings (Python newbie)
References: <54C27E13.5090808@ntlworld.com>
 <mailman.18046.1422035592.18130.python-list@python.org>
Message-ID: <873871fgxk.fsf@elektro.pacujo.net>

Peter Otten <__peter__ at web.de>:

> The standard recommendation is to convert bytes to unicode as early as
> possible and only manipulate unicode.

Unicode doesn't get you off the hook (as you explain later in your
post). Upper/lowercase as well as collation order is ambiguous. Python
even with decent locale support can't be expected to do it all for you.

Well, if Python can't, then who can? Probably nobody in the world, not
generically, anyway.

Example:

    >>> print("re\u0301sume\u0301")
    r?sum?
    >>> print("r\u00e9sum\u00e9")
    r?sum?
    >>> print("re\u0301sume\u0301" == "r\u00e9sum\u00e9")
    False
    >>> print("\ufb01nd")
    find
    >>> print("find")
    find
    >>> print("\ufb01nd" == "find")
    False

If equality can't be determined, words really can't be sorted.


Marko


From rantingrickjohnson at gmail.com  Fri Jan 23 14:23:35 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Fri, 23 Jan 2015 11:23:35 -0800 (PST)
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <mailman.18012.1421983349.18130.python-list@python.org>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <mailman.18012.1421983349.18130.python-list@python.org>
Message-ID: <684d5cdf-4987-4dd1-bc50-76bd019b9d80@googlegroups.com>

On Thursday, January 22, 2015 at 9:22:40 PM UTC-6, Terry Reedy wrote:
> On 1/22/2015 8:15 PM, Rick Johnson wrote:
> 
> > Okay, i have found a solution to the type hinting problem
> > that will appease both sides. On one side we have those who
> > are proposing type hinting annotations within function sigs,
> > and on the other side, we have those who oppose the
> > implementation of type hinting via this method because of
> > the readability concerns. The solution is move the type
> > hinting syntax completely out of the source file and into
> > another file -- think of it as a "Python Type Hinting Header
> > File".
> 
> This idea is so brilliant 

Well thank you kind sir. O:-)
 
> that it is already an option in mypy and is part of the new
> type-hint proposal.

An *OPTION*? If it is not mandatory then why bother? If
authors have a choice between writing type hints into func
sigs or writing them in a "stub file", then the natural
human behavior of "slothfulness" will bring about the
destruction of Python via syntactic noise. Heck, why don't
we just adopt the *REAL* fairness doctrine and make
indentation optional? 

> The separate type-hint files are called 'stub files'.  I
> don't know what the extension is. These will be used for
> the stdlib, which will not have annotations in the .py
> files

So are saying that stubs are mandatory for stdlib source but
optional everywhere else?

> > (1) Removes the noisy syntax from the source file. Python
> > code will remain as clean tomorrow as it is today.
> 
> This will at least be an option.  You are and will be free
> to advocate that people always use stub files.

Well i don't advocate from a selfish perspective here, i'm
trying to save this community! Even though no human cannot 
escape his inherent emotional being, *some-of-us* do 
understand the importance of rational judgment when making 
important decisions!

> > (2) Puts the onerous on the author *NOT* on the reader.
> > This system utilizes a concept known as "Level Of Detail"
> > (or LOD). LOD means that i should not need to see a type
> > hint unless i *WANT* to see a type hint.
> 
> One thing not discussed here (but was in the earlier
> python-ideas thread some months ago) is that some groups
> have standards for using some functions that is stricter
> than the function's full duck-typing generality.  A stub
> file allows a group to specify a restrictive use
> annotation for their static checker without putting lies
> into the code or doc of the function itself.

Yes, there is nothing worse than lies, and comments are already
full of them. Yet again another reason to *FORCE* stub file usage!

> > (3) If i decide i don't want type hints in my code, all i
> > have to do is delete or rename a file, which is much less
> > error prone then editing source code.
> 
> If the annotations are in a separate file, deleting will
> hardly be necessary since the file will be ignored until
> one runs software that uses it.
> 
> > (4) Has the added benefit of aiding when debugging type hints.
> 
> I am not sure what you mean here. It will be easier to
> temporarily comment out an incorrect annotation for a
> function, pending correction, when in a separate file.

To tell you the truth I had not even considered allowing
commenting in the stub files, i was primarily focused on
*EXPORTING* the hints, so you are correct!



From rantingrickjohnson at gmail.com  Fri Jan 23 14:36:33 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Fri, 23 Jan 2015 11:36:33 -0800 (PST)
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <ab558381-d9d7-435e-82fd-1496597d4e6a@googlegroups.com>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <ab558381-d9d7-435e-82fd-1496597d4e6a@googlegroups.com>
Message-ID: <d1a5928b-ff9f-49b0-ba93-970227ef8137@googlegroups.com>

On Thursday, January 22, 2015 at 9:24:01 PM UTC-6, Rustom Mody wrote:
     
> > ============================================================ 
> >  Simplistic Example Code utilizing two files: 
> > ============================================================ 
> > 
> > [...snip code example...]
> > 
> 1. Allow in same file
> 2. Change syntax slightly to:
>    type greeting : str -> str

While i'll agree that removing the hints from sigs is better
than the alternative of injecting noise into sigs, i still
feel as though type hints will "dirty" the purity of source
no matter how wonderful the declaration might to be.

I believe strongly that LOD is the only method we can apply
that will allow us to "bolt on" non-destructive type hints
in Python. So although your idea is an improvement, i'm
sticking with the "stub file solution". (unless something 
better is offered)

> [type is the keyword equivalent to your other typehint file ]
>  and you have essentially the Haskell solution.
> 
> The catch I expect is that haskell is strongly committed to simultaneous
> definitions:
> 
> x = 1
> y = x+2
> 
> is the same as
> y = x+2
> x = 1
> 
> and so definitions can generally be permuted around
> 
> Python is committed to the opposite extreme:
> even def and class are not declarative but imperative

I'm sorry, but i was unable to understand how your last
point was relevant to type hints? 



From rosuav at gmail.com  Fri Jan 23 14:46:41 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 06:46:41 +1100
Subject: [OT] absolute vs. relative URI
In-Reply-To: <53547444-2dd1-4b50-a5ad-0fd162a51ab1@googlegroups.com>
References: <m9tmt8$hbn$1@reader1.panix.com>
 <87twzh34r6.fsf@elektro.pacujo.net>
 <m9tq24$1pu$1@reader1.panix.com>
 <CAMw+j7+EWX+K_c1a368fA5b6BERv0Ah0SxOd-=HkPiVqdt970g@mail.gmail.com>
 <mailman.18045.1422035333.18130.python-list@python.org>
 <53547444-2dd1-4b50-a5ad-0fd162a51ab1@googlegroups.com>
Message-ID: <CAPTjJmoH+OKEsXZ1fKxEv2DiJdb00z8Cs0x6hXOhiRZJFtL8yw@mail.gmail.com>

On Sat, Jan 24, 2015 at 6:02 AM, Rick Johnson
<rantingrickjohnson at gmail.com> wrote:
>> It's not deprecated, and never will be;
>
> Chris, what do you call a statement that is based on an
> un-provable premise? Oh and, GvR told me to tell you that he
> wants his time machine back, and if it has even one dent
> you're going to be in some serious trouble!

Statements from the BDFL committing to maintaining it *at least* until
Python 4000, with clear indication that it is most definitely not
deprecated. Or, looking at it another way: If you want to disagree
with me, find a statement in current, official documentation that says
that it's deprecated.

ChrisA


From rantingrickjohnson at gmail.com  Fri Jan 23 14:48:30 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Fri, 23 Jan 2015 11:48:30 -0800 (PST)
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <mailman.18017.1421985858.18130.python-list@python.org>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
Message-ID: <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>

On Thursday, January 22, 2015 at 10:04:29 PM UTC-6, Chris Angelico wrote:

> It's worth pointing out, too, that the idea isn't
> panaceaic - it's just another tool in the box. Any time
> you break related things into separate places, especially
> separate files, the tendency for them to get out of sync
> grows dramatically.

I wonder how that "poor python interpreter" keeps all those
.pyc and .pyo files in sync with constantly changing source
code? It should be tantamount to torture! Will someone
*PLEASE* start a charity site titled: "Python's sanity fund"?

> Use of stub files for something that's only occasionally
> run (the type-checking linter) increases the potential
> time delay between the error and the fix. Unless you make
> a git/hg hook that runs type checks, chances are you'll
> have those issues in your code.
> 
> Stub files are useful, but they aren't going to magically
> solve everyone's complaints.

We're not trying to solve everyone's complaints, we're
trying to formulate a solution that will cause the least
amount (or completely avert) violating Python's design
philosophy. You act as if the "type hint fan-boys" are the
*ONLY* side of this coin, well, i here to inform you that
coins are two-sided!

Even though type hints may be useful to many programmers,
i'm sure equally as many will find no use for them. But
emotion and opinions *ALONE* is not a wise basis for ANY
decision making.

Therefore, the "MANDATORY-STUB-FILE-SOLUTION" is the *ONLY*
solution (offered so far) that can maintain Python's
philosophical goals whilst appeasing both sides of this two
faced coin.



From rosuav at gmail.com  Fri Jan 23 14:56:19 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 06:56:19 +1100
Subject: Case-insensitive sorting of strings (Python newbie)
In-Reply-To: <873871fgxk.fsf@elektro.pacujo.net>
References: <54C27E13.5090808@ntlworld.com>
 <mailman.18046.1422035592.18130.python-list@python.org>
 <873871fgxk.fsf@elektro.pacujo.net>
Message-ID: <CAPTjJmpQo4MBp=zt=E72GuZLdsLnZUeKJczLM5VBvaBwhi1-3Q@mail.gmail.com>

On Sat, Jan 24, 2015 at 6:14 AM, Marko Rauhamaa <marko at pacujo.net> wrote:
> Well, if Python can't, then who can? Probably nobody in the world, not
> generically, anyway.
>
> Example:
>
>     >>> print("re\u0301sume\u0301")
>     r?sum?
>     >>> print("r\u00e9sum\u00e9")
>     r?sum?
>     >>> print("re\u0301sume\u0301" == "r\u00e9sum\u00e9")
>     False
>     >>> print("\ufb01nd")
>     find
>     >>> print("find")
>     find
>     >>> print("\ufb01nd" == "find")
>     False
>
> If equality can't be determined, words really can't be sorted.

Ah, that's a bit easier to deal with. Just use Unicode normalization.

>>> print(unicodedata.normalize("NFC","re\u0301sume\u0301") == unicodedata.normalize("NFC","r\u00e9sum\u00e9"))
True

It's a bit verbose, but if you're doing a lot of comparisons, you
probably want to make a key-function that folds together everything
that you want to be treated the same way, for instance:

def key(s):
    """Normalize a Unicode string for comparison purposes.

    Composes, case-folds, and trims excess spaces.
    """
    return unicodedata.normalize("NFC",s).strip().casefold()

Then it's much tidier:

>>> print(key("re\u0301sume\u0301") == key("r\u00e9sum\u00e9"))
True
>>> print(key("\ufb01nd") == key("find"))
True

You may want to go further, too; for search comparisons, you'll want
to use NFKC normalization, and probably translate all strings of
Unicode whitespace into single U+0020s, or completely strip out
zero-width non-breaking spaces (and maybe zero-width breaking spaces,
too), etc, etc. It all depends on what you mean by "equality". But
certainly a basic NFC or NFD normalization is safe for general work.

ChrisA


From rosuav at gmail.com  Fri Jan 23 14:59:23 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 06:59:23 +1100
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
Message-ID: <CAPTjJmoxJo1CA=HLqW8L9js5juBBrbyuFVqpEfumDcFzcXd_og@mail.gmail.com>

On Sat, Jan 24, 2015 at 6:48 AM, Rick Johnson
<rantingrickjohnson at gmail.com> wrote:
> On Thursday, January 22, 2015 at 10:04:29 PM UTC-6, Chris Angelico wrote:
>
>> It's worth pointing out, too, that the idea isn't
>> panaceaic - it's just another tool in the box. Any time
>> you break related things into separate places, especially
>> separate files, the tendency for them to get out of sync
>> grows dramatically.
>
> I wonder how that "poor python interpreter" keeps all those
> .pyc and .pyo files in sync with constantly changing source
> code? It should be tantamount to torture! Will someone
> *PLEASE* start a charity site titled: "Python's sanity fund"?

That's where one is directly derived from the other. Edit the .py
file, rebuild the .pyc from it. Any dumb machine can do that... as
long as timestamps can be relied on, the hard drive is correctly
retaining data, etc, etc, etc. And guess what? Python isn't perfect at
it. I had a bizarre problem a while ago that came down to an incorrect
.pyc file in the stdlib. (I still have no idea how that came to be
incorrect. The hard drive doesn't seem to be failing, and the
corruption in the file looks more like a software bug than a hardware
issue.)

ChrisA


From ben+python at benfinney.id.au  Fri Jan 23 15:13:25 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Sat, 24 Jan 2015 07:13:25 +1100
Subject: Random ALL CAPS posts on this group
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
 <38b9177e-e947-4a62-9823-554e5e266c4e@googlegroups.com>
 <CAPTjJmqMF7SDhwbSO28n_NzJsoxZjA0Aj9D=Nq3NZyX3rO2VDA@mail.gmail.com>
 <mailman.17877.1421720150.18130.python-list@python.org>
 <54c23572$0$12977$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <85lhktmf16.fsf@benfinney.id.au>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:

> Ben Finney wrote:
>
> > Freedom of expression entails an obligation on the state to not
> > quash anyone's expression. It does not affect anyone who is not the
> > state; it imposes no obligation on the PSF.
>
> By this reasoning, you would be perfectly comfortable with a state of
> affairs where a media monopoly [?]

What in the above makes you think I'd be at all comfortable with a media
monopoly?

Not so. Rather, my objection to monopolisation of media is rooted in
concerns other than freedom of expression.

Or, in the terms I used above: It is not freedom of expression which
imposes the obligation to avoid monopolisation of media.

-- 
 \     ?Oh, I realize it's a penny here and a penny there, but look at |
  `\      me: I've worked myself up from nothing to a state of extreme |
_o__)                                          poverty.? ?Groucho Marx |
Ben Finney



From israel at ravnalaska.net  Fri Jan 23 15:19:01 2015
From: israel at ravnalaska.net (Israel Brewster)
Date: Fri, 23 Jan 2015 11:19:01 -0900
Subject: Track down SIGABRT
In-Reply-To: <87h9vuoae7.fsf@jester.gateway.pace.com>
References: <B967FFA3-810A-4C9F-A353-A3C5E8C9ED6B@ravnalaska.net>
 <7FF67692-9F7B-4EE1-AD9F-83DAC545A78A@mac.com>
 <mailman.17686.1421168721.18130.python-list@python.org>
 <87h9vuoae7.fsf@jester.gateway.pace.com>
Message-ID: <16DE6703-A761-457E-A942-36C833E32884@ravnalaska.net>

On Jan 13, 2015, at 8:31 AM, Paul Rubin <no.email at nospam.invalid> wrote:

> Israel Brewster <israel at ravnalaska.net> writes:
>>        when it again crashed with a SIGABRT. The crash dump the
>>        system gave me doesn't tell me much, other than that it looks
>>        like python is calling some C function when it crashes. I've
>>        attached the crash report, in case it can mean something more
>>        to someone else.
> 
> Somehow I missed the original post: did you get a core dump?  The
> next thing to do is examine it under gdb.

And somehow I missed your response, so I guess that makes us even :-) I did get a core dump and stack trace, that I attached to my original post. I'll attach the new one from today to this message.

Running it through GDB didn't seem to give me much more information than that crash report - I can see that it is in thread 0, and the call stack is identical to what the crash report shows, but I can't see where in the python code it is.

Memory usage is relatively minimal - at the time of today's crash, top was reporting only around 84MB used - actually down a couple of MB from where it was yesterday.

> 
>> 
>>        Can anyone give me some hints as to how to track down the
>>        cause of this crash? 
> 
> If it's recurring, recompile python with -g to generate debugging
> symbols, so you'll have an easier time examining the dump.  You can even
> run the whole interpreter under gdb, though doing that for 33 days might
> be uncharted territory.

May just have to try it though :-)

In looking back over my GIT change logs, the only change I find that even remotely seems like it might be the issue is a call to del(). Not saying I think that is the issue, min you, but the rest of the changes I made were to things like SQL queries, that might change the data somewhat but not the functioning. Of course, that said I was making more regular changes before, maybe it simply never remained running long enough.

> -- 
> https://mail.python.org/mailman/listinfo/python-list

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-----------------------------------------------
Israel Brewster
Systems Analyst II
Ravn Alaska
5245 Airport Industrial Rd
Fairbanks, AK 99709
(907) 450-7293
-----------------------------------------------


From rantingrickjohnson at gmail.com  Fri Jan 23 15:21:06 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Fri, 23 Jan 2015 12:21:06 -0800 (PST)
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <mailman.18034.1422019400.18130.python-list@python.org>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <CAPTjJmqXLWEkz-KzxWWD4KRkHs4cdC3Z0DKZ8otjqTkytydsmQ@mail.gmail.com>
 <mailman.18018.1421989508.18130.python-list@python.org>
 <54c1e349$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18034.1422019400.18130.python-list@python.org>
Message-ID: <12d74fb6-f7d7-4ff0-88d3-6076a5dc7b57@googlegroups.com>

On Friday, January 23, 2015 at 7:23:34 AM UTC-6, Fetchinson . wrote:
> I really like the idea that in python I don't have lots of
> choices in many areas, certain things are dictated. The
> big advantage is that when I read other people's code I
> know what to expect so me being restricted is a small
> price to pay that is totally worth it. So I'd come down on
> the side of the complainers in this case,

"the complainers"??? O:-) 

Intentional or not, your word choice paints a negative
connotation of the "opposition". We are not "complainers",
we merely hold a contradictory view to that of the
"proposers".

Injecting polarity into debates is dangerous, because, then
we get off into the emotional weeds and a solution may never
be found -- just observe the polarization of American
politics if you don't believe me --> *PUKE*
    
Rational people understand that both sides of any argument
deserve objective consideration, and when a unanimous
solution cannot be found, a compromise must be made on both
sides.

    Even if that means cutting the baby in half.

Sorry to pick on you. Everything else you said was very
rational and articulate!


From breamoreboy at yahoo.co.uk  Fri Jan 23 15:22:40 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Fri, 23 Jan 2015 20:22:40 +0000
Subject: [OT] absolute vs. relative URI
In-Reply-To: <CAPTjJmoH+OKEsXZ1fKxEv2DiJdb00z8Cs0x6hXOhiRZJFtL8yw@mail.gmail.com>
References: <m9tmt8$hbn$1@reader1.panix.com>
 <87twzh34r6.fsf@elektro.pacujo.net> <m9tq24$1pu$1@reader1.panix.com>
 <CAMw+j7+EWX+K_c1a368fA5b6BERv0Ah0SxOd-=HkPiVqdt970g@mail.gmail.com>
 <mailman.18045.1422035333.18130.python-list@python.org>
 <53547444-2dd1-4b50-a5ad-0fd162a51ab1@googlegroups.com>
 <CAPTjJmoH+OKEsXZ1fKxEv2DiJdb00z8Cs0x6hXOhiRZJFtL8yw@mail.gmail.com>
Message-ID: <m9uain$43o$1@ger.gmane.org>

On 23/01/2015 19:46, Chris Angelico wrote:
> On Sat, Jan 24, 2015 at 6:02 AM, Rick Johnson
> <rantingrickjohnson at gmail.com> wrote:
>>> It's not deprecated, and never will be;
>>
>> Chris, what do you call a statement that is based on an
>> un-provable premise? Oh and, GvR told me to tell you that he
>> wants his time machine back, and if it has even one dent
>> you're going to be in some serious trouble!
>
> Statements from the BDFL committing to maintaining it *at least* until
> Python 4000, with clear indication that it is most definitely not
> deprecated. Or, looking at it another way: If you want to disagree
> with me, find a statement in current, official documentation that says
> that it's deprecated.
>
> ChrisA
>

This http://bugs.python.org/issue14123 seems relevant.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From ben+python at benfinney.id.au  Fri Jan 23 15:31:19 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Sat, 24 Jan 2015 07:31:19 +1100
Subject: Random ALL CAPS posts on this group
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
 <38b9177e-e947-4a62-9823-554e5e266c4e@googlegroups.com>
 <CAPTjJmqMF7SDhwbSO28n_NzJsoxZjA0Aj9D=Nq3NZyX3rO2VDA@mail.gmail.com>
 <mailman.17877.1421720150.18130.python-list@python.org>
 <54c23572$0$12977$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <85h9vhme7c.fsf@benfinney.id.au>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:

> Ben Finney wrote:
>
> > Freedom of expression entails an obligation on the state to not
> > quash anyone's expression. It does not affect anyone who is not the
> > state; it imposes no obligation on the PSF.
>
> By this reasoning, you would be perfectly comfortable with a state of
> affairs where a media monopoly suppressed any and all dissenting
> viewpoints, provided that it was a *privately owned* monopoly and not
> the government.

To answer this more directly:

Expression between people ? the field relevant to the freedom we're
discussing ? occurs naturally and with little effort. It is not an
activity requiring high startup costs, and the market for it is as large
as humanity.

A monopoly on media is inherently unstable for this reason, so a
<URL:https://en.wikipedia.org/wiki/Natural_monopoly> is highly unlikely
ever to arise. Competitors will arise frequently to end the monopoly, if
no state action is taken to stop them.

If you are positing a media monopoly capable of suppressing any and all
dissenting viewpoints, it can only persist in this because the state
prevents any competitor to that monopoly. So this is still effectively
the state acting to quash freedom of expression.

-- 
 \          ?Now Maggie, I?ll be watching you too, in case God is busy |
  `\       creating tornadoes or not existing.? ?Homer, _The Simpsons_ |
_o__)                                                                  |
Ben Finney



From sohcahtoa82 at gmail.com  Fri Jan 23 15:44:41 2015
From: sohcahtoa82 at gmail.com (sohcahtoa82 at gmail.com)
Date: Fri, 23 Jan 2015 12:44:41 -0800 (PST)
Subject: kivy secret of mana game
In-Reply-To: <U7www.319380$Um.61244@fx22.am4>
References: <slrnmc2c3g.77n.automn@sigtrans.org>
 <U7www.319380$Um.61244@fx22.am4>
Message-ID: <ef4d2457-bdc6-41ad-b64c-f05da43b39b0@googlegroups.com>

On Friday, January 23, 2015 at 10:10:08 AM UTC-8, Tony the Tiger wrote:
> On Thu, 22 Jan 2015 17:13:12 +0000, Automn wrote:
> 
> > game
> 
> No interest, at all, nada, zilch. zero, nothing.
> 
>  /Grrr

Why don't you like fun?


From larry.martell at gmail.com  Fri Jan 23 15:50:49 2015
From: larry.martell at gmail.com (Larry Martell)
Date: Fri, 23 Jan 2015 15:50:49 -0500
Subject: kivy secret of mana game
In-Reply-To: <ef4d2457-bdc6-41ad-b64c-f05da43b39b0@googlegroups.com>
References: <slrnmc2c3g.77n.automn@sigtrans.org>
 <U7www.319380$Um.61244@fx22.am4>
 <ef4d2457-bdc6-41ad-b64c-f05da43b39b0@googlegroups.com>
Message-ID: <CACwCsY5n+R9049Gpie7yEXWLb2Jk7yQ+uN0trB8XtXWzch3gBg@mail.gmail.com>

On Fri, Jan 23, 2015 at 3:44 PM,  <sohcahtoa82 at gmail.com> wrote:
> On Friday, January 23, 2015 at 10:10:08 AM UTC-8, Tony the Tiger wrote:
>> On Thu, 22 Jan 2015 17:13:12 +0000, Automn wrote:
>>
>> > game
>>
>> No interest, at all, nada, zilch. zero, nothing.
>>
>>  /Grrr
>
> Why don't you like fun?

I spend 10-12 hours a day on the computer - writing code for a living,
paying bills, banking, running my business, shopping, communicating
with family, researching real estate, etc. - the last thing I want to
do is spend more time on it playing a game. There's a lot of fun to be
had without a computer - try it, you may like it.


From rantingrickjohnson at gmail.com  Fri Jan 23 15:59:29 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Fri, 23 Jan 2015 12:59:29 -0800 (PST)
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <mailman.18058.1422043165.18130.python-list@python.org>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <mailman.18058.1422043165.18130.python-list@python.org>
Message-ID: <2e1e9898-f439-40c3-8c25-e280819ef3eb@googlegroups.com>

On Friday, January 23, 2015 at 1:59:38 PM UTC-6, Chris Angelico wrote:
> On Sat, Jan 24, 2015 at 6:48 AM, Sir Rick Johnson wrote:
> > On Thursday, January 22, 2015 at 10:04:29 PM UTC-6, Chris Angelico wrote:
> >
> >> It's worth pointing out, too, that the idea isn't
> >> panaceaic - it's just another tool in the box. Any time
> >> you break related things into separate places, especially
> >> separate files, the tendency for them to get out of sync
> >> grows dramatically.
> >
> > I wonder how that "poor python interpreter" keeps all those
> > .pyc and .pyo files in sync with constantly changing source
> > code? It should be tantamount to torture! Will someone
> > *PLEASE* start a charity site titled: "Python's sanity fund"?
> 
> That's where one is directly derived from the other. Edit the .py
> file, rebuild the .pyc from it. Any dumb machine can do that... as
> long as timestamps can be relied on, the hard drive is correctly
> retaining data, etc, etc, etc. 

Okay, you make a fair point, so let's dig beyond the
superficiality and find the truth shall we? I don't care who
wins, i just want to find the truth.

Your assertion is that since "external hints" are not
directly visible when reading source (as they would be in
func sigs) that the author will forget to update them???

Heck, do you ever read comments? Many of them are not only
out of sync with the code they describe (because an author
forgot to update a corresponding comment after changing the
code), in some cases, they are not even in sync with
*REALITY* (this case being where the author cannot
articulately describe what the code is doing and the
comments become misleading) 

    Yes, there are programmers out there who can write 
    perfectly functioning code but cannot describe what
    it is doing with even a modicum of coherency! Do the 
    phrase "word salad" mean anything to you?

So after observing the lunacy of comment authors, arguing
that by placing hints in source (as opposed to exporting them
to stub files) is somehow going to "magically enforce"
synchronicity -- you have more faith in others than i do!

> And guess what? Python isn't perfect at it. I had a
> bizarre problem a while ago that came down to an incorrect
> .pyc file in the stdlib. (I still have no idea how that
> came to be incorrect. The hard drive doesn't seem to be
> failing, and the corruption in the file looks more like a
> software bug than a hardware issue.)

I too have encountered, when doing some heavy *EDIT-RUN-
EDIT* sessions, where Python was still using an old pyc file
that did not correctly sync with the modified code in my
editor.

And in some cases i was able to verify the bug by changing a
symbol and noting that the exception reports a reference to
the old (now non-existent) symbol.

Sadly when this happens i am usually too busy to stop and
spend time chasing down the source: is it my editor, or is
this a Python issue, or something more subtle??? My quick fix
is to run a Python script that deletes all my .pyc files and
everything is all peaches and cream again.

    Mmm, peaches!

So yes, anecdotal evidence does support your argument that:
"machines can screw up".



From marfig at gmail.com  Fri Jan 23 16:02:39 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Fri, 23 Jan 2015 22:02:39 +0100
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
Message-ID: <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>

In article <5afad59b-5e8c-4821-85cf-9e971c8c7be6 at googlegroups.com>, 
rantingrickjohnson at gmail.com says...
> 
> On Thursday, January 22, 2015 at 10:04:29 PM UTC-6, Chris Angelico wrote:
> 
> > It's worth pointing out, too, that the idea isn't
> > panaceaic - it's just another tool in the box. Any time
> > you break related things into separate places, especially
> > separate files, the tendency for them to get out of sync
> > grows dramatically.
> 
> I wonder how that "poor python interpreter" keeps all those
> .pyc and .pyo files in sync with constantly changing source
> code? It should be tantamount to torture! Will someone
> *PLEASE* start a charity site titled: "Python's sanity fund"?
> 

The process is automatic and based exclusively on timestamps. What you 
propose is manual labor and therein lies the rub. You have to remember 
to update your static analysis files when you update your code. And it 
is not always easy to do it, especially in team development 
environments.

This is also going to complicate user work and the static analysis 
parser work. Function headers need to be matched with the annotated 
description in another file. Because of namespaces this will leave room 
for ambiguity, unless you mirror in the type hinting file the complete 
function signature, which must include its namespace. That is, you need 
a syntax that at the very least includes class declarations, but should 
probably also consider local namespaces and modules. All because you are 
not matching directly a type annotation with the type declaration in the 
code.

...

In any case, I agree entirely with you that type annotation is one ugly 
syntax to a programming language that is touted everywhere as being 
simple and easy to read. I would say that the mistake started 5 years 
ago, and I am surprised how you guys let that horrible PEP pass. I 
wasn't around then, so I'm off the hook.

Some folks in here argue that complex type annotations will be rare, 
since functions should be designed as straightforward units of code with 
simple requirements and respecting certain best practices, like 
separation of concerns, low cyclomatic complexity, adapt well to simple 
unit tests, bla bla bla. But the actual practice of coding software is 
very different. We generally code bad software and generally avoid best 
practices if they get in the way of our schedules, our knowledge, and 
even our ability. And there is always the problem of OOP, which is a 
magnificent source of complex function declarations in terms of the 
types they receive and output.

I think that you are right in that we shouldn't pollute our code with 
static analysis shit. We shouldn't pollute our code period. But There's 
better ways of doing it without resorting to external files.

I'd say Steven D'Aprano example of Cobra hit my sweet spot.


From fetchinson at googlemail.com  Fri Jan 23 16:07:57 2015
From: fetchinson at googlemail.com (Fetchinson .)
Date: Fri, 23 Jan 2015 22:07:57 +0100
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <CAPTjJmq0H_Mad3MG_tOW7k0HxCCgOaCHChV3zDw-xHK5KX5oBg@mail.gmail.com>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <CAPTjJmqXLWEkz-KzxWWD4KRkHs4cdC3Z0DKZ8otjqTkytydsmQ@mail.gmail.com>
 <mailman.18018.1421989508.18130.python-list@python.org>
 <54c1e349$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <CADjSo4REHKArf0fr+3E1wm-Gu4472JQN720e0jLVTRjBgSX5Hw@mail.gmail.com>
 <CAPTjJmq0H_Mad3MG_tOW7k0HxCCgOaCHChV3zDw-xHK5KX5oBg@mail.gmail.com>
Message-ID: <CADjSo4TQJbhVSeqDLy8+1GdPmFz+5PBspKWxA9qdr8fuLSSezw@mail.gmail.com>

On 1/23/15, Chris Angelico <rosuav at gmail.com> wrote:
> On Sat, Jan 24, 2015 at 12:23 AM, Fetchinson .
> <fetchinson at googlemail.com> wrote:
>> In any case, I'm pretty sure it was said before, but I can't really
>> find it anywhere, can someone tell me what the rationale is for
>> *function signature* type hinting?
>>
>> I totally get type hinting in general, but why does it have to be in
>> the function signature? Any reason for that specifically?
>
> Is there any particular reason for the number of arguments to be part
> of the function signature?

I guess this is a rhetorical question :)

> I totally get the notion of declaring how
> many arguments a function takes, but why does it have to be in the
> function signature?

Ditto :)

> Data types are just as much a part of that signature as argument count
> is.

I guess this would be true if there weren't about 5 other alternative
proposals which solve the exact same problem (type hinting) by other
means. Luckily, these will be listed in the PEP soon and the reason
for rejecting them will be there as well, and so my question will
pretty much be answered there.

https://github.com/ambv/typehinting/issues/55


> You could argue that the function's return type isn't part of
> that, but that's about it.

>> If there is a pep for it, people will use it, so the fact that
>> it is optional is irrelevant...
>
> Function annotations were introduced in 2006 (Python 3.0) with PEP 3107:
>
> https://www.python.org/dev/peps/pep-3107/
>
> They were optional then, they are still optional now. Have you been
> overrun with them for the past decade? If not, why do you expect now
> to be?
>
> ChrisA
> --
> https://mail.python.org/mailman/listinfo/python-list
>


-- 
Psss, psss, put it down! - http://www.cafepress.com/putitdown


From marfig at gmail.com  Fri Jan 23 16:12:55 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Fri, 23 Jan 2015 22:12:55 +0100
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <CAPTjJmqXLWEkz-KzxWWD4KRkHs4cdC3Z0DKZ8otjqTkytydsmQ@mail.gmail.com>
 <mailman.18018.1421989508.18130.python-list@python.org>
 <54c1e349$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18034.1422019400.18130.python-list@python.org>
 <12d74fb6-f7d7-4ff0-88d3-6076a5dc7b57@googlegroups.com>
Message-ID: <MPG.2f2cd7a8eb1d5f1798968b@nntp.aioe.org>

In article <12d74fb6-f7d7-4ff0-88d3-6076a5dc7b57 at googlegroups.com>, 
rantingrickjohnson at gmail.com says...
> 
> Injecting polarity into debates is dangerous, because, then
> we get off into the emotional weeds and a solution may never
> be found -- just observe the polarization of American
> politics if you don't believe me --> *PUKE*

I agree entirely. But you have to excuse me... weren't you the one 
calling Guido lapdog (you used worse names) to anyone who agreed with 
the PEP? ;)

Don't been an hypocrit also, when Rantingrick is good enough.


From rantingrickjohnson at gmail.com  Fri Jan 23 16:59:46 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Fri, 23 Jan 2015 13:59:46 -0800 (PST)
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
Message-ID: <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>

On Friday, January 23, 2015 at 3:02:57 PM UTC-6, Mario Figueiredo wrote:

> In any case, I agree entirely with you that type
> annotation is one ugly syntax to a programming language
> that is touted everywhere as being simple and easy to
> read. I would say that the mistake started 5 years ago,
> and I am surprised how you guys let that horrible PEP
> pass. I wasn't around then, so I'm off the hook.
> 
> Some folks in here argue that complex type annotations
> will be rare, since functions should be designed as
> straightforward units of code with simple requirements and
> respecting certain best practices, like separation of
> concerns, low cyclomatic complexity, adapt well to simple
> unit tests, bla bla bla. But the actual practice of coding
> software is very different. We generally code bad software
> and generally avoid best practices if they get in the way
> of our schedules, our knowledge, and even our ability. And
> there is always the problem of OOP, which is a magnificent
> source of complex function declarations in terms of the
> types they receive and output.
> 
> I think that you are right in that we shouldn't pollute
> our code with static analysis shit. We shouldn't pollute
> our code period. But There's better ways of doing it
> without resorting to external files.
> 
> I'd say Steven D'Aprano example of Cobra hit my sweet
> spot.

Yes and this is what i meant when i said "cutting the baby
in half". Although stub files have many advantages, i'll
admit they are onerous for the authors. So the compromise
would be to keep the hints in the same file for which they
are applied, but to separate them from the func arguments:

    (Example modified for PEP8 compliance ;-)

    @typehint(arg1:str, arg2:int, returns:bool)
    def myfunction(arg1, arg2): 
        return True 
        
Of course "@typehint" could be an extension of the decorator
syntax, a keyword, a build-in function or whatever, i don't
care.

That's an acceptable compromise for me. It's not completely
satisfactory, but at least i can read parameters without
needing to ignore type noise -- gawd that is so
annoying!

    Today's repressed look of disapproval brought to you by:
    Angry Java Programmers Everywhere!



From jbailey at emerytelcom.com  Fri Jan 23 17:06:39 2015
From: jbailey at emerytelcom.com (Jason Bailey)
Date: Fri, 23 Jan 2015 15:06:39 -0700
Subject: Check for running DHCP daemon?
In-Reply-To: <CAPTjJmrh2gZLhw6YktCPV5bw1K7VVnSx+Pz1nGO7G6Y8fqpvGA@mail.gmail.com>
References: <54C030E9.8010404@emerytelcom.com>
 <CAGGBd_rbL21MZEh+6PoUYoM-OS-Mpd=sUpSTPiTGhwqJSrqNMw@mail.gmail.com>
 <1e1a7b4bdcf1408799b7f95b5d24851a@ETEXCH2.corp.emerytelcom.com>
 <CAPTjJmrpjdNBf4C79gj2BB5S4+QhtDz0_LPcrn2J8-gVUY4T6g@mail.gmail.com>
 <54C27098.8020708@emerytelcom.com>
 <CAPTjJmrh2gZLhw6YktCPV5bw1K7VVnSx+Pz1nGO7G6Y8fqpvGA@mail.gmail.com>
Message-ID: <54C2C5EF.7020302@emerytelcom.com>

Is there a way to do it without calling external utilities (i.e. a 
Python module, etc)? I'd rather stay within the realm of Python if possible.

Jason



On 01/23/2015 10:04 AM, Chris Angelico wrote:
> On Sat, Jan 24, 2015 at 3:02 AM, Jason Bailey <jbailey at emerytelcom.com> wrote:
>> I'm actually wondering if it might be more beneficial for me to check if the
>> local DHCP port (udp 67) is bound and in use. I had tried to do this some
>> time ago, and couldn't get it working right (it would always test true, even
>> when it shouldn't have). Can anyone steer me in the right direction on port
>> status?
> You can check with netstat:
>
> $ sudo netstat -n4lp|grep ':67 '
> udp        0      0 0.0.0.0:67              0.0.0.0:*
>           22466/dhcpd
>
> On my system, there's a /proc/net/udp which carries this information.
> Everything's in hex, so port 67 is shown as 0043:
>
> $ grep :0043 /proc/net/udp
>   5755: 00000000:0043 00000000:0000 07 00000000:00000000 00:00000000
> 00000000     0        0 8334454 2 ffff880403e60b40 0
>
> You'd have to check your own system to know what's truly reliable and
> worth using.
>
> ChrisA




From rantingrickjohnson at gmail.com  Fri Jan 23 17:26:27 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Fri, 23 Jan 2015 14:26:27 -0800 (PST)
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <MPG.2f2cd7a8eb1d5f1798968b@nntp.aioe.org>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <CAPTjJmqXLWEkz-KzxWWD4KRkHs4cdC3Z0DKZ8otjqTkytydsmQ@mail.gmail.com>
 <mailman.18018.1421989508.18130.python-list@python.org>
 <54c1e349$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18034.1422019400.18130.python-list@python.org>
 <12d74fb6-f7d7-4ff0-88d3-6076a5dc7b57@googlegroups.com>
 <MPG.2f2cd7a8eb1d5f1798968b@nntp.aioe.org>
Message-ID: <72dec946-b6c9-4572-9427-e887c8bb60dc@googlegroups.com>

On Friday, January 23, 2015 at 3:13:12 PM UTC-6, Mario Figueiredo wrote:
> In article <12d74fb6-f7d7-4ff0-88d3-6076a5dc7b57 at googlegroups.com>, 
> Sir Richard Johnson The First says...
> > 
> > Injecting polarity into debates is dangerous, because,
> > then we get off into the emotional weeds and a solution
> > may never be found -- just observe the polarization of
> > American politics if you don't believe me --> *PUKE*
> 
> I agree entirely. But you have to excuse me... weren't you
> the one calling Guido lapdog (you used worse names) to
> anyone who agreed with the PEP? ;)

I was not calling *ANYONE* who agreed with the PEP "a
lapdog", my statement was more specific. I called Chris a
"lapdog of" and a "rabbid fanboy" -- Guido was merely the
"implied Satan".

Of course i'm not suggesting that Guido is a malevolent
godlike being, his inclusion in the expression is merely a
incidental result of Chris's idol worship of "everything Guido".
Although, to be fair, I guess i may have embellished a bit
by using the word "rabbid", and for that i apologize.

But to respond to your assertion that i'm being
hypocritical: nonsense. Stating facts is *NEVER*
hypocritical. Just because a fact happens to be an
"inconvenient truth" does not invalidate it's truthfulness.

Chris (or anybody for that matter) can choose to be a free
thinking individual, or a brainwashed disciple, the choice is
his. Even intelligent people (like Chris) can fall under the
spell of a "implicit cult of personality". 


From sohcahtoa82 at gmail.com  Fri Jan 23 17:38:42 2015
From: sohcahtoa82 at gmail.com (sohcahtoa82 at gmail.com)
Date: Fri, 23 Jan 2015 14:38:42 -0800 (PST)
Subject: Check for running DHCP daemon?
In-Reply-To: <mailman.18063.1422050804.18130.python-list@python.org>
References: <54C030E9.8010404@emerytelcom.com>
 <CAGGBd_rbL21MZEh+6PoUYoM-OS-Mpd=sUpSTPiTGhwqJSrqNMw@mail.gmail.com>
 <1e1a7b4bdcf1408799b7f95b5d24851a@ETEXCH2.corp.emerytelcom.com>
 <CAPTjJmrpjdNBf4C79gj2BB5S4+QhtDz0_LPcrn2J8-gVUY4T6g@mail.gmail.com>
 <54C27098.8020708@emerytelcom.com>
 <CAPTjJmrh2gZLhw6YktCPV5bw1K7VVnSx+Pz1nGO7G6Y8fqpvGA@mail.gmail.com>
 <mailman.18063.1422050804.18130.python-list@python.org>
Message-ID: <2d134592-6983-471e-ba5a-2124502af782@googlegroups.com>

On Friday, January 23, 2015 at 2:07:04 PM UTC-8, Jason Bailey wrote:
> Is there a way to do it without calling external utilities (i.e. a 
> Python module, etc)? I'd rather stay within the realm of Python if possible.
> 
> Jason
> 
> 
> 
> On 01/23/2015 10:04 AM, Chris Angelico wrote:
> > On Sat, Jan 24, 2015 at 3:02 AM, Jason Bailey <jbailey at emerytelcom.com> wrote:
> >> I'm actually wondering if it might be more beneficial for me to check if the
> >> local DHCP port (udp 67) is bound and in use. I had tried to do this some
> >> time ago, and couldn't get it working right (it would always test true, even
> >> when it shouldn't have). Can anyone steer me in the right direction on port
> >> status?
> > You can check with netstat:
> >
> > $ sudo netstat -n4lp|grep ':67 '
> > udp        0      0 0.0.0.0:67              0.0.0.0:*
> >           22466/dhcpd
> >
> > On my system, there's a /proc/net/udp which carries this information.
> > Everything's in hex, so port 67 is shown as 0043:
> >
> > $ grep :0043 /proc/net/udp
> >   5755: 00000000:0043 00000000:0000 07 00000000:00000000 00:00000000
> > 00000000     0        0 8334454 2 ffff880403e60b40 0
> >
> > You'd have to check your own system to know what's truly reliable and
> > worth using.
> >
> > ChrisA

First off, don't top post.  Either use the interleaved or bottom-posting style.  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

Secondly, even if you find a module, keep in mind that the module probably won't stay in Python land.  It will probably call an external utility itself.

If you REALLY wanted to check it without calling an external utility, you could connect to port 67 and see what happens, but that could cause problems.


From sohcahtoa82 at gmail.com  Fri Jan 23 17:40:15 2015
From: sohcahtoa82 at gmail.com (sohcahtoa82 at gmail.com)
Date: Fri, 23 Jan 2015 14:40:15 -0800 (PST)
Subject: Random ALL CAPS posts on this group
In-Reply-To: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
Message-ID: <efe94ce3-7401-49f0-9853-4e475726c0d2@googlegroups.com>

On Monday, January 19, 2015 at 4:16:13 PM UTC-8, Luke Tomaneng wrote:
> Has anyone noticed these? There have been about three of them recently and they don't seem to have anything to do with Python at all. Does anyone know if there is a good reason they are here?

My question is, does anyone know what the hell they're ranting about?


From marfig at gmail.com  Fri Jan 23 17:42:36 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Fri, 23 Jan 2015 23:42:36 +0100
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
Message-ID: <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>

In article <4b3b498a-c9b0-443d-8514-87ccd8e98f43 at googlegroups.com>, 
rantingrickjohnson at gmail.com says...
> 
>     (Example modified for PEP8 compliance ;-)
> 
>     @typehint(arg1:str, arg2:int, returns:bool)
>     def myfunction(arg1, arg2): 
>         return True 
>         
> Of course "@typehint" could be an extension of the decorator
> syntax, a keyword, a build-in function or whatever, i don't
> care.

I'd rather it'd be a docstring parameter.

- Decorators are transformation tools. Which type hints are not.
- keywords should be few and used only for language features. Static 
analysis isn't and should never be a language feature. It's an 
extension, perhaps.
- Same with built-in functions... although a case could be made for a 
static analysis package, hmmm.

So I'd rather see:

     def myfunction(arg1, arg2):
     """
     Normal docstring.
     """ 
     "@typehint: (str, int) -> bool"
         return True 

This conforms to PEP 258, but not to PEP 8, but you can always use the 
triple quotes. I would just use the single-quote myself for matters of 
taste.

I removed the arguments names on purpose. They are only necessary on the 
PEP because type hinting is a part of the function header there. 
However, when using a documentation like pattern as above (or as in your 
own example), they can be safely removed, with the added benefit of 
making the syntax simpler.

Alternatively, because dangling strings are always considered 
documentation and completely ignored by the interpreter (PEP 258), one 
could also do:

     "@typehint: (str, int) -> bool"
     def myfunction(arg1, arg2):
     """
     Normal docstring.
     """ 
         return True 

Again the choice of triple quotes or not is something not worth 
debating.


From marfig at gmail.com  Fri Jan 23 17:45:47 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Fri, 23 Jan 2015 23:45:47 +0100
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
Message-ID: <MPG.2f2ced6df496308698968d@nntp.aioe.org>

In article <MPG.2f2cecb4624e49c498968c at nntp.aioe.org>, marfig at gmail.com 
says...
> 
> 
> So I'd rather see:
> 
>      def myfunction(arg1, arg2):
>      """
>      Normal docstring.
>      """ 
>      "@typehint: (str, int) -> bool"
>          return True 
> 

Actually that is idiotic. Much better is:

      def myfunction(arg1, arg2):
      """
      Normal docstring...
      @typehint: (str, int) -> bool
      """ 
          return True 

Why would I need to insert an extra docstring, if I'm already defining a 
parameter?


From sohcahtoa82 at gmail.com  Fri Jan 23 17:48:05 2015
From: sohcahtoa82 at gmail.com (sohcahtoa82 at gmail.com)
Date: Fri, 23 Jan 2015 14:48:05 -0800 (PST)
Subject: What killed Smalltalk could kill Python
In-Reply-To: <m9smpv$48q$1@dont-email.me>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
 <mailman.17933.1421884677.18130.python-list@python.org>
 <MPG.2f2a5e01b517d4db989682@nntp.aioe.org>
 <54c06d26$0$12915$c3e8da3$5496439d@news.astraweb.com>
 <m9smpv$48q$1@dont-email.me>
Message-ID: <562db36e-6b73-4c35-9239-dfba099d0635@googlegroups.com>

On Thursday, January 22, 2015 at 9:39:53 PM UTC-8, alex23 wrote:
> On 22/01/2015 1:23 PM, Steven D'Aprano wrote:
> > Modern games *are* part of "today's complex application systems", and games
> > developers may need the same skills used by "serious developers"
> 
> I wish more game developers would understand this. I've lost count of 
> the number of games that have failed during development because all of 
> the source code was stolen or destroyed. I've had arguments with game 
> devs (some who've worked at some of the bigger studios) because they're 
> convinced that nothing outside of game development has anything to teach 
> them...when their (for eg) revision control entails zipping up their 
> daily changes and emailing them to the rest of the team...

Could be worse.

I seem to recall an interview with someone from Blizzard Entertainment mentioning that the first Warcraft game (Released in 1994) was developed by passing around floppy disks with new code among the developers.

Though I imagine that was actually probably pretty common back then.

But yeah...if you have more than 1 developer, version control of some sort just isn't optional.  Having to manually merge changes is extremely tedious.  If you're a solo developer, its still a good idea.  Even if you don't take advantage of branching and undoing commits, it's good to at least have a backup of your code somewhere.


From rosuav at gmail.com  Fri Jan 23 17:49:18 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 09:49:18 +1100
Subject: Check for running DHCP daemon?
In-Reply-To: <2d134592-6983-471e-ba5a-2124502af782@googlegroups.com>
References: <54C030E9.8010404@emerytelcom.com>
 <CAGGBd_rbL21MZEh+6PoUYoM-OS-Mpd=sUpSTPiTGhwqJSrqNMw@mail.gmail.com>
 <1e1a7b4bdcf1408799b7f95b5d24851a@ETEXCH2.corp.emerytelcom.com>
 <CAPTjJmrpjdNBf4C79gj2BB5S4+QhtDz0_LPcrn2J8-gVUY4T6g@mail.gmail.com>
 <54C27098.8020708@emerytelcom.com>
 <CAPTjJmrh2gZLhw6YktCPV5bw1K7VVnSx+Pz1nGO7G6Y8fqpvGA@mail.gmail.com>
 <mailman.18063.1422050804.18130.python-list@python.org>
 <2d134592-6983-471e-ba5a-2124502af782@googlegroups.com>
Message-ID: <CAPTjJmrZpThwRatJtUo5a_148eRK0dJPYDk+yEUfkwNqGYzcig@mail.gmail.com>

On Sat, Jan 24, 2015 at 9:38 AM,  <sohcahtoa82 at gmail.com> wrote:
> Secondly, even if you find a module, keep in mind that the module probably won't stay in Python land.  It will probably call an external utility itself.
>
> If you REALLY wanted to check it without calling an external utility, you could connect to port 67 and see what happens, but that could cause problems.

We're talking UDP here, so there's no "connect to" concept. You have
to send a packet and listen for a reply, and that might have
consequences (eg if you send a DHCPDISCOVER just to find out if
there's a DHCP server, you potentially cause a temporary IP
allocation).

Reading from /proc or running an external program would be the best
ways to find out.

ChrisA


From tundra at tundraware.com  Fri Jan 23 17:51:04 2015
From: tundra at tundraware.com (Tim Daneliuk)
Date: Fri, 23 Jan 2015 16:51:04 -0600
Subject: What killed Smalltalk could kill Python
In-Reply-To: <mailman.17932.1421884530.18130.python-list@python.org>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <spp5pb-0tt1.ln1@ozzie.tundraware.com>
 <mailman.17932.1421884530.18130.python-list@python.org>
Message-ID: <54C2D058.8060809@tundraware.com>

On 01/21/2015 05:55 PM, Chris Angelico wrote:
> On Thu, Jan 22, 2015 at 10:37 AM, Tim Daneliuk <tundra at tundraware.com> wrote:
>> I find these kinds of discussions sort of silly.  Once there is a critical
>> mass of installed base, no language EVER dies.
> 
> Not sure about that. Back in the 1990s, I wrote most of my code in
> REXX, either command-line or using a GUI toolkit like VX-REXX. Where's
> REXX today? Well, let's see. It's still the native-ish language of
> OS/2. Where's OS/2 today? Left behind. REXX has no Unicode support (it
> does, however, support DBCS - useful, no?), no inbuilt networking
> support (there are third-party TCP/IP socket libraries for OS/2 REXX,
> but I don't know that other REXX implementations have socket services;
> and that's just basic BSD sockets, no higher-level protocol handling
> at all), etc, etc. Sure, it's not technically dead... but is anyone
> developing the language further? I don't think so. Is new REXX code
> being written? Not a lot. Yet when OS/2 was more popular, REXX
> definitely had its installed base. It was the one obvious scripting
> language for any OS/2 program. Languages can definitely die, or at
> least be so left behind that they may as well be dead.
> 
> ChrisA
> 

Rexx is still well used on mainframes.
-- 
----------------------------------------------------------------------------
Tim Daneliuk     tundra at tundraware.com
PGP Key:         http://www.tundraware.com/PGP/



From tundra at tundraware.com  Fri Jan 23 17:51:04 2015
From: tundra at tundraware.com (Tim Daneliuk)
Date: Fri, 23 Jan 2015 16:51:04 -0600
Subject: What killed Smalltalk could kill Python
In-Reply-To: <mailman.17932.1421884530.18130.python-list@python.org>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <spp5pb-0tt1.ln1@ozzie.tundraware.com>
 <mailman.17932.1421884530.18130.python-list@python.org>
Message-ID: <54C2D058.8060809@tundraware.com>

On 01/21/2015 05:55 PM, Chris Angelico wrote:
> On Thu, Jan 22, 2015 at 10:37 AM, Tim Daneliuk <tundra at tundraware.com> wrote:
>> I find these kinds of discussions sort of silly.  Once there is a critical
>> mass of installed base, no language EVER dies.
> 
> Not sure about that. Back in the 1990s, I wrote most of my code in
> REXX, either command-line or using a GUI toolkit like VX-REXX. Where's
> REXX today? Well, let's see. It's still the native-ish language of
> OS/2. Where's OS/2 today? Left behind. REXX has no Unicode support (it
> does, however, support DBCS - useful, no?), no inbuilt networking
> support (there are third-party TCP/IP socket libraries for OS/2 REXX,
> but I don't know that other REXX implementations have socket services;
> and that's just basic BSD sockets, no higher-level protocol handling
> at all), etc, etc. Sure, it's not technically dead... but is anyone
> developing the language further? I don't think so. Is new REXX code
> being written? Not a lot. Yet when OS/2 was more popular, REXX
> definitely had its installed base. It was the one obvious scripting
> language for any OS/2 program. Languages can definitely die, or at
> least be so left behind that they may as well be dead.
> 
> ChrisA
> 

Rexx is still well used on mainframes.
-- 
----------------------------------------------------------------------------
Tim Daneliuk     tundra at tundraware.com
PGP Key:         http://www.tundraware.com/PGP/



From sohcahtoa82 at gmail.com  Fri Jan 23 17:52:30 2015
From: sohcahtoa82 at gmail.com (sohcahtoa82 at gmail.com)
Date: Fri, 23 Jan 2015 14:52:30 -0800 (PST)
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <MPG.2f2ced6df496308698968d@nntp.aioe.org>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
 <MPG.2f2ced6df496308698968d@nntp.aioe.org>
Message-ID: <c1d9c448-31b0-4bbc-8c6f-5194678a6f87@googlegroups.com>

On Friday, January 23, 2015 at 2:46:01 PM UTC-8, Mario Figueiredo wrote:
> In article <MPG.2f2cecb4624e49c498968c at nntp.aioe.org>, marfig at gmail.com 
> says...
> > 
> > 
> > So I'd rather see:
> > 
> >      def myfunction(arg1, arg2):
> >      """
> >      Normal docstring.
> >      """ 
> >      "@typehint: (str, int) -> bool"
> >          return True 
> > 
> 
> Actually that is idiotic. Much better is:
> 
>       def myfunction(arg1, arg2):
>       """
>       Normal docstring...
>       @typehint: (str, int) -> bool
>       """ 
>           return True 
> 
> Why would I need to insert an extra docstring, if I'm already defining a 
> parameter?

I really like that implementation.

Its unobtrusive and doesn't clutter the function definition, and putting in the docstring makes it get colored like a comment (At least, with my IDE setup it does) so it is easily ignored by my eyes as I'm scrolling through.


From rosuav at gmail.com  Fri Jan 23 17:57:39 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 09:57:39 +1100
Subject: What killed Smalltalk could kill Python
In-Reply-To: <54C2D058.8060809@tundraware.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <spp5pb-0tt1.ln1@ozzie.tundraware.com>
 <mailman.17932.1421884530.18130.python-list@python.org>
 <54C2D058.8060809@tundraware.com>
Message-ID: <CAPTjJmr7wF40QEVOpM=R=EF8Zt3_A8jRmD_D2DqSh_U3qoFnag@mail.gmail.com>

On Sat, Jan 24, 2015 at 9:51 AM, Tim Daneliuk <tundra at tundraware.com> wrote:
> On 01/21/2015 05:55 PM, Chris Angelico wrote:
>> On Thu, Jan 22, 2015 at 10:37 AM, Tim Daneliuk <tundra at tundraware.com> wrote:
>>> I find these kinds of discussions sort of silly.  Once there is a critical
>>> mass of installed base, no language EVER dies.
>>
>> Not sure about that. Back in the 1990s, I wrote most of my code in
>> REXX, either command-line or using a GUI toolkit like VX-REXX. Where's
>> REXX today? Well, let's see. It's still the native-ish language of
>> OS/2. Where's OS/2 today? Left behind. REXX has no Unicode support (it
>> does, however, support DBCS - useful, no?), no inbuilt networking
>> support (there are third-party TCP/IP socket libraries for OS/2 REXX,
>> but I don't know that other REXX implementations have socket services;
>> and that's just basic BSD sockets, no higher-level protocol handling
>> at all), etc, etc. Sure, it's not technically dead... but is anyone
>> developing the language further? I don't think so. Is new REXX code
>> being written? Not a lot. Yet when OS/2 was more popular, REXX
>> definitely had its installed base. It was the one obvious scripting
>> language for any OS/2 program. Languages can definitely die, or at
>> least be so left behind that they may as well be dead.
>>
>> ChrisA
>>
>
> Rexx is still well used on mainframes.

Oh, is it? Cool! Maybe some day I'll be interviewing for a job, and
they'll ask if I know REXX.. and I'll actually be able to say yes. :)

ChrisA


From emile at fenx.com  Fri Jan 23 17:58:10 2015
From: emile at fenx.com (Emile van Sebille)
Date: Fri, 23 Jan 2015 14:58:10 -0800
Subject: What killed Smalltalk could kill Python
In-Reply-To: <562db36e-6b73-4c35-9239-dfba099d0635@googlegroups.com>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <873873ae91.fsf@jester.gateway.sonic.net>
 <mailman.17933.1421884677.18130.python-list@python.org>
 <MPG.2f2a5e01b517d4db989682@nntp.aioe.org>
 <54c06d26$0$12915$c3e8da3$5496439d@news.astraweb.com>
 <m9smpv$48q$1@dont-email.me>
 <562db36e-6b73-4c35-9239-dfba099d0635@googlegroups.com>
Message-ID: <m9ujm6$m4j$1@ger.gmane.org>

On 1/23/2015 2:48 PM, sohcahtoa82 at gmail.com wrote:
> On Thursday, January 22, 2015 at 9:39:53 PM UTC-8, alex23 wrote:

> I seem to recall an interview with someone from Blizzard Entertainment mentioning that the first Warcraft game (Released in 1994) was developed by passing around floppy disks with new code among the developers.
>
> Though I imagine that was actually probably pretty common back then.
>

It even had a formal name -- sneakernet

Emile





From marfig at gmail.com  Fri Jan 23 18:14:31 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sat, 24 Jan 2015 00:14:31 +0100
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
 <MPG.2f2ced6df496308698968d@nntp.aioe.org>
 <c1d9c448-31b0-4bbc-8c6f-5194678a6f87@googlegroups.com>
Message-ID: <MPG.2f2cf43691593c0998968e@nntp.aioe.org>

In article <c1d9c448-31b0-4bbc-8c6f-5194678a6f87 at googlegroups.com>, 
sohcahtoa82 at gmail.com says...
> 
> >       def myfunction(arg1, arg2):
> >       """
> >       Normal docstring...
> >       @typehint: (str, int) -> bool
> >       """ 
> >           return True 
> > 
> 
> I really like that implementation.
> 
> Its unobtrusive and doesn't clutter the function definition, and
> putting in the docstring makes it get colored like a comment (At
> least, with my IDE setup it does) so it is easily ignored by my eyes
> as I'm scrolling through.

It has the side effect of being included in __doc__. A purist may have 
an issue with that, since type hinting, for the purposes of static 
analysis, should have no place in that attribute.

But you could always fall back to the previous version:

       def myfunction(arg1, arg2):
       """
       Normal docstring...
       """
       "@typehint: (str, int) -> bool"
           return True 

And __doc__ would be free of it. It would be up to the user to choose.

For something completely different, I like @hint: better than @typehint:


From sohcahtoa82 at gmail.com  Fri Jan 23 18:21:34 2015
From: sohcahtoa82 at gmail.com (sohcahtoa82 at gmail.com)
Date: Fri, 23 Jan 2015 15:21:34 -0800 (PST)
Subject: Check for running DHCP daemon?
In-Reply-To: <mailman.18064.1422053367.18130.python-list@python.org>
References: <54C030E9.8010404@emerytelcom.com>
 <CAGGBd_rbL21MZEh+6PoUYoM-OS-Mpd=sUpSTPiTGhwqJSrqNMw@mail.gmail.com>
 <1e1a7b4bdcf1408799b7f95b5d24851a@ETEXCH2.corp.emerytelcom.com>
 <CAPTjJmrpjdNBf4C79gj2BB5S4+QhtDz0_LPcrn2J8-gVUY4T6g@mail.gmail.com>
 <54C27098.8020708@emerytelcom.com>
 <CAPTjJmrh2gZLhw6YktCPV5bw1K7VVnSx+Pz1nGO7G6Y8fqpvGA@mail.gmail.com>
 <mailman.18063.1422050804.18130.python-list@python.org>
 <2d134592-6983-471e-ba5a-2124502af782@googlegroups.com>
 <mailman.18064.1422053367.18130.python-list@python.org>
Message-ID: <fc23d82d-16fe-4a6e-8d1f-c91c83023ce0@googlegroups.com>

On Friday, January 23, 2015 at 2:50:12 PM UTC-8, Chris Angelico wrote:
> On Sat, Jan 24, 2015 at 9:38 AM,  <sohcahtoa82 at gmail.com> wrote:
> > Secondly, even if you find a module, keep in mind that the module probably won't stay in Python land.  It will probably call an external utility itself.
> >
> > If you REALLY wanted to check it without calling an external utility, you could connect to port 67 and see what happens, but that could cause problems.
> 
> We're talking UDP here, so there's no "connect to" concept. You have
> to send a packet and listen for a reply, and that might have
> consequences (eg if you send a DHCPDISCOVER just to find out if
> there's a DHCP server, you potentially cause a temporary IP
> allocation).
> 
> Reading from /proc or running an external program would be the best
> ways to find out.
> 
> ChrisA

I forgot that DHCP uses UDP.  My mistake.


From rantingrickjohnson at gmail.com  Fri Jan 23 18:39:22 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Fri, 23 Jan 2015 15:39:22 -0800 (PST)
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
Message-ID: <9ba02184-0138-49dd-bbc5-6881fc0fb4af@googlegroups.com>

On Friday, January 23, 2015 at 4:42:51 PM UTC-6, Mario Figueiredo wrote:
> I'd rather it'd be a docstring parameter.
>
> - Decorators are transformation tools. Which type hints
> are not.

Valid point.

> - keywords should be few and used only for language
> features. Static analysis isn't and should never be a
> language feature. It's an extension, perhaps.

Indeed. I've always been fond of Python's relatively small
set of keywords, and avoiding additions is a noble goal. It
seems like we've entered an era of increasing feature creep.

> - Same with built-in functions... although a case could be
> made for a static analysis package, hmmm.
>
> So I'd rather see:
>
>      def myfunction(arg1, arg2):
>      """
>      Normal docstring.
>      """
>      "@typehint: (str, int) -> bool"
>          return True
>

I think extending the doc-string syntax is good idea since
there is nothing going on in there anyway. It's sort of like
a treasure just waiting to be plundered. Plus, I find i can
easily ignore doc-strings, whereas, adding a new syntax is
going to be a syntactical distraction no matter how "clean"
it may be. Heck, even after years of reading Python source,
function decorators still jump out at me like lions from
behind a bush!

And although i think one could make a good argument that
decorators *ought-to-be* obvious because of the resulting
unavoidable implications of them, i don't believe the same
argument applies to a feature which simply serves as an
"optional hook" for static analysis tools -- for which the
implications are entirely dependent on purposeful actions by
a programmer -- any other time it's just dead code.

> Alternatively, because dangling strings are always
> considered documentation and completely ignored by the
> interpreter (PEP 258), one could also do:
>
>      "@typehint: (str, int) -> bool"
>      def myfunction(arg1, arg2):
>      """
>      Normal docstring.
>      """
>          return True
>

Ha, well one of the more wonderful aspects of being an
"opposer" (as opposed to a "proposer") is that you can omit
yourself from the headaches of the implementation details
O:-). I say: they wanted type hints, fine, let them suffer
the headaches of hacking the interpreter.

My only goal (at this point) is ensuring that their little
intellectual "problem child" does not walk on my wonderfully
lush and finely manicured lawn.

    KEEP OFF MY GRASS!!!



From rosuav at gmail.com  Fri Jan 23 18:39:25 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 10:39:25 +1100
Subject: Check for running DHCP daemon?
In-Reply-To: <fc23d82d-16fe-4a6e-8d1f-c91c83023ce0@googlegroups.com>
References: <54C030E9.8010404@emerytelcom.com>
 <CAGGBd_rbL21MZEh+6PoUYoM-OS-Mpd=sUpSTPiTGhwqJSrqNMw@mail.gmail.com>
 <1e1a7b4bdcf1408799b7f95b5d24851a@ETEXCH2.corp.emerytelcom.com>
 <CAPTjJmrpjdNBf4C79gj2BB5S4+QhtDz0_LPcrn2J8-gVUY4T6g@mail.gmail.com>
 <54C27098.8020708@emerytelcom.com>
 <CAPTjJmrh2gZLhw6YktCPV5bw1K7VVnSx+Pz1nGO7G6Y8fqpvGA@mail.gmail.com>
 <mailman.18063.1422050804.18130.python-list@python.org>
 <2d134592-6983-471e-ba5a-2124502af782@googlegroups.com>
 <mailman.18064.1422053367.18130.python-list@python.org>
 <fc23d82d-16fe-4a6e-8d1f-c91c83023ce0@googlegroups.com>
Message-ID: <CAPTjJmrpzdLdHrQQoFimketw67-JGvEVCzC4Fizw-44R36Bu+A@mail.gmail.com>

On Sat, Jan 24, 2015 at 10:21 AM,  <sohcahtoa82 at gmail.com> wrote:
> On Friday, January 23, 2015 at 2:50:12 PM UTC-8, Chris Angelico wrote:
>> On Sat, Jan 24, 2015 at 9:38 AM,  <sohcahtoa82 at gmail.com> wrote:
>> > Secondly, even if you find a module, keep in mind that the module probably won't stay in Python land.  It will probably call an external utility itself.
>> >
>> > If you REALLY wanted to check it without calling an external utility, you could connect to port 67 and see what happens, but that could cause problems.
>>
>> We're talking UDP here, so there's no "connect to" concept. You have
>> to send a packet and listen for a reply, and that might have
>> consequences (eg if you send a DHCPDISCOVER just to find out if
>> there's a DHCP server, you potentially cause a temporary IP
>> allocation).
>>
>> Reading from /proc or running an external program would be the best
>> ways to find out.
>>
>> ChrisA
>
> I forgot that DHCP uses UDP.  My mistake.

Yeah, it's usually easier to probe a TCP service. You can either
connect to it, or - often - simply try to bind to the same port, as
you'll usually get an error. Not always, though, so connecting is the
reliable test.

ChrisA


From marko at pacujo.net  Fri Jan 23 18:52:45 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sat, 24 Jan 2015 01:52:45 +0200
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
 <MPG.2f2ced6df496308698968d@nntp.aioe.org>
Message-ID: <87sif1dpgy.fsf@elektro.pacujo.net>

Mario Figueiredo <marfig at gmail.com>:
> Much better is:
>
>       def myfunction(arg1, arg2):
>       """
>       Normal docstring...
>       @typehint: (str, int) -> bool
>       """ 
>           return True 

I seem to remember an idea floated on the Scheme mailing list of using
assertions for such a purpose:

   def myfunction(arg1, arg2):
       assert isinstance(arg1, str) and isinstance(arg2, int)
       return True

The advantage is that the assertions can be as complex as you'd like:

   def weekday(day):
       assert isinstance(day, int) and 0 <= day <= 6
       ...

   def str_product(x, y):
       assert isinstance(x, int) and isinstance(y, str) or \
           isinstance(x, str) and isinstance(y, int)
       ...

Also, they have always been present in the language and assertion
semantics is fully compatible with static analysis.

Only I'd hate if that style became standard boilerplate...


Marko


From sturla.molden at gmail.com  Fri Jan 23 20:00:19 2015
From: sturla.molden at gmail.com (Sturla Molden)
Date: Sat, 24 Jan 2015 02:00:19 +0100
Subject: Python is DOOMED! Again!
In-Reply-To: <54c1c5c1$0$13001$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
 <mailman.17984.1421952098.18130.python-list@python.org>
 <MPG.2f2b697d288c74b2989685@nntp.aioe.org>
 <mailman.17990.1421956437.18130.python-list@python.org>
 <MPG.2f2b75c814639267989686@nntp.aioe.org>
 <mailman.18006.1421973642.18130.python-list@python.org>
 <54c1c5c1$0$13001$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <m9uqr0$41g$1@ger.gmane.org>

On 23/01/15 04:53, Steven D'Aprano wrote:

> If your manager is so bad, why isn't he insisting that you program in PHP or
> Java or Algol 68 [insert name of some language you dislike] instead of
> Python? Is your bad manager forcing you to write Java-style code in Python,
> or insisting on Hungarian Notation?

Nobody is forcing me to do anything.

But without a thriving community, Python has no value to me.

If we add type hinting, then that community will go away, because other 
languages are better options.

Who will win? Julia? Ruby? They are all waiting in line for Python to 
fail. Then Python will be like Smalltalk.


Sturla




From tjreedy at udel.edu  Fri Jan 23 20:08:49 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Fri, 23 Jan 2015 20:08:49 -0500
Subject: Random ALL CAPS posts on this group
In-Reply-To: <efe94ce3-7401-49f0-9853-4e475726c0d2@googlegroups.com>
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
 <efe94ce3-7401-49f0-9853-4e475726c0d2@googlegroups.com>
Message-ID: <m9urb2$4l1$2@ger.gmane.org>

On 1/23/2015 5:40 PM, sohcahtoa82 at gmail.com wrote:
> On Monday, January 19, 2015 at 4:16:13 PM UTC-8, Luke Tomaneng wrote:
>> Has anyone noticed these? There have been about three of them recently and they don't seem to have anything to do with Python at all. Does anyone know if there is a good reason they are here?

They are spam that made it past the spam filter.  Ignore them.

-- 
Terry Jan Reedy



From rosuav at gmail.com  Fri Jan 23 20:15:45 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 12:15:45 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <m9uqr0$41g$1@ger.gmane.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
 <mailman.17984.1421952098.18130.python-list@python.org>
 <MPG.2f2b697d288c74b2989685@nntp.aioe.org>
 <mailman.17990.1421956437.18130.python-list@python.org>
 <MPG.2f2b75c814639267989686@nntp.aioe.org>
 <mailman.18006.1421973642.18130.python-list@python.org>
 <54c1c5c1$0$13001$c3e8da3$5496439d@news.astraweb.com>
 <m9uqr0$41g$1@ger.gmane.org>
Message-ID: <CAPTjJmqk52tuzXcm=Cq+AGZxihu6YyNhR=YZ0NuyTJhhf8RXqQ@mail.gmail.com>

On Sat, Jan 24, 2015 at 12:00 PM, Sturla Molden <sturla.molden at gmail.com> wrote:
> But without a thriving community, Python has no value to me.
>
> If we add type hinting, then that community will go away, because other
> languages are better options.
>
> Who will win? Julia? Ruby? They are all waiting in line for Python to fail.
> Then Python will be like Smalltalk.

The Python community that was already killed by Python 3.0? Funny, it
seems to be a bit more resilient than the naysayers would have us
believe.

ChrisA


From rantingrickjohnson at gmail.com  Fri Jan 23 22:00:01 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Fri, 23 Jan 2015 19:00:01 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <9a6694a5-5774-415a-b28a-7a9425a9112a@googlegroups.com>

On Thursday, January 22, 2015 at 10:23:48 PM UTC-6, Steven D'Aprano wrote:
> Rick Johnson wrote:
> 
> > The solution is move the type hinting syntax completely
> > out of the source file and into another file -- think of
> > it as a "Python Type Hinting Header File".
> 
> The 1970s called, they want their bad ideas back. [...]
> Things that go together should appear together. Imagine a
> language where you declared the function name in one file,
> the function parameters in a second file, any default
> values in a third file, and the function body in a fourth
> file. Ridiculous. Ideally, all these things should be
> found together, preferably close enough for the reader to
> take it all in at a glance (although some function bodies
> may be too large).

Anyone else care for a pipping hot cup of Reductio ad absurdum?

> There may be times where splitting related things are
> unavoidable, but they should be a last resort, only to be
> used when any other solution is unacceptable.

Duh! Do you think i just pulled stub files out my arse
without giving all the other alternatives due consideration?

But you had your fun so that's all that matters. ;-)

PS: Man, you need to invest in some formatting tools. I format
all my posts with a max width of 60, but then when you quote
them back i see strange line breaks. Does your editor think
that 60 chars is too wide? What's going on?


From rustompmody at gmail.com  Fri Jan 23 22:13:00 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 23 Jan 2015 19:13:00 -0800 (PST)
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <mailman.18051.1422036308.18130.python-list@python.org>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
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 <54B72D32.3090209@r3dsolutions.com>
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 <54B76B0A.7050706@r3dsolutions.com>
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Message-ID: <970f0828-0d39-4b0c-9102-bbc8a42800fc@googlegroups.com>

On Friday, January 23, 2015 at 11:35:49 PM UTC+5:30, Ian wrote:
> On Fri, Jan 23, 2015 at 10:03 AM, Rustom Mody wrote:
> > On Friday, January 23, 2015 at 10:22:06 PM UTC+5:30, Ian wrote:
> >> On Fri, Jan 23, 2015 at 8:31 AM, Rustom Mody wrote:
> >> > Can you tell me what of the following code does not satisfy your requirements?
> >> > [Needs python 3.4]
> >> >
> >> >
> >> >>>> from enum import IntEnum
> >> >>>> class B4(IntEnum):
> >> >         F1 = 0
> >> >         F2 = 0
> >> >         F3 = 0
> >> >         T  = 1
> >>
> >> This strikes me as a potential problem:
> >>
> >> >>> B4.F1 is B4.F2 is B4.F3
> >> True
> >> >>> list(B4)
> >> [<B4.F1: 0>, <B4.T: 1>]
> >>
> >> Enum members with the same values are just aliases for one another,
> >> not distinct entities.
> >
> > Yeah....
> >
> > The only workaround I have been able to come up with is:
> >
> > class B4(IntEnum):
> >>         F1 = 0
> >>         F2 = ""
> >>         F3 = None
> >>         T  = 1
> >
> > which is not bad; its ridiculous
> > [Like going around with a broken broom searching for falsey objects :-) ]
> 
> How about something like this:
> 
> >>> from enum import Enum
> >>> class B4(Enum):
> ...     F1 = (False, 1)
> ...     F2 = (False, 2)
> ...     F3 = (False, 3)
> ...     T = (True, 4)
> ...     def __bool__(self):
> ...         return self.value[0]
> ...
> >>> B4.F1 is B4.F2
> False
> >>> bool(B4.F1)
> False
> >>> bool(B4.T)
> True

?Perfect?
For the OP you may like to read the following:

[And if you dont short version is use __bool__ in python3 __nonzero__ in python2
]

http://stackoverflow.com/questions/8909932/how-to-overload-pythons-bool-method
http://stackoverflow.com/questions/2233786/overriding-bool-for-custom-class
https://docs.python.org/2/reference/datamodel.html#object.__nonzero__


From rustompmody at gmail.com  Fri Jan 23 22:21:34 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 23 Jan 2015 19:21:34 -0800 (PST)
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <mailman.18051.1422036308.18130.python-list@python.org>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
 <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
 <mailman.18030.1422013652.18130.python-list@python.org>
 <bad017ab-490f-4daa-a552-33591c559398@googlegroups.com>
 <mailman.18039.1422031903.18130.python-list@python.org>
 <5a785a32-3855-457f-be3f-76066dfb20c8@googlegroups.com>
 <mailman.18051.1422036308.18130.python-list@python.org>
Message-ID: <0eec1312-9674-4edc-b65d-5a2801ff4730@googlegroups.com>

On Friday, January 23, 2015 at 11:35:49 PM UTC+5:30, Ian wrote:
> On Fri, Jan 23, 2015 at 10:03 AM, Rustom Mody  wrote:
> > On Friday, January 23, 2015 at 10:22:06 PM UTC+5:30, Ian wrote:
> >> On Fri, Jan 23, 2015 at 8:31 AM, Rustom Mody wrote:
> >> > Can you tell me what of the following code does not satisfy your requirements?
> >> > [Needs python 3.4]
> >> >
> >> >
> >> >>>> from enum import IntEnum
> >> >>>> class B4(IntEnum):
> >> >         F1 = 0
> >> >         F2 = 0
> >> >         F3 = 0
> >> >         T  = 1
> >>
> >> This strikes me as a potential problem:
> >>
> >> >>> B4.F1 is B4.F2 is B4.F3
> >> True
> >> >>> list(B4)
> >> [<B4.F1: 0>, <B4.T: 1>]
> >>
> >> Enum members with the same values are just aliases for one another,
> >> not distinct entities.
> >
> > Yeah....
> >
> > The only workaround I have been able to come up with is:
> >
> > class B4(IntEnum):
> >>         F1 = 0
> >>         F2 = ""
> >>         F3 = None
> >>         T  = 1
> >
> > which is not bad; its ridiculous
> > [Like going around with a broken broom searching for falsey objects :-) ]
> 
> How about something like this:
> 
> >>> from enum import Enum
> >>> class B4(Enum):
> ...     F1 = (False, 1)
> ...     F2 = (False, 2)
> ...     F3 = (False, 3)
> ...     T = (True, 4)
> ...     def __bool__(self):
> ...         return self.value[0]
> ...
> >>> B4.F1 is B4.F2
> False
> >>> bool(B4.F1)
> False
> >>> bool(B4.T)
> True

Simpler (though less general)

class B4(Enum):
	F1 = 1
	F2 = 2
	F3 = 3
	T  = 4
	def __bool__(self): return self.value == 4


From rantingrickjohnson at gmail.com  Fri Jan 23 22:34:54 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Fri, 23 Jan 2015 19:34:54 -0800 (PST)
Subject: Random ALL CAPS posts on this group
In-Reply-To: <mailman.18032.1422014690.18130.python-list@python.org>
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
 <38b9177e-e947-4a62-9823-554e5e266c4e@googlegroups.com>
 <CAPTjJmqMF7SDhwbSO28n_NzJsoxZjA0Aj9D=Nq3NZyX3rO2VDA@mail.gmail.com>
 <mailman.17877.1421720150.18130.python-list@python.org>
 <54c23572$0$12977$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18032.1422014690.18130.python-list@python.org>
Message-ID: <0b4121bc-f9f6-46a8-92a6-d22e4fabea9a@googlegroups.com>

On Friday, January 23, 2015 at 6:05:02 AM UTC-6, Chris Angelico wrote:
> It's definitely not "state vs non-state". Freedom of
> expression should allow me to say anything I like in my
> own home

I also hereby declare that man should be free to ponder
thoughts in his own mind, and sing in his own shower,
and watch his own TV, and even yank his own wank! 

Now hurry along Chris. MAKE HASTE! We must liberate the
people of this world with knowledge of these newly found
rights!!!





From cs at zip.com.au  Fri Jan 23 22:59:30 2015
From: cs at zip.com.au (Cameron Simpson)
Date: Sat, 24 Jan 2015 14:59:30 +1100
Subject: multiprocessing.Queue & vim python interpreter
In-Reply-To: <d4aeba08-023d-4e57-8a30-367a128a8e50@googlegroups.com>
References: <d4aeba08-023d-4e57-8a30-367a128a8e50@googlegroups.com>
Message-ID: <20150124035930.GA5485@cskk.homeip.net>

On 18Jan2015 16:20, unknown3000 at gmail.com <unknown3000 at gmail.com> wrote:
>I am experimenting on a fork of vim-plug for managing vim plugins. I wanted to add parallel update support for python since ruby isn't nearly as common. I've come across a weird bug that only seems to happen when I'm inside vim, I'm wondering if someone could tell me why.
>
>This problem can be reproduced by sourcing a vim file with the following snippet. Then execute the command PyCrash.
>command! -nargs=0 PyCrash call s:py_crash()
>function! s:py_crash()
>    python << EOF
>import multiprocessing as multi
>queue = multi.Queue()
>queue.put('a')
>queue.close()
>EOF
>endfunction
>
>This prints to messages the following:
>Traceback (most recent call last):
>  File "/usr/lib/python2.7/multiprocessing/queues.py", line 266, in _feed
>    send(obj)
>IOError: [Errno 32] Broken pipe

Please include the entire traceback in errors.

I would guess this is because you have made a Queue but have not got subprocess 
to read from it. So when you .put onto it, you get a broken pipe.

Cheers,
Cameron Simpson <cs at zip.com.au>

Nothing is impossible for the man who doesn't have to do it.


From rustompmody at gmail.com  Fri Jan 23 23:06:40 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 23 Jan 2015 20:06:40 -0800 (PST)
Subject: kivy secret of mana game
In-Reply-To: <slrnmc2c3g.77n.automn@sigtrans.org>
References: <slrnmc2c3g.77n.automn@sigtrans.org>
Message-ID: <16887f2c-7c09-4f61-a56a-46ba3e0aebfc@googlegroups.com>

On Thursday, January 22, 2015 at 10:43:30 PM UTC+5:30, Automn wrote:
> Hello,
> 
> I am programming a "Secret of Mana" (Seiken Densetsu) game in kivy, it runs
> on a phone with kivy launcher.
> 
> Features for now are : movement by swiping, polygon collision and image state
> changes with resource handling.
> 
> The codebase can be found at : 
> https://sourceforge.net/projects/kivypriestsoflore2
> 
> The graphics have been licensed for this.
> 
> Automn
> -- 
> my blog : http://thediaryofelvishhealer.blogspot.com/
> Time heals.

Is this runnable on a  computer?
[I mean the old fashioned ones that sit on desks]

I tried installing it and am getting
                             
rusi at Gpa:~$ python3 kk.py 
[INFO   ] Kivy v1.8.0
[INFO   ] [Logger      ] Record log in /home/rusi/.kivy/logs/kivy_15-01-24_3.txt
[INFO   ] [Factory     ] 157 symbols loaded
[DEBUG  ] [Cache       ] register <kv.lang> with limit=None, timeout=Nones
[DEBUG  ] [Cache       ] register <kv.image> with limit=None, timeout=60s
[DEBUG  ] [Cache       ] register <kv.atlas> with limit=None, timeout=Nones
[INFO   ] [Image       ] Providers: img_tex, img_dds, img_gif (img_pygame, img_pil ignored)
[DEBUG  ] [Cache       ] register <kv.texture> with limit=1000, timeout=60s
[DEBUG  ] [Cache       ] register <kv.shader> with limit=1000, timeout=3600s
[DEBUG  ] [App         ] Loading kv <./pong.kv>
[DEBUG  ] [App         ] kv <./pong.kv> not found
[DEBUG  ] [Window      ] Ignored <egl_rpi> (import error)
[DEBUG  ] [Window      ] Ignored <pygame> (import error)
[WARNING] [WinPygame   ] SDL wrapper failed to import!
[DEBUG  ] [Window      ] Ignored <sdl> (import error)
[DEBUG  ] [Window      ] Ignored <x11> (import error)
[CRITICAL] [Window      ] Unable to find any valuable Window provider at all!
[CRITICAL] [App         ] Unable to get a Window, abort.


From rustompmody at gmail.com  Fri Jan 23 23:14:00 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 23 Jan 2015 20:14:00 -0800 (PST)
Subject: kivy secret of mana game
In-Reply-To: <16887f2c-7c09-4f61-a56a-46ba3e0aebfc@googlegroups.com>
References: <slrnmc2c3g.77n.automn@sigtrans.org>
 <16887f2c-7c09-4f61-a56a-46ba3e0aebfc@googlegroups.com>
Message-ID: <7108d8cd-c149-4eb0-9a84-47ac1930825c@googlegroups.com>

On Saturday, January 24, 2015 at 9:36:56 AM UTC+5:30, Rustom Mody wrote:
> On Thursday, January 22, 2015 at 10:43:30 PM UTC+5:30, Automn wrote:
> > Hello,
> > 
> > I am programming a "Secret of Mana" (Seiken Densetsu) game in kivy, it runs
> > on a phone with kivy launcher.
> > 
> > Features for now are : movement by swiping, polygon collision and image state
> > changes with resource handling.
> > 
> > The codebase can be found at : 
> > https://sourceforge.net/projects/kivypriestsoflore2
> > 
> > The graphics have been licensed for this.
> > 
> > Automn
> > -- 
> > my blog : http://thediaryofelvishhealer.blogspot.com/
> > Time heals.
> 
> Is this runnable on a  computer?
> [I mean the old fashioned ones that sit on desks]
> 
> I tried installing it and am getting
>                              
> rusi at Gpa:~$ python3 kk.py 
> [INFO   ] Kivy v1.8.0
> [INFO   ] [Logger      ] Record log in /home/rusi/.kivy/logs/kivy_15-01-24_3.txt
> [INFO   ] [Factory     ] 157 symbols loaded
> [DEBUG  ] [Cache       ] register <kv.lang> with limit=None, timeout=Nones
> [DEBUG  ] [Cache       ] register <kv.image> with limit=None, timeout=60s
> [DEBUG  ] [Cache       ] register <kv.atlas> with limit=None, timeout=Nones
> [INFO   ] [Image       ] Providers: img_tex, img_dds, img_gif (img_pygame, img_pil ignored)
> [DEBUG  ] [Cache       ] register <kv.texture> with limit=1000, timeout=60s
> [DEBUG  ] [Cache       ] register <kv.shader> with limit=1000, timeout=3600s
> [DEBUG  ] [App         ] Loading kv <./pong.kv>
> [DEBUG  ] [App         ] kv <./pong.kv> not found
> [DEBUG  ] [Window      ] Ignored <egl_rpi> (import error)
> [DEBUG  ] [Window      ] Ignored <pygame> (import error)
> [WARNING] [WinPygame   ] SDL wrapper failed to import!
> [DEBUG  ] [Window      ] Ignored <sdl> (import error)
> [DEBUG  ] [Window      ] Ignored <x11> (import error)
> [CRITICAL] [Window      ] Unable to find any valuable Window provider at all!
> [CRITICAL] [App         ] Unable to get a Window, abort.

Ok
After installing pygame
I get the black window of the first pong example
However Ive to run it as root else I get

 PermissionError: [Errno 13] Permission denied: '/dev/input/event4'
 
     self._fd = os.open(filename, os.O_NONBLOCK | os.O_RDONLY)
 PermissionError: [Errno 13] Permission denied: '/dev/input/event9


From steve+comp.lang.python at pearwood.info  Fri Jan 23 23:53:17 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 24 Jan 2015 15:53:17 +1100
Subject: kivy secret of mana game
References: <slrnmc2c3g.77n.automn@sigtrans.org>
 <U7www.319380$Um.61244@fx22.am4>
 <ef4d2457-bdc6-41ad-b64c-f05da43b39b0@googlegroups.com>
Message-ID: <54c3253d$0$12979$c3e8da3$5496439d@news.astraweb.com>

sohcahtoa82 at gmail.com wrote:

> On Friday, January 23, 2015 at 10:10:08 AM UTC-8, Tony the Tiger wrote:
>> On Thu, 22 Jan 2015 17:13:12 +0000, Automn wrote:
>> 
>> > game
>> 
>> No interest, at all, nada, zilch. zero, nothing.
>> 
>>  /Grrr
> 
> Why don't you like fun?


I had fun once. It was horrible.



-- 
Steven



From rosuav at gmail.com  Fri Jan 23 23:58:20 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 15:58:20 +1100
Subject: kivy secret of mana game
In-Reply-To: <54c3253d$0$12979$c3e8da3$5496439d@news.astraweb.com>
References: <slrnmc2c3g.77n.automn@sigtrans.org>
 <U7www.319380$Um.61244@fx22.am4>
 <ef4d2457-bdc6-41ad-b64c-f05da43b39b0@googlegroups.com>
 <54c3253d$0$12979$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmpysp3O1Dokz4SXYk0wtkwpV-=w+iZKFxhaF=Z-7w4mmQ@mail.gmail.com>

On Sat, Jan 24, 2015 at 3:53 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> I had fun once. It was horrible.

You probably had it boiled. The proper way to have fun is fried in
garlic butter, with a bit of salt. Try having some real home-cooked
fresh fun, I think you'll like it.

ChrisA


From steve+comp.lang.python at pearwood.info  Sat Jan 24 00:01:09 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 24 Jan 2015 16:01:09 +1100
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
 <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
 <mailman.18030.1422013652.18130.python-list@python.org>
 <bad017ab-490f-4daa-a552-33591c559398@googlegroups.com>
 <mailman.18039.1422031903.18130.python-list@python.org>
 <5a785a32-3855-457f-be3f-76066dfb20c8@googlegroups.com>
Message-ID: <54c32716$0$13009$c3e8da3$5496439d@news.astraweb.com>

Rustom Mody wrote:

> On Friday, January 23, 2015 at 10:22:06 PM UTC+5:30, Ian wrote:
>> On Fri, Jan 23, 2015 at 8:31 AM, Rustom Mody wrote:
>> > Can you tell me what of the following code does not satisfy your
>> > requirements?
>> > [Needs python 3.4]
>> >
>> >
>> >>>> from enum import IntEnum
>> >>>> class B4(IntEnum):
>> >         F1 = 0
>> >         F2 = 0
>> >         F3 = 0
>> >         T  = 1
>> 
>> This strikes me as a potential problem:
>> 
>> >>> B4.F1 is B4.F2 is B4.F3
>> True
>> >>> list(B4)
>> [<B4.F1: 0>, <B4.T: 1>]
>> 
>> Enum members with the same values are just aliases for one another,
>> not distinct entities.
> 
> Yeah....
> 
> The only workaround I have been able to come up with is:
> 
> class B4(IntEnum):
>>         F1 = 0
>>         F2 = ""
>>         F3 = None
>>         T  = 1
> 
> which is not bad; its ridiculous
> [Like going around with a broken broom searching for falsey objects :-) ]


It certainly is. But fortunately it is not necessary.

# Untested
class B4(IntEnum):
    F1 = 0
    F2 = 1
    F3 = 2
    T  = 3
    def __bool__(self):
        return self is B4.T
    def __str__(self):
        if self is B4.F1: return "Certainly False"
        if self is B4.F2: return "Maybe False"
        if self is B4.F3: return "Maybe True"
        if self is B4.T: return "Certainly True"



-- 
Steven



From steve+comp.lang.python at pearwood.info  Sat Jan 24 00:29:17 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 24 Jan 2015 16:29:17 +1100
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
 <MPG.2f2ced6df496308698968d@nntp.aioe.org>
 <87sif1dpgy.fsf@elektro.pacujo.net>
Message-ID: <54c32dae$0$13000$c3e8da3$5496439d@news.astraweb.com>

Marko Rauhamaa wrote:

> I seem to remember an idea floated on the Scheme mailing list of using
> assertions for such a purpose:
> 
>    def myfunction(arg1, arg2):
>        assert isinstance(arg1, str) and isinstance(arg2, int)
>        return True
> 
> The advantage is that the assertions can be as complex as you'd like:
> 
>    def weekday(day):
>        assert isinstance(day, int) and 0 <= day <= 6
>        ...
> 
>    def str_product(x, y):
>        assert isinstance(x, int) and isinstance(y, str) or \
>            isinstance(x, str) and isinstance(y, int)
>        ...
> 
> Also, they have always been present in the language and assertion
> semantics is fully compatible with static analysis.

Not really. Well, I suppose technically they could be, if the type-checker
included a full Python interpreter.

Requiring the type-checker to parse and understand arbitrarily complex
assertions would require the type-checker to be as complex as Python
itself:


def f(something):
    assert (__import__("somemodule") is 
            some_function(spam, eggs, *ham, **cheese).attr.x[y](z) or
            any(some_expression and another_expression
                for a, b, c, d in my_module.map(something, fe, fi, fo, fum)
                if some_condition(a) or b == c[d]) and
            are_you_confused_yet() if foo else bar or eval(expr, ns) < 23
            or open('config').read(100)[23:27] == 'okay')


Fortunately, type systems are generally not fully Turing complete and are
usually significantly more restricted. PEP 484 doesn't mandate an upper
limit to how clever the type-checker must be, it only sets a common syntax
which type-checkers are expected to support. That is significant less
complex than a full Python parser, and should be lightweight enough that
IDEs and editors can use type-hints for providing text completion and
hints.

(This means that type-checkers are permitted to parse assertions, but they
aren't required to.)

Assertions also have the problem that they execute arbitrarily complex code
at runtime. Type annotations also execute code at runtime, but they're not
expected to be arbitrarily complex: mostly name lookups.

Lastly, this use of assertions clashes with "best practice" for assertions.
Since assertions may be disabled, you should not use them for testing
user-supplied arguments. So that means you have to write:

def func(arg):
    assert isinstance(arg, int)  # satisfy the type checker
    if isinstance(arg, int):  # support times when assert is disabled
        ...


which is not only ugly, but every call requires *two* isinstance checks. It
also means that when asserts are enabled you get a different exception for
bad data than when they are disabled.

This doesn't apply to annotations:

def func(arg:int):
    # since this is a public function, not private, we cannot assume the
    # caller will run the type-checker
    if isinstance(arg, int):
        ...

In this case, the overhead from the "arg:int" annotation is trivial: a
single name lookup and binding when the function is created, not when it is
called.

Sufficiently clever type-checkers may use assertions to infer types, but
requiring this is a non-starter.



-- 
Steven



From rosuav at gmail.com  Sat Jan 24 00:38:48 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 16:38:48 +1100
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <54c32dae$0$13000$c3e8da3$5496439d@news.astraweb.com>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
 <MPG.2f2ced6df496308698968d@nntp.aioe.org>
 <87sif1dpgy.fsf@elektro.pacujo.net>
 <54c32dae$0$13000$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmqYb5mt1gFMdEfC=70D7=33GH_6ki8yKbYDObCT0aQM7Q@mail.gmail.com>

On Sat, Jan 24, 2015 at 4:29 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Sufficiently clever type-checkers may use assertions to infer types, but
> requiring this is a non-starter.

Or they could use the isinstance checks themselves to infer types.

def func(arg):
    if not isinstance(arg, int): raise ValueError("Expected an integer")

It's fairly straight-forward to do an AST parse on a module, iterate
over it for functions, and then look for a specific pattern like the
above:

If(test=UnaryOp(op=Not(), operand=Call(func=Name(id='isinstance',
ctx=Load()), args=[Name(id='arg', ctx=Load()), Name(id='int',
ctx=Load())], keywords=[], starargs=None, kwargs=None)),
body=[Raise(exc=Call(func=Name(id='ValueError', ctx=Load()),
args=[Str(s='Expected an integer')], keywords=[], starargs=None,
kwargs=None), cause=None)], orelse=[])

... okay, that's not exactly pretty, but it's still a straight-forward
structure. But having just watched a PyCon talk about PyPy and RPython
and type inference, it's pretty clear that static analysis can do a
*lot* more than this; so really, looking for isinstance checks is both
too hard and too simplistic to be really worth doing. Type hinting is
a different beast.

ChrisA


From rosuav at gmail.com  Sat Jan 24 00:43:32 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 16:43:32 +1100
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54c32716$0$13009$c3e8da3$5496439d@news.astraweb.com>
References: <54ABB88A.7070504@r3dsolutions.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
 <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
 <mailman.18030.1422013652.18130.python-list@python.org>
 <bad017ab-490f-4daa-a552-33591c559398@googlegroups.com>
 <mailman.18039.1422031903.18130.python-list@python.org>
 <5a785a32-3855-457f-be3f-76066dfb20c8@googlegroups.com>
 <54c32716$0$13009$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmqDwtqLHE3nKs90ik27JuO9QhohwUc0joHOy2VB8f9rsw@mail.gmail.com>

On Sat, Jan 24, 2015 at 4:01 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> # Untested
> class B4(IntEnum):
>     F1 = 0
>     F2 = 1
>     F3 = 2
>     T  = 3
>     def __bool__(self):
>         return self is B4.T
>     def __str__(self):
>         if self is B4.F1: return "Certainly False"
>         if self is B4.F2: return "Maybe False"
>         if self is B4.F3: return "Maybe True"
>         if self is B4.T: return "Certainly True"

I keep expecting to hear Bluebottle asking about why we didn't figure
this out B4... anyway.

class B4(IntEnum):
    CertainlyFalse = 0
    MaybeFalse = 1
    MaybeTrue = 2
    CertainlyTrue  = 3
    def __bool__(self):
        return self is B4.CertainlyTrue

Now you don't need a __str__ function. :)

ChrisA


From steve+comp.lang.python at pearwood.info  Sat Jan 24 00:51:38 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 24 Jan 2015 16:51:38 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
 <mailman.17984.1421952098.18130.python-list@python.org>
 <MPG.2f2b697d288c74b2989685@nntp.aioe.org>
 <mailman.17990.1421956437.18130.python-list@python.org>
 <MPG.2f2b75c814639267989686@nntp.aioe.org>
 <mailman.18006.1421973642.18130.python-list@python.org>
 <54c1c5c1$0$13001$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18069.1422061233.18130.python-list@python.org>
Message-ID: <54c332ec$0$12993$c3e8da3$5496439d@news.astraweb.com>

Sturla Molden wrote:

> On 23/01/15 04:53, Steven D'Aprano wrote:
> 
>> If your manager is so bad, why isn't he insisting that you program in PHP
>> or Java or Algol 68 [insert name of some language you dislike] instead of
>> Python? Is your bad manager forcing you to write Java-style code in
>> Python, or insisting on Hungarian Notation?
> 
> Nobody is forcing me to do anything.
> 
> But without a thriving community, Python has no value to me.
> 
> If we add type hinting, then that community will go away, because other
> languages are better options.
> 
> Who will win? Julia? Ruby? They are all waiting in line for Python to
> fail. Then Python will be like Smalltalk.

How ironic. Julia *already uses* a type system much like the proposed Python
one:

http://julia.readthedocs.org/en/latest/manual/types/

and Ruby has an experimental one:

http://blog.codeclimate.com/blog/2014/05/06/gradual-type-checking-for-ruby/

Javascript has one available too:

https://code.facebook.com/posts/1505962329687926/flow-a-new-static-type-checker-for-javascript/

So does Groovy:

http://groovy.codehaus.org/Runtime+vs+Compile+time,+Static+vs+Dynamic

And Erlang, Clojure, Racket and many more. Python is falling behind, not
racing ahead.



-- 
Steven



From steve+comp.lang.python at pearwood.info  Sat Jan 24 01:21:10 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 24 Jan 2015 17:21:10 +1100
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <CAPTjJmqXLWEkz-KzxWWD4KRkHs4cdC3Z0DKZ8otjqTkytydsmQ@mail.gmail.com>
 <mailman.18018.1421989508.18130.python-list@python.org>
 <54c1e349$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18034.1422019400.18130.python-list@python.org>
Message-ID: <54c339d7$0$13005$c3e8da3$5496439d@news.astraweb.com>

Fetchinson . wrote:

> On 1/23/15, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
[...]
>> Cobra is especially close to Python-like syntax, and supports unit tests
>> as well:
>>
>>
>>     def sqroot(i as int) as float
>>         require
>>            i > 0
>>         ensure
>>            result > 0
>>         tests
>>            assert sqroot(25) == 5.0
>>         body
>>             ...
>>
>> It would be nice to be able to include at least *some* tests right there
>> in the code rather than in a separate file.
> 
> I completely agree. A cobra-style type hinting implementation would
> satisfy everyone who doesn't want to make function signatures noisy
> (including me) and would also satisfy those who advocate for the
> actual feature (type hinting) without worrying much about the
> implementation detail. These two groups are overlapping by the way :)

I don't understand this. Cobra's type-hints are right there in the function
signature, just like Python annotations.


# Cobra
def sqroot(i as int) as float

# Python
def sqroot(i:int)->float:


Cobra's use of "as" clashes with Python. In Python, "as" is used for
name-binding:

import module as name
with open('file') as f
except Exception as e

but apart from that minor difference, they're virtually identical.


> In any case, I'm pretty sure it was said before, but I can't really
> find it anywhere, can someone tell me what the rationale is for
> *function signature* type hinting?

The basic principle is that things which are related should be found
together. The further away they are, the worse.

Bad:
- the parameter name and the type are in different files

Better:
- the parameter name and the type are only a few lines apart

Best:
- the parameter name and type are right next to each other


The closer they are, the easier it is to keep them in sync, and the easier
it is to see the relevant information at a glance. Putting them together
also means that you don't have to repeat the argument name:

int n
def spam(n): ...

versus

def spam(n:int): ...


Those reasons are why decorators have the syntax which they do:

@decorator
def spam(n): 
    do_this()
    do_that()
    do_something_else()


is better than the old way of using decorators:

def spam(n): 
    do_this()
    do_that()
    do_something_else()

spam = decorator(spam)


The decorator is only a single line away from the signature, and you don't
have to repeat the name.


We can see this at work in Pascal. Pascal functions have type declarations
in the signature, and variable declarations between the signature and the
body:


function sqroot(arg: Integer): Real;
  var
    x: Integer;
    y: Real;
    z: Something_Else;
  begin
    do_this(1, 2);
    do_that(3, 4);
    do_something_else(5, 6);
    x := some expression;  { what's the type of x again? }
  end;


The declarations in the signature work very well and are easy to use, but
the "var" section, not so much. Especially in large functions, the place
where you declare the variable and its type, and the place where you first
use it, can be separated by many lines. This makes maintenance and reading
of the code more difficult.

Newer languages like Java let you declare the variable the first time you
use it:

    int x = some expression; 

and you don't have to search very far to find out what sort of thing x is,
it is right there.



-- 
Steven



From rosuav at gmail.com  Sat Jan 24 01:28:41 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 17:28:41 +1100
Subject: Alternative to multi-line lambdas: Assign-anywhere def statements
Message-ID: <CAPTjJmrAQgtauH74dwCzb_-6T09D0dLVkxiGrAxJMp_OOwgS0g@mail.gmail.com>

In some random and rambling discussion about Python, the notion came
up that multi-line lambda functions are often sought as a means of
populating dictionaries and other such structures. Conceptually, "def
foo(...): ..." is broadly equivalent to "foo = FunctionType(...)"; but
the only type of assignment that can be done is to a simple name.
(It's affected by global statements, so it might be global or local,
but still just a simple name.)

The theory was mooted that it would be nice to be able to assign to anything:

cmd = {} # Command dispatch table

def cmd["foo"](*args):
    print("You asked to foo.")

def cmd["bar"](*args):
    print("There's no wine in the bar.")

def cmd["asdf"](*args):
    print("Asdf! Asdf!")

Obviously this doesn't (currently) work syntactically; but in theory,
a decorator ought to be able to do the same job. The question is, can
it be done generically? For the specific case of the dispatch table,
it would be easy enough to make a function that stuffs its argument
into that one specific dictionary:

cmd = {}
def command(func):
    cmd[func.__name__] = func
    return func

@command
def foo(*args):
    print("You asked to foo.")

but this is hardly generic. There's no convenient way to give an
argument to a decorator that says "please assign this here", short of
using some stupid eval hack... is there?

(Incidentally, for a non-generic dispatch table, a callable dict
subclass could be pretty clean:

class DispatchTable(dict):
    """Self-populating dictionary - use this as a function decorator
to stuff functions into it."""
    def __call__(self, func):
        self[func.__name__] = func
        return func

cmd = DispatchTable()

@cmd
def foo(*args):
    print("You asked to foo.")

It's still specific to one exact purpose, though.)

ChrisA


From steve+comp.lang.python at pearwood.info  Sat Jan 24 01:35:11 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 24 Jan 2015 17:35:11 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17973.1421939508.18130.python-list@python.org>
 <54c2299d$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18029.1422013105.18130.python-list@python.org>
Message-ID: <54c33d20$0$13011$c3e8da3$5496439d@news.astraweb.com>

Chris Angelico wrote:

> On Fri, Jan 23, 2015 at 9:59 PM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:

>> (Don't use binary floating point numbers for anything related to money.
>> Just don't.)
> 
> While I generally agree, it's not quite as hard-and-fast as that. It's
> just important to know that binary floating point can't accurately
> represent many commonly-used real numbers... the same consideration
> that they always need.

I think it is that hard-and-fast.

If you sometimes use floats and sometimes don't use floats, you're forever
worrying about coercing your values from one type to another, worrying
whether the representation error of this value is sufficiently small to use
a float or whether you have to use something else... the whole thing gets
messy and ugly. Or worse, you're *not* worrying about these things, and
when your users complain that their pay is sometimes a cent off and their
account doesn't balance at the end of the year, you "fix the bug" by
arbitrarily adjusting the printing routines.

Better to just have a hard rule: never use binary floats for anything to do
with money, if you care about the result.

Obviously I'm not a fanatic. If I'm working out my share of a $37 meal split
three ways, I just do 37/3 the same as anyone else :-)



-- 
Steven



From steve+comp.lang.python at pearwood.info  Sat Jan 24 01:36:59 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 24 Jan 2015 17:36:59 +1100
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
 <MPG.2f2ced6df496308698968d@nntp.aioe.org>
 <87sif1dpgy.fsf@elektro.pacujo.net>
 <54c32dae$0$13000$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18074.1422077931.18130.python-list@python.org>
Message-ID: <54c33d8c$0$13011$c3e8da3$5496439d@news.astraweb.com>

Chris Angelico wrote:

> But having just watched a PyCon talk about PyPy and RPython
> and type inference

Ooh! Got a link?


-- 
Steven



From rosuav at gmail.com  Sat Jan 24 01:47:59 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 17:47:59 +1100
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <54c33d8c$0$13011$c3e8da3$5496439d@news.astraweb.com>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
 <MPG.2f2ced6df496308698968d@nntp.aioe.org>
 <87sif1dpgy.fsf@elektro.pacujo.net>
 <54c32dae$0$13000$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18074.1422077931.18130.python-list@python.org>
 <54c33d8c$0$13011$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmoOD6c6KV4pa1u4nKO+pQTmAVUFCWQzjLbGcGmpt3B39w@mail.gmail.com>

On Sat, Jan 24, 2015 at 5:36 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Chris Angelico wrote:
>
>> But having just watched a PyCon talk about PyPy and RPython
>> and type inference
>
> Ooh! Got a link?

Well, it's not primarily about type inference, but the matter is
mentioned. It's mainly about PyPy, RPython, and what a VW Beetle would
look like if python-ideas got to it:

http://youtu.be/6_-5XZzJyt0

ChrisA


From steve+comp.lang.python at pearwood.info  Sat Jan 24 02:48:54 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 24 Jan 2015 18:48:54 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <9a6694a5-5774-415a-b28a-7a9425a9112a@googlegroups.com>
Message-ID: <54c34e68$0$12976$c3e8da3$5496439d@news.astraweb.com>

Rick Johnson wrote:

> On Thursday, January 22, 2015 at 10:23:48 PM UTC-6, Steven D'Aprano wrote:
>> Rick Johnson wrote:
>> 
>> > The solution is move the type hinting syntax completely
>> > out of the source file and into another file -- think of
>> > it as a "Python Type Hinting Header File".
>> 
>> The 1970s called, they want their bad ideas back. [...]
>> Things that go together should appear together. Imagine a
>> language where you declared the function name in one file,
>> the function parameters in a second file, any default
>> values in a third file, and the function body in a fourth
>> file. Ridiculous. Ideally, all these things should be
>> found together, preferably close enough for the reader to
>> take it all in at a glance (although some function bodies
>> may be too large).
> 
> Anyone else care for a pipping hot cup of Reductio ad absurdum?


Rick, you seem to be under the misapprehension that a reductio ad absurdum
argument is a fallacy. It is not. From Webster's dictionary:

   Indirect demonstration, or Negative demonstration (called
     also reductio ad absurdum), in which the correct
     conclusion is an inference from the demonstration that any
     other hypothesis must be incorrect.


And from Wordnet:

  reductio ad absurdum
    n 1: (reduction to the absurd) a disproof by showing that the
         consequences of the proposition are absurd; or a proof of a
         proposition by showing that its negation leads to a
         contradiction [syn: reductio ad absurdum, reductio]


Example:

    Argument: 

    Human population growth can continue forever, without any limits
    at all. There shall never come a time where lack of resources 
    will constrain growth.

    Refutation by reductio ad absurdum:

    If human population doubles every fifty years, in 718 years every
    square metre of the world's land surface will have a person in it.
    In 840 years we will be jammed shoulder-to-shoulder. In 2335 years
    there will be a million people per square inch of the planet's 
    surface (including oceans). Before that, after just 2155 years, the
    entire mass of the planet will be converted to human flesh. In 6760
    years, the entire solar system will be a solid sphere of humans,
    expanding outward at 15840400 km per hour.

    Since this is clearly absurd, something (war, famine, disease, 
    reduced fertility) must reduce or halt population growth.

(Aside: those numbers are more or less correct, as best as I can calculate
them.)

Reductio arguments can, of course, be fallacious. "The world cannot be a
sphere. If the world was a sphere, people on the bottom would fall off!"
This argument is fallacious because it fails to understand that gravity
acts towards the centre of the Earth, not "down" relative to outer space.


>> There may be times where splitting related things are
>> unavoidable, but they should be a last resort, only to be
>> used when any other solution is unacceptable.
> 
> Duh! Do you think i just pulled stub files out my arse
> without giving all the other alternatives due consideration?

Actually, yes.

I think that had Guido proclaimed that C-style header files were the only
way to give type hints, you would be arguing right now that they were awful
and that the one and only correct way to do type-hinting is to use
annotations.


> But you had your fun so that's all that matters. ;-)
> 
> PS: Man, you need to invest in some formatting tools. I format
> all my posts with a max width of 60, but then when you quote
> them back i see strange line breaks. Does your editor think
> that 60 chars is too wide? What's going on?

I don't know what you are talking about. My editor doesn't re-wrap quoted
text unless it exceeds 76 columns wide, which yours does not, and I don't
see any strange line breaks. Can you point me to an example in the
archives?



-- 
Steven



From bob.martin at excite.com  Sat Jan 24 03:09:51 2015
From: bob.martin at excite.com (Bob Martin)
Date: Sat, 24 Jan 2015 08:09:51 GMT
Subject: What killed Smalltalk could kill Python
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18065.1422053606.18130.python-list@python.org>
Message-ID: <cih2afF6b1mU1@mid.individual.net>

in 734904 20150123 225104 Tim Daneliuk <tundra at tundraware.com> wrote:
>On 01/21/2015 05:55 PM, Chris Angelico wrote:
>> On Thu, Jan 22, 2015 at 10:37 AM, Tim Daneliuk <tundra at tundraware.com> wrote:
>>> I find these kinds of discussions sort of silly.  Once there is a critical
>>> mass of installed base, no language EVER dies.
>>
>> Not sure about that. Back in the 1990s, I wrote most of my code in
>> REXX, either command-line or using a GUI toolkit like VX-REXX. Where's
>> REXX today? Well, let's see. It's still the native-ish language of
>> OS/2. Where's OS/2 today? Left behind. REXX has no Unicode support (it
>> does, however, support DBCS - useful, no?), no inbuilt networking
>> support (there are third-party TCP/IP socket libraries for OS/2 REXX,
>> but I don't know that other REXX implementations have socket services;
>> and that's just basic BSD sockets, no higher-level protocol handling
>> at all), etc, etc. Sure, it's not technically dead... but is anyone
>> developing the language further? I don't think so. Is new REXX code
>> being written? Not a lot. Yet when OS/2 was more popular, REXX
>> definitely had its installed base. It was the one obvious scripting
>> language for any OS/2 program. Languages can definitely die, or at
>> least be so left behind that they may as well be dead.
>>
>> ChrisA
>>
>
>Rexx is still well used on mainframes.

http://www.oorexx.org/

I use ooRexx every day, on Linux mostly, but also available on Windows.


From rosuav at gmail.com  Sat Jan 24 03:16:58 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 24 Jan 2015 19:16:58 +1100
Subject: What killed Smalltalk could kill Python
In-Reply-To: <cih2afF6b1mU1@mid.individual.net>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18065.1422053606.18130.python-list@python.org>
 <cih2afF6b1mU1@mid.individual.net>
Message-ID: <CAPTjJmqe+p7kqSPyXq4kuTDFGtjrWTPU79jqn-eX3UyhN6XZjg@mail.gmail.com>

On Sat, Jan 24, 2015 at 7:09 PM, Bob Martin <bob.martin at excite.com> wrote:
> http://www.oorexx.org/
>
> I use ooRexx every day, on Linux mostly, but also available on Windows.

So the question really is: Why that, as opposed to some other
language? Can you say, in one sentence, what ooRexx has that other
languages don't have?

ChrisA


From steve+comp.lang.python at pearwood.info  Sat Jan 24 03:27:36 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 24 Jan 2015 19:27:36 +1100
Subject: Comparisons and sorting of a numeric class....
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <54B76B0A.7050706@r3dsolutions.com>
 <CALwzid=oTdoMPR+zTOiWOv0HWawYwD=Q6xHusywHPQaJmKOtiA@mail.gmail.com>
 <mailman.18030.1422013652.18130.python-list@python.org>
Message-ID: <54c35779$0$12995$c3e8da3$5496439d@news.astraweb.com>

Andrew Robinson wrote:

> But let me explain a bit more why I'm picking on Python: ?For even if we
> set the electronic engineering concerns aside that I've raised (and they
> are valid, as OOP is supposed to model reality, not reality be bent to
> match OOP) -- People's facile explanations about why Python's version of
> bool is the way it is -- still bothers me here in the python mail list
> -- because people seem to have a very wrong idea about bool's nature as
> a dualton being somehow justified solely by the fact that there are only
> two values in Boolean logic; 

Nobody has suggested that except you. Earlier I even stated that I didn't
know GvR's motivation in making True and False singletons, but suggested
that it might have been a matter of efficiency.

Right here, right now, the reason doesn't matter. It doesn't matter if some
other language chooses differently, or that Python might have been designed
differently. What matters is:

(1) Python is the way it is, not the way it might have been had it been
designed differently;
(2) it isn't going to change; and
(3) it doesn't matter for what you are trying to do.

You have invented an imaginary problem then spent your time complaining that
Python doesn't allow you to solve this non-existent problem in a specific
way.


[...]
> -- And I know 
> Charles bool didn't use singletons in his algebra, ?-- just read his
> work and you'll see he never mentions them or describes them, but he
> does actually use dozens of instances of the True and False objects he
> was talking about -- for the obvious reason that he would have needed
> special mirrors, dichroic or partially silvered, to be even able to
> attempt to make one instance of True written on paper show up in
> multiple places; And that's silly to do when there's no compelling
> reason to do it.

In the words of physicist Wolfgang Pauli, that is not even wrong.

http://en.wikipedia.org/wiki/Not_even_wrong

I'm actually gobsmacked that you could seriously argue that because Boole
wrote down true and false (using whatever notation he choose) more than
once, that proves that they aren't singletons. That's as sensible as
claiming that if I write your name down twice, you must be two people.


> Yet -- people here seem to want to insist that the bool type with only
> two instances is some kind of pure re-creation of what Charles Bool
> did -- when clearly it isn't.

Nobody has argued that Boole (note the spelling of his name) considered True
and False to be singletons. Being a mathematician, he probably considered
that there is a single unique True value and a single unique False value,
in the same way that there is a single unique value pi (3.1415...) and a
single unique value 0.

But "the number of instances" and "singleton" are concepts from object
oriented programming, which didn't exist when Boole was alive. It is not
even wrong to ask the question whether Boole thought of true and false to
be singleton objects. He no more had an opinion on that than Julius Caesar
had an opinion on whether the Falkland Islands belong to the UK or
Argentina.


> It's a amalgamation of enhancements such 
> as binary words instead of just True/False and many other things
> (operators that work on words rather than single bits.). ?So -- I don't
> see that Python's implementation of Bool is justified by either a purist
> appeal to Charles bool, or by ignoring pragmatic concerns that have been
> attached to Bool's work for years by Electrical Engineers in order to
> make it more useful for practical computer problems. ?Yet these two
> things are what this python list has sort of harped on.

Python's bools are objects, and they represent Boolean values, not strings,
not lists, not floats, and not three-value or four-value logic values. They
are designed for Boolean two-valued logic, like the bulk of programming
languages, not for simulating hardware. You might as well be complaining
that Python's bools are no use for doing vector arithmetic. Correct. That's
not what they're designed for. If you want vectors, don't use a bool, write
a vector class.

Three- or four-value logic is of great use to the hardware engineer making
electrical circuits, we get that, thank you. But they are of little use in
solving most programming problems, which is why no general purpose
programming language I am aware of supports non-Boolean logic in the
language itself.

Simulating physical hardware is a niche. I am impressed by your anecdote of
running Python on an operating system running on a simulated computer,
that's very impressive, but it is still a niche requirement.


[...]
> Where python is different from other languages regarding bool -- and
> deserves a little extra picking on, is that Guido has imposed four
> constraints simultaneously to bool which together cause a conflict
> that I don't think (offhand) I've ever encountered in another language;
> Definitely not in C/C++!
> 
> The four things are: 1 -- he cut off subtyping and created no alternate
> method of doing type checking of duck-types,

The point of duck-typing is that you *don't* type check, not that there is a
special kind of thing called a "duck-type" that you need to check for. Nor
is there some sort of special test for "duck-typing" (although abstract
base classes and isinstance comes close). If you write something like this:

    if isinstance(flag, bool):
        if flag: do_this()
        else: do_that()

that is the opposite of duck-typing. This is duck-typing, where you just
assume that your object is of the expected type and allow it to raise an
exception if it isn't:

    if flag: do_this()
    else: do_that()

Ironically, duck-typing bools is almost unique in Python in that it is
virtually impossible for this to fail. By default, every object regardless
of its type (list, int, str, one of your 4-value logic instances,
everything) can successfully be used as if it were a bool. This makes your
insistence that you have to subclass bool even more inexplicable.


> 2 -- he does not allow 
> multiple instances, ?3 -- he himself did not implement bool using the
> standard alternative methodology to subclassing -- eg: as a composite
> structure with delegation. 

3 is irrelevant. Just because the bool type is "final" (in Java terms) and
un-subclassable doesn't mean that its parent must also be "final".

Subtyping int is allowed. There is no restriction on subtyping int to make
bool, and indeed you can subtype int to make your four-value logic class if
you wish.


> 4. ?and he has made bool into the default 
> return type for base type comparison operators; which means that general
> programmers expect a bool for base types and may check for it, even if
> Python's built in functions do not.

Believe me, nobody writes code like this:

flag = x < y
if not isinstance(flag, bool):
    raise TypeError('expected bool, got something else')
if flag:
    print "x is less than y"


when they can write:

if x < y:
    print "x is less than y"


Provided your 4-value logic instances support conversion to bool via the
__bool__ special method (Python 3) or __nonzero__ special method (Python
2), it will be exceedingly rare that anyone will notice that your
fuzzy-numbers return MaybeFalse instead of False (etc).

The only time somebody will notice is if they pass the comparison result to
a flag which insists on a bool and nothing but a bool:

def somefunc(flag):
    if not instance(flag, bool): raise TypeError
    ...


somefunc(fuzzy_a < fuzzy_b)


But you can't solve every example of bad programming! What if the function
was written like this?

def somefunc(flag):
    if not (flag is True or flag is False): raise TypeError
    ...


That will reject your MaybeFalse and MaybeTrue *no matter what you do*. (You
cannot override identity checks in Python.) The only solution is to educate
your users that, *if and only if* they need to pass a fuzzy-bool to
something which requires an actual bool, they can explicitly normalise it
using:

somefunc(bool(fuzzy_a < fuzzy_b))


[...]
> As far a subtyping goes; The very fact that Guido used subtyping to
> create bool in the first place (subtype of int), precludes any real
> claim that bool should not itself be subclassable 

That's simply wrong.

Have you heard of the saying "Don't run with scissors",  usually told to
small children? (I know a nominally mature adult who stabbed himself after
tripping over while running with scissors. Oh how we laughed. Fortunately
his injury was mild and more embarrassing than life-threatening.)

Scissors are usually made from pieces of steel. Would you argue this?

"There is no prohibition on running with arbitrary pieces of steel. Scissors
are made from steel. Therefore, that precludes any claim that we should not
run with scissors."

That int is subclassable has no bearing on whether or not bool (made from
int via subclassing) is subclassable.



> just because bools 
> only have two values; ?I mean, seriously -- ?Guido's 'strict' Bool is
> already an impure form of OOP that is borderline hypocrisy, as it can
> '+' to 2 or 3... 

Not in the least.

Python's bools are "impure" only in the sense that they violate some
people's expectations that bools should be an abstraction. In the case of
Python, they are not abstractions, they are ints. (Specifically a subclass
of int.) But by the rules of OOP, including the Liskov Substitution
Principle, bools are perfectly good ints. Anywhere you use an int, you
could use a bool instead, and they will work.

Personally, as an ex-Pascal programmer, it took me a long time to get used
to the fact that True and False weren't purely abstract values with no
methods and no operations other than `or`, `and`, `if...else`. But I not
only got used to it, but I came to appreciate that this is actually useful.


> and many other things; ?and worse I've just come across 
> a couple of papers which suggest that Guido doesn't like subclassing
> when Composite object structures could be used instead to replace the
> subclass 'is' relationship with a 'has a' relationship.

I would like to see these papers.



-- 
Steven



From nicholas.cole at gmail.com  Sat Jan 24 04:04:50 2015
From: nicholas.cole at gmail.com (Nicholas Cole)
Date: Sat, 24 Jan 2015 09:04:50 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <54c332ec$0$12993$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
 <mailman.17984.1421952098.18130.python-list@python.org>
 <MPG.2f2b697d288c74b2989685@nntp.aioe.org>
 <mailman.17990.1421956437.18130.python-list@python.org>
 <MPG.2f2b75c814639267989686@nntp.aioe.org>
 <mailman.18006.1421973642.18130.python-list@python.org>
 <54c1c5c1$0$13001$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18069.1422061233.18130.python-list@python.org>
 <54c332ec$0$12993$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAAu18heBdgJ2Y9obWBD+L-bgxrEgc-4NonK=A41k6M-xGBSV5w@mail.gmail.com>

On Sat, Jan 24, 2015 at 5:51 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:


> and Ruby has an experimental one:
>
> http://blog.codeclimate.com/blog/2014/05/06/gradual-type-checking-for-ruby/

Interesting.  Ruby has avoided the magic comment, and the typing is
done in annotations rather than in the function signatures.  It's
interesting to see them go a different way so that we can compare the
two approaches.

I rather like it.  It's a shame that the rest of Ruby's syntax is
inferior to python's..... ;-)

N.


From marko at pacujo.net  Sat Jan 24 04:27:12 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sat, 24 Jan 2015 11:27:12 +0200
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
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 <MPG.2f2ced6df496308698968d@nntp.aioe.org>
 <87sif1dpgy.fsf@elektro.pacujo.net>
 <54c32dae$0$13000$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <87ppa434wf.fsf@elektro.pacujo.net>

Steven D'Aprano <steve+comp.lang.python at pearwood.info>:

> Marko Rauhamaa wrote:
>
>>    def weekday(day):
>>        assert isinstance(day, int) and 0 <= day <= 6
>>        ...
>
> [...]
>
> Requiring the type-checker to parse and understand arbitrarily complex
> assertions would require the type-checker to be as complex as Python
> itself:

The static type checker / optimizer would of course be limited to a set
of known fixed expression patterns. More complex expressions would
simply be ignored by it.

Moreover, the type checker would probably operate in a compile-time
environment where you assume "isinstance" and "int" retain their usual
meanings. 

Scheme already employs somewhat analogous dirty tricks like that in its
macro preprocessing.

> Assertions also have the problem that they execute arbitrarily complex
> code at runtime.

Assertions don't *have* to execute anything, anywhere, any time. The
static analysis can decide when executing assertions is worth the
trouble. All of the above can also be done JIT.

> Lastly, this use of assertions clashes with "best practice" for
> assertions. Since assertions may be disabled, you should not use them
> for testing user-supplied arguments. So that means you have to write:
>
> def func(arg):
>     assert isinstance(arg, int)  # satisfy the type checker
>     if isinstance(arg, int):  # support times when assert is disabled
>         ...

I think that's a silly argument. You never second-guess assertions.

> This doesn't apply to annotations:
>
> def func(arg:int):
>     # since this is a public function, not private, we cannot assume the
>     # caller will run the type-checker
>     if isinstance(arg, int):
>         ...

I think that usage is plainly bad style as well. Reminds me of the old
adage:

   Dad is always right, and even when he isn't, he's never wrong.


Marko


From marfig at gmail.com  Sat Jan 24 04:30:48 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sat, 24 Jan 2015 09:30:48 +0000 (UTC)
Subject: Python is DOOMED! Again!
References: <54c34e68$0$12976$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <1a194e0a0b3f8d205d7f4660b75@nntp.aioe.org>

 Steven D'Aprano,

> Rick, you seem to be under the misapprehension that a reductio ad
> absurdum argument is a fallacy. It is not. From Webster's dictionary:
> 
> Indirect demonstration, or Negative demonstration (called
> also reductio ad absurdum), in which the correct
> conclusion is an inference from the demonstration that any
> other hypothesis must be incorrect.
> And from Wordnet:
> 
> reductio ad absurdum
> n 1: (reduction to the absurd) a disproof by showing that the
> consequences of the proposition are absurd; or a proof of a
> proposition by showing that its negation leads to a
> contradiction [syn: reductio ad absurdum, reductio]
> Example:
> 
> Argument:
> 
> Human population growth can continue forever, without any limits
> at all. There shall never come a time where lack of resources
> will constrain growth.
> Refutation by reductio ad absurdum:
> 
> If human population doubles every fifty years, in 718 years every
> square metre of the world's land surface will have a person in it.
> In 840 years we will be jammed shoulder-to-shoulder. In 2335 years
> there will be a million people per square inch of the planet's
> surface (including oceans). Before that, after just 2155 years,
> the
> entire mass of the planet will be converted to human flesh. In
> 6760
> years, the entire solar system will be a solid sphere of humans,
> expanding outward at 15840400 km per hour.
> Since this is clearly absurd, something (war, famine, disease,
> reduced fertility) must reduce or halt population growth.
> (Aside: those numbers are more or less correct, as best as I can
> calculate them.)
> 
> Reductio arguments can, of course, be fallacious. "The world cannot be
> a sphere. If the world was a sphere, people on the bottom would fall
> off!" This argument is fallacious because it fails to understand that
> gravity acts towards the centre of the Earth, not "down" relative to
> outer space.

And that's cherry picking. Another fallacy. That is, presenting only results 
that support your argument.

When Reductio ad absurdum fails to respect the principle of non-contradition 
it is no longer a proof by contradiction devise, but  a proper fallacy. Reductio 
ad absurdum becomes then one of the well know forms of straw man argument.

Your argument that the 70s things were bad and Rick wanted to go back to 
those times is both debatable (the 70s brought much of what we use today 
as gospel, like design patterns, for instance). You also try to reduce rick 
argument to the absurd by insinuating he is trying to support the idea that 
we should declare function names in one file, function parameters in another 
file and the function body in another file. That's a proper reductio ad absurdum 
straw man argument if I ever saw one.




From marfig at gmail.com  Sat Jan 24 05:16:26 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sat, 24 Jan 2015 10:16:26 +0000 (UTC)
Subject: __bases__ misleading error message
Message-ID: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>


Consider the following code at your REPL of choice

        class Super:
            pass

        class Sub:
            pass

        foo = Sub()

        Sub.__bases__
        foo.__bases__

The last statement originates the following error:

        AttributeError: 'Sub' object has no attribute '__bases__'

Naturally the 'Sub' object has an attribute __bases__. It's the instance 
that has not. So shouldn't the error read like:

        AttributeError: 'Sub' instance has no attribute '__bases__', or
        AttributeError: 'foo' object has no attribute '__bases__'




From alister.nospam.ware at ntlworld.com  Sat Jan 24 05:32:59 2015
From: alister.nospam.ware at ntlworld.com (alister)
Date: Sat, 24 Jan 2015 10:32:59 GMT
Subject: Random ALL CAPS posts on this group
References: <14af0873-c00f-4ff5-85a2-81028950714a@googlegroups.com>
 <efe94ce3-7401-49f0-9853-4e475726c0d2@googlegroups.com>
Message-ID: <vxKww.227573$T94.4918@fx26.am4>

On Fri, 23 Jan 2015 14:40:15 -0800, sohcahtoa82 wrote:

> On Monday, January 19, 2015 at 4:16:13 PM UTC-8, Luke Tomaneng wrote:
>> Has anyone noticed these? There have been about three of them recently
>> and they don't seem to have anything to do with Python at all. Does
>> anyone know if there is a good reason they are here?
> 
> My question is, does anyone know what the hell they're ranting about?

Does anyone care?
i just kill file the author (i could instigate the other suggestions made 
here but i like to make my on decisions rather than fully automating) 



-- 
Death comes on every passing breeze,
He lurks in every flower;
Each season has its own disease,
Its peril -- every hour.
	--Reginald Heber


From wxjmfauth at gmail.com  Sat Jan 24 05:34:43 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Sat, 24 Jan 2015 02:34:43 -0800 (PST)
Subject: Case-insensitive sorting of strings (Python newbie)
In-Reply-To: <mailman.18046.1422035592.18130.python-list@python.org>
References: <54C27E13.5090808@ntlworld.com>
 <mailman.18046.1422035592.18130.python-list@python.org>
Message-ID: <2260ad2f-6581-4c2f-896f-b2c3d7a27ebc@googlegroups.com>

Le vendredi 23 janvier 2015 18:54:11 UTC+1, Peter Otten a ?crit?:
> John Sampson wrote:
> 
> > I notice that the string method 'lower' seems to convert some strings
> > (input from a text file) to Unicode but not others.
> > This messes up sorting if it is used on arguments of 'sorted' since
> > Unicode strings come before ordinary ones.
> > 
> > Is there a better way of case-insensitive sorting of strings in a list?
> > Is it necessary to convert strings read from a plaintext file
> > to Unicode? If so, how? This is Python 2.7.8.
> 
> The standard recommendation is to convert bytes to unicode as early as 
> possible and only manipulate unicode. This is more likely to give correct 
> results when slicing or converting a string.
> 
> $ cat tmp.txt
> ?hnlich
> ?blich
> n?tig
> m?glich
> Ma?
> Ma?e
> Masse
> ?HNLICH
> $ python
> Python 2.7.6 (default, Mar 22 2014, 22:59:56) 
> [GCC 4.8.2] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
> >>> for line in open("tmp.txt"):
> ...     line = line.strip()
> ...     print line, line.lower()
> ... 
> ?hnlich ?hnlich
> ?blich ?blich
> n?tig n?tig
> m?glich m?glich
> Ma? ma?
> Ma?e ma?e
> Masse masse
> ?HNLICH ?hnlich
> 
> Now the same with unicode. To read text with a specific encoding use either 
> codecs.open() or io.open() instead of the built-in (replace utf-8 with your 
> actual encoding):
> 
> >>> import io
> >>> for line in io.open("tmp.txt", encoding="utf-8"): 
> ...     line = line.strip()
> ...     print line, line.lower()
> ... 
> ?hnlich ?hnlich
> ?blich ?blich
> n?tig n?tig
> m?glich m?glich
> Ma? ma?
> Ma?e ma?e
> Masse masse
> ?HNLICH ?hnlich
> 
> Unfortunately this will not give the order that you (or a german speaker in 
> the example below) will probably expect:
> 
> >>> print "".join(sorted(io.open("tmp.txt"), key=unicode.lower))
> Masse
> Ma?
> Ma?e
> m?glich
> n?tig
> ?hnlich
> ?HNLICH
> ?blich
> 
> For case-insensitive sorting you get better results with locale.strxfrm() -- 
> but this doesn't accept unicode:
> 
> >>> import locale
> >>> locale.setlocale(locale.LC_ALL, "")
> 'de_DE.UTF-8'
> >>> print "".join(sorted(io.open("tmp.txt"), key=locale.strxfrm))
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> UnicodeEncodeError: 'ascii' codec can't encode character u'\xe4' in position 
> 0: ordinal not in range(128)
> 
> As a workaround you can sort first:
> 
> >>> print "".join(sorted(open("tmp.txt"), key=locale.strxfrm))
> ?hnlich
> ?HNLICH
> Ma?
> Masse
> Ma?e
> m?glich
> n?tig
> ?blich
> 
> You should still convert the result to unicode if you want to do further 
> processing in Python.

-------
Hard drive archeology. Python 2 and Python 3.

One (among other) way(s) to work is to use the Unicode
Collation Algorithm (Default Unicode Collation Element
Table (DUCET)).


In action with a reduced (latin only, > ~1000 code points)
characters set from allkeys.txt. Dirty work.
I added the French word ?l?phant.

code:

[...]

    li = ['?hnlich', '?HNLICH', 'Ma?', 'Masse', 'Ma?e', \
          'm?glich', 'n?tig', '?blich']
    li.insert(0, '?l?phant')
    print(li)
    r = sorted(li, key=c.tri)
    print(r)

[...]

output:

>c:\python32\pythonw -u "unicodecollation.py"

['?l?phant', '?hnlich', '?HNLICH', 'Ma?', 'Masse', 'Ma?e', 'm?glich', 'n?tig', '?blich']
['?hnlich', '?HNLICH', '?l?phant', 'Ma?', 'Ma?e', 'Masse', 'm?glich', 'n?tig', '?blich']
>Exit code: 0


---

Why to continue to waste time with this product?
Its ridiculous(?), absurd(?), ascii-centric, non std,
buggy (definitively) Unicode implementation?

This just become only nice for pedacogical purposes.

jmf


From michael at stroeder.com  Sat Jan 24 05:43:28 2015
From: michael at stroeder.com (=?UTF-8?Q?Michael_Str=c3=b6der?=)
Date: Sat, 24 Jan 2015 11:43:28 +0100
Subject: Check for running DHCP daemon?
In-Reply-To: <mailman.18064.1422053367.18130.python-list@python.org>
References: <54C030E9.8010404@emerytelcom.com>
 <CAGGBd_rbL21MZEh+6PoUYoM-OS-Mpd=sUpSTPiTGhwqJSrqNMw@mail.gmail.com>
 <1e1a7b4bdcf1408799b7f95b5d24851a@ETEXCH2.corp.emerytelcom.com>
 <CAPTjJmrpjdNBf4C79gj2BB5S4+QhtDz0_LPcrn2J8-gVUY4T6g@mail.gmail.com>
 <54C27098.8020708@emerytelcom.com>
 <CAPTjJmrh2gZLhw6YktCPV5bw1K7VVnSx+Pz1nGO7G6Y8fqpvGA@mail.gmail.com>
 <mailman.18063.1422050804.18130.python-list@python.org>
 <2d134592-6983-471e-ba5a-2124502af782@googlegroups.com>
 <mailman.18064.1422053367.18130.python-list@python.org>
Message-ID: <m9vsvg$tj8$2@dont-email.me>

Chris Angelico wrote:
> On Sat, Jan 24, 2015 at 9:38 AM,  <sohcahtoa82 at gmail.com> wrote:
>> Secondly, even if you find a module, keep in mind that the module probably won't stay in Python land.  It will probably call an external utility itself.
>>
>> If you REALLY wanted to check it without calling an external utility, you could connect to port 67 and see what happens, but that could cause problems.
> 
> We're talking UDP here, so there's no "connect to" concept. You have
> to send a packet and listen for a reply,

If I'd want to implement a serious DHCP monitoring I'd use a DHCP module and
try to renew a certain monitoring lease. With that approach you'd also see
whether the DHCP server does something meaningful.

Ciao, Michael.



From qualsivoglia at dovetipare.nz  Sat Jan 24 05:48:02 2015
From: qualsivoglia at dovetipare.nz (maurog)
Date: Sat, 24 Jan 2015 10:48:02 +0000 (UTC)
Subject: OpenCv: different behavior of cv2.imread and cv2.imdecode
Message-ID: <m9vt92$uv$1@speranza.aioe.org>

The starting point is an invalid jpg file, grabbed from a site showing 
pictures from a webcam while the site is updating the picture itself. So 
the upper part of the picture is ok, the lower part no.

If I execute this code
flags = cv2.CV_LOAD_IMAGE_COLOR
img = cv2.imread('bad.jpg', flags)

this message is printed on stderr

"Premature end of JPEG file"

and in the part of img np array related to the lower part of the picture 
all the values are 128 for all the RGB layers, that is black pixels.

If I execute this code, as suggested here 

https://stackoverflow.com/questions/13329445/how-to-read-image-from-in-
memory-buffer-stringio-or-from-url-with-opencv-pytho

r = open('bad.jpg','rb').read()
img_array = np.asarray(bytearray(r), dtype=np.uint8)
flags = cv2.CV_LOAD_IMAGE_COLOR
img = cv2.imdecode(img_array, flags)

no error message is shown and in the img np array there are mixed values 
in the part related to the lower part of the picture

So it looks to me that cv2.imread and cv2.imdecode handle in a different 
way the loading of a jpg image. Is it like that or am I missing something?


From gheskett at wdtv.com  Sat Jan 24 06:34:20 2015
From: gheskett at wdtv.com (Gene Heskett)
Date: Sat, 24 Jan 2015 06:34:20 -0500
Subject: What killed Smalltalk could kill Python
In-Reply-To: <cih2afF6b1mU1@mid.individual.net>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18065.1422053606.18130.python-list@python.org>
 <cih2afF6b1mU1@mid.individual.net>
Message-ID: <201501240634.20116.gheskett@wdtv.com>

On Saturday 24 January 2015 03:09:51 Bob Martin did opine
And Gene did reply:
> in 734904 20150123 225104 Tim Daneliuk <tundra at tundraware.com> wrote:
> >On 01/21/2015 05:55 PM, Chris Angelico wrote:
> >> On Thu, Jan 22, 2015 at 10:37 AM, Tim Daneliuk 
<tundra at tundraware.com> wrote:
> >>> I find these kinds of discussions sort of silly.  Once there is a
> >>> critical mass of installed base, no language EVER dies.
> >> 
> >> Not sure about that. Back in the 1990s, I wrote most of my code in
> >> REXX, either command-line or using a GUI toolkit like VX-REXX.
> >> Where's REXX today? Well, let's see. It's still the native-ish
> >> language of OS/2. Where's OS/2 today? Left behind. REXX has no
> >> Unicode support (it does, however, support DBCS - useful, no?), no
> >> inbuilt networking support (there are third-party TCP/IP socket
> >> libraries for OS/2 REXX, but I don't know that other REXX
> >> implementations have socket services; and that's just basic BSD
> >> sockets, no higher-level protocol handling at all), etc, etc. Sure,
> >> it's not technically dead... but is anyone developing the language
> >> further? I don't think so. Is new REXX code being written? Not a
> >> lot. Yet when OS/2 was more popular, REXX definitely had its
> >> installed base. It was the one obvious scripting language for any
> >> OS/2 program. Languages can definitely die, or at least be so left
> >> behind that they may as well be dead.
> >> 
> >> ChrisA
> >
> >Rexx is still well used on mainframes.
> 
> http://www.oorexx.org/
> 
> I use ooRexx every day, on Linux mostly, but also available on Windows.

Can it run typical AREXX source?  I don't see a single syllable on that 
now 5 year old site indicating any such capability.

Example: Something needs to be synchronized to occur in the first tick of 
the next minute, and has nothing to do until then, so it queries the 
system for the number of ticks remaining in this minute, then puts itself 
to sleep for that long.

Is this possible in ooRexx?

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>
US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS


From python.list at tim.thechases.com  Sat Jan 24 07:23:38 2015
From: python.list at tim.thechases.com (Tim Chase)
Date: Sat, 24 Jan 2015 06:23:38 -0600
Subject: Alternative to multi-line lambdas: Assign-anywhere def statements
In-Reply-To: <CAPTjJmrAQgtauH74dwCzb_-6T09D0dLVkxiGrAxJMp_OOwgS0g@mail.gmail.com>
References: <CAPTjJmrAQgtauH74dwCzb_-6T09D0dLVkxiGrAxJMp_OOwgS0g@mail.gmail.com>
Message-ID: <20150124062338.62d0bbf5@bigbox.christie.dr>

On 2015-01-24 17:28, Chris Angelico wrote:
> but this is hardly generic. There's no convenient way to give an
> argument to a decorator that says "please assign this here", short
> of using some stupid eval hack... is there?
> 
> (Incidentally, for a non-generic dispatch table, a callable dict
> subclass could be pretty clean:
> 
> class DispatchTable(dict):
>     """Self-populating dictionary - use this as a function decorator
> to stuff functions into it."""
>     def __call__(self, func):
>         self[func.__name__] = func
>         return func
> 
> cmd = DispatchTable()
> 
> @cmd
> def foo(*args):
>     print("You asked to foo.")

As best I can tell, your question is "is there a better way to do
dispatch tables without duplicating the storage location while
remaining sufficiently generic?"

The closest I've seen is something like cmd.Cmd does where you have a
class and dispatch methods on it with a certain naming convention
(this prevents odd access to dunder methods).  Akin to your first
example [reordered from your original post]

> cmd = {} # Command dispatch table
> 
> def cmd["foo"](*args):
>     print("You asked to foo.")
> 
> def cmd["bar"](*args):
>     print("There's no wine in the bar.")
> 
> def cmd["asdf"](*args):
>     print("Asdf! Asdf!")

It usually looks something like

  class Dispatcher(object):
    def __getitem__(self, name):
      return getattr(self, "do_" + name)

  class MyExample(Dispatcher):
    def do_hello(self, who):
      print("Hello, %s" % who)
    def do_goodbye(self, who, feeling):
      print("Goodbye, %s. I'm %s to see you go" % (
        who, feeling))

  mydispatch = MyExample()
  mydispatch["hello"]("world")
  mydispatch["goodbye"]("cruel world", "sorry")
  mydispatch["does not exist"]("give me an AttributeError")

The root Dispatcher object can grow helpful methods like

  class Dispatcher(object):
    # ...
    def get_help(self, name):
      return getattr(self, name, "No help for %r" % name)
    def __iter__(self):
      for name in dir(self):
        if name.startswith("do_") and callable(getattr(self, "do_" + name)):
          yield name
  # ...
    def do_hello(self, who):
      "Say hello to a person"
      # ...

  # print out all known methods and their help
  for method in mydispatch:
    print("%s: %s" % (method, mydispatch.get_help(method_name)))

-tkc







From steve+comp.lang.python at pearwood.info  Sat Jan 24 07:43:17 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 24 Jan 2015 23:43:17 +1100
Subject: __bases__ misleading error message
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
Message-ID: <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>

Mario Figueiredo wrote:

> 
> Consider the following code at your REPL of choice
> 
>         class Super:
>             pass

Super is irrelevant here, since it isn't used.

>         class Sub:
>             pass
> 
>         foo = Sub()
> 
>         Sub.__bases__
>         foo.__bases__
> 
> The last statement originates the following error:
> 
>         AttributeError: 'Sub' object has no attribute '__bases__'

It's a bit ambiguous, but the way to read it is to think of object as a
synonym for instance. This is, in my opinion, a Java-ism which is
inappropriate for Python where classes are objects too, but we seem to be
stuck with it.

So we have a Sub instance (object) which has no attribute '__bases__'. This
is no different from:

py> (23).spam
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'int' object has no attribute 'spam'



> Naturally the 'Sub' object has an attribute __bases__. 

Correct, in the sense that classes are objects too. But in the sense of
object=instance, no. Isn't ambiguous terminology wonderful?


> It's the instance 
> that has not. So shouldn't the error read like:
> 
>         AttributeError: 'Sub' instance has no attribute '__bases__', or
>         AttributeError: 'foo' object has no attribute '__bases__'

The first would be nice. The second is impossible: objects may have no name,
one name, or many names, and they do not know what names they are bound to.
So the Sub instance bound to the name 'foo' doesn't know that its name
is 'foo', so it cannot display it in the error message.



-- 
Steven



From python.list at tim.thechases.com  Sat Jan 24 07:47:03 2015
From: python.list at tim.thechases.com (Tim Chase)
Date: Sat, 24 Jan 2015 06:47:03 -0600
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <54c339d7$0$13005$c3e8da3$5496439d@news.astraweb.com>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <CAPTjJmqXLWEkz-KzxWWD4KRkHs4cdC3Z0DKZ8otjqTkytydsmQ@mail.gmail.com>
 <mailman.18018.1421989508.18130.python-list@python.org>
 <54c1e349$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18034.1422019400.18130.python-list@python.org>
 <54c339d7$0$13005$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <20150124064703.1dad85a7@bigbox.christie.dr>

On 2015-01-24 17:21, Steven D'Aprano wrote:
> # Cobra
> def sqroot(i as int) as float
> 
> # Python
> def sqroot(i:int)->float:
> 
> 
> Cobra's use of "as" clashes with Python. In Python, "as" is used for
> name-binding:
> 
> import module as name
> with open('file') as f
> except Exception as e
> 
> but apart from that minor difference, they're virtually identical.

Though given that

 def sqrt(i as int) as float:

is invalid Python syntax (both in the parameter list and as the
return value of the function), the meaning of "as" could be overloaded
in both senses to allow for the Cobra-like syntax.

-tkc




From steve+comp.lang.python at pearwood.info  Sat Jan 24 08:29:42 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 25 Jan 2015 00:29:42 +1100
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
Message-ID: <54c39e48$0$12996$c3e8da3$5496439d@news.astraweb.com>

Mario Figueiredo wrote:

> In article <4b3b498a-c9b0-443d-8514-87ccd8e98f43 at googlegroups.com>,
> rantingrickjohnson at gmail.com says...
>> 
>>     (Example modified for PEP8 compliance ;-)
>> 
>>     @typehint(arg1:str, arg2:int, returns:bool)
>>     def myfunction(arg1, arg2):
>>         return True
>>         
>> Of course "@typehint" could be an extension of the decorator
>> syntax, a keyword, a build-in function or whatever, i don't
>> care.
> 
> I'd rather it'd be a docstring parameter.
> 
> - Decorators are transformation tools. Which type hints are not.

But they can be. Python annotations are available at runtime, they are not
mere declarations for the compiler like in Pascal or C:

py> def spam(x:int, y:float)->float:
...     return x+y
...
py> spam.__annotations__
{'x': <class 'int'>, 'y': <class 'float'>, 'return': <class 'float'>}


They're writable too:

py> def eggs(x, y):
...     return x + y
...
py> eggs.__annotations__ = spam.__annotations__
py> eggs.__annotations__['x']
<class 'int'>


So we can write a transformation tool which adds, modifies or deletes
annotations:

@annotate(x=int, y=float)  # return is a little tricky...
def eggs(x, y):
    return x+y

eggs.__annotations__['x']
# returns int


Except we don't need such a tool. Python 3 already has syntax for it, and it
supports annotating the return result too. Annotation syntax is just
syntactic sugar for a transformation.


> - keywords should be few and used only for language features. Static
> analysis isn't and should never be a language feature. It's an
> extension, perhaps.

I'm not sure if you're making a general observation or one which is specific
to Python. Plenty of languages have static analysis as a language feature.
Are you arguing they are wrong to do so?

In the case of Python, there are no plans for CPython to include static
analysis, or for it to be general language feature. Other implementations,
such as MyPy, and other tools, are intended to perform the analysis, not
the CPython reference implementation.


> - Same with built-in functions... although a case could be made for a
> static analysis package, hmmm.

I'm not sure what you mean here.



> So I'd rather see:
> 
>      def myfunction(arg1, arg2):
>      """
>      Normal docstring.
>      """
>      "@typehint: (str, int) -> bool"
>          return True

By the rules of implicit (compile-time) concatenation of string literals,
that is equivalent to:

def myfunction(arg1, arg2):
    """
    Normal docstring.
    @typehint: (str, int) -> bool"""
    return True

One of the problems with this is that it put the information about
parameters far away from the parameter list itself. Most docstrings are
considerable more than a single line:

py> from random import sample
py> len(sample.__doc__.split('\n'))
16


I consider 16 lines a short docstring! I've written docstrings which are 40
or 50 lines long, so potentially the annotations are almost a full page
away from the function signature.

The usual convention among document generator tools is that parameter
metadata is at the start of the docstring, not the end:

def myfunction(arg1, arg2):
    """
    One line summary.

    @param arg1: str
    @param arg2: int
    @returns bool

    Longer discussion of the function.
    """
    return True

I'm not keen on that, but at least it puts the types close to the function
signature, and it's a defacto standard.


> I removed the arguments names on purpose. They are only necessary on the
> PEP because type hinting is a part of the function header there.
> However, when using a documentation like pattern as above (or as in your
> own example), they can be safely removed, with the added benefit of
> making the syntax simpler.

Only at the cost of making it hard to read. I go to look up a function which
I am unfamiliar with, and find the function signature:

def open(file, mode='r', buffering=-1, encoding=None,
        errors=None, newline=None, closefd=True, opener=None):
    """Open a file.

    blah blah blah blah...
    thirty lines of documentation...


My documentation view shows only the first thirty lines, so I hit the Page
Down key and see:

    blah blah blah blah...
    thirty lines of documentation...
    
I page down again:

    blah blah blah...
    @typehint: (str, str, int, Optional[str], Optional[str], 
                Optional[str], bool, Callable)


Well that's rather less than useful. Which argument is newline again? Number
3 or 4 or 5?

Syntax which appears reasonable with toy examples (one-line docstring, two
arguments) is less reasonable with real-world cases (docstrings can be a
page or more in length, there may be five or a dozen arguments to a
function).


> Alternatively, because dangling strings are always considered
> documentation and completely ignored by the interpreter (PEP 258), one
> could also do:
> 
>      "@typehint: (str, int) -> bool"
>      def myfunction(arg1, arg2):

That's somewhat better, in that at least the hint is close to the function
signature. But it has a lot of disadvantages: it is compile-time only, the
type hints aren't available at runtime. It requires extra complexity to the
parser, so that decorators may be separated from the function by a hint:

@decorate
"@typehint: (str, int) -> bool"
def myfunction(arg1, arg2):


No doubt some people will get them the wrong way around, and the type
checker may silently ignore their hints:

"@typehint: (str, int) -> bool"
@decorate
def myfunction(arg1, arg2):

And others will write:

@decorate
@typehint(str, int) -> bool
def myfunction(arg1, arg2):


and be annoyed or perplexed by the syntax error.

Some syntax will be a bug magnet. This is one.


-- 
Steven



From steve+comp.lang.python at pearwood.info  Sat Jan 24 08:40:15 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 25 Jan 2015 00:40:15 +1100
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <CAPTjJmqXLWEkz-KzxWWD4KRkHs4cdC3Z0DKZ8otjqTkytydsmQ@mail.gmail.com>
 <mailman.18018.1421989508.18130.python-list@python.org>
 <54c1e349$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18034.1422019400.18130.python-list@python.org>
 <54c339d7$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18084.1422103514.18130.python-list@python.org>
Message-ID: <54c3a0c1$0$13013$c3e8da3$5496439d@news.astraweb.com>

Tim Chase wrote:

> On 2015-01-24 17:21, Steven D'Aprano wrote:
>> # Cobra
>> def sqroot(i as int) as float
>> 
>> # Python
>> def sqroot(i:int)->float:
>> 
>> 
>> Cobra's use of "as" clashes with Python. In Python, "as" is used for
>> name-binding:
>> 
>> import module as name
>> with open('file') as f
>> except Exception as e
>> 
>> but apart from that minor difference, they're virtually identical.
> 
> Though given that
> 
>  def sqrt(i as int) as float:
> 
> is invalid Python syntax (both in the parameter list and as the
> return value of the function), the meaning of "as" could be overloaded
> in both senses to allow for the Cobra-like syntax.

OF course it could. But it shouldn't, because "as" already has an
established and consistent meaning: it is used for name binding.

Things which look similar should be similar. "i as int" and "module as name"
look similar, but they are the same syntax for different concepts. "foo as
bar" will sometimes mean that bar is the name bound to foo, and sometimes
it will mean that foo is declared to be type bar. That's messy and
inconsistent and best avoided.



-- 
Steven



From roy at panix.com  Sat Jan 24 09:06:57 2015
From: roy at panix.com (Roy Smith)
Date: Sat, 24 Jan 2015 09:06:57 -0500
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <CAPTjJmqXLWEkz-KzxWWD4KRkHs4cdC3Z0DKZ8otjqTkytydsmQ@mail.gmail.com>
 <mailman.18018.1421989508.18130.python-list@python.org>
 <54c1e349$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18034.1422019400.18130.python-list@python.org>
 <54c339d7$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18084.1422103514.18130.python-list@python.org>
 <54c3a0c1$0$13013$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <roy-9C5340.09062724012015@news.panix.com>

In article <54c3a0c1$0$13013$c3e8da3$5496439d at news.astraweb.com>,
 Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:

> Tim Chase wrote:
> 
> > On 2015-01-24 17:21, Steven D'Aprano wrote:
> >> # Cobra
> >> def sqroot(i as int) as float
> >> 
> >> # Python
> >> def sqroot(i:int)->float:
> >> 
> >> 
> >> Cobra's use of "as" clashes with Python. In Python, "as" is used for
> >> name-binding:
> >> 
> >> import module as name
> >> with open('file') as f
> >> except Exception as e
> >> 
> >> but apart from that minor difference, they're virtually identical.
> > 
> > Though given that
> > 
> >  def sqrt(i as int) as float:
> > 
> > is invalid Python syntax (both in the parameter list and as the
> > return value of the function), the meaning of "as" could be overloaded
> > in both senses to allow for the Cobra-like syntax.
> 
> OF course it could. But it shouldn't, because "as" already has an
> established and consistent meaning: it is used for name binding.
> 
> Things which look similar should be similar. "i as int" and "module as name"
> look similar, but they are the same syntax for different concepts. "foo as
> bar" will sometimes mean that bar is the name bound to foo, and sometimes
> it will mean that foo is declared to be type bar. That's messy and
> inconsistent and best avoided.

On the other hand, flip it around and say:

def sqrt(int as i):

and now the name-binding semantics works.  "The first argument is an 
int, which is bound to the name i".  Not sure how you would apply that 
to the return type, though.


From bob.martin at excite.com  Sat Jan 24 09:09:15 2015
From: bob.martin at excite.com (Bob Martin)
Date: Sat, 24 Jan 2015 14:09:15 GMT
Subject: What killed Smalltalk could kill Python
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18078.1422087420.18130.python-list@python.org>
Message-ID: <cihncbFbntbU1@mid.individual.net>

in 734937 20150124 081658 Chris Angelico <rosuav at gmail.com> wrote:
>On Sat, Jan 24, 2015 at 7:09 PM, Bob Martin <bob.martin at excite.com> wrote:
>> http://www.oorexx.org/
>>
>> I use ooRexx every day, on Linux mostly, but also available on Windows.
>
>So the question really is: Why that, as opposed to some other
>language? Can you say, in one sentence, what ooRexx has that other
>languages don't have?

I was a mainframe programmer from 1963 to 2003 and used Rexx from its 
beginnings in 1981; also on OS/2 and Linux. 
I've never found anything to replace it, and it's the most readable language.
 


From marfig at gmail.com  Sat Jan 24 09:09:40 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sat, 24 Jan 2015 15:09:40 +0100
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
 <54c39e48$0$12996$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <MPG.2f2dc5f7f281009b98968f@nntp.aioe.org>

In article <54c39e48$0$12996$c3e8da3$5496439d at news.astraweb.com>, 
steve+comp.lang.python at pearwood.info says...
> 
> I'm not sure if you're making a general observation or one which is
> specific
> to Python. Plenty of languages have static analysis as a language feature.
> Are you arguing they are wrong to do so?
> 

No. I'm arguing static analysis should not consume a programming 
language keyword space. Static analysis is just a development tool.

> 
> def myfunction(arg1, arg2):
>     """
>     Normal docstring.
>     @typehint: (str, int) -> bool"""
>     return True
> 
> One of the problems with this is that it put the information about
> parameters far away from the parameter list itself.

Then move it to the first line of the docstring...


> > I removed the arguments names on purpose. They are only necessary on 
> > the
> > PEP because type hinting is a part of the function header there.
> > However, when using a documentation like pattern as above (or as in your
> > own example), they can be safely removed, with the added benefit of
> > making the syntax simpler.
> 
> Only at the cost of making it hard to read.

If you want the redundancy and a potential source of new bugs by having 
a type hint in a docstring include argument names... You see, there's 
always a downside to everything.

Meanwhile, object names have nothing to do with type analsys, which 
makes arguments names rather irrelevant in the context of static 
analysis. I'd rather promote types than names. Remove names and you 
will.

> > 
> >      "@typehint: (str, int) -> bool"
> >      def myfunction(arg1, arg2):
> 
> That's somewhat better, in that at least the hint is close to the function
> signature. But it has a lot of disadvantages: it is compile-time only, the
> type hints aren't available at runtime.

It's static analysis. You don't need runtime execution.

> It requires extra complexity to the
> parser, so that decorators may be separated from the function by a hint:
> 
> @decorate
> "@typehint: (str, int) -> bool"
> def myfunction(arg1, arg2):
> 
> No doubt some people will get them the wrong way around, and the type
> checker may silently ignore their hints:
> 
> "@typehint: (str, int) -> bool"
> @decorate
> def myfunction(arg1, arg2):
> 
> And others will write:
> 
> @decorate
> @typehint(str, int) -> bool
> def myfunction(arg1, arg2):
> 

That seems like you are fishing. What is exactly your point? That people 
will not be able to understand the rules of type hinting? And that 
somehow is going to be an universal problem?

> Some syntax will be a bug magnet. This is one.

You think?


From marco.buttu at gmail.com  Sat Jan 24 09:12:36 2015
From: marco.buttu at gmail.com (Marco Buttu)
Date: Sat, 24 Jan 2015 15:12:36 +0100
Subject: __bases__ misleading error message
In-Reply-To: <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <54C3A854.6000709@oa-cagliari.inaf.it>

On 24/01/2015 13:43, Steven D'Aprano wrote:

> Mario Figueiredo wrote:
>> >         class Sub:
>> >             pass
>> >
>> >         foo = Sub()
>> >
>> >         Sub.__bases__
>> >         foo.__bases__
>> >
>> >The last statement originates the following error:
>> >
>> >         AttributeError: 'Sub' object has no attribute '__bases__'
> It's a bit ambiguous, but the way to read it is to think of object as a
> synonym for instance.

In my opinion it is not ambiguous, because as you say in Python an 
object is a synonym for instance. We can say in Python an object is an 
instance of the type object, that's all. And that's why everything is an 
object in Python:

 >>> isisntace(foo, object) # For every foo
True

So a class (a type) is an instance too (of its metaclass). Therefore, 
the message says that the Sub instance has no attribute '__bases__'. In 
fact the Sub object (instance) has no attribute '__bases__' because it 
is not an instance of type, and only types (classes) have this attribute.

That means in Python sometimes, like the OP one, we have to underline 
the difference between types (classes) and non-types (non-classes) 
objects, instead of between objects and classes. The problem is in the 
Python documentation there is also a bit of confusion about this... In 
the descriptor howto: "The details of invocation depend on whether obj 
is an object or a class" :/

-- 
Marco Buttu

INAF-Osservatorio Astronomico di Cagliari
Via della Scienza n. 5, 09047 Selargius (CA)
Phone: 070 711 80 217
Email: mbuttu at oa-cagliari.inaf.it



From bob.martin at excite.com  Sat Jan 24 09:14:18 2015
From: bob.martin at excite.com (Bob Martin)
Date: Sat, 24 Jan 2015 14:14:18 GMT
Subject: What killed Smalltalk could kill Python
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18082.1422099271.18130.python-list@python.org>
Message-ID: <cihnlqFbntbU2@mid.individual.net>

in 734949 20150124 113420 Gene Heskett <gheskett at wdtv.com> wrote:
>On Saturday 24 January 2015 03:09:51 Bob Martin did opine
>And Gene did reply:
>> in 734904 20150123 225104 Tim Daneliuk <tundra at tundraware.com> wrote:
>> >On 01/21/2015 05:55 PM, Chris Angelico wrote:
>> >> On Thu, Jan 22, 2015 at 10:37 AM, Tim Daneliuk
><tundra at tundraware.com> wrote:
>> >>> I find these kinds of discussions sort of silly.  Once there is a
>> >>> critical mass of installed base, no language EVER dies.
>> >>
>> >> Not sure about that. Back in the 1990s, I wrote most of my code in
>> >> REXX, either command-line or using a GUI toolkit like VX-REXX.
>> >> Where's REXX today? Well, let's see. It's still the native-ish
>> >> language of OS/2. Where's OS/2 today? Left behind. REXX has no
>> >> Unicode support (it does, however, support DBCS - useful, no?), no
>> >> inbuilt networking support (there are third-party TCP/IP socket
>> >> libraries for OS/2 REXX, but I don't know that other REXX
>> >> implementations have socket services; and that's just basic BSD
>> >> sockets, no higher-level protocol handling at all), etc, etc. Sure,
>> >> it's not technically dead... but is anyone developing the language
>> >> further? I don't think so. Is new REXX code being written? Not a
>> >> lot. Yet when OS/2 was more popular, REXX definitely had its
>> >> installed base. It was the one obvious scripting language for any
>> >> OS/2 program. Languages can definitely die, or at least be so left
>> >> behind that they may as well be dead.
>> >>
>> >> ChrisA
>> >
>> >Rexx is still well used on mainframes.
>>
>> http://www.oorexx.org/
>>
>> I use ooRexx every day, on Linux mostly, but also available on Windows.
>
>Can it run typical AREXX source?  I don't see a single syllable on that
>now 5 year old site indicating any such capability.

AREXX is based on Mike Cowlishaw's original mainframe Rexx so I doubt there
was much difference.
ooRexx is compatible with Rexx and is actively maintained by current & past IBMers.
A new version is coming soon.

>
>Example: Something needs to be synchronized to occur in the first tick of
>the next minute, and has nothing to do until then, so it queries the
>system for the number of ticks remaining in this minute, then puts itself
>to sleep for that long.
>
>Is this possible in ooRexx?

Yes, you'll find all you need in the utility classes at
http://www.oorexx.org/docs/rexxref/book1.htm



From marco.buttu at gmail.com  Sat Jan 24 09:25:35 2015
From: marco.buttu at gmail.com (Marco Buttu)
Date: Sat, 24 Jan 2015 15:25:35 +0100
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <MPG.2f2dc5f7f281009b98968f@nntp.aioe.org>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
 <54c39e48$0$12996$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2dc5f7f281009b98968f@nntp.aioe.org>
Message-ID: <54C3AB5F.1060200@oa-cagliari.inaf.it>

On 24/01/2015 15:09, Mario Figueiredo wrote:

>> >def myfunction(arg1, arg2):
>> >     """
>> >     Normal docstring.
>> >     @typehint: (str, int) -> bool"""
>> >     return True
>> >
>> >One of the problems with this is that it put the information about
>> >parameters far away from the parameter list itself.
> Then move it to the first line of the docstring...

I like this idea, because nevertheless the type hinting is optional, the 
mypy syntax affects every Python programmer who has to read other code 
that will use this syntax, while the docstring one does not.

-- 
Marco Buttu

INAF-Osservatorio Astronomico di Cagliari
Via della Scienza n. 5, 09047 Selargius (CA)
Phone: 070 711 80 217
Email: mbuttu at oa-cagliari.inaf.it



From marfig at gmail.com  Sat Jan 24 09:32:55 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sat, 24 Jan 2015 15:32:55 +0100
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
 <54c39e48$0$12996$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2dc5f7f281009b98968f@nntp.aioe.org>
Message-ID: <MPG.2f2dcb7d6f032c56989690@nntp.aioe.org>

In article <MPG.2f2dc5f7f281009b98968f at nntp.aioe.org>, marfig at gmail.com 
says...
> 
> In article <54c39e48$0$12996$c3e8da3$5496439d at news.astraweb.com>, 
> steve+comp.lang.python at pearwood.info says...
> > 
> > def myfunction(arg1, arg2):
> >     """
> >     Normal docstring.
> >     @typehint: (str, int) -> bool"""
> >     return True
> > 
> > One of the problems with this is that it put the information about
> > parameters far away from the parameter list itself.
> 
> Then move it to the first line of the docstring...

Here's a more concrete example of what can be done in the docstring, 
taken from one of the examples in PEP 484. (Remember, we just moving the 
whole structure of type hinting to a new docstring parameter, instead of 
having it in the function header.

"PEP 484"
def handle_employees(e: Union[Employee, Sequence[Employee]]):
    if isinstance(e, Employee):
        e = [e]
    ...

"My proposal:"

def handle_employees(e):
    """
    Handles an employee or list of employees by firing the whole
    bunch of 'em lazy sods.

    @hint: Union[Employee, Sequence[Employee]]
    :param e: A single employee or a list of employees 
    :return: None
    """
    if isinstance(e, Employee):
        e = [e]
    ...

If you find that hard to read or feel you still can't match type hints 
to their respective arguments in the function header... then, yeah, 
there's no convincing you.

My only pet peevee with this is that @int: becomes part of __doc__ and 
some pundits may argue against that inclusion. I don't have a real 
answer to that problem. I personally see that as a minor consequence, 
but can understand static analysis isn't really a part of a function 
documentation.


From breamoreboy at yahoo.co.uk  Sat Jan 24 09:40:20 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 24 Jan 2015 14:40:20 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <CAPTjJmqk52tuzXcm=Cq+AGZxihu6YyNhR=YZ0NuyTJhhf8RXqQ@mail.gmail.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <m9rfg8$vuv$1@ger.gmane.org>
 <mailman.17984.1421952098.18130.python-list@python.org>
 <MPG.2f2b697d288c74b2989685@nntp.aioe.org>
 <mailman.17990.1421956437.18130.python-list@python.org>
 <MPG.2f2b75c814639267989686@nntp.aioe.org>
 <mailman.18006.1421973642.18130.python-list@python.org>
 <54c1c5c1$0$13001$c3e8da3$5496439d@news.astraweb.com>
 <m9uqr0$41g$1@ger.gmane.org>
 <CAPTjJmqk52tuzXcm=Cq+AGZxihu6YyNhR=YZ0NuyTJhhf8RXqQ@mail.gmail.com>
Message-ID: <ma0asr$8v6$1@ger.gmane.org>

On 24/01/2015 01:15, Chris Angelico wrote:
> On Sat, Jan 24, 2015 at 12:00 PM, Sturla Molden <sturla.molden at gmail.com> wrote:
>> But without a thriving community, Python has no value to me.
>>
>> If we add type hinting, then that community will go away, because other
>> languages are better options.
>>
>> Who will win? Julia? Ruby? They are all waiting in line for Python to fail.
>> Then Python will be like Smalltalk.
>
> The Python community that was already killed by Python 3.0? Funny, it
> seems to be a bit more resilient than the naysayers would have us
> believe.
>
> ChrisA
>

That's unfair as there was a distinct fall back position, what with 
Python 2.8 and RickedPython(3).  Is anybody aware of just how far 
advanced these projects are?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From breamoreboy at yahoo.co.uk  Sat Jan 24 09:42:18 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 24 Jan 2015 14:42:18 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <54c33d20$0$13011$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17973.1421939508.18130.python-list@python.org>
 <54c2299d$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18029.1422013105.18130.python-list@python.org>
 <54c33d20$0$13011$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <ma0b0h$8v6$2@ger.gmane.org>

On 24/01/2015 06:35, Steven D'Aprano wrote:
> Obviously I'm not a fanatic. If I'm working out my share of a $37 meal split
> three ways, I just do 37/3 the same as anyone else :-)
>

Always rounding down I take it? :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From vinay_sajip at yahoo.co.uk  Sat Jan 24 10:35:48 2015
From: vinay_sajip at yahoo.co.uk (Vinay Sajip)
Date: Sat, 24 Jan 2015 15:35:48 +0000 (UTC)
Subject: ANN: Version 0.1.4 of sarge (a subprocess wrapper library) has been
 released.
Message-ID: <1016598375.687725.1422113748451.JavaMail.yahoo@mail.yahoo.com>

Version 0.1.4 of Sarge, a cross-platform library which wraps the subprocess
module in the standard library, has been released.

What changed?
-------------

- Fixed issue #20: Now runs a pipeline in a separate thread if async.

- Fixed issue #21: The command line isn't parsed if shell=True is specified.

- Added Coveralls to Travis configuration.

- Tests added to cover added functionality and reported issues.

- Numerous documentation updates.

What does Sarge do?
-------------------

Sarge tries to make interfacing with external programs from your
Python applications easier than just using subprocess alone.

Sarge offers the following features:

* A simple way to run command lines which allows a rich subset of Bash-
style shell command syntax, but parsed and run by sarge so that you
can run on Windows without cygwin (subject to having those commands
available):

>>> from sarge import capture_stdout
>>> p = capture_stdout('echo foo | cat; echo bar')
>>> for line in p.stdout: print(repr(line))
...
'foo\n'
'bar\n'

* The ability to format shell commands with placeholders, such that
variables are quoted to prevent shell injection attacks.

* The ability to capture output streams without requiring you to
program your own threads. You just use a Capture object and then you
can read from it as and when you want.

* The ability to look for patterns in captured output and to interact
accordingly with the child process.

Advantages over subprocess
---------------------------

Sarge offers the following benefits compared to using subprocess:

* The API is very simple.

* It's easier to use command pipelines - using subprocess out of the
box often leads to deadlocks because pipe buffers get filled up.

* It would be nice to use Bash-style pipe syntax on Windows, but
Windows shells don't support some of the syntax which is useful, like
&&, ||, |& and so on. Sarge gives you that functionality on Windows,
without cygwin.

* Sometimes, subprocess.Popen.communicate() is not flexible enough for
one's needs - for example, when one needs to process output a line at
a time without buffering the entire output in memory.

* It's desirable to avoid shell injection problems by having the
ability to quote command arguments safely.

* subprocess allows you to let stderr be the same as stdout, but not
the other way around - and sometimes, you need to do that.

Python version and platform compatibility
-----------------------------------------

Sarge is intended to be used on any Python version >= 2.6 and is
tested on Python versions 2.6, 2.7, 3.1, 3.2, 3.3 and 3.4 on Linux,
Windows, and Mac OS X (not all versions are tested on all platforms,
but sarge is expected to work correctly on all these versions on all
these platforms).

Finding out more
----------------

You can read the documentation at

http://sarge.readthedocs.org/

There's a lot more information, with examples, than I can put into
this post.

You can install Sarge using "pip install sarge" to try it out. The
project is hosted on BitBucket at

https://bitbucket.org/vinay.sajip/sarge/

And you can leave feedback on the issue tracker there.

I hope you find Sarge useful!

Regards,

Vinay Sajip


From steve+comp.lang.python at pearwood.info  Sat Jan 24 11:00:49 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 25 Jan 2015 03:00:49 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17973.1421939508.18130.python-list@python.org>
 <54c2299d$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18029.1422013105.18130.python-list@python.org>
 <54c33d20$0$13011$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18086.1422110705.18130.python-list@python.org>
Message-ID: <54c3c1b1$0$13011$c3e8da3$5496439d@news.astraweb.com>

Mark Lawrence wrote:

> On 24/01/2015 06:35, Steven D'Aprano wrote:
>> Obviously I'm not a fanatic. If I'm working out my share of a $37 meal
>> split three ways, I just do 37/3 the same as anyone else :-)
>>
> 
> Always rounding down I take it? :)

I'm hurt. I have a maths degree, I know how to do division:

  _____
3| 37


3 goes into 3 once, and 3 goes into 7 twice with one remainder. So the
answer is 12 and 1/3.



-- 
Steven



From steve+comp.lang.python at pearwood.info  Sat Jan 24 11:05:33 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 25 Jan 2015 03:05:33 +1100
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
 <54c39e48$0$12996$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2dc5f7f281009b98968f@nntp.aioe.org>
Message-ID: <54c3c2ce$0$13011$c3e8da3$5496439d@news.astraweb.com>

Mario Figueiredo wrote:

> In article <54c39e48$0$12996$c3e8da3$5496439d at news.astraweb.com>,
> steve+comp.lang.python at pearwood.info says...
>> 
>> I'm not sure if you're making a general observation or one which is
>> specific
>> to Python. Plenty of languages have static analysis as a language
>> feature. Are you arguing they are wrong to do so?
>> 
> 
> No. I'm arguing static analysis should not consume a programming
> language keyword space. Static analysis is just a development tool.

Hmmm. I don't see how that could possible work in practice. Let's take C
syntax for example:

int i;

declares i to be an int. How is this supposed to work without making int a
reserved word? Likewise for Pascal:

i: Integer;

In Python, built-in functions aren't reserved words, but we surely don't
expect a lexical type-checker to evaluate arbitrary code in order to check
whether int has been shadowed:

import random
if random.random() < 0.5:
    int = str

def spam(n:int):
    """Or if you prefer docstrings:
    @param n: int
    """

Even though int is not actually reserved, the type-checker is permitted to
behave as if it were, and it is difficult to see how it could possibly work
in practice if it did not behave that way.

At least it is difficult for me.


>> def myfunction(arg1, arg2):
>>     """
>>     Normal docstring.
>>     @typehint: (str, int) -> bool"""
>>     return True
>> 
>> One of the problems with this is that it put the information about
>> parameters far away from the parameter list itself.
> 
> Then move it to the first line of the docstring...

Which is close to the current convention used by document generators.


>> > I removed the arguments names on purpose. They are only necessary on
>> > the
>> > PEP because type hinting is a part of the function header there.
>> > However, when using a documentation like pattern as above (or as in
>> > your own example), they can be safely removed, with the added benefit
>> > of making the syntax simpler.
>> 
>> Only at the cost of making it hard to read.
> 
> If you want the redundancy and a potential source of new bugs by having
> a type hint in a docstring include argument names... You see, there's
> always a downside to everything.

True, true.

But you can't really avoid duplicating the name in the documentation, just
as you can't avoid duplicating the name in the body of the function. How
can you talk about the parameter if you don't refer to it by name? Such
unavoidable duplication of names is not what most people call "redundancy".


> Meanwhile, object names have nothing to do with type analsys, which
> makes arguments names rather irrelevant in the context of static
> analysis. I'd rather promote types than names. Remove names and you
> will.

How can type analyse avoid dealing with names?

def function(arg: int):
    x = arg + 1
    arg.append(None)


How does the type checker know that "x = arg + 1" is legal, but arg.append
is not? It has to know that since arg has not been rebinded yet, arg is an
int, not a list. It cannot do that unless it knows the name arg.

Type analysis has to deal with more than *just* names. Ideally, it should be
able to infer the type of a whole expression. But it *must* be able to deal
with names -- it would be a pretty poor type-checker that couldn't warn
about this:

    n = 1
    n.sort()


>> >      "@typehint: (str, int) -> bool"
>> >      def myfunction(arg1, arg2):
>> 
>> That's somewhat better, in that at least the hint is close to the
>> function signature. But it has a lot of disadvantages: it is compile-time
>> only, the type hints aren't available at runtime.
> 
> It's static analysis. You don't need runtime execution.

You don't "need" it, but Python has it, so that's what any alternative has
to target. If an alternative fails to met that target, that doesn't
necessarily rule the alternative out, but it is a point against it.

If you want to talk about programming languages in their full generality,
please say so, otherwise I'll assume you're referring to Python. Python
offers rich and powerful introspection abilities, and annotations are
available at runtime, which enables runtime access to the type hints. Any
alternative which does not offer that same runtime introspection is missing
an important piece of functionality.


>> It requires extra complexity to the
>> parser, so that decorators may be separated from the function by a hint:
>> 
>> @decorate
>> "@typehint: (str, int) -> bool"
>> def myfunction(arg1, arg2):
>> 
>> No doubt some people will get them the wrong way around, and the type
>> checker may silently ignore their hints:
>> 
>> "@typehint: (str, int) -> bool"
>> @decorate
>> def myfunction(arg1, arg2):
>> 
>> And others will write:
>> 
>> @decorate
>> @typehint(str, int) -> bool
>> def myfunction(arg1, arg2):
>> 
> 
> That seems like you are fishing. What is exactly your point? That people
> will not be able to understand the rules of type hinting?

No. My point was in the next sentence of my post:

"Some syntax will be a bug magnet. This is one."

I believe that your suggestion of a magic string that looks like a decorator
but isn't would be a bug magnet. You have no help from the compiler. If you
get the syntax of an annotation wrong, you get a syntax error:

py> def spam(x int):
  File "<stdin>", line 1
    def spam(x int):
                 ^
SyntaxError: invalid syntax


but if you get one of your magic strings wrong, nothing happens because it's
just a string and the compiler ignores it. The type-checker, on the other
hand, is caught between two bad alternatives:

- complain about every string it doesn't know how to parse, which 
  will annoy anyone who uses bare strings for any other purpose; or

- silently ignore any such string with an error.

Both alternatives are bad. There is no good way to deal with this, either
annoy the user with false positives, or fail silently. 

Not all alternatives are equally good. There are at least five choices for
where to put type hints/declarations:

- in the function signature (annotations);
- in the docstring;
- applied using a decorator;
- using a specially formatted string (other than the docstring);
- using a stub file.

These are not equally as good, and the choice between them is not merely a
matter of personal preference of what looks nicer. There is about 60 years
worth of prior art on type declarations, going back to Fortran in the
1950s, and we can be certain that putting the type declaration in the
signature is the least likely to go wrong. We may need (e.g.) stub files as
a fallback for when we can't use the function signature, but that doesn't
mean we should forgo the best solution when it is available.


> And that 
> somehow is going to be an universal problem?
> 
>> Some syntax will be a bug magnet. This is one.
> 
> You think?

Yes I do.



-- 
Steven



From rosuav at gmail.com  Sat Jan 24 11:27:40 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 25 Jan 2015 03:27:40 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <54c3c1b1$0$13011$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17973.1421939508.18130.python-list@python.org>
 <54c2299d$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18029.1422013105.18130.python-list@python.org>
 <54c33d20$0$13011$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18086.1422110705.18130.python-list@python.org>
 <54c3c1b1$0$13011$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmqE0DLvdZgam3eE=p_BbB52ba0+DJnmJ1M6NQ-VeDTwEA@mail.gmail.com>

On Sun, Jan 25, 2015 at 3:00 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Mark Lawrence wrote:
>
>> On 24/01/2015 06:35, Steven D'Aprano wrote:
>>> Obviously I'm not a fanatic. If I'm working out my share of a $37 meal
>>> split three ways, I just do 37/3 the same as anyone else :-)
>>>
>>
>> Always rounding down I take it? :)
>
> I'm hurt. I have a maths degree, I know how to do division:
>
>   _____
> 3| 37
>
>
> 3 goes into 3 once, and 3 goes into 7 twice with one remainder. So the
> answer is 12 and 1/3.

I'm not sure whereabouts you are, but I don't have a $1/3 coin in my
pocket most of the time. Mark probably doesn't have many ?1/3 coins
either. So... rounding up or down? :)

ChrisA


From droolz202 at googlemail.com  Sat Jan 24 11:32:23 2015
From: droolz202 at googlemail.com (Jules Stevenson)
Date: Sat, 24 Jan 2015 16:32:23 +0000
Subject: pysftp connection not sending files, hanging on 'put'
Message-ID: <CAJHG2AR6PF6rbBQS5o+6J=94gUn1yyzwRuwzDe4f_xXCG7=YYA@mail.gmail.com>

Hi List,

I'm trying to send some files via pysftp, authentication seems fine, but
actually putting the file results in it hanging, doing nothing. The files
are small (<200kb) so I don't believe it's an upload issue (internet access
is fine). Eventually the connection times out.

Code:

if os.listdir(ftp_path):# only do if files are there
with pysftp.Connection(FTP_SERVER,

port=2222

username=FTP_USER,

private_key=FTP_SSH_PRIVATE_KEY_PATH

) as sftp:

with sftp.cd(FTP_REMOTE_FOLDER):

for f in os.listdir(ftp_path):

if os.path.isfile(os.path.join(ftp_path,f)) :

# upload image to server

self.log.info("HB FTP, Start upload: "+f)

print(ftp_path+"\\"+f)

sftp.put(os.path.join(ftp_path,f))

self.log.info("HB FTP, Finished Upload: "+f)


Logging output here:

FSW_COMMS paramiko.transport 01/24/2015 04:23:58 PM: INFO: Authentication
(publickey) successful!
FSW_COMMS paramiko.transport 01/24/2015 04:23:58 PM: DEBUG: [chan 1] Max
packet in: 32768 bytes
FSW_COMMS paramiko.transport 01/24/2015 04:23:58 PM: DEBUG: [chan 1] Max
packet out: 0 bytes
FSW_COMMS paramiko.transport 01/24/2015 04:23:58 PM: DEBUG: Secsh channel 1
opened.
FSW_COMMS paramiko.transport 01/24/2015 04:23:58 PM: DEBUG: [chan 1] Sesch
channel 1 request ok
FSW_COMMS paramiko.transport.sftp 01/24/2015 04:23:58 PM: INFO: [chan 1]
Opened sftp connection (server version 3)
FSW_COMMS paramiko.transport.sftp 01/24/2015 04:23:58 PM: DEBUG: [chan 1]
normalize('.')
FSW_COMMS paramiko.transport.sftp 01/24/2015 04:23:58 PM: DEBUG: [chan 1]
stat('files')
FSW_COMMS paramiko.transport.sftp 01/24/2015 04:23:58 PM: DEBUG: [chan 1]
normalize('files')
FSW_COMMS root 01/24/2015 04:23:58 PM: INFO: HB FTP, Start upload:
2015-01-17-19-37-07.jpg
D:\FSW\ftp\2015-01-17-19-37-07.jpg
FSW_COMMS paramiko.transport.sftp 01/24/2015 04:23:58 PM: DEBUG: [chan 1]
open('/files/2015-01-17-19-37-07.jpg', 'wb')
FSW_COMMS paramiko.transport.sftp 01/24/2015 04:23:58 PM: DEBUG: [chan 1]
open('/files/2015-01-17-19-37-07.jpg', 'wb') ->
34613039393262343666383036653839

Any help much appreciated,

Jules
-------------- next part --------------
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From rantingrickjohnson at gmail.com  Sat Jan 24 11:41:55 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Sat, 24 Jan 2015 08:41:55 -0800 (PST)
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <54c39e48$0$12996$c3e8da3$5496439d@news.astraweb.com>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
 <54c39e48$0$12996$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <7db16477-1dd6-4f93-adfe-54f7b7a690b2@googlegroups.com>

On Saturday, January 24, 2015 at 7:30:02 AM UTC-6, Steven D'Aprano wrote:
> [...] It requires extra complexity to the parser, so that
> decorators may be separated from the function by a hint:
> 
> @decorate
> "@typehint: (str, int) -> bool"
> def myfunction(arg1, arg2):
> 
> No doubt some people will get them the wrong way around,
> and the type checker may silently ignore their hints:
> 
> "@typehint: (str, int) -> bool"
> @decorate
> def myfunction(arg1, arg2):
> 
> And others will write:
> 
> @decorate
> @typehint(str, int) -> bool
> def myfunction(arg1, arg2):
> 
> 
> and be annoyed or perplexed by the syntax error.
> 
> Some syntax will be a bug magnet. This is one.

Your argument is weak here. If the interpreter cannot
distinguish between "@typehint ..." and "@ ..." then those
who defined the logic need to go back to CS-101. Secondly,
why set *ANY* rules as to the order of typehints -vs-
decorators? Who cares about the "syntactical order", when
they can be parsed and then applied in *ANY* order.
Syntactical order need not *ALWAYS* be significant. In fact,
in this case, syntactic ordering rules are superfluously 
onerous on the human.

And that is how you kill two birds with one stone.




From steve+comp.lang.python at pearwood.info  Sat Jan 24 12:26:39 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 25 Jan 2015 04:26:39 +1100
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
 <54c39e48$0$12996$c3e8da3$5496439d@news.astraweb.com>
 <7db16477-1dd6-4f93-adfe-54f7b7a690b2@googlegroups.com>
Message-ID: <54c3d5d0$0$12977$c3e8da3$5496439d@news.astraweb.com>

Rick Johnson wrote:

> On Saturday, January 24, 2015 at 7:30:02 AM UTC-6, Steven D'Aprano wrote:
>> [...] It requires extra complexity to the parser, so that
>> decorators may be separated from the function by a hint:
>> 
>> @decorate
>> "@typehint: (str, int) -> bool"
>> def myfunction(arg1, arg2):
>> 
>> No doubt some people will get them the wrong way around,
>> and the type checker may silently ignore their hints:
>> 
>> "@typehint: (str, int) -> bool"
>> @decorate
>> def myfunction(arg1, arg2):
>> 
>> And others will write:
>> 
>> @decorate
>> @typehint(str, int) -> bool
>> def myfunction(arg1, arg2):
>> 
>> 
>> and be annoyed or perplexed by the syntax error.
>> 
>> Some syntax will be a bug magnet. This is one.
> 
> Your argument is weak here. If the interpreter cannot
> distinguish between "@typehint ..." and "@ ..." 

Thank you for demonstrating my point for me.

The difference is not

@typehint(...)
def func(...): 

versus any other decorator, but the STRING:

"@typehint(...)"

being used where a decorator would normally be expected.

If a genius of the degree like Rick can be fooled, what hope do ordinary
mortals have?



-- 
Steven



From steve+comp.lang.python at pearwood.info  Sat Jan 24 12:31:03 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 25 Jan 2015 04:31:03 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17973.1421939508.18130.python-list@python.org>
 <54c2299d$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18029.1422013105.18130.python-list@python.org>
 <54c33d20$0$13011$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18086.1422110705.18130.python-list@python.org>
 <54c3c1b1$0$13011$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18088.1422116868.18130.python-list@python.org>
Message-ID: <54c3d6d8$0$12988$c3e8da3$5496439d@news.astraweb.com>

Chris Angelico wrote:

> On Sun, Jan 25, 2015 at 3:00 AM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> Mark Lawrence wrote:
>>
>>> On 24/01/2015 06:35, Steven D'Aprano wrote:
>>>> Obviously I'm not a fanatic. If I'm working out my share of a $37 meal
>>>> split three ways, I just do 37/3 the same as anyone else :-)
>>>>
>>>
>>> Always rounding down I take it? :)
>>
>> I'm hurt. I have a maths degree, I know how to do division:
>>
>>   _____
>> 3| 37
>>
>>
>> 3 goes into 3 once, and 3 goes into 7 twice with one remainder. So the
>> answer is 12 and 1/3.
> 
> I'm not sure whereabouts you are, but I don't have a $1/3 coin in my
> pocket most of the time. Mark probably doesn't have many ?1/3 coins
> either. So... rounding up or down? :)

I'm right here, in front of my computer. Where are you?

Of course we don't have $1/3 dollar coins, but I do have a pair of tin-snips
and can easily cut a $1 coin into three equal pieces.

Either that, or make up change with 20?, 10? and 5? (we practice
round-to-nearest-5-cents here).



-- 
Steven



From breamoreboy at yahoo.co.uk  Sat Jan 24 12:36:06 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 24 Jan 2015 17:36:06 +0000
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <54c3d5d0$0$12977$c3e8da3$5496439d@news.astraweb.com>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
 <54c39e48$0$12996$c3e8da3$5496439d@news.astraweb.com>
 <7db16477-1dd6-4f93-adfe-54f7b7a690b2@googlegroups.com>
 <54c3d5d0$0$12977$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <ma0l6d$f4b$1@ger.gmane.org>

On 24/01/2015 17:26, Steven D'Aprano wrote:
> Rick Johnson wrote:
>
>> On Saturday, January 24, 2015 at 7:30:02 AM UTC-6, Steven D'Aprano wrote:
>>> [...] It requires extra complexity to the parser, so that
>>> decorators may be separated from the function by a hint:
>>>
>>> @decorate
>>> "@typehint: (str, int) -> bool"
>>> def myfunction(arg1, arg2):
>>>
>>> No doubt some people will get them the wrong way around,
>>> and the type checker may silently ignore their hints:
>>>
>>> "@typehint: (str, int) -> bool"
>>> @decorate
>>> def myfunction(arg1, arg2):
>>>
>>> And others will write:
>>>
>>> @decorate
>>> @typehint(str, int) -> bool
>>> def myfunction(arg1, arg2):
>>>
>>>
>>> and be annoyed or perplexed by the syntax error.
>>>
>>> Some syntax will be a bug magnet. This is one.
>>
>> Your argument is weak here. If the interpreter cannot
>> distinguish between "@typehint ..." and "@ ..."
>
> Thank you for demonstrating my point for me.
>
> The difference is not
>
> @typehint(...)
> def func(...):
>
> versus any other decorator, but the STRING:
>
> "@typehint(...)"
>
> being used where a decorator would normally be expected.
>
> If a genius of the degree like Rick can be fooled, what hope do ordinary
> mortals have?
>

So Rick is having a bad hair day, hence using fuzzy logic?  Ooh, that 
one is so bad even my stomach hurts :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From no.email at nospam.invalid  Sat Jan 24 12:37:36 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Sat, 24 Jan 2015 09:37:36 -0800
Subject: Python Sanity Proposal: Type Hinting Solution
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
 <54c39e48$0$12996$c3e8da3$5496439d@news.astraweb.com>
 <7db16477-1dd6-4f93-adfe-54f7b7a690b2@googlegroups.com>
 <54c3d5d0$0$12977$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <87bnlo5bbz.fsf@jester.gateway.sonic.net>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:
> versus any other decorator, but the STRING:
> "@typehint(...)"
> being used where a decorator would normally be expected.

I didn't catch that either.  I think if hints are to go in decorators,
then it's best to extend the decorator mechanism to allow arbitrary
syntax, e.g.

@-typehint (str, int) -> bool

The @- would signify that the typehint function is to receive an AST as
its argument, rather than its callable.  The AST would be the parse tree
for the rest of the line.  Alternatively, it could get the line as a
string and parse it with appropriate functions from the ast module.


From python.list at tim.thechases.com  Sat Jan 24 13:46:55 2015
From: python.list at tim.thechases.com (Tim Chase)
Date: Sat, 24 Jan 2015 12:46:55 -0600
Subject: Python is DOOMED! Again!
In-Reply-To: <54c3d6d8$0$12988$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17973.1421939508.18130.python-list@python.org>
 <54c2299d$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18029.1422013105.18130.python-list@python.org>
 <54c33d20$0$13011$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18086.1422110705.18130.python-list@python.org>
 <54c3c1b1$0$13011$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18088.1422116868.18130.python-list@python.org>
 <54c3d6d8$0$12988$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <20150124124655.1ab58491@bigbox.christie.dr>

On 2015-01-25 04:31, Steven D'Aprano wrote:
> Of course we don't have $1/3 dollar coins, but I do have a pair of
> tin-snips and can easily cut a $1 coin into three equal pieces.

I'm impressed that you can use tin-snips to cut it into exactly three
equal pieces with greater precision than the floating point numbers
that you're cautioning against in Python.  I believe at that point,
you're talking about at least the sub-sub-sub-atomic scale. :-)

-tkc





From ethan at stoneleaf.us  Sat Jan 24 13:56:17 2015
From: ethan at stoneleaf.us (Ethan Furman)
Date: Sat, 24 Jan 2015 10:56:17 -0800
Subject: Alternative to multi-line lambdas: Assign-anywhere def statements
In-Reply-To: <CAPTjJmrAQgtauH74dwCzb_-6T09D0dLVkxiGrAxJMp_OOwgS0g@mail.gmail.com>
References: <CAPTjJmrAQgtauH74dwCzb_-6T09D0dLVkxiGrAxJMp_OOwgS0g@mail.gmail.com>
Message-ID: <54C3EAD1.2010501@stoneleaf.us>

On 01/23/2015 10:28 PM, Chris Angelico wrote:
> 
> cmd = {}
> def command(func):
>     cmd[func.__name__] = func
>     return func
> 
> @command
> def foo(*args):
>     print("You asked to foo.")
> 
> but this is hardly generic. There's no convenient way to give an
> argument to a decorator that says "please assign this here", short of
> using some stupid eval hack... is there?

If the non-generic is what you're concerned about:

# not tested
dispatch_table_a = {}
dispatch_table_b = {}
dispatch_table_c = {}

class dispatch:
  def __init__(self, dispatch_table):
    self.dispatch = dispatch_table
  def __call__(self, func):
    self.dispatch[func.__name__] = func
    return func

@dispatch(dispatch_table_a)
def foo(...):
   pass

--
~Ethan~

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From rustompmody at gmail.com  Sat Jan 24 13:59:37 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Sat, 24 Jan 2015 10:59:37 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <mailman.18091.1422125112.18130.python-list@python.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17973.1421939508.18130.python-list@python.org>
 <54c2299d$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18029.1422013105.18130.python-list@python.org>
 <54c33d20$0$13011$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18086.1422110705.18130.python-list@python.org>
 <54c3c1b1$0$13011$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18088.1422116868.18130.python-list@python.org>
 <54c3d6d8$0$12988$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18091.1422125112.18130.python-list@python.org>
Message-ID: <53cdeb68-90ff-44af-a006-51be3ae3728e@googlegroups.com>

On Sunday, January 25, 2015 at 12:15:28 AM UTC+5:30, Tim Chase wrote:
> On 2015-01-25 04:31, Steven D'Aprano wrote:
> > Of course we don't have $1/3 dollar coins, but I do have a pair of
> > tin-snips and can easily cut a $1 coin into three equal pieces.
> 
> I'm impressed that you can use tin-snips to cut it into exactly three
> equal pieces with greater precision than the floating point numbers
> that you're cautioning against in Python.  I believe at that point,
> you're talking about at least the sub-sub-sub-atomic scale. :-)
> 
> -tkc

With Superman?, you should expect nails that cut electrons precisely

? And other s-starting names


From tjreedy at udel.edu  Sat Jan 24 14:24:41 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Sat, 24 Jan 2015 14:24:41 -0500
Subject: __bases__ misleading error message
In-Reply-To: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
Message-ID: <ma0rhs$iv5$1@ger.gmane.org>

On 1/24/2015 5:16 AM, Mario Figueiredo wrote:
>
> Consider the following code at your REPL of choice

>         class Sub:
>             pass
>
>         foo = Sub()
>
>         Sub.__bases__
>         foo.__bases__
>
> The last statement originates the following error:

This is an anomalous situation.  Normally, if a class has an attribute, 
instances have the same attribute (unless overriden).  But this does not 
matter.

>         AttributeError: 'Sub' object has no attribute '__bases__'

In this message, 'Sub' is an adjective, modifying 'object, not naming 
it.  If you attend to the last line of the traceback

     foo.__bases__

which is an integral part of the total error message, the interpretation 
of this exception message should be clear.

>         AttributeError: 'Sub' instance has no attribute '__bases__',

'Sub' is an instance of 'type', so "'Sub' instance" could also be taken 
to mean the class if the traceback were ignored.  But that would also be 
wrong.  An attribute error for the class, such as "Sub.xyz" give a 
message ending with
...
     Sub.xyz
AttributeError: type object 'Sub' has no attribute 'xyz'

-- 
Terry Jan Reedy



From rosuav at gmail.com  Sat Jan 24 14:55:49 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 25 Jan 2015 06:55:49 +1100
Subject: Alternative to multi-line lambdas: Assign-anywhere def statements
In-Reply-To: <54C3EAD1.2010501@stoneleaf.us>
References: <CAPTjJmrAQgtauH74dwCzb_-6T09D0dLVkxiGrAxJMp_OOwgS0g@mail.gmail.com>
 <54C3EAD1.2010501@stoneleaf.us>
Message-ID: <CAPTjJmohdQbK9_ikh8heaMRbpJ270UW6C1AE2oNVgV_4AoYfQg@mail.gmail.com>

On Sun, Jan 25, 2015 at 5:56 AM, Ethan Furman <ethan at stoneleaf.us> wrote:
> If the non-generic is what you're concerned about:
>
> # not tested
> dispatch_table_a = {}
> dispatch_table_b = {}
> dispatch_table_c = {}
>
> class dispatch:
>   def __init__(self, dispatch_table):
>     self.dispatch = dispatch_table
>   def __call__(self, func):
>     self.dispatch[func.__name__] = func
>     return func
>
> @dispatch(dispatch_table_a)
> def foo(...):
>    pass

That's still only able to assign to a key of a dictionary, using the
function name. There's no way to represent fully arbitrary assignment
in Python - normally, you can assign to a name, an attribute, a
subscripted item, etc. (Augmented assignment is a different beast
altogether, and doesn't really make sense with functions.) There's no
easy way to say "@stash(dispatch_table_a['asdf'])" and have that end
up assigning to exactly that.

ChrisA


From rosuav at gmail.com  Sat Jan 24 14:59:10 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 25 Jan 2015 06:59:10 +1100
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <87bnlo5bbz.fsf@jester.gateway.sonic.net>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <mailman.18017.1421985858.18130.python-list@python.org>
 <5afad59b-5e8c-4821-85cf-9e971c8c7be6@googlegroups.com>
 <MPG.2f2cd54cf9ff377e98968a@nntp.aioe.org>
 <4b3b498a-c9b0-443d-8514-87ccd8e98f43@googlegroups.com>
 <MPG.2f2cecb4624e49c498968c@nntp.aioe.org>
 <54c39e48$0$12996$c3e8da3$5496439d@news.astraweb.com>
 <7db16477-1dd6-4f93-adfe-54f7b7a690b2@googlegroups.com>
 <54c3d5d0$0$12977$c3e8da3$5496439d@news.astraweb.com>
 <87bnlo5bbz.fsf@jester.gateway.sonic.net>
Message-ID: <CAPTjJmruCmpCb+KDRGyVgndk3EN+NP0b0xJ6hvjgkr9gxP+yRA@mail.gmail.com>

On Sun, Jan 25, 2015 at 4:37 AM, Paul Rubin <no.email at nospam.invalid> wrote:
> Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:
>> versus any other decorator, but the STRING:
>> "@typehint(...)"
>> being used where a decorator would normally be expected.
>
> I didn't catch that either.  I think if hints are to go in decorators,
> then it's best to extend the decorator mechanism to allow arbitrary
> syntax, e.g.
>
> @-typehint (str, int) -> bool
>
> The @- would signify that the typehint function is to receive an AST as
> its argument, rather than its callable.  The AST would be the parse tree
> for the rest of the line.  Alternatively, it could get the line as a
> string and parse it with appropriate functions from the ast module.

That seems extremely messy. Why not use what can already be done?
Since you talk about getting the line as a string...

@typehint("(str, int) -> bool")

ChrisA


From jeanpierreda at gmail.com  Sat Jan 24 15:35:03 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Sat, 24 Jan 2015 12:35:03 -0800
Subject: Alternative to multi-line lambdas: Assign-anywhere def statements
In-Reply-To: <CAPTjJmohdQbK9_ikh8heaMRbpJ270UW6C1AE2oNVgV_4AoYfQg@mail.gmail.com>
References: <CAPTjJmrAQgtauH74dwCzb_-6T09D0dLVkxiGrAxJMp_OOwgS0g@mail.gmail.com>
 <54C3EAD1.2010501@stoneleaf.us>
 <CAPTjJmohdQbK9_ikh8heaMRbpJ270UW6C1AE2oNVgV_4AoYfQg@mail.gmail.com>
Message-ID: <CABicbJK61Li3Ce4Sx0B34tS6nAm+Yxf=r8dzwMcs9NoeyNagSw@mail.gmail.com>

On Sat, Jan 24, 2015 at 11:55 AM, Chris Angelico <rosuav at gmail.com> wrote:
> That's still only able to assign to a key of a dictionary, using the
> function name. There's no way to represent fully arbitrary assignment
> in Python - normally, you can assign to a name, an attribute, a
> subscripted item, etc. (Augmented assignment is a different beast
> altogether, and doesn't really make sense with functions.) There's no
> easy way to say "@stash(dispatch_table_a['asdf'])" and have that end
> up assigning to exactly that.

Obviously, nobody will be happy until you can do:

def call(*a, **kw): return lambda f: f(*a, **kw)

@call()
def x, y ():
    yield 1
    yield 2

Actually, maybe not even then.

-- Devin


From python at mrabarnett.plus.com  Sat Jan 24 15:35:41 2015
From: python at mrabarnett.plus.com (MRAB)
Date: Sat, 24 Jan 2015 20:35:41 +0000
Subject: Alternative to multi-line lambdas: Assign-anywhere def statements
In-Reply-To: <CAPTjJmohdQbK9_ikh8heaMRbpJ270UW6C1AE2oNVgV_4AoYfQg@mail.gmail.com>
References: <CAPTjJmrAQgtauH74dwCzb_-6T09D0dLVkxiGrAxJMp_OOwgS0g@mail.gmail.com>
 <54C3EAD1.2010501@stoneleaf.us>
 <CAPTjJmohdQbK9_ikh8heaMRbpJ270UW6C1AE2oNVgV_4AoYfQg@mail.gmail.com>
Message-ID: <54C4021D.9010205@mrabarnett.plus.com>

On 2015-01-24 19:55, Chris Angelico wrote:
> On Sun, Jan 25, 2015 at 5:56 AM, Ethan Furman <ethan at stoneleaf.us> wrote:
>> If the non-generic is what you're concerned about:
>>
>> # not tested
>> dispatch_table_a = {}
>> dispatch_table_b = {}
>> dispatch_table_c = {}
>>
>> class dispatch:
>>   def __init__(self, dispatch_table):
>>     self.dispatch = dispatch_table
>>   def __call__(self, func):
>>     self.dispatch[func.__name__] = func
>>     return func
>>
>> @dispatch(dispatch_table_a)
>> def foo(...):
>>    pass
>
> That's still only able to assign to a key of a dictionary, using the
> function name. There's no way to represent fully arbitrary assignment
> in Python - normally, you can assign to a name, an attribute, a
> subscripted item, etc. (Augmented assignment is a different beast
> altogether, and doesn't really make sense with functions.) There's no
> easy way to say "@stash(dispatch_table_a['asdf'])" and have that end
> up assigning to exactly that.
>
Here's a slight variation on the theme:


class DispatchTable(dict):
     def __call__(self, name):
         def setter(func):
             self[name] = func
             return func
         return setter

command = DispatchTable()

@command("foo")
def _(*args):
     print("You asked to foo.")

@command("bar")
def _(*args):
     print("There's no wine in the bar.")

@command("asdf")
def _(*args):
     print("Asdf! Asdf!")



From fetchinson at googlemail.com  Sat Jan 24 16:01:16 2015
From: fetchinson at googlemail.com (Fetchinson .)
Date: Sat, 24 Jan 2015 22:01:16 +0100
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <54c339d7$0$13005$c3e8da3$5496439d@news.astraweb.com>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <m9sep8$p53$1@ger.gmane.org>
 <CAPTjJmqXLWEkz-KzxWWD4KRkHs4cdC3Z0DKZ8otjqTkytydsmQ@mail.gmail.com>
 <mailman.18018.1421989508.18130.python-list@python.org>
 <54c1e349$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18034.1422019400.18130.python-list@python.org>
 <54c339d7$0$13005$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CADjSo4SyJyVyeccOy=5X7B-FaVp821XiBed42qrOazzrWa7zFA@mail.gmail.com>

On 1/24/15, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
> Fetchinson . wrote:
>
>> On 1/23/15, Steven D'Aprano <steve+comp.lang.python at pearwood.info> wrote:
> [...]
>>> Cobra is especially close to Python-like syntax, and supports unit tests
>>> as well:
>>>
>>>
>>>     def sqroot(i as int) as float
>>>         require
>>>            i > 0
>>>         ensure
>>>            result > 0
>>>         tests
>>>            assert sqroot(25) == 5.0
>>>         body
>>>             ...
>>>
>>> It would be nice to be able to include at least *some* tests right there
>>> in the code rather than in a separate file.
>>
>> I completely agree. A cobra-style type hinting implementation would
>> satisfy everyone who doesn't want to make function signatures noisy
>> (including me) and would also satisfy those who advocate for the
>> actual feature (type hinting) without worrying much about the
>> implementation detail. These two groups are overlapping by the way :)
>
> I don't understand this. Cobra's type-hints are right there in the function
> signature, just like Python annotations.
>
>
> # Cobra
> def sqroot(i as int) as float
>
> # Python
> def sqroot(i:int)->float:

You are right. This aspect is pretty close, what I had in mind, but
expressed myself poorly is this idiom in cobra:

def myfunc( a, b )
    require
        something_about( a, b )
    ensure
        something_about_the_return_value

Yes, type hinting and arbitrary constraints on the function arguments
and return types are different things, but closely related. I'd say it
makes sense to combine the two.

>
> Cobra's use of "as" clashes with Python. In Python, "as" is used for
> name-binding:
>
> import module as name
> with open('file') as f
> except Exception as e
>
> but apart from that minor difference, they're virtually identical.
>
>
>> In any case, I'm pretty sure it was said before, but I can't really
>> find it anywhere, can someone tell me what the rationale is for
>> *function signature* type hinting?
>
> The basic principle is that things which are related should be found
> together. The further away they are, the worse.
>
> Bad:
> - the parameter name and the type are in different files
>
> Better:
> - the parameter name and the type are only a few lines apart
>
> Best:
> - the parameter name and type are right next to each other
>
>
> The closer they are, the easier it is to keep them in sync, and the easier
> it is to see the relevant information at a glance. Putting them together
> also means that you don't have to repeat the argument name:
>
> int n
> def spam(n): ...
>
> versus
>
> def spam(n:int): ...
>
>
> Those reasons are why decorators have the syntax which they do:
>
> @decorator
> def spam(n):
>     do_this()
>     do_that()
>     do_something_else()
>
>
> is better than the old way of using decorators:
>
> def spam(n):
>     do_this()
>     do_that()
>     do_something_else()
>
> spam = decorator(spam)
>
>
> The decorator is only a single line away from the signature, and you don't
> have to repeat the name.
>
>
> We can see this at work in Pascal. Pascal functions have type declarations
> in the signature, and variable declarations between the signature and the
> body:
>
>
> function sqroot(arg: Integer): Real;
>   var
>     x: Integer;
>     y: Real;
>     z: Something_Else;
>   begin
>     do_this(1, 2);
>     do_that(3, 4);
>     do_something_else(5, 6);
>     x := some expression;  { what's the type of x again? }
>   end;
>
>
> The declarations in the signature work very well and are easy to use, but
> the "var" section, not so much. Especially in large functions, the place
> where you declare the variable and its type, and the place where you first
> use it, can be separated by many lines. This makes maintenance and reading
> of the code more difficult.
>
> Newer languages like Java let you declare the variable the first time you
> use it:
>
>     int x = some expression;
>
> and you don't have to search very far to find out what sort of thing x is,
> it is right there.
>
>
>
> --
> Steven
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>


-- 
Psss, psss, put it down! - http://www.cafepress.com/putitdown


From marfig at gmail.com  Sat Jan 24 16:03:22 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sat, 24 Jan 2015 22:03:22 +0100
Subject: __bases__ misleading error message
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <mailman.18093.1422127493.18130.python-list@python.org>
Message-ID: <MPG.2f2e26f46dbc1475989691@nntp.aioe.org>

In article <mailman.18093.1422127493.18130.python-list at python.org>, 
tjreedy at udel.edu says...
> >         AttributeError: 'Sub' object has no attribute '__bases__'
> 
> In this message, 'Sub' is an adjective, modifying 'object, not naming 
> it.  If you attend to the last line of the traceback
> 

My first reaction is to look at 'Sub' as a noun, not an adjective, since 
I know that NAME well on my code as being a noun. Meanwhile I know that 
objects may be qualified (adjectivized) as class objects or instance 
objects. So, I also happen to look at the word "object" as an adjective, 
as Python object semantics would me do.

What you propose is that I look at that phrase the other way around, 
which is kind of contrarian to how you actually use them in your code.


> >         AttributeError: 'Sub' instance has no attribute '__bases__',
> 
> 'Sub' is an instance of 'type', so "'Sub' instance" could also be taken 
> to mean the class if the traceback were ignored.

I agree. Sub instance is still somewhat ambiguous. So, maybe:

     AttributeError: Instance of object 'Sub' has no attribute 
'__bases__'


From marfig at gmail.com  Sat Jan 24 16:14:24 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sat, 24 Jan 2015 22:14:24 +0100
Subject: __bases__ misleading error message
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <MPG.2f2e298c14dbed69989692@nntp.aioe.org>

In article <54c39366$0$13006$c3e8da3$5496439d at news.astraweb.com>, 
steve+comp.lang.python at pearwood.info says...
> >         AttributeError: 'Sub' instance has no attribute '__bases__', 
> >         AttributeError: 'foo' object has no attribute '__bases__'
> 
> The first would be nice. The second is impossible: objects may have no name,
> one name, or many names, and they do not know what names they are bound to.
> So the Sub instance bound to the name 'foo' doesn't know that its name
> is 'foo', so it cannot display it in the error message.

Thanks for the information! :)

But that begs the OT question: How does Python maps names to memory 
addresses in the interpreter?

    "__main__"
    from module import a_name
    y = a_name + 1

How does python interpreter know how to map 'name' to the correct memory 
location, if this __main__ code is only ran after 'module' code?  


From alister.nospam.ware at ntlworld.com  Sat Jan 24 16:14:38 2015
From: alister.nospam.ware at ntlworld.com (alister)
Date: Sat, 24 Jan 2015 21:14:38 GMT
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17973.1421939508.18130.python-list@python.org>
 <54c2299d$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18029.1422013105.18130.python-list@python.org>
 <54c33d20$0$13011$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18086.1422110705.18130.python-list@python.org>
 <54c3c1b1$0$13011$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18088.1422116868.18130.python-list@python.org>
 <54c3d6d8$0$12988$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <2XTww.350898$lm5.140746@fx36.am4>

> 
> Of course we don't have $1/3 dollar coins, but I do have a pair of
> tin-snips and can easily cut a $1 coin into three equal pieces.

wow you have just given a physical demonstration of integer Maths
$1 /3 =$0
as the coin is now worthless ;-)
> 
> Either that, or make up change with 20?, 10? and 5? (we practice
> round-to-nearest-5-cents here).

I suppose if you all pay 35?  it at least gives the waitress a tip.





-- 
Many pages make a thick book.


From auriocus at gmx.de  Sat Jan 24 16:14:50 2015
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Sat, 24 Jan 2015 22:14:50 +0100
Subject: Python Sanity Proposal: Type Hinting Solution
In-Reply-To: <684d5cdf-4987-4dd1-bc50-76bd019b9d80@googlegroups.com>
References: <6da1eb58-a0bb-4d37-8293-0a8cafe6a89c@googlegroups.com>
 <mailman.18012.1421983349.18130.python-list@python.org>
 <684d5cdf-4987-4dd1-bc50-76bd019b9d80@googlegroups.com>
Message-ID: <ma11va$muj$1@dont-email.me>

Am 23.01.15 um 20:23 schrieb Rick Johnson:
> On Thursday, January 22, 2015 at 9:22:40 PM UTC-6, Terry Reedy wrote:
>> that it is already an option in mypy and is part of the new
>> type-hint proposal.
> 
> An *OPTION*? If it is not mandatory then why bother? If
> authors have a choice between writing type hints into func
> sigs or writing them in a "stub file", then the natural
> human behavior of "slothfulness" will bring about the
> destruction of Python via syntactic noise. Heck, why don't
> we just adopt the *REAL* fairness doctrine and make
> indentation optional? 

Actually, optional indentation is not a bad idea in itself. For example
in Haskell, you can use indentation much in the same way as you use it
in Python. But you can also add semicolons and braces instead, which
override the indentation, on a per-statement basis. This permits more
freedom in code layout, for example it allows reasonable one-line ifs.


	Christian


From ian.g.kelly at gmail.com  Sat Jan 24 16:45:32 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Sat, 24 Jan 2015 14:45:32 -0700
Subject: __bases__ misleading error message
In-Reply-To: <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
Message-ID: <CALwzidmMWvm04jxgna9=dwqD+jytepJ5sq7ARDWorVa+sqw8Rg@mail.gmail.com>

On Sat, Jan 24, 2015 at 2:14 PM, Mario Figueiredo <marfig at gmail.com> wrote:
> In article <54c39366$0$13006$c3e8da3$5496439d at news.astraweb.com>,
> steve+comp.lang.python at pearwood.info says...
>> >         AttributeError: 'Sub' instance has no attribute '__bases__',
>> >         AttributeError: 'foo' object has no attribute '__bases__'
>>
>> The first would be nice. The second is impossible: objects may have no name,
>> one name, or many names, and they do not know what names they are bound to.
>> So the Sub instance bound to the name 'foo' doesn't know that its name
>> is 'foo', so it cannot display it in the error message.
>
> Thanks for the information! :)
>
> But that begs the OT question:

No, it doesnt. http://en.wikipedia.org/wiki/Begging_the_question

> How does Python maps names to memory
> addresses in the interpreter?

Global variables are looked up in the current stack frame's globals dict.

>>> a = 1
>>> b = 2
>>> globals()['a']
1
>>> globals()['b']
2

Local variables of functions could be handled the same way, but for
efficiency the compiler instead maps the names to indices of a local
variable array associated with the stack frame. Either way, at the C
level the value stored in the dict or array is a pointer to the memory
location of the object.

>     "__main__"
>     from module import a_name
>     y = a_name + 1
>
> How does python interpreter know how to map 'name' to the correct memory
> location, if this __main__ code is only ran after 'module' code?

I'm not sure I'm understanding what you're asking, but the import
statement imports the module, looks up "a_name" in that module's
globals dict, and binds the same object to a_name in the current
module's globals dict.


From marco.buttu at gmail.com  Sat Jan 24 16:51:32 2015
From: marco.buttu at gmail.com (Marco Buttu)
Date: Sat, 24 Jan 2015 22:51:32 +0100
Subject: __bases__ misleading error message
In-Reply-To: <mailman.18093.1422127493.18130.python-list@python.org>
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <mailman.18093.1422127493.18130.python-list@python.org>
Message-ID: <54C413E4.5060208@gmail.com>

On 24/01/2015 20:24, Terry Reedy wrote:

> On 1/24/2015 5:16 AM, Mario Figueiredo wrote:
>>
>> Consider the following code at your REPL of choice
>
>>         class Sub:
>>             pass
>>
>>         foo = Sub()
>>
>>         Sub.__bases__
>>         foo.__bases__
>>
>> The last statement originates the following error:
>
> This is an anomalous situation.  Normally, if a class has an attribute,
> instances have the same attribute (unless overriden).  But this does not
> matter.

That is not true: if a class has an attribute, you can not say its 
instances have the same attribute. You can just say if a type defines an 
attribute, all its instances have that attribute. Look at this example:

 >>> class Foo(type):
...     foo = 33
...
 >>> Foo.foo
33
 >>> MyClass = Foo('MyClass', (), {})

MyClass is an instance of Foo, so it must have the attribute foo:

 >>> isinstance(MyClass, Foo)
True
 >>> MyClass.foo
33

But an instance of MyClass is not an instance of Foo, and so MyClass() 
must not have the attribute foo. In fact:

 >>> m = MyClass()
 >>> isinstance(m, Foo)
False
 >>> m.foo
Traceback (most recent call last):
     ...
AttributeError: 'MyClass' object has no attribute 'foo'


-- 
Marco Buttu


From marco.buttu at gmail.com  Sat Jan 24 16:51:32 2015
From: marco.buttu at gmail.com (Marco Buttu)
Date: Sat, 24 Jan 2015 22:51:32 +0100
Subject: __bases__ misleading error message
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <mailman.18093.1422127493.18130.python-list@python.org>
Message-ID: <54C413E4.5060208@gmail.com>

On 24/01/2015 20:24, Terry Reedy wrote:

> On 1/24/2015 5:16 AM, Mario Figueiredo wrote:
>>
>> Consider the following code at your REPL of choice
>
>>         class Sub:
>>             pass
>>
>>         foo = Sub()
>>
>>         Sub.__bases__
>>         foo.__bases__
>>
>> The last statement originates the following error:
>
> This is an anomalous situation.  Normally, if a class has an attribute,
> instances have the same attribute (unless overriden).  But this does not
> matter.

That is not true: if a class has an attribute, you can not say its 
instances have the same attribute. You can just say if a type defines an 
attribute, all its instances have that attribute. Look at this example:

 >>> class Foo(type):
...     foo = 33
...
 >>> Foo.foo
33
 >>> MyClass = Foo('MyClass', (), {})

MyClass is an instance of Foo, so it must have the attribute foo:

 >>> isinstance(MyClass, Foo)
True
 >>> MyClass.foo
33

But an instance of MyClass is not an instance of Foo, and so MyClass() 
must not have the attribute foo. In fact:

 >>> m = MyClass()
 >>> isinstance(m, Foo)
False
 >>> m.foo
Traceback (most recent call last):
     ...
AttributeError: 'MyClass' object has no attribute 'foo'


-- 
Marco Buttu


From ian.g.kelly at gmail.com  Sat Jan 24 16:51:41 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Sat, 24 Jan 2015 14:51:41 -0700
Subject: Python is DOOMED! Again!
In-Reply-To: <2XTww.350898$lm5.140746@fx36.am4>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17973.1421939508.18130.python-list@python.org>
 <54c2299d$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18029.1422013105.18130.python-list@python.org>
 <54c33d20$0$13011$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18086.1422110705.18130.python-list@python.org>
 <54c3c1b1$0$13011$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18088.1422116868.18130.python-list@python.org>
 <54c3d6d8$0$12988$c3e8da3$5496439d@news.astraweb.com>
 <2XTww.350898$lm5.140746@fx36.am4>
Message-ID: <CALwzidmtbwfB7BZxD=xsGPb2fhcFym9cVp5hLxexDkLArvLuNw@mail.gmail.com>

On Sat, Jan 24, 2015 at 2:14 PM, alister
<alister.nospam.ware at ntlworld.com> wrote:
>>
>> Either that, or make up change with 20?, 10? and 5? (we practice
>> round-to-nearest-5-cents here).
>
> I suppose if you all pay 35?  it at least gives the waitress a tip.

"""
In the Pacific States they have made a bolder push for complexity, and
settle their affairs by a coin that no longer exists ? the BIT, or old
Mexican real. The supposed value of the bit is twelve and a half
cents, eight to the dollar. When it comes to two bits, the
quarter-dollar stands for the required amount. But how about an odd
bit? The nearest coin to it is a dime, which is, short by a fifth.
That, then, is called a SHORT bit. If you have one, you lay it
triumphantly down, and save two and a half cents. But if you have not,
and lay down a quarter, the bar-keeper or shopman calmly tenders you a
dime by way of change; and thus you have paid what is called a LONG
BIT, and lost two and a half cents, or even, by comparison with a
short bit, five cents.
"""
    -- Robert Louis Stevenson


From tjreedy at udel.edu  Sat Jan 24 16:58:10 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Sat, 24 Jan 2015 16:58:10 -0500
Subject: __bases__ misleading error message
In-Reply-To: <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
Message-ID: <ma14hk$p8s$1@ger.gmane.org>

On 1/24/2015 4:14 PM, Mario Figueiredo wrote:
> In article <54c39366$0$13006$c3e8da3$5496439d at news.astraweb.com>,
> steve+comp.lang.python at pearwood.info says...
>>>          AttributeError: 'Sub' instance has no attribute '__bases__',
>>>          AttributeError: 'foo' object has no attribute '__bases__'
>>
>> The first would be nice. The second is impossible: objects may have no name,
>> one name, or many names, and they do not know what names they are bound to.
>> So the Sub instance bound to the name 'foo' doesn't know that its name
>> is 'foo', so it cannot display it in the error message.
>
> Thanks for the information! :)
>
> But that begs the OT question: How does Python maps names to memory
> addresses in the interpreter?

Python the language maps names to objects that have identity, type, and 
value.  The CPython implementation does the mapping with a hash table 
and C pointers (to computer memory addresses), but addresses are not 
part of the language definition.  Neuroscientists still puzzle over how 
we do such mapping.

>      "__main__"
>      from module import a_name

A module is a namespace associating names with objects.  This statememt 
says to import the a_name to object association from module and add it 
to __main__

>      y = a_name + 1

This statement uses the imported association in __main__ to access the 
object and add 1, and bind 'y' to the resulting object.

-- 
Terry Jan Reedy



From marfig at gmail.com  Sat Jan 24 17:02:19 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sat, 24 Jan 2015 23:02:19 +0100
Subject: __bases__ misleading error message
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
 <mailman.18102.1422136703.18130.python-list@python.org>
Message-ID: <MPG.2f2e34c1b650760e989693@nntp.aioe.org>

In article <mailman.18102.1422136703.18130.python-list at python.org>, 
tjreedy at udel.edu says...
> 
> >      "__main__"
> >      from module import a_name
> 
> A module is a namespace associating names with objects.  This statememt 
> says to import the a_name to object association from module and add it 
> to __main__
> 
> >      y = a_name + 1
> 
> This statement uses the imported association in __main__ to access the 
> object and add 1, and bind 'y' to the resulting object.


But I'm being told the interpreter has no knowledge of a variable name. 
So, how does the interpreter know, once it reaches the assigment line 
above, how to map a_name to the correct object in memory?


From marfig at gmail.com  Sat Jan 24 17:09:02 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sat, 24 Jan 2015 23:09:02 +0100
Subject: __bases__ misleading error message
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
 <mailman.18099.1422135976.18130.python-list@python.org>
Message-ID: <MPG.2f2e3651befa4c9989694@nntp.aioe.org>

In article <mailman.18099.1422135976.18130.python-list at python.org>, 
ian.g.kelly at gmail.com says...
> 
> On Sat, Jan 24, 2015 at 2:14 PM, Mario Figueiredo <marfig at gmail.com> wrote:
> > But that begs the OT question:
> 
> No, it doesnt. http://en.wikipedia.org/wiki/Begging_the_question

Cute.

> I'm not sure I'm understanding what you're asking, but the import
> statement imports the module, looks up "a_name" in that module's
> globals dict, and binds the same object to a_name in the current
> module's globals dict.

Meaning the interpreter knows a variable's name. Which would allow it to 
produce an error message such as:

    AttributeError: 'foo' object has no attribute '__bases__'

For the following code:

    class Sub:
        pass
 
    foo = Sub()
    foo.__bases__




From marco.buttu at gmail.com  Sat Jan 24 17:09:31 2015
From: marco.buttu at gmail.com (Marco Buttu)
Date: Sat, 24 Jan 2015 23:09:31 +0100
Subject: __bases__ misleading error message
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <ma156n$5qj$1@speranza.aioe.org>

On 24/01/2015 13:43, Steven D'Aprano wrote:

> Mario Figueiredo wrote:
>
>> >         class Sub:
>> >             pass
>> >
>> >         foo = Sub()
>> >
>> >         Sub.__bases__
>> >         foo.__bases__
>> >
>> >The last statement originates the following error:
>> >
>> >         AttributeError: 'Sub' object has no attribute '__bases__'
> It's a bit ambiguous, but the way to read it is to think of object as a
> synonym for instance.
...
>
>> >Naturally the 'Sub' object has an attribute __bases__.
> Correct, in the sense that classes are objects too. But in the sense of
> object=instance, no. Isn't ambiguous terminology wonderful?

In my opinion it is not ambiguous, because as you say in Python an 
object is a synonym for instance. We can say in Python an object is an 
instance of the type object, that's all. And that's why everything is an 
object in Python:

 >>> isisntace(foo, object) # For every foo
True

So a class (a type) is an instance too, an instance of its metaclass. 
Therefore, the message says that the Sub instance has no attribute 
'__bases__'. In fact the Sub object (instance) has no attribute 
'__bases__' because it is not an instance of type, and only types 
(classes) have this attribute.

So if we want to find some differences between objects, we have to 
distinguish between types (classes) and non-types (non-classes) objects, 
and not between objects and classes.
In the Python documentation there is also a bit of confusion about 
this... In the descriptor howto: "The details of invocation depend on 
whether obj is an object or a class" :/


-- 
Marco Buttu


From ian.g.kelly at gmail.com  Sat Jan 24 17:16:45 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Sat, 24 Jan 2015 15:16:45 -0700
Subject: __bases__ misleading error message
In-Reply-To: <MPG.2f2e34c1b650760e989693@nntp.aioe.org>
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
 <mailman.18102.1422136703.18130.python-list@python.org>
 <MPG.2f2e34c1b650760e989693@nntp.aioe.org>
Message-ID: <CALwzidnww4zz0uybTFVNveC-_arCTjC-QH2ZQYF9BZeFJ5r9Ag@mail.gmail.com>

On Sat, Jan 24, 2015 at 3:02 PM, Mario Figueiredo <marfig at gmail.com> wrote:
> In article <mailman.18102.1422136703.18130.python-list at python.org>,
> tjreedy at udel.edu says...
>>
>> >      "__main__"
>> >      from module import a_name
>>
>> A module is a namespace associating names with objects.  This statememt
>> says to import the a_name to object association from module and add it
>> to __main__
>>
>> >      y = a_name + 1
>>
>> This statement uses the imported association in __main__ to access the
>> object and add 1, and bind 'y' to the resulting object.
>
>
> But I'm being told the interpreter has no knowledge of a variable name.
> So, how does the interpreter know, once it reaches the assigment line
> above, how to map a_name to the correct object in memory?

No, you're being told that the *object* doesn't know the names of the
variables that it's bound to. In the context above, the variable is
right there under that name in the globals dict, as can be seen in the
disassembly:

>>> import dis
>>> dis.dis("y = a_name + 1")
  1           0 LOAD_NAME                0 (a_name)
              3 LOAD_CONST               0 (1)
              6 BINARY_ADD
              7 STORE_NAME               1 (y)
             10 LOAD_CONST               1 (None)
             13 RETURN_VALUE

Now what happens in the byte code if we try to access an attribute on
that object?

>>> dis.dis("a_name.__bases__")
  1           0 LOAD_NAME                0 (a_name)
              3 LOAD_ATTR                1 (__bases__)
              6 RETURN_VALUE

1) The value of a_name is looked up and pushed onto the stack.

2) The interpreter attempts to load the attribute __bases__ of
whatever object is on the top of the stack. There is no name
associated with that object at this point; it's just an object.

Now imagine if the Python code in question were instead this:

    def get_an_object(): return "foo"
    get_an_object().__bases__

Would you really expect the interpreter to come up with a message like
"Return value of get_an_object() has no attribute '__bases__'"?


From rosuav at gmail.com  Sat Jan 24 17:25:51 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 25 Jan 2015 09:25:51 +1100
Subject: __bases__ misleading error message
In-Reply-To: <MPG.2f2e3651befa4c9989694@nntp.aioe.org>
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
 <mailman.18099.1422135976.18130.python-list@python.org>
 <MPG.2f2e3651befa4c9989694@nntp.aioe.org>
Message-ID: <CAPTjJmrwxJGC1RbijcK4Uw8Y975uPer+aCCb443q7f_EJhxNkQ@mail.gmail.com>

On Sun, Jan 25, 2015 at 9:09 AM, Mario Figueiredo <marfig at gmail.com> wrote:
> Meaning the interpreter knows a variable's name. Which would allow it to
> produce an error message such as:
>
>     AttributeError: 'foo' object has no attribute '__bases__'
>
> For the following code:
>
>     class Sub:
>         pass
>
>     foo = Sub()
>     foo.__bases__

Let me explain by way of analogy. You have ten shoeboxes to store your
stuff in. I hand you a thing and say "Here, put this into shoebox #4".
Then someone else comes along and says, "I need the thing from shoebox
#4", so you give him that thing. Now, he hands that thing to someone
else and asks him which shoebox it came out of, just by looking at the
thing itself. How can he say? The thing doesn't have any way of
knowing what shoebox it came out of.

Python names reference objects. But once you get an object, there's no
way of knowing which name was used to get to it. There might be one
such name; there might be more than one; and there might not be any.
You can't identify an object by the name it's bound to, but you can
identify it by something that's always true of the object itself, like
its type.

There are a few cases where names are so useful that they get attached
to the objects themselves. The 'def' and 'class' statements create
objects and also record the names used. But you still can't identify
what name was used to reference something:

>>> def func(x): print("x = %s"%x)
...
>>> func(123)
x = 123
>>> show = func
>>> show(234)
x = 234
>>> func = "not a function"
>>> func(123)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'str' object is not callable
>>> show(123)
x = 123
>>> show
<function func at 0x7f36744a30d0>

No matter what name I use to reference the function, it's still called
"func". Nobody can ever know that I'm identifying it by the name
'show' now.

ChrisA


From marfig at gmail.com  Sat Jan 24 17:30:11 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sat, 24 Jan 2015 23:30:11 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17973.1421939508.18130.python-list@python.org>
 <54c2299d$0$13005$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <MPG.2f2e3b4acb2e5d9a989695@nntp.aioe.org>

In article <54c2299d$0$13005$c3e8da3$5496439d at news.astraweb.com>, 
steve+comp.lang.python at pearwood.info says...
> 
> I don't think that a raise of 0.10000000000000001 (10%),
> 0.035000000000000003 (3.5%) or 0.070000000000000007 (7%) is quite what
> people intended.
> 
> (Don't use binary floating point numbers for anything related to
> money. Just don't.)

Few rules are written in stone and that rule isn't either. It all 
depends on the context. People often read these bits of well intentioned 
advise and go on to immediately make some kind of gospel out of it. Why 
is that?

And why is that? Why do you think I can't ever use floats for money? Is 
there some kind of unspoken rule that money must always be dealt with 
with enough precision to give a microscope an headache?

- What if I am storing money as an integer or a 2 decimal place Decimal 
to manage my electrical bill and I use a float to express a percentage?
- What if the float operation is not a repetitive operation that would 
indeed invariably lead to round errors, but instead a once in a lifetime 
operation?

I'm not saying I don't agree we should avoid it. I'm saying we need also 
to properly contextualize it before we decide to do so. If I'm writing a 
banking system, or a POS, you will be damn sure it will be hard to spot 
a float in my code.

But if I'm writing my household electrical bill yearly report, or I'm 
writting a damn code snippet on a python group to illustrate how type 
hinting mangles your code, who gives a flying arse if I'm using a float 
to express money? Sheesh!


From marfig at gmail.com  Sat Jan 24 17:33:10 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sat, 24 Jan 2015 23:33:10 +0100
Subject: __bases__ misleading error message
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
 <mailman.18099.1422135976.18130.python-list@python.org>
 <MPG.2f2e3651befa4c9989694@nntp.aioe.org>
 <mailman.18104.1422138354.18130.python-list@python.org>
Message-ID: <MPG.2f2e3c017bcaae94989696@nntp.aioe.org>

In article <mailman.18104.1422138354.18130.python-list at python.org>, 
rosuav at gmail.com says...
> 
> Let me explain by way of analogy. 
[snipped]

Gotcha! Thanks for the explanation :)



From marfig at gmail.com  Sat Jan 24 17:36:06 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sat, 24 Jan 2015 23:36:06 +0100
Subject: __bases__ misleading error message
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
 <mailman.18102.1422136703.18130.python-list@python.org>
 <MPG.2f2e34c1b650760e989693@nntp.aioe.org>
 <mailman.18103.1422137849.18130.python-list@python.org>
Message-ID: <MPG.2f2e3cae35dc9068989697@nntp.aioe.org>

In article <mailman.18103.1422137849.18130.python-list at python.org>, 
ian.g.kelly at gmail.com says...
> 
> No, you're being told that the *object* doesn't know the names of the
> variables that it's bound to. In the context above, the variable is
> right there under that name in the globals dict, as can be seen in the
> disassembly:
[snipped]

Yes. I got it now. I misinterpreted Steven words.


From rosuav at gmail.com  Sat Jan 24 17:37:35 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 25 Jan 2015 09:37:35 +1100
Subject: __bases__ misleading error message
In-Reply-To: <MPG.2f2e3c017bcaae94989696@nntp.aioe.org>
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
 <mailman.18099.1422135976.18130.python-list@python.org>
 <MPG.2f2e3651befa4c9989694@nntp.aioe.org>
 <mailman.18104.1422138354.18130.python-list@python.org>
 <MPG.2f2e3c017bcaae94989696@nntp.aioe.org>
Message-ID: <CAPTjJmqQkf9_f1h35Xp24rKarJU6WwVjEVB9SCLPZw8fttFrCQ@mail.gmail.com>

On Sun, Jan 25, 2015 at 9:33 AM, Mario Figueiredo <marfig at gmail.com> wrote:
> In article <mailman.18104.1422138354.18130.python-list at python.org>,
> rosuav at gmail.com says...
>>
>> Let me explain by way of analogy.
> [snipped]
>
> Gotcha! Thanks for the explanation :)

Awesome! I'm always a bit wary of analogies... sometimes they're
really helpful, other times they're unhelpful and confusing. Glad this
was one of the better cases.

ChrisA


From noone at nowhere.net  Sat Jan 24 17:57:00 2015
From: noone at nowhere.net (Brian Gladman)
Date: Sat, 24 Jan 2015 22:57:00 +0000
Subject: Delegation in Python
Message-ID: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>

I would appreciate advice on how to set up delgation in Python.

I am continuously implementing a function to test whether a Python
Fraction is an integer so I wanted to define a new class, based on
Fraction, that includes this new method.

But I am not clear on how to delegate from my new class to the existing
Fraction class.  This is what I have:

--------------------------
class RF(Fraction):

  def __new__(self, x, y):
    super().__new__(self, x, y)

  def is_integer(self):
    return self.numerator % self.denominator == 0

  def __getattr__(self, attr):
    return getattr(self, attr)
--------------------------

which doesn't work.

Any advice on how to do this would be much appreciated.

   Brian


From marfig at gmail.com  Sat Jan 24 17:59:28 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sat, 24 Jan 2015 23:59:28 +0100
Subject: __bases__ misleading error message
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
 <mailman.18099.1422135976.18130.python-list@python.org>
 <MPG.2f2e3651befa4c9989694@nntp.aioe.org>
 <mailman.18104.1422138354.18130.python-list@python.org>
 <MPG.2f2e3c017bcaae94989696@nntp.aioe.org>
 <mailman.18105.1422139063.18130.python-list@python.org>
Message-ID: <MPG.2f2e42298df5a9c2989698@nntp.aioe.org>

In article <mailman.18105.1422139063.18130.python-list at python.org>, 
rosuav at gmail.com says...
> Awesome! I'm always a bit wary of analogies... sometimes they're
> really helpful, other times they're unhelpful and confusing.

Yeah. Your's was all it took :)

The thing with analogies is to never take them literally. They are 
analogies, after all. But there is this old funny thing we humans seem 
to share that an analogy should be dissected like it was a scientific 
paper.

- You say shoes in a box? Why, but memory addresses aren't boxes. 
Besides a box can only take shoes this big. Memory addresses can take 
any size object.

- No I meant.. Look, just imagine shoes in a box.

- Alright...

- Now the other person will be handed the shoe you asked. They don't 
know what box it came from. What this mea...

- How come?

- How come what?

- Why don't they know? They could just agree to know what box the shoe 
came from. Problem solved.

- No, but I am trying to illustrate how it works. Not how it could work.

- I still don't get it. Why does it work like that. Seems stupid...

- It's not. There are specific reasons to not know. It's got to do with 
the process stack and efficiency and...

- Right.

And there's also the most annoying of all, the smartasses that like to 
stay hidden in the shadows and as soon as they see an analogy they jump 
in and tada!

"It's not true that memory spaces can hold any object size. It is 
limited by the computer available memory" -- well, duh!

"Is that a float you are using to compute a salary raise in your code 
snippet meant as an example to illustrate code syntax? Hahaha" -- Sigh!


From yawar.amin at gmail.com  Sat Jan 24 18:00:43 2015
From: yawar.amin at gmail.com (Yawar Amin)
Date: Sat, 24 Jan 2015 15:00:43 -0800 (PST)
Subject: Alternative to multi-line lambdas: Assign-anywhere def statements
In-Reply-To: <mailman.18096.1422131746.18130.python-list@python.org>
References: <CAPTjJmrAQgtauH74dwCzb_-6T09D0dLVkxiGrAxJMp_OOwgS0g@mail.gmail.com>
 <54C3EAD1.2010501@stoneleaf.us>
 <CAPTjJmohdQbK9_ikh8heaMRbpJ270UW6C1AE2oNVgV_4AoYfQg@mail.gmail.com>
 <mailman.18096.1422131746.18130.python-list@python.org>
Message-ID: <d59af9f9-bc23-4683-b678-f3c3380b0c26@googlegroups.com>

Hi,

On Saturday, January 24, 2015 at 3:36:04 PM UTC-5, Devin Jeanpierre
wrote:
> [...]
> Obviously, nobody will be happy until you can do:
> 
> def call(*a, **kw): return lambda f: f(*a, **kw)
> 
> @call()
> def x, y ():
>     yield 1
>     yield 2
> 
> Actually, maybe not even then.

You're probably right, because someone already _has_ come up with that: 

    https://github.com/carymrobbins/python-blocks/blob/f51d10bd2439990cce7e2cb78e6e56ed05e78648/src/blocks.py#L191

Anyway Chris, to answer your question, the python-blocks repo shows the
'functional decorator style' taken to its logical conclusion, with
decorators for all the various functional building blocks like mapping,
folding, currying, etc.

Incidentally, with a properly-defined decorator 'factory', you could get
a pretty generic decorator for your dispatch example:

    cmd = {}
    dispatch = make_dispatch(cmd)

    @dispatch
    def foo(*args): print("You asked to foo.")

    @dispatch
    def bar(*args): print("There's no wine in the bar.")

    @dispatch
    def cmd2(*args): print("Asdf! Asdf!")

    cmd["foo"]()
    # Etc.

Regards,

Yawar


From rantingrickjohnson at gmail.com  Sat Jan 24 18:20:16 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Sat, 24 Jan 2015 15:20:16 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <54c34e68$0$12976$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <9a6694a5-5774-415a-b28a-7a9425a9112a@googlegroups.com>
 <54c34e68$0$12976$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <e072e82f-1faa-4be3-814f-9addaea971ef@googlegroups.com>

On Saturday, January 24, 2015 at 1:49:08 AM UTC-6, Steven D'Aprano wrote:
> Rick Johnson wrote:
> 
> [... snip absurdities...]
> 
> > Duh! Do you think i just pulled stub files out my arse
> > without giving all the other alternatives due consideration?
> 
> Actually, yes. I think that had Guido proclaimed that
> C-style header files were the only way to give type hints,
> you would be arguing right now that they were awful and
> that the one and only correct way to do type-hinting is to
> use annotations.

So now we arrive at the true nature of our conflict: your
"false projections" of my "true intentions".

Listen, I hold a deep respect for Guido's achievements and
his intellectual prowess, but i'm not about to kiss is
backside when i feel he is wrong, and this "type hints" idea
is dangerously wrong!

Diversity, dissension, and conflict are our friends, not
enemies to be feared. We must embrace those ideas that are
foreign to us, give them due consideration, and objectively
apply "weighted values" to them. Whereas, sitting in a room
surrounded by mirrors and becoming lost in the recursive
"reflection of self", is not evolution, but merely, an
illusion.

Besides, why does he need *ME* to lick his boots when he
already has plenty of fan-boys over at python-ideas and
python-dev lining up. This community is *NOT*, and should
never be, a homogeneous block -- for we would be doing
ourselves a disservice.

So if you cannot provide me with respect that i *DESERVE* as
a member of this fine community, then you should at least
admit that my presence is a vital counterbalance to prevent
this tiny life-vessel from capsizing as it's thrashed around
the treacherous "seas of evolution".



From rosuav at gmail.com  Sat Jan 24 18:22:10 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 25 Jan 2015 10:22:10 +1100
Subject: Delegation in Python
In-Reply-To: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>
References: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>
Message-ID: <CAPTjJmoVxi_VXKJ93W=rPNnZiud6O_mXyxm+2tMG8BoQBqH-Ew@mail.gmail.com>

On Sun, Jan 25, 2015 at 9:57 AM, Brian Gladman <noone at nowhere.net> wrote:
> But I am not clear on how to delegate from my new class to the existing
> Fraction class.  This is what I have:
>
> --------------------------
> class RF(Fraction):
>
>   def __new__(self, x, y):
>     super().__new__(self, x, y)
>
>   def is_integer(self):
>     return self.numerator % self.denominator == 0
>
>   def __getattr__(self, attr):
>     return getattr(self, attr)

If you just drop everything but your new method, it should work just fine.

class RF(Fraction):
    def is_integer(self):
       return self.numerator % self.denominator == 0

However, this doesn't ensure that operations on RFs will return more
RFs - they'll often return Fractions instead. There's no easy fix for
that, sorry.

ChrisA


From rosuav at gmail.com  Sat Jan 24 18:30:42 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 25 Jan 2015 10:30:42 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <e072e82f-1faa-4be3-814f-9addaea971ef@googlegroups.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <9a6694a5-5774-415a-b28a-7a9425a9112a@googlegroups.com>
 <54c34e68$0$12976$c3e8da3$5496439d@news.astraweb.com>
 <e072e82f-1faa-4be3-814f-9addaea971ef@googlegroups.com>
Message-ID: <CAPTjJmqZn_ez9zu0j23QoLOGi4iLg8eMyYcEH5bHn65bbicAig@mail.gmail.com>

On Sun, Jan 25, 2015 at 10:20 AM, Rick Johnson
<rantingrickjohnson at gmail.com> wrote:
> Besides, why does he need *ME* to lick his boots when he
> already has plenty of fan-boys over at python-ideas and
> python-dev lining up. This community is *NOT*, and should
> never be, a homogeneous block -- for we would be doing
> ourselves a disservice.

Wow. You think that, without you, python-ideas is homogeneous? I don't
think so. If it were, it would be called python-idea.

ChrisA


From noone at nowhere.net  Sat Jan 24 18:38:20 2015
From: noone at nowhere.net (Brian Gladman)
Date: Sat, 24 Jan 2015 23:38:20 +0000
Subject: Delegation in Python
In-Reply-To: <mailman.18106.1422141738.18130.python-list@python.org>
References: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>
 <mailman.18106.1422141738.18130.python-list@python.org>
Message-ID: <5ZKdnd6rbdZ3sVnJnZ2dnUVZ8mCdnZ2d@brightview.co.uk>

On 24/01/2015 23:22, Chris Angelico wrote:
> class RF(Fraction):
>     def is_integer(self):
>        return self.numerator % self.denominator == 0

Thanks for your help on this.  I must admit that nowhere in a lot of
searching did I find that delegation is achieved by doing nothing!

   Brian





From marfig at gmail.com  Sat Jan 24 18:39:35 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sun, 25 Jan 2015 00:39:35 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <9a6694a5-5774-415a-b28a-7a9425a9112a@googlegroups.com>
 <54c34e68$0$12976$c3e8da3$5496439d@news.astraweb.com>
 <e072e82f-1faa-4be3-814f-9addaea971ef@googlegroups.com>
 <mailman.18107.1422142244.18130.python-list@python.org>
Message-ID: <MPG.2f2e4b8fbbfa6d22989699@nntp.aioe.org>

In article <mailman.18107.1422142244.18130.python-list at python.org>, 
rosuav at gmail.com says...
> 
> On Sun, Jan 25, 2015 at 10:20 AM, Rick Johnson
> <rantingrickjohnson at gmail.com> wrote:
> > Besides, why does he need *ME* to lick his boots when he
> > already has plenty of fan-boys over at python-ideas and
> > python-dev lining up. This community is *NOT*, and should
> > never be, a homogeneous block -- for we would be doing
> > ourselves a disservice.
> 
> Wow. You think that, without you, python-ideas is homogeneous? I don't
> think so. If it were, it would be called python-idea.

He didn't say python-ideas is homogeneous. He didn't say either that he 
is the only one who dissents.

There's already too much of "not wanting to listen to what the other 
person is saying" by both sides of this debate. Let's not add more...




From gherron at digipen.edu  Sat Jan 24 18:41:17 2015
From: gherron at digipen.edu (Gary Herron)
Date: Sat, 24 Jan 2015 15:41:17 -0800
Subject: Delegation in Python
In-Reply-To: <CAPTjJmoVxi_VXKJ93W=rPNnZiud6O_mXyxm+2tMG8BoQBqH-Ew@mail.gmail.com>
References: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>
 <CAPTjJmoVxi_VXKJ93W=rPNnZiud6O_mXyxm+2tMG8BoQBqH-Ew@mail.gmail.com>
Message-ID: <54C42D9D.7010305@digipen.edu>

On 01/24/2015 03:22 PM, Chris Angelico wrote:
> On Sun, Jan 25, 2015 at 9:57 AM, Brian Gladman <noone at nowhere.net> wrote:
>> But I am not clear on how to delegate from my new class to the existing
>> Fraction class.  This is what I have:
>>
>> --------------------------
>> class RF(Fraction):
>>
>>    def __new__(self, x, y):
>>      super().__new__(self, x, y)
>>
>>    def is_integer(self):
>>      return self.numerator % self.denominator == 0
>>
>>    def __getattr__(self, attr):
>>      return getattr(self, attr)
> If you just drop everything but your new method, it should work just fine.
>
> class RF(Fraction):
>      def is_integer(self):
>         return self.numerator % self.denominator == 0
>
> However, this doesn't ensure that operations on RFs will return more
> RFs - they'll often return Fractions instead. There's no easy fix for
> that, sorry.
>
> ChrisA

You can always "monkey-path" the Fraction class on the fly to add a new 
method to it.  I think most would consider this a bad idea, but it does 
work.
Try this:

 >>> from fractions import Fraction
 >>> def is_integer(self):
...     return self.numerator % self.denominator == 0
...
 >>> Fraction.is_integer = is_integer # Monkey-patch Fraction
 >>>
 >>> Fraction(1,2).is_integer()
False
 >>> Fraction(2,1).is_integer()
True


Gary Herron


-- 
Dr. Gary Herron
Department of Computer Science
DigiPen Institute of Technology
(425) 895-4418



From rosuav at gmail.com  Sat Jan 24 18:43:33 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 25 Jan 2015 10:43:33 +1100
Subject: Delegation in Python
In-Reply-To: <5ZKdnd6rbdZ3sVnJnZ2dnUVZ8mCdnZ2d@brightview.co.uk>
References: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>
 <mailman.18106.1422141738.18130.python-list@python.org>
 <5ZKdnd6rbdZ3sVnJnZ2dnUVZ8mCdnZ2d@brightview.co.uk>
Message-ID: <CAPTjJmpOg=ApgkWJCnTkASP63QyMf8om+RQta9HgpuQvRDEjrw@mail.gmail.com>

On Sun, Jan 25, 2015 at 10:38 AM, Brian Gladman <noone at nowhere.net> wrote:
> On 24/01/2015 23:22, Chris Angelico wrote:
>> class RF(Fraction):
>>     def is_integer(self):
>>        return self.numerator % self.denominator == 0
>
> Thanks for your help on this.  I must admit that nowhere in a lot of
> searching did I find that delegation is achieved by doing nothing!

Hehe :) If you want a technical look at it, what you have is the
fundamental nature of subclassing: you derive from another class, and
your class is identical to that with certain exceptions (in your case,
an additional method). Python's way of handling that is called the
Method Resolution Order or MRO, and you can find info on it on the
web, eg:

http://python-history.blogspot.com/2010/06/method-resolution-order.html

Enjoy!

ChrisA


From rosuav at gmail.com  Sat Jan 24 18:44:42 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 25 Jan 2015 10:44:42 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <MPG.2f2e4b8fbbfa6d22989699@nntp.aioe.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <9a6694a5-5774-415a-b28a-7a9425a9112a@googlegroups.com>
 <54c34e68$0$12976$c3e8da3$5496439d@news.astraweb.com>
 <e072e82f-1faa-4be3-814f-9addaea971ef@googlegroups.com>
 <mailman.18107.1422142244.18130.python-list@python.org>
 <MPG.2f2e4b8fbbfa6d22989699@nntp.aioe.org>
Message-ID: <CAPTjJmpOdPD79yN0MYu7h_jOOMBKCWGXUQsRWXS8CN238_oKcg@mail.gmail.com>

On Sun, Jan 25, 2015 at 10:39 AM, Mario Figueiredo <marfig at gmail.com> wrote:
> In article <mailman.18107.1422142244.18130.python-list at python.org>,
> rosuav at gmail.com says...
>>
>> On Sun, Jan 25, 2015 at 10:20 AM, Rick Johnson
>> <rantingrickjohnson at gmail.com> wrote:
>> > Besides, why does he need *ME* to lick his boots when he
>> > already has plenty of fan-boys over at python-ideas and
>> > python-dev lining up. This community is *NOT*, and should
>> > never be, a homogeneous block -- for we would be doing
>> > ourselves a disservice.
>>
>> Wow. You think that, without you, python-ideas is homogeneous? I don't
>> think so. If it were, it would be called python-idea.
>
> He didn't say python-ideas is homogeneous. He didn't say either that he
> is the only one who dissents.
>
> There's already too much of "not wanting to listen to what the other
> person is saying" by both sides of this debate. Let's not add more...

True. But anyone who's actually participated in python-ideas knows
that there are PLENTY of dissenting voices. :)

ChrisA


From gherron at digipen.edu  Sat Jan 24 18:47:56 2015
From: gherron at digipen.edu (Gary Herron)
Date: Sat, 24 Jan 2015 15:47:56 -0800
Subject: Delegation in Python
In-Reply-To: <5ZKdnd6rbdZ3sVnJnZ2dnUVZ8mCdnZ2d@brightview.co.uk>
References: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>
 <mailman.18106.1422141738.18130.python-list@python.org>
 <5ZKdnd6rbdZ3sVnJnZ2dnUVZ8mCdnZ2d@brightview.co.uk>
Message-ID: <54C42F2C.7070301@digipen.edu>

On 01/24/2015 03:38 PM, Brian Gladman wrote:
> On 24/01/2015 23:22, Chris Angelico wrote:
>> class RF(Fraction):
>>      def is_integer(self):
>>         return self.numerator % self.denominator == 0
> Thanks for your help on this.  I must admit that nowhere in a lot of
> searching did I find that delegation is achieved by doing nothing!
>
>     Brian

That's *not* "doing nothing".   And it's not even really "delegation".  
It's just sub-classing Fraction to add one new method and inherit all 
other methods.

Gary Herron


-- 
Dr. Gary Herron
Department of Computer Science
DigiPen Institute of Technology
(425) 895-4418



From noone at nowhere.net  Sat Jan 24 18:52:06 2015
From: noone at nowhere.net (Brian Gladman)
Date: Sat, 24 Jan 2015 23:52:06 +0000
Subject: Delegation in Python
In-Reply-To: <mailman.18108.1422142883.18130.python-list@python.org>
References: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>
 <CAPTjJmoVxi_VXKJ93W=rPNnZiud6O_mXyxm+2tMG8BoQBqH-Ew@mail.gmail.com>
 <mailman.18108.1422142883.18130.python-list@python.org>
Message-ID: <UridnbK49sm5rVnJnZ2dnUVZ7radnZ2d@brightview.co.uk>

On 24/01/2015 23:41, Gary Herron wrote:

[snip]>
> You can always "monkey-path" the Fraction class on the fly to add a new
> method to it.  I think most would consider this a bad idea, but it does
> work.
> Try this:
> 
>>>> from fractions import Fraction
>>>> def is_integer(self):
> ...     return self.numerator % self.denominator == 0
> ...
>>>> Fraction.is_integer = is_integer # Monkey-patch Fraction
>>>>
>>>> Fraction(1,2).is_integer()
> False
>>>> Fraction(2,1).is_integer()
> True

Thanks Gary.  As Chris says, the method he suggests is problematic since
anything delegated returns a Fraction, not an RF.  Patching Fraction
looks nicer to use even if it is frowned on.

   Brian



From cpisz at austin.rr.com  Sat Jan 24 18:53:19 2015
From: cpisz at austin.rr.com (Christopher J. Pisz)
Date: Sat, 24 Jan 2015 17:53:19 -0600
Subject: Hello World in Python
Message-ID: <ma1b8f$pgf$1@dont-email.me>

I am trying to help a buddy out. I am a C++ on Windows guy. This buddy 
of mine is learning Python at work on a Mac. I figured I could 
contribute with non language specific questions and such.

When learning any new language, I said, the first step would be a Hello 
World program. Let's see if we can get that to work.

So my buddy creates opens the IDE they gave at the workplace, creates a 
new project, adds a demo.py file, writes one line : print "Hello World", 
hits Run in the IDE and indeed the display is shown at the bottom when 
it executes.

I say the next step would be to get that to run on the command line. So 
(keep in mind I know nothing about macs) my buddy opens a "zsh?" window, 
cd to the directory, and I say the command i most likely: python demo.py

It looks like it executes but there is no output to the command line window.

Can anyone explain why there is no output?
Can anyone recommend a good walkthrough of getting set up and doing basics?

It seems they jumped ahead at my buddy's workplace and want them to 
write a complicated script called by a "harness". I can only assume this 
harness is some compiled executable that takes python scripts as 
arguments and calls certain functions defined within them.

I'll probably end up learning python myself, just to help out. I hate to 
see someone making an effort to learn and not having the resources.


From breamoreboy at yahoo.co.uk  Sat Jan 24 18:55:31 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 24 Jan 2015 23:55:31 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <e072e82f-1faa-4be3-814f-9addaea971ef@googlegroups.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <9a6694a5-5774-415a-b28a-7a9425a9112a@googlegroups.com>
 <54c34e68$0$12976$c3e8da3$5496439d@news.astraweb.com>
 <e072e82f-1faa-4be3-814f-9addaea971ef@googlegroups.com>
Message-ID: <ma1bdq$sq1$1@ger.gmane.org>

On 24/01/2015 23:20, Rick Johnson wrote:
> On Saturday, January 24, 2015 at 1:49:08 AM UTC-6, Steven D'Aprano wrote:
>> Rick Johnson wrote:
>>
>> [... snip absurdities...]
>>
>>> Duh! Do you think i just pulled stub files out my arse
>>> without giving all the other alternatives due consideration?
>>
>> Actually, yes. I think that had Guido proclaimed that
>> C-style header files were the only way to give type hints,
>> you would be arguing right now that they were awful and
>> that the one and only correct way to do type-hinting is to
>> use annotations.
>
> So now we arrive at the true nature of our conflict: your
> "false projections" of my "true intentions".
>
> Listen, I hold a deep respect for Guido's achievements and
> his intellectual prowess, but i'm not about to kiss is
> backside when i feel he is wrong, and this "type hints" idea
> is dangerously wrong!

For at least the third time the PEP was written by three people, one of 
whom was the BDFL.  Why do you keep insisting that "he" is wrong, surely 
it should be "they" ?

>
> Diversity, dissension, and conflict are our friends, not
> enemies to be feared. We must embrace those ideas that are
> foreign to us, give them due consideration, and objectively
> apply "weighted values" to them. Whereas, sitting in a room
> surrounded by mirrors and becoming lost in the recursive
> "reflection of self", is not evolution, but merely, an
> illusion.
>
> Besides, why does he need *ME* to lick his boots when he
> already has plenty of fan-boys over at python-ideas and
> python-dev lining up. This community is *NOT*, and should
> never be, a homogeneous block -- for we would be doing
> ourselves a disservice.

A substantial number of people on both lists are perfectly happy to 
speak their mind, to the extent that Guido has been known to do u-turns. 
  Nobody has any need to lick anybody's boots, and to suggest that this 
is the case I find highly insulting to the entire Python community.

>
> So if you cannot provide me with respect that i *DESERVE* as
> a member of this fine community, then you should at least
> admit that my presence is a vital counterbalance to prevent
> this tiny life-vessel from capsizing as it's thrashed around
> the treacherous "seas of evolution".
>

You (singular) have to *EARN* respect, you do not deserve it.  If you 
were to stick to subjects that you have knowledge of, such as 
tkinter/IDLE, you would earn that respect.  Serving up dross as you do 
so often gets you nothing except plonks.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From noone at nowhere.net  Sat Jan 24 18:58:39 2015
From: noone at nowhere.net (Brian Gladman)
Date: Sat, 24 Jan 2015 23:58:39 +0000
Subject: Delegation in Python
In-Reply-To: <mailman.18111.1422143281.18130.python-list@python.org>
References: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>
 <mailman.18106.1422141738.18130.python-list@python.org>
 <5ZKdnd6rbdZ3sVnJnZ2dnUVZ8mCdnZ2d@brightview.co.uk>
 <mailman.18111.1422143281.18130.python-list@python.org>
Message-ID: <2didnRFXOrIwrFnJnZ2dnUVZ8iednZ2d@brightview.co.uk>

On 24/01/2015 23:47, Gary Herron wrote:
> On 01/24/2015 03:38 PM, Brian Gladman wrote:
>> On 24/01/2015 23:22, Chris Angelico wrote:
>>> class RF(Fraction):
>>>      def is_integer(self):
>>>         return self.numerator % self.denominator == 0
>> Thanks for your help on this.  I must admit that nowhere in a lot of
>> searching did I find that delegation is achieved by doing nothing!
>>
>>     Brian
> 
> That's *not* "doing nothing".   And it's not even really "delegation". 
> It's just sub-classing Fraction to add one new method and inherit all
> other methods.

I realised that - I was being whimsical.

I really did want true delgation so that I get an RF returned even when
I delegate to Fractions.

   Brian



From breamoreboy at yahoo.co.uk  Sat Jan 24 18:59:35 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 24 Jan 2015 23:59:35 +0000
Subject: Delegation in Python
In-Reply-To: <54C42D9D.7010305@digipen.edu>
References: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>
 <CAPTjJmoVxi_VXKJ93W=rPNnZiud6O_mXyxm+2tMG8BoQBqH-Ew@mail.gmail.com>
 <54C42D9D.7010305@digipen.edu>
Message-ID: <ma1ble$cn$1@ger.gmane.org>

On 24/01/2015 23:41, Gary Herron wrote:
> On 01/24/2015 03:22 PM, Chris Angelico wrote:
>> On Sun, Jan 25, 2015 at 9:57 AM, Brian Gladman <noone at nowhere.net> wrote:
>>> But I am not clear on how to delegate from my new class to the existing
>>> Fraction class.  This is what I have:
>>>
>>> --------------------------
>>> class RF(Fraction):
>>>
>>>    def __new__(self, x, y):
>>>      super().__new__(self, x, y)
>>>
>>>    def is_integer(self):
>>>      return self.numerator % self.denominator == 0
>>>
>>>    def __getattr__(self, attr):
>>>      return getattr(self, attr)
>> If you just drop everything but your new method, it should work just
>> fine.
>>
>> class RF(Fraction):
>>      def is_integer(self):
>>         return self.numerator % self.denominator == 0
>>
>> However, this doesn't ensure that operations on RFs will return more
>> RFs - they'll often return Fractions instead. There's no easy fix for
>> that, sorry.
>>
>> ChrisA
>
> You can always "monkey-path" the Fraction class on the fly to add a new
> method to it.  I think most would consider this a bad idea, but it does
> work.
> Try this:
>
>  >>> from fractions import Fraction
>  >>> def is_integer(self):
> ...     return self.numerator % self.denominator == 0
> ...
>  >>> Fraction.is_integer = is_integer # Monkey-patch Fraction
>  >>>
>  >>> Fraction(1,2).is_integer()
> False
>  >>> Fraction(2,1).is_integer()
> True
>
>
> Gary Herron
>

As regards this being a bad idea I'd suggest the latest score is 
Practicality 1 Purity 0 :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rosuav at gmail.com  Sat Jan 24 19:05:12 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 25 Jan 2015 11:05:12 +1100
Subject: Hello World in Python
In-Reply-To: <ma1b8f$pgf$1@dont-email.me>
References: <ma1b8f$pgf$1@dont-email.me>
Message-ID: <CAPTjJmorSLDsGHgSMyOsCzpjW5bJsD4y0C0488uPjA7v4Hz7hw@mail.gmail.com>

On Sun, Jan 25, 2015 at 10:53 AM, Christopher J. Pisz
<cpisz at austin.rr.com> wrote:
> So my buddy creates opens the IDE they gave at the workplace, creates a new
> project, adds a demo.py file, writes one line : print "Hello World", hits
> Run in the IDE and indeed the display is shown at the bottom when it
> executes.
>
> I say the next step would be to get that to run on the command line. So
> (keep in mind I know nothing about macs) my buddy opens a "zsh?" window, cd
> to the directory, and I say the command i most likely: python demo.py
>
> It looks like it executes but there is no output to the command line window.
>
> Can anyone explain why there is no output?
> Can anyone recommend a good walkthrough of getting set up and doing basics?

Your broad methodology is fine! I'd normally expect that to work
correctly. Was the file properly saved? Ask him to display the file
(cat demo.py) to make sure it's what he thinks. Or maybe he's in a
different directory to the one he thinks he's in; again, catting the
file will help. Otherwise, it might be a weird problem with his shell,
but that's hard to diagnose.

One thing that I really like doing with my Python students (full
disclosure: I'm a mentor with www.thinkful.com and am thus at times
paid to help people learn Python) is some form of screen-sharing, so I
can watch him/her trying things. There are a number of zero-dollar
ways to do this, and it helps enormously. Flip on screen-share, ask
him to run the script, and see where that leads.

Good luck!

ChrisA


From rosuav at gmail.com  Sat Jan 24 19:07:53 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 25 Jan 2015 11:07:53 +1100
Subject: Delegation in Python
In-Reply-To: <ma1ble$cn$1@ger.gmane.org>
References: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>
 <CAPTjJmoVxi_VXKJ93W=rPNnZiud6O_mXyxm+2tMG8BoQBqH-Ew@mail.gmail.com>
 <54C42D9D.7010305@digipen.edu> <ma1ble$cn$1@ger.gmane.org>
Message-ID: <CAPTjJmopb5XmwEyov8V4yXRDROAqzpLeH+BOs4pg6t5bRgocEg@mail.gmail.com>

On Sun, Jan 25, 2015 at 10:59 AM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
>> You can always "monkey-path" the Fraction class on the fly to add a new
>> method to it.  I think most would consider this a bad idea, but it does
>> work.
>
> As regards this being a bad idea I'd suggest the latest score is
> Practicality 1 Purity 0 :)

Indeed. But there's a huge difference between simple and complex
projects. I had a bit of a nightmare trying to figure out what was
going on with a project's logging... it looked like the Python logging
module, but there was another argument being processed, courtesy of
some monkey-patching. Try to keep these changes to small projects,
where it's easier to keep everything in your head; or for a temporary
bit of debugging, where you just want to do this temporarily and then
undo it again when you find the bug. Otherwise, it gets confusing for
the subsequent reader.

ChrisA


From salem055 at gmail.com  Sat Jan 24 19:16:16 2015
From: salem055 at gmail.com (Salem Alqahtani)
Date: Sat, 24 Jan 2015 16:16:16 -0800 (PST)
Subject: Python simple Code
Message-ID: <4e283f62-0b6a-4ef7-a784-b9b3da73f510@googlegroups.com>

Hi Guys,

I just joined the group and I hope that I can help and be active.

I have a question about python. I wrote a code on python 2.7 and I want to choose from the list of names that I provide n!. I execute the code but the result or output is the numbers. I want the people names are the result.


Sincerely

import sys
import array
a=['salem','Ali','sultan']
m = len(a)
def Factorials(m):
    if m == 0:
        return 1
    else:
        print m
        return m * Factorials(m-1)
def output():
    print a
def main():
    print Factorials(m)
    output()
main()


From noone at nowhere.net  Sat Jan 24 19:18:50 2015
From: noone at nowhere.net (Brian Gladman)
Date: Sun, 25 Jan 2015 00:18:50 +0000
Subject: Delegation in Python
In-Reply-To: <mailman.18109.1422143020.18130.python-list@python.org>
References: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>
 <mailman.18106.1422141738.18130.python-list@python.org>
 <5ZKdnd6rbdZ3sVnJnZ2dnUVZ8mCdnZ2d@brightview.co.uk>
 <mailman.18109.1422143020.18130.python-list@python.org>
Message-ID: <K8KdncuoKPL1q1nJnZ2dnUVZ8h2dnZ2d@brightview.co.uk>

On 24/01/2015 23:43, Chris Angelico wrote:
> On Sun, Jan 25, 2015 at 10:38 AM, Brian Gladman <noone at nowhere.net> wrote:
>> On 24/01/2015 23:22, Chris Angelico wrote:
>>> class RF(Fraction):
>>>     def is_integer(self):
>>>        return self.numerator % self.denominator == 0
>>
>> Thanks for your help on this.  I must admit that nowhere in a lot of
>> searching did I find that delegation is achieved by doing nothing!
> 
> Hehe :) If you want a technical look at it, what you have is the
> fundamental nature of subclassing: you derive from another class, and
> your class is identical to that with certain exceptions (in your case,
> an additional method). Python's way of handling that is called the
> Method Resolution Order or MRO, and you can find info on it on the
> web, eg:
> 
> http://python-history.blogspot.com/2010/06/method-resolution-order.html

Thanks for the further background.

Is there a way of doing delegation rather than sub-classing?

That is, can I create a class (say RF) that passes some of its methods
to Fraction for implementation but always returns an RF?

   Brian



From rosuav at gmail.com  Sat Jan 24 19:28:34 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 25 Jan 2015 11:28:34 +1100
Subject: Delegation in Python
In-Reply-To: <K8KdncuoKPL1q1nJnZ2dnUVZ8h2dnZ2d@brightview.co.uk>
References: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>
 <mailman.18106.1422141738.18130.python-list@python.org>
 <5ZKdnd6rbdZ3sVnJnZ2dnUVZ8mCdnZ2d@brightview.co.uk>
 <mailman.18109.1422143020.18130.python-list@python.org>
 <K8KdncuoKPL1q1nJnZ2dnUVZ8h2dnZ2d@brightview.co.uk>
Message-ID: <CAPTjJmq1_7BcJ1WjPvgBcY=XcW6-T7mw2UZcpbKCFddkMX6AwQ@mail.gmail.com>

On Sun, Jan 25, 2015 at 11:18 AM, Brian Gladman <noone at nowhere.net> wrote:
> Is there a way of doing delegation rather than sub-classing?
>
> That is, can I create a class (say RF) that passes some of its methods
> to Fraction for implementation but always returns an RF?

Hmm. The key here is that you want more than just delegation; you want
to transform every return value. That's not going to be easy. It would
be easiest and cleanest to skip the whole thing, and have a separate
function for what you're doing here - not a method, a stand-alone
function.

def is_integer(fr):
    return fr.numerator % fr.denominator == 0

Next best would be the monkey-patching option. Delegation with
transformation is a lot of effort for what you want.

ChrisA


From denismfmcmahon at gmail.com  Sat Jan 24 19:38:07 2015
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Sun, 25 Jan 2015 00:38:07 +0000 (UTC)
Subject: Python simple Code
References: <4e283f62-0b6a-4ef7-a784-b9b3da73f510@googlegroups.com>
Message-ID: <ma1dtf$v4t$1@dont-email.me>

On Sat, 24 Jan 2015 16:16:16 -0800, Salem Alqahtani wrote:

> import sys
> import array

> a=['salem','Ali','sultan']
> m = len(a)

> def Factorials(m):
>     if m == 0:
>         return 1
>     else:
>         print m
>         return m * Factorials(m-1)

> def output():
>     print a

> def main():
>     print Factorials(m)
>     output()

> main()

When I run the program, the output is:

3
2
1
6
['salem', 'Ali', 'sultan']

I'm not sure which output you think is wrong, or is not doing what you 
expect.

Observations:

a) There is no need to import array, you are only using a list.
b) If you try and index into a list using a number greater than the list 
length, you will receive an error "IndexError: list index out of range", 
hence if you have a list where len(list) is x items you will never be 
able to use x! as an index to the list.
c) To refer to a single member of a list, use list[n] where n is the zero 
indexed element you wish to refer to.
d) Note point b. l[len(l)!] (or l[Factorials(len(l))]) will always fail.

-- 
Denis McMahon, denismfmcmahon at gmail.com


From tjreedy at udel.edu  Sat Jan 24 19:55:18 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Sat, 24 Jan 2015 19:55:18 -0500
Subject: __bases__ misleading error message
In-Reply-To: <54C413E4.5060208@gmail.com>
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <mailman.18093.1422127493.18130.python-list@python.org>
 <54C413E4.5060208@gmail.com>
Message-ID: <ma1eto$emj$1@ger.gmane.org>

On 1/24/2015 4:51 PM, Marco Buttu wrote:
> On 24/01/2015 20:24, Terry Reedy wrote:
>
>> On 1/24/2015 5:16 AM, Mario Figueiredo wrote:
>>>
>>> Consider the following code at your REPL of choice
>>
>>>         class Sub:
>>>             pass
>>>
>>>         foo = Sub()
>>>
>>>         Sub.__bases__
>>>         foo.__bases__
>>>
>>> The last statement originates the following error:
>>
>> This is an anomalous situation.

'This situation' being that Someclass.attro works but Someclass().attro 
raises.

   Normally, if a class has an attribute,

In other words, if 'Someclass.attro' evaluates to an object

>> instances have the same attribute

then 'Someclass().attro' *normally* evaluates to the same object

>> (unless overriden).

(unless 'Someclass().attro' has been bound to a different object)
because attribute lookup on an instance reverts to attribute lookup on 
the class and even its super classes (__bases__).  Someclass.__bases__ 
is special; it is not listed by dir(Someclass), and it is not accessible 
via an instance.

> That is not true:

What I said, as I meant it to be understood, is true.

-- 
Terry Jan Reedy



From rantingrickjohnson at gmail.com  Sat Jan 24 20:00:24 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Sat, 24 Jan 2015 17:00:24 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <mailman.18112.1422143751.18130.python-list@python.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <9a6694a5-5774-415a-b28a-7a9425a9112a@googlegroups.com>
 <54c34e68$0$12976$c3e8da3$5496439d@news.astraweb.com>
 <e072e82f-1faa-4be3-814f-9addaea971ef@googlegroups.com>
 <mailman.18112.1422143751.18130.python-list@python.org>
Message-ID: <a40df9a9-a343-4459-b973-bd8a2bc2fd76@googlegroups.com>

On Saturday, January 24, 2015 at 5:56:02 PM UTC-6, Mark Lawrence wrote:
> For at least the third time the PEP was written by three
> people, one of whom was the BDFL.  Why do you keep
> insisting that "he" is wrong, surely it should be "they" ?

TWO REASONS:

  (1) I don't know either of those people. And they have
  never attempted to contact me, or even participate in
  discussions on this list.
  
  BUT MORE IMPORTANTLY:
  
  (2) Final decisions for additions to Python are via GvR.
  Why should i waste my time "appealing for sanity" to
  numerous people, when i can focus my attention on the only
  one that matters? 

But why must Guido be sheltered from dissent? With power 
comes responsibility!
  
> A substantial number of people on both lists are perfectly
> happy to speak their mind, to the extent that Guido has
> been known to do u-turns. Nobody has any need to lick
> anybody's boots, and to suggest that this is the case I
> find highly insulting to the entire Python community.

Enough with the spin-doctoring of my words, only boot
lickers would be offended by what i said, and that is the
whole point of saying it! Do you think boot lickers are a
valuable resource of this (or any) community? Or could it 
be that you just cannot accept an inconvenient truth.

> You (singular) have to *EARN* respect, you do not deserve
> it.  If you were to stick to subjects that you have
> knowledge of, such as tkinter/IDLE, 

Oh i see. I'm allowed to participate so long as i don't step
on YOUR toes or offend YOUR delicate sensibilities? So long
as i volunteer to be locked in YOUR little rat cage, and do
exactly what YOU say. Sorry Mark, but YOUR secret
aspirations for tyrannical rule are not going to be
"entertained" by THIS community.

This character assassination of me has to stop, and your one
of the prolific assassins on this list. Show me one time
that i have *EVER* intentionally misled a noob on this
list? You may find a sample where i've made an honest
mistake, or mis-comprehended a question, but don't you
*DARE* question my morals! 

I am one of the most honest and trustworthy people in this
community. You may find my style to be annoying, (that is
your opinion), but you have no right (and no evidence) to
question my integrity.

You can call me any name in the book you want; you can curse
me; you can ridicule me; and all of it i can ignore; but i
will NOT allow you to paint me as dishonest. I hold honesty
as the most important of *ALL* virtues. 

You owe me an apology for slandering my integrity! 


From tjreedy at udel.edu  Sat Jan 24 20:12:51 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Sat, 24 Jan 2015 20:12:51 -0500
Subject: Hello World in Python
In-Reply-To: <ma1b8f$pgf$1@dont-email.me>
References: <ma1b8f$pgf$1@dont-email.me>
Message-ID: <ma1fum$sjp$1@ger.gmane.org>

On 1/24/2015 6:53 PM, Christopher J. Pisz wrote:
> I am trying to help a buddy out. I am a C++ on Windows guy. This buddy
> of mine is learning Python at work on a Mac. I figured I could
> contribute with non language specific questions and such.
>
> When learning any new language, I said, the first step would be a Hello
> World program. Let's see if we can get that to work.
>
> So my buddy creates opens the IDE they gave at the workplace, creates a
> new project, adds a demo.py file, writes one line : print "Hello World",
> hits Run in the IDE and indeed the display is shown at the bottom when
> it executes.
>
> I say the next step would be to get that to run on the command line. So
> (keep in mind I know nothing about macs) my buddy opens a "zsh?" window,
> cd to the directory, and I say the command i most likely: python demo.py
>
> It looks like it executes but there is no output to the command line
> window.

It should.  In a Windows console, using 3.4:
C:\Programs\Python34>type tem.py  # cat on Mac?
print('Hello World!')

C:\Programs\Python34>python tem.py
Hello World!

 > Can anyone explain why there is no output?

Without a copy of the file and command, as above, no.

 > Can anyone recommend a good walkthrough of getting set up and doing 
basics?

Since you used 2.x  print syntax: https://docs.python.org/2.7/

"Python Setup and Usage
how to use Python on different platforms"

"Tutorial
start here"

 > I'll probably end up learning python myself, just to help out.

You might possibly enjoy Python as a complement to C++.  Some people 
prototype in Python and rewrite time critical functions in C++.  One can 
access .dlls either directly (via the ctypes module) and write a wrapper 
file in C or C++.  I believe Python has also been used to write tests 
for C++ functions (I know this is true for Python and Java, via Jython).

-- 
Terry Jan Reedy



From tjreedy at udel.edu  Sat Jan 24 20:15:56 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Sat, 24 Jan 2015 20:15:56 -0500
Subject: Python simple Code
In-Reply-To: <4e283f62-0b6a-4ef7-a784-b9b3da73f510@googlegroups.com>
References: <4e283f62-0b6a-4ef7-a784-b9b3da73f510@googlegroups.com>
Message-ID: <ma1g4e$utr$1@ger.gmane.org>

On 1/24/2015 7:16 PM, Salem Alqahtani wrote:
> Hi Guys,
>
> I just joined the group and I hope that I can help and be active.
>
> I have a question about python. I wrote a code on python 2.7 and I want to choose from the list of names that I provide n!. I execute the code but the result or output is the numbers. I want the people names are the result.
>
>
> Sincerely
>
> import sys
> import array
> a=['salem','Ali','sultan']
> m = len(a)
> def Factorials(m):
>      if m == 0:
>          return 1
>      else:
>          print m
>          return m * Factorials(m-1)
> def output():
>      print a
> def main():
>      print Factorials(m)
>      output()
> main()

When I copy, paste, and run this in Idle editor, I get the expected
 >>>
3
2
1
6
['salem', 'Ali', 'sultan']

-- 
Terry Jan Reedy



From tjreedy at udel.edu  Sat Jan 24 20:31:31 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Sat, 24 Jan 2015 20:31:31 -0500
Subject: Delegation in Python
In-Reply-To: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>
References: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>
Message-ID: <ma1h1l$bhr$1@ger.gmane.org>

On 1/24/2015 5:57 PM, Brian Gladman wrote:
> I would appreciate advice on how to set up delgation in Python.
>
> I am continuously implementing a function to test whether a Python
> Fraction is an integer

Since Fractions are reduced to lowest terms,
 >>> from fractions import Fraction as F
 >>> F(4, 2)
Fraction(2, 1)
 >>> F(12, 3)
Fraction(4, 1)

the test is that the denominator is 1

 >>> F(12,3).denominator == 1
True
 >>> F(12,5).denominator == 1
False

it may not be worth the bother to define a function,

def fint(F): return F.denominator == 1

>so I wanted to define a new class, based on
> Fraction, that includes this new method.

but if you do, there is little need to make it a method.  You are not 
overriding an existing method or adding a new special method.  The math 
module has float and int functions that have *not* been turned into 
methods.  Ditto for cmath.  I would just leave the function a function. 
  Python is not Java.

-- 
Terry Jan Reedy



From ethan at stoneleaf.us  Sat Jan 24 20:58:55 2015
From: ethan at stoneleaf.us (Ethan Furman)
Date: Sat, 24 Jan 2015 17:58:55 -0800
Subject: Alternative to multi-line lambdas: Assign-anywhere def statements
In-Reply-To: <CAPTjJmohdQbK9_ikh8heaMRbpJ270UW6C1AE2oNVgV_4AoYfQg@mail.gmail.com>
References: <CAPTjJmrAQgtauH74dwCzb_-6T09D0dLVkxiGrAxJMp_OOwgS0g@mail.gmail.com>
 <54C3EAD1.2010501@stoneleaf.us>
 <CAPTjJmohdQbK9_ikh8heaMRbpJ270UW6C1AE2oNVgV_4AoYfQg@mail.gmail.com>
Message-ID: <54C44DDF.3030107@stoneleaf.us>

On 01/24/2015 11:55 AM, Chris Angelico wrote:
> On Sun, Jan 25, 2015 at 5:56 AM, Ethan Furman <ethan at stoneleaf.us> wrote:
>> If the non-generic is what you're concerned about:
>>
>> # not tested
>> dispatch_table_a = {}
>> dispatch_table_b = {}
>> dispatch_table_c = {}
>>
>> class dispatch:
>>   def __init__(self, dispatch_table):
>>     self.dispatch = dispatch_table
>>   def __call__(self, func):
>>     self.dispatch[func.__name__] = func
>>     return func
>>
>> @dispatch(dispatch_table_a)
>> def foo(...):
>>    pass
> 
> That's still only able to assign to a key of a dictionary, using the
> function name. 

This is a Good Thing.  The def statement populates a few items, __name__ being one of them.  One of the reasons lambda
is not encouraged is because its name is always '<lambda>', which just ain't helpful when the smelly becomes air borne!  ;)

--
~Ethan~

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From drsalists at gmail.com  Sat Jan 24 21:11:43 2015
From: drsalists at gmail.com (Dan Stromberg)
Date: Sat, 24 Jan 2015 18:11:43 -0800
Subject: Benchmarking some modules - strange result
Message-ID: <CAGGBd_rSazrC4yAt+CebeuvCJYjZWOXohoZHgTUtfGNZZtr5Ww@mail.gmail.com>

Hi folks.

I've been benchmarking some python modules that are mostly variations
on the same theme.

For simplicity, let's say I've been running the suite of performance
tests within a single interpreter - so I test one module thoroughly,
then move on to the next without exiting the interpreter.

I'm finding that if I prune the list of modules down to just the best
performers, I get pretty different results - what was best no longer
is.  This strikes me as strange.

I'm forcing a garbage collection between tests with gc.collect(), but
even that yields the oddball results.

Is there something else I should do to restore the interpreter to a
known-pristine state for the sake of such tests?

BTW, there isn't much else going on on this computer, except some
possible small cronjobs.

I'm about ready to rewrite things to run each individual test in a
fresh interpreter. But is there a better way?

If I do the rewrite, I might run 1 run of module A, 1 run of module B,
1 run of module C, then another run of module A, another run of module
B, and another run of module C - to spread any possible timing
oddities more evenly.

Thanks.


From steve+comp.lang.python at pearwood.info  Sat Jan 24 21:22:17 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 25 Jan 2015 13:22:17 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17973.1421939508.18130.python-list@python.org>
 <54c2299d$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18029.1422013105.18130.python-list@python.org>
 <54c33d20$0$13011$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18086.1422110705.18130.python-list@python.org>
 <54c3c1b1$0$13011$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18088.1422116868.18130.python-list@python.org>
 <54c3d6d8$0$12988$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18091.1422125112.18130.python-list@python.org>
Message-ID: <54c45359$0$12975$c3e8da3$5496439d@news.astraweb.com>

Tim Chase wrote:

> On 2015-01-25 04:31, Steven D'Aprano wrote:
>> Of course we don't have $1/3 dollar coins, but I do have a pair of
>> tin-snips and can easily cut a $1 coin into three equal pieces.
> 
> I'm impressed that you can use tin-snips to cut it into exactly three
> equal pieces with greater precision than the floating point numbers
> that you're cautioning against in Python.  I believe at that point,
> you're talking about at least the sub-sub-sub-atomic scale. :-)

They're really good quality tin-snips.



-- 
Steven



From rosuav at gmail.com  Sat Jan 24 21:24:25 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 25 Jan 2015 13:24:25 +1100
Subject: Benchmarking some modules - strange result
In-Reply-To: <CAGGBd_rSazrC4yAt+CebeuvCJYjZWOXohoZHgTUtfGNZZtr5Ww@mail.gmail.com>
References: <CAGGBd_rSazrC4yAt+CebeuvCJYjZWOXohoZHgTUtfGNZZtr5Ww@mail.gmail.com>
Message-ID: <CAPTjJmr+9heLd44Ly=5oKrMcGBdBhWuDxmi_n1+izg=TxTB=sg@mail.gmail.com>

On Sun, Jan 25, 2015 at 1:11 PM, Dan Stromberg <drsalists at gmail.com> wrote:
> For simplicity, let's say I've been running the suite of performance
> tests within a single interpreter - so I test one module thoroughly,
> then move on to the next without exiting the interpreter.
> [chomp more details]

Do the modules import stuff that's staying imported? That could
majorly affect performance. What about .pyc files?

I don't know if you can truly reset the interpreter. Snapshotting
sys.modules and reinstating it afterwards would help, but there are
other concerns too. I would personally just restart the interpreter
each time, frankly; it's the easiest way to be sure.

ChrisA


From breamoreboy at yahoo.co.uk  Sat Jan 24 21:28:24 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 25 Jan 2015 02:28:24 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <a40df9a9-a343-4459-b973-bd8a2bc2fd76@googlegroups.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <9a6694a5-5774-415a-b28a-7a9425a9112a@googlegroups.com>
 <54c34e68$0$12976$c3e8da3$5496439d@news.astraweb.com>
 <e072e82f-1faa-4be3-814f-9addaea971ef@googlegroups.com>
 <mailman.18112.1422143751.18130.python-list@python.org>
 <a40df9a9-a343-4459-b973-bd8a2bc2fd76@googlegroups.com>
Message-ID: <ma1kcg$lao$1@ger.gmane.org>

On 25/01/2015 01:00, Rick Johnson wrote:
> On Saturday, January 24, 2015 at 5:56:02 PM UTC-6, Mark Lawrence wrote:
>> For at least the third time the PEP was written by three
>> people, one of whom was the BDFL.  Why do you keep
>> insisting that "he" is wrong, surely it should be "they" ?
>
> TWO REASONS:
>
>    (1) I don't know either of those people. And they have
>    never attempted to contact me, or even participate in
>    discussions on this list.
>
>    BUT MORE IMPORTANTLY:
>
>    (2) Final decisions for additions to Python are via GvR.
>    Why should i waste my time "appealing for sanity" to
>    numerous people, when i can focus my attention on the only
>    one that matters?
>
> But why must Guido be sheltered from dissent? With power
> comes responsibility!
>
>> A substantial number of people on both lists are perfectly
>> happy to speak their mind, to the extent that Guido has
>> been known to do u-turns. Nobody has any need to lick
>> anybody's boots, and to suggest that this is the case I
>> find highly insulting to the entire Python community.
>
> Enough with the spin-doctoring of my words, only boot
> lickers would be offended by what i said, and that is the
> whole point of saying it! Do you think boot lickers are a
> valuable resource of this (or any) community? Or could it
> be that you just cannot accept an inconvenient truth.
>
>> You (singular) have to *EARN* respect, you do not deserve
>> it.  If you were to stick to subjects that you have
>> knowledge of, such as tkinter/IDLE,
>
> Oh i see. I'm allowed to participate so long as i don't step
> on YOUR toes or offend YOUR delicate sensibilities? So long
> as i volunteer to be locked in YOUR little rat cage, and do
> exactly what YOU say. Sorry Mark, but YOUR secret
> aspirations for tyrannical rule are not going to be
> "entertained" by THIS community.
>
> This character assassination of me has to stop, and your one
> of the prolific assassins on this list. Show me one time
> that i have *EVER* intentionally misled a noob on this
> list? You may find a sample where i've made an honest
> mistake, or mis-comprehended a question, but don't you
> *DARE* question my morals!
>
> I am one of the most honest and trustworthy people in this
> community. You may find my style to be annoying, (that is
> your opinion), but you have no right (and no evidence) to
> question my integrity.
>
> You can call me any name in the book you want; you can curse
> me; you can ridicule me; and all of it i can ignore; but i
> will NOT allow you to paint me as dishonest. I hold honesty
> as the most important of *ALL* virtues.
>
> You owe me an apology for slandering my integrity!
>

You are now getting what I should have done some time ago as my patience 
with you has run out.

*plonk*

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From yawar.amin at gmail.com  Sat Jan 24 21:30:49 2015
From: yawar.amin at gmail.com (Yawar Amin)
Date: Sat, 24 Jan 2015 18:30:49 -0800 (PST)
Subject: Alternative to multi-line lambdas: Assign-anywhere def statements
In-Reply-To: <mailman.18121.1422151185.18130.python-list@python.org>
References: <CAPTjJmrAQgtauH74dwCzb_-6T09D0dLVkxiGrAxJMp_OOwgS0g@mail.gmail.com>
 <54C3EAD1.2010501@stoneleaf.us>
 <CAPTjJmohdQbK9_ikh8heaMRbpJ270UW6C1AE2oNVgV_4AoYfQg@mail.gmail.com>
 <mailman.18121.1422151185.18130.python-list@python.org>
Message-ID: <4741da2c-8fc5-4c06-bc3a-cfadca890abf@googlegroups.com>

Hi Ethan,

On Saturday, January 24, 2015 at 9:00:12 PM UTC-5, Ethan Furman wrote:
> [...]
> __name__ being one of them.  One of the reasons lambda
> is not encouraged is because its name is always '<lambda>', which just
> ain't helpful when the smelly becomes air borne!  ;)

Doesn't the traceback tell us exactly where the lambda was called from?

Regards,

Yawar


From drsalists at gmail.com  Sat Jan 24 21:36:01 2015
From: drsalists at gmail.com (Dan Stromberg)
Date: Sat, 24 Jan 2015 18:36:01 -0800
Subject: Benchmarking some modules - strange result
In-Reply-To: <CAPTjJmr+9heLd44Ly=5oKrMcGBdBhWuDxmi_n1+izg=TxTB=sg@mail.gmail.com>
References: <CAGGBd_rSazrC4yAt+CebeuvCJYjZWOXohoZHgTUtfGNZZtr5Ww@mail.gmail.com>
 <CAPTjJmr+9heLd44Ly=5oKrMcGBdBhWuDxmi_n1+izg=TxTB=sg@mail.gmail.com>
Message-ID: <CAGGBd_q33YGH9ZwOv4oTE6LERxbf55HyOM07TpWznjMumz1yKw@mail.gmail.com>

On Sat, Jan 24, 2015 at 6:24 PM, Chris Angelico <rosuav at gmail.com> wrote:
> On Sun, Jan 25, 2015 at 1:11 PM, Dan Stromberg <drsalists at gmail.com> wrote:
>> For simplicity, let's say I've been running the suite of performance
>> tests within a single interpreter - so I test one module thoroughly,
>> then move on to the next without exiting the interpreter.
>> [chomp more details]
>
> Do the modules import stuff that's staying imported? That could
> majorly affect performance. What about .pyc files?

The modules are all imported up at the top of the script.  I haven't
verified this, but I'm guessing the .pyc's are created at the
beginning too.

> I don't know if you can truly reset the interpreter. Snapshotting
> sys.modules and reinstating it afterwards would help, but there are
> other concerns too. I would personally just restart the interpreter
> each time, frankly; it's the easiest way to be sure.

Maybe so ^_^


From rosuav at gmail.com  Sat Jan 24 21:37:52 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 25 Jan 2015 13:37:52 +1100
Subject: Benchmarking some modules - strange result
In-Reply-To: <CAGGBd_q33YGH9ZwOv4oTE6LERxbf55HyOM07TpWznjMumz1yKw@mail.gmail.com>
References: <CAGGBd_rSazrC4yAt+CebeuvCJYjZWOXohoZHgTUtfGNZZtr5Ww@mail.gmail.com>
 <CAPTjJmr+9heLd44Ly=5oKrMcGBdBhWuDxmi_n1+izg=TxTB=sg@mail.gmail.com>
 <CAGGBd_q33YGH9ZwOv4oTE6LERxbf55HyOM07TpWznjMumz1yKw@mail.gmail.com>
Message-ID: <CAPTjJmpokq3EoAOMSKLAz7gp1kXPMon6_+TzhqetT4FoyhOGZQ@mail.gmail.com>

On Sun, Jan 25, 2015 at 1:36 PM, Dan Stromberg <drsalists at gmail.com> wrote:
> On Sat, Jan 24, 2015 at 6:24 PM, Chris Angelico <rosuav at gmail.com> wrote:
>> On Sun, Jan 25, 2015 at 1:11 PM, Dan Stromberg <drsalists at gmail.com> wrote:
>>> For simplicity, let's say I've been running the suite of performance
>>> tests within a single interpreter - so I test one module thoroughly,
>>> then move on to the next without exiting the interpreter.
>>> [chomp more details]
>>
>> Do the modules import stuff that's staying imported? That could
>> majorly affect performance. What about .pyc files?
>
> The modules are all imported up at the top of the script.  I haven't
> verified this, but I'm guessing the .pyc's are created at the
> beginning too.

Yeah, so it's probably not that. I should have known you'd have
covered the easy possibilities already :)

That's me out of ideas.

ChrisA


From rantingrickjohnson at gmail.com  Sat Jan 24 21:56:31 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Sat, 24 Jan 2015 18:56:31 -0800 (PST)
Subject: apostrophe not considered with tkinter's wordstart and wordend
In-Reply-To: <m9rtd8$15e$1@dont-email.me>
References: <e6143cd5-3475-431a-b2cf-17fd9659681c@googlegroups.com>
 <655cce0d-2db3-4a0d-ab3d-64d5db5e1634@googlegroups.com>
 <714d9211-9b50-4e62-a7dd-25ff94a32d8a@googlegroups.com>
 <f1bcb866-b07f-478d-83a4-dcf4b2b096e5@googlegroups.com>
 <m9rtd8$15e$1@dont-email.me>
Message-ID: <c1bc4c74-0360-4816-884a-4ebff24e2bab@googlegroups.com>

On Thursday, January 22, 2015 at 4:26:29 PM UTC-6, Christian Gollwitzer wrote:

> Well, it turns out you actually can. We don't have Guido's
> time machine, but still there is a configuration option in
> Tk, albeit a very obscure one: you have to set the global
> Tcl variables tcl_wordchars and tcl_nonwordchars after
> loading Tk to a regexp which defines the word boundaries:
> 
> 	http://wiki.tcl.tk/1655
> 
> Strangely, there is a different preset for Windows and
> X11. The Windows preset - consider everything besides
> space as part of the word - makes more sense to me than
> the Unix default, which only counts letters, numbers and
> underscores as part of the word. To set the Windows
> preset, do this:
> 
> tk.eval('set tcl_wordchars {\S}');
> tk.eval('set tcl_nonwordchars {\s}');
> 
> (untested in Python, only tested directly from a wish shell)

Hmm. Thanks for posting this, but i could not get it to
work??? I tried all sorts of sensible patterns but
nothing works.

Below is a simple testing app with bindings which highlight the
word under the mouse like the OP requested. If you can modify
the word boundaries so that it captures the equivalent of this
pattern r"'\w+'", then i will write a wrapper method for the
Tkinter module for arbitrarily modifying the boundaries. 

Here is the code, happy hacking ;-)

## START CODE ##

import Tkinter as tk
from Tkconstants import YES, BOTH, END

SIDX = '1.0'
STR = """
My humble dictators,
ask not what the 'boot_lickers' can do for you,
ask what *YOU* can do to for *YOUR* community!
"""

class MyText(tk.Text):
    def __init__(self, master, **kw):
        tk.Text.__init__(self, master, **kw)
        self.bind("<Button-1>", self.evtButtonOneDown)
        self.tag_add('hit', END)
        self.tag_config('hit', background='red')

    def evtButtonOneDown(self, event):
        sLC = self.index('current wordstart')
        eLC = self.index('current wordend')
        print 'hitspan from {0!r} to {1!r}'.format(sLC, eLC)
        self.tag_remove('hit', SIDX, 'end')
        self.tag_add('hit', sLC, eLC)
        
if __name__ == '__main__':
    root = tk.Tk()
##    root.eval("set tcl_wordchars {psst: over here!}")
##    root.eval("set tcl_nonwordchars {psst: and here too!}")
    et = MyText(root, undo=True)
    et.insert(SIDX, STR)
    et.pack(fill=BOTH, expand=YES)
    root.mainloop()
    
## END CODE ##



From ravas at outlook.com  Sat Jan 24 22:17:40 2015
From: ravas at outlook.com (ravas)
Date: Sat, 24 Jan 2015 19:17:40 -0800 (PST)
Subject: apostrophe not considered with tkinter's wordstart and wordend
In-Reply-To: <c1bc4c74-0360-4816-884a-4ebff24e2bab@googlegroups.com>
References: <e6143cd5-3475-431a-b2cf-17fd9659681c@googlegroups.com>
 <655cce0d-2db3-4a0d-ab3d-64d5db5e1634@googlegroups.com>
 <714d9211-9b50-4e62-a7dd-25ff94a32d8a@googlegroups.com>
 <f1bcb866-b07f-478d-83a4-dcf4b2b096e5@googlegroups.com>
 <m9rtd8$15e$1@dont-email.me>
 <c1bc4c74-0360-4816-884a-4ebff24e2bab@googlegroups.com>
Message-ID: <b1ea0c95-38aa-47b8-a8a2-dd80c3dcb8a5@googlegroups.com>

We resolved it over at the comp.lang.tcl group.
It turns out what Christian suggested affects what is selected when you double click a word. He later discovered a different method for producing what I want.
Below is my test code that implements both of these things
(tested with Python 3.4 and PyCharm).

import tkinter
import tkinter.messagebox as messagebox

class Creator(object):

    def __init__(self):

        root = self.root = tkinter.Tk()
       
        # Main Frame
        f_main = tkinter.Frame(root, borderwidth=6, relief='flat')
        f_main.grid(row=0, column=0, sticky='nsew')

        # Text widget, its font and frame
        f_txt = tkinter.Frame(f_main, borderwidth=2, relief="sunken")
        f_txt.config(width=768, height=768)

        f_txt.grid_propagate(False)  # ensures a consistent GUI size
        f_txt.pack(padx=4, pady=4, side="bottom", fill="both", expand=True)

        my_txt = tkinter.Text(f_txt, name='t')
        my_txt.config(undo=True, wrap='word')
        my_txt.grid(row=0, column=0, sticky="nsew")
        self.text = my_txt

        # Scrollbar and config
        f_scroll = tkinter.Frame(root, borderwidth=4, relief="groove")
        f_scroll.grid(row=0, column=1, sticky='nsew')
        scrollbar = tkinter.Scrollbar(f_scroll, command=my_txt.yview)
        scrollbar.pack(side='left', fill='y', pady=2, padx=0, expand=True)

        my_txt.config(yscrollcommand=scrollbar.set)
        scrollbar.columnconfigure(0, weight=1)

        # Stretchable
        root.columnconfigure(0, weight=1)
        root.rowconfigure(0, weight=1)
        f_main.columnconfigure(0, weight=1)
        f_main.rowconfigure(0, weight=1)
        f_txt.rowconfigure(0, weight=1)
        f_txt.columnconfigure(0, weight=1)

        my_txt.bind("<ButtonRelease-3>", self.test)
        my_txt.focus_set()

    def test(self, event=None):
        txt = str(self.text)
        a = "::tk::TextPrevPos {} current tcl_wordBreakBefore".format(txt)
        b = "::tk::TextNextPos {} current tcl_wordBreakAfter".format(txt)
        ind1 = self.root.tk.eval(a)
        ind2 = self.root.tk.eval(b)
        x = self.text.get(ind1, ind2)
        messagebox.showinfo('info', x)

# ===========================================================================
# start up
# ===========================================================================

GUI = Creator()
GUI.root.tk.eval("catch {tcl_endOfWord}")
GUI.root.tk.eval("catch {tcl_startOfPreviousWord}")
GUI.root.tk.eval("set tcl_wordchars {[[:alnum:]']}")
GUI.root.tk.eval("set tcl_nonwordchars {[^[:alnum:]']}")
GUI.root.mainloop()


From steve+comp.lang.python at pearwood.info  Sat Jan 24 22:18:01 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 25 Jan 2015 14:18:01 +1100
Subject: __bases__ misleading error message
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
Message-ID: <54c4606a$0$13002$c3e8da3$5496439d@news.astraweb.com>

Mario Figueiredo wrote:

> But that begs the OT question: How does Python maps names to memory
> addresses in the interpreter?

It doesn't.

You are thinking of an execution model like C or Pascal, where variables are
best thought of as fixed memory addresses. But Python, like many modern
languages (Java, Ruby, Lua, ...) uses a name-binding model.

Semantically, the fixed memory address model means that each variable is
like a fixed-width bucket, where the size depends on the type. That's why
the compiler needs to associate a fixed type with each variable, so it
knows how much space to allocate and how to initialise the bytes:

m = [0000]
n = [0000]
x = [8FFFFFFF]

Assigning a value to a variable ("m = 42", hex 2A) results in the compiler
storing that value in the bucket; assignment makes a copy: "n = m" leads to
two independent buckets with the same value:

m = [002A]
n = [002A]

Values and variables are dependent on each other. You can't have a variable
with no value, and you can't have a value with no variable. (This is an
over-simplification, but mostly true.)

The name-binding model is different. Values (objects) and names are
independent. Values can exist even if they have no name (although the
garbage collector will delete them as soon as they are unused). The
compiler associates a name to a value. One good mental model is to think of
the compiler attaching a piece of string from the name to its associated
object. Assigning n = m means that both names end up tied to the same
object, and there can be objects with no associated name. (So long as
*something* refers to them, the garbage collector will leave them be.)


m -----------------+----------- 0x2A
n ----------------/
x ----------------------------- 1.2345
s -----\                        "Hello world"
        +---------------------- "Goodbye now"


Under the hood, this is usually implemented using pointers. If you are
familiar with pointer semantics, you might think of these pieces of string
as pointers, except that you cannot do pointer arithmetic on them. But that
is merely the *implementation* of the language's variable model.

In Python, global variables use a dict, and there is a function to retrieve
that dict:


py> d = globals()
py> d['x'] = 23  # don't do this!
py> x
23


It's not *wrong* or forbidden to write to globals this way. It's just
unnecessary.


>     "__main__"
>     from module import a_name
>     y = a_name + 1
> 
> How does python interpreter know how to map 'name' to the correct memory
> location, if this __main__ code is only ran after 'module' code?

When the statement `from module import a_name` executes, Python:

(1) imports module;
(2) looks up "a_name" in module's namespace (a dict);
(3) creates an entry "a_name" in the current namespace (assuming 
    one doesn't already exist);
(4) and binds it to the object found in Step 2.

When it executes `y = a_name + 1`, Python:

(1) looks up the name "a_name" in the current namespace;
(2) creates the anonymous object 1, unbound to any name;
(3) calls + with those two objects;
(4) which (assuming it succeeds) creates a new object;
(5) creates an entry "y" in the current namespace;
(6) and binds it to the object returned in Step 4.



-- 
Steven



From drsalists at gmail.com  Sat Jan 24 22:26:05 2015
From: drsalists at gmail.com (Dan Stromberg)
Date: Sat, 24 Jan 2015 19:26:05 -0800
Subject: Benchmarking some modules - strange result
In-Reply-To: <CAPTjJmpokq3EoAOMSKLAz7gp1kXPMon6_+TzhqetT4FoyhOGZQ@mail.gmail.com>
References: <CAGGBd_rSazrC4yAt+CebeuvCJYjZWOXohoZHgTUtfGNZZtr5Ww@mail.gmail.com>
 <CAPTjJmr+9heLd44Ly=5oKrMcGBdBhWuDxmi_n1+izg=TxTB=sg@mail.gmail.com>
 <CAGGBd_q33YGH9ZwOv4oTE6LERxbf55HyOM07TpWznjMumz1yKw@mail.gmail.com>
 <CAPTjJmpokq3EoAOMSKLAz7gp1kXPMon6_+TzhqetT4FoyhOGZQ@mail.gmail.com>
Message-ID: <CAGGBd_oAKeW7dHg4mGn6P0JZPHzhXZ1gZ-GUFiMfkZREw6S9Dw@mail.gmail.com>

On Sat, Jan 24, 2015 at 6:37 PM, Chris Angelico <rosuav at gmail.com> wrote:
> On Sun, Jan 25, 2015 at 1:36 PM, Dan Stromberg <drsalists at gmail.com> wrote:
>> On Sat, Jan 24, 2015 at 6:24 PM, Chris Angelico <rosuav at gmail.com> wrote:
>>> On Sun, Jan 25, 2015 at 1:11 PM, Dan Stromberg <drsalists at gmail.com> wrote:
>>>> For simplicity, let's say I've been running the suite of performance
>>>> tests within a single interpreter - so I test one module thoroughly,
>>>> then move on to the next without exiting the interpreter.
>>>> [chomp more details]
>>>
>>> Do the modules import stuff that's staying imported? That could
>>> majorly affect performance. What about .pyc files?
>>
>> The modules are all imported up at the top of the script.  I haven't
>> verified this, but I'm guessing the .pyc's are created at the
>> beginning too.
>
> Yeah, so it's probably not that. I should have known you'd have
> covered the easy possibilities already :)

No problem!  Thanks for helping me make sure I covered the easy stuff.


From rantingrickjohnson at gmail.com  Sat Jan 24 22:57:26 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Sat, 24 Jan 2015 19:57:26 -0800 (PST)
Subject: apostrophe not considered with tkinter's wordstart and wordend
In-Reply-To: <b1ea0c95-38aa-47b8-a8a2-dd80c3dcb8a5@googlegroups.com>
References: <e6143cd5-3475-431a-b2cf-17fd9659681c@googlegroups.com>
 <655cce0d-2db3-4a0d-ab3d-64d5db5e1634@googlegroups.com>
 <714d9211-9b50-4e62-a7dd-25ff94a32d8a@googlegroups.com>
 <f1bcb866-b07f-478d-83a4-dcf4b2b096e5@googlegroups.com>
 <m9rtd8$15e$1@dont-email.me>
 <c1bc4c74-0360-4816-884a-4ebff24e2bab@googlegroups.com>
 <b1ea0c95-38aa-47b8-a8a2-dd80c3dcb8a5@googlegroups.com>
Message-ID: <f7664734-b001-4b56-a0cd-38c8e2125da8@googlegroups.com>

On Saturday, January 24, 2015 at 9:17:57 PM UTC-6, ravas wrote:
> We resolved it over at the comp.lang.tcl group. It turns
> out what Christian suggested affects what is selected when
> you double click a word. He later discovered a different
> method for producing what I want. Below is my test code
> that implements both of these things

Great. I did not run the code so i'll take your word that
it solved the issue for you. *wink* 

However, i must admit i did find your design a bit strange
to my eyes though. It seems you may be encapsulating too
much in that Creator class, whilst not exposing enough.  I
wonder why you did not subclass a tk.Text? 

Also, instead of packing multiple frames into a "master
grid" you could just use the grid for everything and remove
all those frames -- might help reduce some syntactical
density.

But hey, if you're happy, no need to change it! Working code
is better than incomprehensible code. In any event, i'm
happy you guys sorted it out. Posting a solution for the
next guy is always a good thing to do. 


From steve+comp.lang.python at pearwood.info  Sat Jan 24 23:07:54 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 25 Jan 2015 15:07:54 +1100
Subject: Benchmarking some modules - strange result
References: <mailman.18122.1422151905.18130.python-list@python.org>
Message-ID: <54c46c1a$0$13004$c3e8da3$5496439d@news.astraweb.com>

Dan Stromberg wrote:

> Hi folks.
> 
> I've been benchmarking some python modules that are mostly variations
> on the same theme.
> 
> For simplicity, let's say I've been running the suite of performance
> tests within a single interpreter - so I test one module thoroughly,
> then move on to the next without exiting the interpreter.

In principle, that could mean that you have more available memory when the
first module runs than when the last one runs. If one module leaves behind
a large data structure, that might make it harder to allocate memory for
the modules that follow.


> I'm finding that if I prune the list of modules down to just the best
> performers, I get pretty different results - what was best no longer
> is.  This strikes me as strange.

Without seeing exactly what is going on, I cannot comment except to say that
on modern computers, timing results are always strange :-)

There are just too many variables to make sense of what is going on. Do the
modules create large data structures which may still be hanging around from
one run to the next? Are you modifying the code in the source file and then
using reload()? Are you re-using instances created before the reload?

How are you timing your code? Are you timing fast operations or slow
operations? The right way to do things will depend on whether you are
trying to time a fast operation that completes in a few milliseconds, or a
slow one that takes a minute or two.

Is garbage collection enabled or disabled during the tests?

Ideally, you should try to eliminate as much of that complexity as possible.
Set up a single set of tests as a script, then run the script. Make your
changes to the modules, then run the script again.

 
> I'm forcing a garbage collection between tests with gc.collect(), but
> even that yields the oddball results.

Just because you run the gc between tests doesn't necessarily mean it won't
run in the middle of a test too.


> Is there something else I should do to restore the interpreter to a
> known-pristine state for the sake of such tests?

Yes. Kill the interpreter and re-start it.



> BTW, there isn't much else going on on this computer, except some
> possible small cronjobs.

There's *always* something else going on. Here's my computer right now:

[steve at ando ~]$ ps aux | wc -l  # count how many processes are active
272

And running top:

top - 14:45:10 up 85 days, 14:44, 25 users,  load average: 0.08, 0.19, 0.26
Tasks: 270 total,   1 running, 269 sleeping,   0 stopped,   0 zombie
Cpu(s):  4.3%us,  2.7%sy,  0.0%ni, 87.4%id,  3.6%wa,  0.5%hi,  1.5%si, 
0.0%st
Mem:   3106896k total,  3001412k used,   105484k free,    61864k buffers
Swap:  4192824k total,  1305304k used,  2887520k free,   408776k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
28392 steve     15   0 2407m 2.0g  14m S  7.6 69.1  12:40.48 opera
 3303 root      15   0  478m  23m 2084 S  2.3  0.8   4900:02 Xorg
 2654 root      15   0     0    0    0 S  1.7  0.0  33:51.45 nfsd
  426 root      10  -5     0    0    0 S  1.3  0.0 279:37.70 md3_raid1
 2651 root      16   0     0    0    0 S  0.7  0.0  33:36.65 nfsd
 2652 root      15   0     0    0    0 S  0.7  0.0  33:38.93 nfsd
 3525 steve     15   0 1035m 8532 4864 S  0.7  0.3 374:58.94 swriter.bin
28897 steve     15   0  2444 1144  808 R  0.7  0.0   0:00.13 top
 2467 root      21   0 23220  652  512 S  0.3  0.0   4:00.86 pcscd
 2653 root      15   0     0    0    0 S  0.3  0.0  33:13.85 nfsd
 4251 steve     15   0 36360 7504 4512 S  0.3  0.2   1:00.62 konsole
26841 annie     15   0  2744 1032  916 S  0.3  0.0   0:00.12 imap
    1 root      15   0  2176  412  388 S  0.0  0.0   0:02.65 init
    2 root      RT  -5     0    0    0 S  0.0  0.0   0:01.49 migration/0
    3 root      34  19     0    0    0 S  0.0  0.0   0:18.77 ksoftirqd/0
    4 root      RT  -5     0    0    0 S  0.0  0.0   0:00.00 watchdog/0
    5 root      RT  -5     0    0    0 S  0.0  0.0   0:01.19 migration/1
    6 root      34  19     0    0    0 S  0.0  0.0   0:21.81 ksoftirqd/1
    7 root      RT  -5     0    0    0 S  0.0  0.0   0:00.00 watchdog/1
[...]


Even with a load average of 0.08 (practically idling), I have nearly 300
running processes. Most of them are sleeping at any specific instance, but
the OS is constantly waking them, letting them run for a fraction of a
second, then putting them back to sleep. The above snapshot of my system
just happened to catch the system at the moment that only top itself was
active (or rather, top's output was generated at a moment when only top was
active), but that's just luck. If you sit and watch top for a minute or so,
with your hands off the keyboard and mouse so you aren't changing anything,
you will see the number of running processes go up and down, and even the
number of processes going up and down.

And remember, top only updates every two seconds or so, so you're only
seeing a fraction of the activity that is going on. Most of the activity
falls in between the snapshots.

 
> I'm about ready to rewrite things to run each individual test in a
> fresh interpreter. But is there a better way?
> 
> If I do the rewrite, I might run 1 run of module A, 1 run of module B,
> 1 run of module C, then another run of module A, another run of module
> B, and another run of module C - to spread any possible timing
> oddities more evenly.

I think that may be counter-productive. It means that any processor cache
issues etc. are more likely to occur, not less. I'm not an expert, but as I
understand it modern processors have caches to hold frequently used code,
and they are pretty good at predicting what code will be reused, but it
takes a while for the predictions to get good.

What that means from the point of view of timing Python code is that you
shouldn't do this, since you are defeating the CPU's attempts to predict
commonly used code:

# Time each function running 1000 times.
results = {}
for i in range(1000):
    for func in list_of_funcs:
        name = func.__name__
        t = time.time()
        x = func()
        t = time.time() - t
        results[name] = results.get(name, 0) + t

This results in running code A, B, C, D, A, B, C, D, ... which vastly
reduces the chances of code prediction and CPU caches being helpful. It
makes the times taken (1) longer and (2) more variable. But if you run your
tests A, A, A, ... A, B, B, B, ... B, C, C, C, ... you are working with the
CPU instead of against it, and timings may be less variable and faster.

As I said, I'm not an expert on modern CPUs, and everything I have just said
may have been utter nonsense :-)



-- 
Steven



From steve+comp.lang.python at pearwood.info  Sat Jan 24 23:27:20 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 25 Jan 2015 15:27:20 +1100
Subject: Alternative to multi-line lambdas: Assign-anywhere def statements
References: <CAPTjJmrAQgtauH74dwCzb_-6T09D0dLVkxiGrAxJMp_OOwgS0g@mail.gmail.com>
 <54C3EAD1.2010501@stoneleaf.us>
 <CAPTjJmohdQbK9_ikh8heaMRbpJ270UW6C1AE2oNVgV_4AoYfQg@mail.gmail.com>
 <mailman.18121.1422151185.18130.python-list@python.org>
 <4741da2c-8fc5-4c06-bc3a-cfadca890abf@googlegroups.com>
Message-ID: <54c470a9$0$12983$c3e8da3$5496439d@news.astraweb.com>

Yawar Amin wrote:

> Hi Ethan,
> 
> On Saturday, January 24, 2015 at 9:00:12 PM UTC-5, Ethan Furman wrote:
>> [...]
>> __name__ being one of them.  One of the reasons lambda
>> is not encouraged is because its name is always '<lambda>', which just
>> ain't helpful when the smelly becomes air borne!  ;)
> 
> Doesn't the traceback tell us exactly where the lambda was called from?

Yes (assuming the source code is available, which it may not be), but even
so, which is easier?

"Oh, the exception occurred in myfunc"

versus

"Hmmm, the exception occurred in a lambda, lets see now, that was called
by "f", but f might have called seven different lambdas, which one was it?
Oh, I see, f was called by g, and when we call g, this variable is set to
foo which only happens when bar was called first, which means that the
lambda must have been this one here..."


Using lambda is trading off convenience when writing the code for ease of
debugging the code when a problem occurs. Whether that trade-off is
worthwhile or not depends on factors such as how likely the lambda is to
have a bug, how many of them there are, and whether or not there is
uncertainty as to which one is called from where.



-- 
Steven



From jeanpierreda at gmail.com  Sat Jan 24 23:36:22 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Sat, 24 Jan 2015 20:36:22 -0800
Subject: Alternative to multi-line lambdas: Assign-anywhere def statements
In-Reply-To: <54C44DDF.3030107@stoneleaf.us>
References: <CAPTjJmrAQgtauH74dwCzb_-6T09D0dLVkxiGrAxJMp_OOwgS0g@mail.gmail.com>
 <54C3EAD1.2010501@stoneleaf.us>
 <CAPTjJmohdQbK9_ikh8heaMRbpJ270UW6C1AE2oNVgV_4AoYfQg@mail.gmail.com>
 <54C44DDF.3030107@stoneleaf.us>
Message-ID: <CABicbJJoGJfnsdfNagA40hLkML5g7QWWiYXGYu7EdEV=tDd1Ew@mail.gmail.com>

On Sat, Jan 24, 2015 at 5:58 PM, Ethan Furman <ethan at stoneleaf.us> wrote:
> On 01/24/2015 11:55 AM, Chris Angelico wrote:
>> On Sun, Jan 25, 2015 at 5:56 AM, Ethan Furman <ethan at stoneleaf.us> wrote:
>>> If the non-generic is what you're concerned about:
>>>
>>> # not tested
>>> dispatch_table_a = {}
>>> dispatch_table_b = {}
>>> dispatch_table_c = {}
>>>
>>> class dispatch:
>>>   def __init__(self, dispatch_table):
>>>     self.dispatch = dispatch_table
>>>   def __call__(self, func):
>>>     self.dispatch[func.__name__] = func
>>>     return func
>>>
>>> @dispatch(dispatch_table_a)
>>> def foo(...):
>>>    pass
>>
>> That's still only able to assign to a key of a dictionary, using the
>> function name.
>
> This is a Good Thing.  The def statement populates a few items, __name__ being one of them.  One of the reasons lambda
> is not encouraged is because its name is always '<lambda>', which just ain't helpful when the smelly becomes air borne!  ;)

Actually, in this case you'd probably want the function's __name__ to
be something different, since it'd be confusing if all three dispatch
tables had a 'foo' entry, using functions whose name was 'foo'.

No reason a function's name can't be "dispatch_table_a['foo']"

-- Devin


From cpisz at austin.rr.com  Sat Jan 24 23:53:12 2015
From: cpisz at austin.rr.com (Christopher J. Pisz)
Date: Sat, 24 Jan 2015 22:53:12 -0600
Subject: Hello World in Python
In-Reply-To: <mailman.18118.1422148393.18130.python-list@python.org>
References: <ma1b8f$pgf$1@dont-email.me>
 <mailman.18118.1422148393.18130.python-list@python.org>
Message-ID: <54C476B8.2040100@austin.rr.com>

On 1/24/2015 7:12 PM, Terry Reedy wrote:
> On 1/24/2015 6:53 PM, Christopher J. Pisz wrote:
>> I am trying to help a buddy out. I am a C++ on Windows guy. This buddy
>> of mine is learning Python at work on a Mac. I figured I could
>> contribute with non language specific questions and such.
>>
>> When learning any new language, I said, the first step would be a Hello
>> World program. Let's see if we can get that to work.
>>
>> So my buddy creates opens the IDE they gave at the workplace, creates a
>> new project, adds a demo.py file, writes one line : print "Hello World",
>> hits Run in the IDE and indeed the display is shown at the bottom when
>> it executes.
>>
>> I say the next step would be to get that to run on the command line. So
>> (keep in mind I know nothing about macs) my buddy opens a "zsh?" window,
>> cd to the directory, and I say the command i most likely: python demo.py
>>
>> It looks like it executes but there is no output to the command line
>> window.
>
> It should.  In a Windows console, using 3.4:
> C:\Programs\Python34>type tem.py  # cat on Mac?
> print('Hello World!')
>
> C:\Programs\Python34>python tem.py
> Hello World!
>
>  > Can anyone explain why there is no output?
>
> Without a copy of the file and command, as above, no.
>
>  > Can anyone recommend a good walkthrough of getting set up and doing
> basics?
>
> Since you used 2.x  print syntax: https://docs.python.org/2.7/
>
> "Python Setup and Usage
> how to use Python on different platforms"
>
> "Tutorial
> start here"
>
>  > I'll probably end up learning python myself, just to help out.
>
> You might possibly enjoy Python as a complement to C++.  Some people
> prototype in Python and rewrite time critical functions in C++.  One can
> access .dlls either directly (via the ctypes module) and write a wrapper
> file in C or C++.  I believe Python has also been used to write tests
> for C++ functions (I know this is true for Python and Java, via Jython).
>

Good docs. I got setup in Windows in 10 minutes.




From ravas at outlook.com  Sun Jan 25 00:20:17 2015
From: ravas at outlook.com (ravas)
Date: Sat, 24 Jan 2015 21:20:17 -0800 (PST)
Subject: apostrophe not considered with tkinter's wordstart and wordend
In-Reply-To: <f7664734-b001-4b56-a0cd-38c8e2125da8@googlegroups.com>
References: <e6143cd5-3475-431a-b2cf-17fd9659681c@googlegroups.com>
 <655cce0d-2db3-4a0d-ab3d-64d5db5e1634@googlegroups.com>
 <714d9211-9b50-4e62-a7dd-25ff94a32d8a@googlegroups.com>
 <f1bcb866-b07f-478d-83a4-dcf4b2b096e5@googlegroups.com>
 <m9rtd8$15e$1@dont-email.me>
 <c1bc4c74-0360-4816-884a-4ebff24e2bab@googlegroups.com>
 <b1ea0c95-38aa-47b8-a8a2-dd80c3dcb8a5@googlegroups.com>
 <f7664734-b001-4b56-a0cd-38c8e2125da8@googlegroups.com>
Message-ID: <9b69dde6-eb25-40f3-bb00-5f21a0ec134c@googlegroups.com>

I copied the GUI creation from my personal text editor. 
The scrollbar and stretchability could have been left out, for sure. 
You're only seeing a portion of a more complex GUI.

After writing several Tkinter applications, 
I decided that subclassing without a clear reason 
only had the effect of polluting the namespace of my class. 
I like seeing only my attributes and methods during code completion.

Thanks for your interest and help.


From rustompmody at gmail.com  Sun Jan 25 02:14:53 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Sat, 24 Jan 2015 23:14:53 -0800 (PST)
Subject: Hello World in Python
In-Reply-To: <mailman.18114.1422144321.18130.python-list@python.org>
References: <ma1b8f$pgf$1@dont-email.me>
 <mailman.18114.1422144321.18130.python-list@python.org>
Message-ID: <7027fbaf-c124-40f6-894c-a4be6cce32b1@googlegroups.com>

On Sunday, January 25, 2015 at 5:36:02 AM UTC+5:30, Chris Angelico wrote:

> One thing that I really like doing with my Python students (full
> disclosure: I'm a mentor with www.thinkful.com and am thus at times
> paid to help people learn Python) is some form of screen-sharing, so I
> can watch him/her trying things. There are a number of zero-dollar
> ways to do this, and it helps enormously. Flip on screen-share, ask
> him to run the script, and see where that leads.

Would be interested in how you manage that!
Am teaching a class where everyone has a laptop.
Having them setup with a bare modicum of uniformity is turning out some challenge.
Some windows, some linux(es), even one blessed mac!


From rosuav at gmail.com  Sun Jan 25 02:27:30 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 25 Jan 2015 18:27:30 +1100
Subject: Hello World in Python
In-Reply-To: <7027fbaf-c124-40f6-894c-a4be6cce32b1@googlegroups.com>
References: <ma1b8f$pgf$1@dont-email.me>
 <mailman.18114.1422144321.18130.python-list@python.org>
 <7027fbaf-c124-40f6-894c-a4be6cce32b1@googlegroups.com>
Message-ID: <CAPTjJmrOB7_2f=TGR=XcOFV4YwsCVZpJWPFKGOoAKCqKiQXN+g@mail.gmail.com>

On Sun, Jan 25, 2015 at 6:14 PM, Rustom Mody <rustompmody at gmail.com> wrote:
> On Sunday, January 25, 2015 at 5:36:02 AM UTC+5:30, Chris Angelico wrote:
>
>> One thing that I really like doing with my Python students (full
>> disclosure: I'm a mentor with www.thinkful.com and am thus at times
>> paid to help people learn Python) is some form of screen-sharing, so I
>> can watch him/her trying things. There are a number of zero-dollar
>> ways to do this, and it helps enormously. Flip on screen-share, ask
>> him to run the script, and see where that leads.
>
> Would be interested in how you manage that!
> Am teaching a class where everyone has a laptop.
> Having them setup with a bare modicum of uniformity is turning out some challenge.
> Some windows, some linux(es), even one blessed mac!

Generally we use Google Hangouts - video chat, with options for
screen-share (replacing the camera; let's face it, when you're
discussing code, staring at talking heads isn't all that useful) and a
few other neat features. But if uniformity is an issue, you might want
to look into some kind of virtual Linux box like http://nitrous.io/ -
that way, everyone's using the same system, and nobody has to worry
about the stupid hassles of trying to support three different OSes.
Though Nitrous mightn't be as important for you as it is for the
Thinkful course; as part of the course, we teach PostgreSQL + Python +
PsycoPG2 + SQLAlchemy, and if you're on a Mac and your student is on
Windows, you'll *really* appreciate not having to figure out how to
install that lot on a foreign platform! (In theory, the situation
should be getting better. Installing stuff from PyPI under Windows has
long been a massive nuisance, but it's starting to become a bit
easier. But it's still a massive pain for someone who doesn't know
Windows to try to walk a Windows person through the setup.)

And hey. If you want a pay-for Python programming course, do check 'em
out - www.thinkful.com. You get regular one-on-one mentorship, a
highly responsive team of staff, and all sorts of random fun. There,
I'm done advertising now. :)

ChrisA


From noone at nowhere.net  Sun Jan 25 02:43:59 2015
From: noone at nowhere.net (Brian Gladman)
Date: Sun, 25 Jan 2015 07:43:59 +0000
Subject: Delegation in Python
In-Reply-To: <mailman.18120.1422149503.18130.python-list@python.org>
References: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>
 <mailman.18120.1422149503.18130.python-list@python.org>
Message-ID: <_YmdnTx6rZsjA1nJnZ2dnUVZ8hOdnZ2d@brightview.co.uk>

On 25/01/2015 01:31, Terry Reedy wrote:
> On 1/24/2015 5:57 PM, Brian Gladman wrote:
>> I would appreciate advice on how to set up delgation in Python.
>>
>> I am continuously implementing a function to test whether a Python
>> Fraction is an integer
> 
> Since Fractions are reduced to lowest terms,
>>>> from fractions import Fraction as F
>>>> F(4, 2)
> Fraction(2, 1)
>>>> F(12, 3)
> Fraction(4, 1)
> 
> the test is that the denominator is 1

Thanks Terry, I should have realised this but didn't.

>>>> F(12,3).denominator == 1
> True
>>>> F(12,5).denominator == 1
> False
> 
> it may not be worth the bother to define a function,
> 
> def fint(F): return F.denominator == 1
> 
>> so I wanted to define a new class, based on
>> Fraction, that includes this new method.
> 
> but if you do, there is little need to make it a method.  You are not
> overriding an existing method or adding a new special method.  The math
> module has float and int functions that have *not* been turned into
> methods.  Ditto for cmath.  I would just leave the function a function.

Yes, it seems so.

   Brian







From noone at nowhere.net  Sun Jan 25 02:49:12 2015
From: noone at nowhere.net (Brian Gladman)
Date: Sun, 25 Jan 2015 07:49:12 +0000
Subject: Delegation in Python
In-Reply-To: <mailman.18116.1422145722.18130.python-list@python.org>
References: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>
 <mailman.18106.1422141738.18130.python-list@python.org>
 <5ZKdnd6rbdZ3sVnJnZ2dnUVZ8mCdnZ2d@brightview.co.uk>
 <mailman.18109.1422143020.18130.python-list@python.org>
 <K8KdncuoKPL1q1nJnZ2dnUVZ8h2dnZ2d@brightview.co.uk>
 <mailman.18116.1422145722.18130.python-list@python.org>
Message-ID: <KYednbizIP5rAlnJnZ2dnUVZ7sidnZ2d@brightview.co.uk>

On 25/01/2015 00:28, Chris Angelico wrote:
> On Sun, Jan 25, 2015 at 11:18 AM, Brian Gladman <noone at nowhere.net> wrote:
>> Is there a way of doing delegation rather than sub-classing?
>>
>> That is, can I create a class (say RF) that passes some of its methods
>> to Fraction for implementation but always returns an RF?
> 
> Hmm. The key here is that you want more than just delegation; you want
> to transform every return value. That's not going to be easy. It would
> be easiest and cleanest to skip the whole thing, and have a separate
> function for what you're doing here - not a method, a stand-alone
> function.
> 
> def is_integer(fr):
>     return fr.numerator % fr.denominator == 0
> 
> Next best would be the monkey-patching option. Delegation with
> transformation is a lot of effort for what you want.

Thanks, a part of this was a wish to understand how to map what I can do
in other languages into Python.  I felt that it might just be possible
in Python to avoid having to wrap all the methods of the base class in
the derived class.  But it seems that __getattr__ etc are not quite as
magic as I hoped.

Thanks again for your help.

   Brian



From rosuav at gmail.com  Sun Jan 25 03:07:30 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 25 Jan 2015 19:07:30 +1100
Subject: Delegation in Python
In-Reply-To: <KYednbizIP5rAlnJnZ2dnUVZ7sidnZ2d@brightview.co.uk>
References: <FeCdnXdsTpunvlnJnZ2dnUVZ8judnZ2d@brightview.co.uk>
 <mailman.18106.1422141738.18130.python-list@python.org>
 <5ZKdnd6rbdZ3sVnJnZ2dnUVZ8mCdnZ2d@brightview.co.uk>
 <mailman.18109.1422143020.18130.python-list@python.org>
 <K8KdncuoKPL1q1nJnZ2dnUVZ8h2dnZ2d@brightview.co.uk>
 <mailman.18116.1422145722.18130.python-list@python.org>
 <KYednbizIP5rAlnJnZ2dnUVZ7sidnZ2d@brightview.co.uk>
Message-ID: <CAPTjJmr=2TP3UJe_Y_kzrShHR-1NmoXbMFy5fEqubdYtzOQkdw@mail.gmail.com>

On Sun, Jan 25, 2015 at 6:49 PM, Brian Gladman <noone at nowhere.net> wrote:
> Thanks, a part of this was a wish to understand how to map what I can do
> in other languages into Python.  I felt that it might just be possible
> in Python to avoid having to wrap all the methods of the base class in
> the derived class.  But it seems that __getattr__ etc are not quite as
> magic as I hoped.

They do exactly what they're documented to, nothing more and nothing
less :) It's certainly possible to use them to hook into missing
attributes, for instance:

>>> class RF:
    def __init__(self, *args, **kw):
        self._frac = Fraction(*args, **kw)
    def __getattr__(self, attr):
        return getattr(self._frac, attr)
    def __repr__(self):
        return "RF(%d, %d)" % (self._frac.numerator, self._frac.denominator)
    def is_integer(self):
        return self._frac.denominator==1

>>> RF(1,4).numerator
1

But it doesn't work for everything:
>>> RF(1,4)*2
Traceback (most recent call last):
  File "<pyshell#37>", line 1, in <module>
    RF(1,4)*2
TypeError: unsupported operand type(s) for *: 'RF' and 'int'

The only solution would be to go through every operation that you care
about, and manually hook them. Something like this:

    def __mul__(self, other):
        result = self._frac * other
        if isinstance(result, Fraction):
            return RF(result.numerator, result.denominator)
        return result

>>> RF(1,4)*2
RF(1, 2)

And do that for every other operation, method, etc. Tedious, but can
be effective if you need it.

ChrisA


From marco.buttu at gmail.com  Sun Jan 25 05:30:05 2015
From: marco.buttu at gmail.com (Marco Buttu)
Date: Sun, 25 Jan 2015 11:30:05 +0100
Subject: __bases__ misleading error message
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <mailman.18093.1422127493.18130.python-list@python.org>
 <54C413E4.5060208@gmail.com>
 <mailman.18117.1422147330.18130.python-list@python.org>
Message-ID: <ma2gjf$3na$1@speranza.aioe.org>

On 25/01/2015 01:55, Terry Reedy wrote:

> 'This situation' being that Someclass.attro works but Someclass().attro
> raises...
>
> In other words, if 'Someclass.attro' evaluates to an object ...
> then 'Someclass().attro' *normally* evaluates to the same object

I am sorry Terry, but I do not agree, because the word "normally" in 
this context does not have any meaning, and instroduces just confusion. 
In facts this is exactly the case where "Someclass.attro' evaluates to 
an object" *but* hasattr(Someclass(), 'attro'), as expected, is False. 
What do you mean with "normally"?

> because attribute lookup on an instance reverts to attribute lookup on
> the class and even its super classes

Here's the point. The __bases__ attribute is defined by the class type. 
So if isinstance(obj, type) is true, then hasattr(obj, '__bases__') is 
true. In the OP case:

   >>> class Sub: # Python 3
   ...     pass
   ...
   >>> isinstance(Sub, type)
   True
   >>> hasattr(Sub, '__bases__')
   True

But Sub() is not an instance of type (because Sub is not a subclass of 
type), and so Sub() does not have to get the attributes, like __bases__, 
from type, and here's we are:

   >>> foo = Sub()
   >>> isinstance(foo, type)
   False
   >>> foo.__bases__
   Traceback (most recent call last):
     ...
   AttributeError: 'Sub' object has no attribute '__bases__'


In other words, speaking about the lookup machinery, because '__bases__' 
is not in foo.__dict__ Python looks for __bases__ in Sub.__dict__, but 
it does not found it. So it looks in the Sub bases, and we went back to 
the point: Sub is an instance of type, not a subclass of type.


> Someclass.__bases__
> is special; it is not listed by dir(Someclass), and it is not accessible
> via an instance.

In my point of view no attribute is special (maybe just a descriptor is 
a bit special, in some ways). To undestand what happens in these 
situations, we do not have to give a special meaning to the attribute. 
Given `obj.attr`, we just have to know what kind of object is `obj`: 
usually, like in this case, we have to differentiate between classes and 
non-classes objects. In fact __bases__ is not listed by dir(Sub) because 
Sub is a class, and the distinction between classes and non-classes 
objects matters, especially for dir()

-- 
Marco Buttu


From marko at pacujo.net  Sun Jan 25 05:59:32 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sun, 25 Jan 2015 12:59:32 +0200
Subject: Benchmarking some modules - strange result
References: <mailman.18122.1422151905.18130.python-list@python.org>
Message-ID: <87wq4bcei3.fsf@elektro.pacujo.net>

Dan Stromberg <drsalists at gmail.com>:

> BTW, there isn't much else going on on this computer, except some
> possible small cronjobs.

The OS caches the files in RAM. You'd expect the file I/O performance to
get much better on test reruns. On the other hand, OS cache flushing
happens at random times, which affects the results in the other
direction.

Also, I take it you aren't running your tests in a virtual machine or on
the cloud, right?

Finally, you should run each test case in isolation. IOW, restart Python
between each test case so the test cases don't interfere with each
other. The startup overhead could be reduced by starting the test cases
with an os.fork(). However, the performance tests should run long enough
to overwhelm to startup and teardown overhead.


Marko


From marfig at gmail.com  Sun Jan 25 06:07:28 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sun, 25 Jan 2015 12:07:28 +0100
Subject: __bases__ misleading error message
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
 <54c4606a$0$13002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <MPG.2f2eecca37bc450998969a@nntp.aioe.org>

In article <54c4606a$0$13002$c3e8da3$5496439d at news.astraweb.com>, 
steve+comp.lang.python at pearwood.info says...
> 
> It doesn't.

Your explanation was great Steven. Thank you. But raises one question...

> 
> Assigning a value to a variable ("m = 42", hex 2A) results in the compiler
> storing that value in the bucket; assignment makes a copy: "n = m" leads to
> two independent buckets with the same value:
> 
> m = [002A]
> n = [002A]

I'm still in the process of learning Python. So, that's probably why 
this is unexpected to me.

I was under the impression that what python did was keep a lookup table 
pointing to memory. Every variable gets an entry as type descriptor and 
a pointer to a memory address, where the variable data resides.

(UDTs may be special in that they would have more than one entry, one 
for each enclosing def and declared attribute)

In the example above, the n and m buckets would hold pointers, not 
binary values. And because they are immutable objects, n and m pointers 
would be different. Not equal. But in the case of mutable objects, n = m 
would result in m having the same pointer address as n.


From steve+comp.lang.python at pearwood.info  Sun Jan 25 07:00:31 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 25 Jan 2015 23:00:31 +1100
Subject: __bases__ misleading error message
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
 <54c4606a$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2eecca37bc450998969a@nntp.aioe.org>
Message-ID: <54c4dae1$0$13005$c3e8da3$5496439d@news.astraweb.com>

Mario Figueiredo wrote:

> In article <54c4606a$0$13002$c3e8da3$5496439d at news.astraweb.com>,
> steve+comp.lang.python at pearwood.info says...
>> 
>> It doesn't.
> 
> Your explanation was great Steven. Thank you. But raises one question...
> 
>> 
>> Assigning a value to a variable ("m = 42", hex 2A) results in the
>> compiler storing that value in the bucket; assignment makes a copy: "n =
>> m" leads to two independent buckets with the same value:
>> 
>> m = [002A]
>> n = [002A]


Maybe I wasn't clear enough. The above is used by languages like C or
Pascal, which use fixed memory locations for variables. If I gave the
impression this was Python, I am sorry.


> I'm still in the process of learning Python. So, that's probably why
> this is unexpected to me.
> 
> I was under the impression that what python did was keep a lookup table
> pointing to memory. Every variable gets an entry as type descriptor and
> a pointer to a memory address, where the variable data resides.

This sounds more or less correct, at least for CPython. CPython is
the "reference implementation", and probably the version you use when you
run Python. But it is not the only one, and they can be different.

(E.g. in Jython, the Python interpreter is built using Java, not C. You
can't work with pointers to memory addresses in Java, and the Java garbage
collector is free to move objects around when needed.)

In CPython, objects live in the heap, and Python tracks them using a
pointer. So when you bind a name to a value:

    x = 23  # what you type

what happens is that Python sets a key + value in the global namespace (a
dictionary):

    globals()['x'] = 23  # what Python runs

and the globals() dict will then look something like this:

    {'x': 23, 'colour': 'red', 'y': 42}

(Note: *local* variables are similar but not quite the same. They're also
more complicated, so let's skip them for now.)

What happens inside the dictionary? Dictionaries are "hash tables", so they
are basically a big array of cells, and each cell is a pair of pointers,
one for the key and one for the value:

    [dictionary header]
    [blank] 
    [blank] 
    [ptr to the string 'y', ptr to the int 42]
    [blank] 
    [ptr to 'x', ptr to 23]
    [blank]
    [blank]
    [blank]
    [ptr to 'colour', ptr to 'red']
    [blank]
    ...


Notice that the order is unpredictable. Also, don't take this picture too
literally. Dicts are highly optimized, highly tuned and in active
development, the *actual* design of Python dicts may vary. But this is a
reasonable simplified view of how they could be designed.

The important thing to remember is that while CPython uses pointers under
the hood to make the interpreter work, pointers are not part of the Python
language. There is no way in Python to get a pointer to an object, or
increment a pointer, or dereference a pointer. You just use objects, and
the interpreter handles all the pointer stuff behind the scenes.


> (UDTs may be special in that they would have more than one entry, one
> for each enclosing def and declared attribute)
> 
> In the example above, the n and m buckets would hold pointers, not
> binary values. And because they are immutable objects, n and m pointers
> would be different. Not equal. But in the case of mutable objects, n = m
> would result in m having the same pointer address as n.

No, this is certainly not the case! Python uses *exactly* the same rules for
mutable and immutable objects. In fact, Python can't tell what values are
mutable or immutable until it tries to modify it.

Remember I said that name-binding languages operate using a model of pieces
of string between the name and the object? Here are two names bound to the
same object:


m -----------+--------------- 0x2a
n ----------/ 


Obviously Python doesn't *literally* use a piece of string :-) so what
happens under the hood? Pointers again, at least in CPython.

In this case, if we look deep inside our globals dictionary again, we will
see two cells:

     [ptr to the string "m", ptr to the int 0x2a]
     [ptr to the string "n", ptr to the int 0x2a]

The two int pointers point to the same object. This is guaranteed by the
language:

m = 42
n = m
assert id(m) == id(n)

Both objects have the same ID and are the same object at the same memory
location. Assignment in Python NEVER makes a copy of the value being
assigned.


-- 
Steven



From __peter__ at web.de  Sun Jan 25 07:24:40 2015
From: __peter__ at web.de (Peter Otten)
Date: Sun, 25 Jan 2015 13:24:40 +0100
Subject: Benchmarking some modules - strange result
References: <CAGGBd_rSazrC4yAt+CebeuvCJYjZWOXohoZHgTUtfGNZZtr5Ww@mail.gmail.com>
Message-ID: <ma2nac$rln$1@ger.gmane.org>

Dan Stromberg wrote:

> I've been benchmarking some python modules that are mostly variations
> on the same theme.
> 
> For simplicity, let's say I've been running the suite of performance
> tests within a single interpreter - so I test one module thoroughly,
> then move on to the next without exiting the interpreter.
> 
> I'm finding that if I prune the list of modules down to just the best
> performers, I get pretty different results - what was best no longer
> is.  This strikes me as strange.

> I'm about ready to rewrite things to run each individual test in a
> fresh interpreter. But is there a better way?

You could run combinations of two modules in the same interpreter to see if 
there are specific modules that slow down the following module.
If you can identify such modules you could then look into their code to try 
and find the cause of the slowdown.

Requires some work, but the results might be interesting to the greater 
public -- many real-world applications make do with a single interpreter ;)




From marfig at gmail.com  Sun Jan 25 07:49:32 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sun, 25 Jan 2015 13:49:32 +0100
Subject: __bases__ misleading error message
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
 <54c4606a$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2eecca37bc450998969a@nntp.aioe.org>
 <54c4dae1$0$13005$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <MPG.2f2f0499338c0a6598969b@nntp.aioe.org>

In article <54c4dae1$0$13005$c3e8da3$5496439d at news.astraweb.com>, 
steve+comp.lang.python at pearwood.info says...
> [...]

Most excellent. Thanks for the hard work, explaining this to me. :)

Knowing Python internals is something that will end benefiting me in the 
long run. There's much to be gained by knowing the inner working of your 
programming language...

Python is missing an under-the-hood book, I suppose. Tracing through 
Python source code to learn this stuff isn't easy unless we know what we 
are looking for.




From marko at pacujo.net  Sun Jan 25 07:53:42 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sun, 25 Jan 2015 14:53:42 +0200
Subject: __bases__ misleading error message
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
 <54c4606a$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2eecca37bc450998969a@nntp.aioe.org>
 <54c4dae1$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2f0499338c0a6598969b@nntp.aioe.org>
Message-ID: <87lhkrc97t.fsf@elektro.pacujo.net>

Mario Figueiredo <marfig at gmail.com>:

> Knowing Python internals is something that will end benefiting me in
> the long run. There's much to be gained by knowing the inner working
> of your programming language...
>
> Python is missing an under-the-hood book, I suppose. Tracing through
> Python source code to learn this stuff isn't easy unless we know what
> we are looking for.

One must only be careful to distinguish implementation choices from the
abstract definitions. The Python Language Reference is the official
standard:

   <URL: https://docs.python.org/3/reference/index.html>


Marko


From dan at tombstonezero.net  Sun Jan 25 10:46:31 2015
From: dan at tombstonezero.net (Dan Sommers)
Date: Sun, 25 Jan 2015 15:46:31 +0000 (UTC)
Subject: Benchmarking some modules - strange result
References: <CAGGBd_rSazrC4yAt+CebeuvCJYjZWOXohoZHgTUtfGNZZtr5Ww@mail.gmail.com>
 <mailman.18131.1422188697.18130.python-list@python.org>
Message-ID: <ma334n$3fj$1@dont-email.me>

On Sun, 25 Jan 2015 13:24:40 +0100, Peter Otten wrote:

> Dan Stromberg wrote:
> 
>> I've been benchmarking some python modules that are mostly variations
>> on the same theme.
>> 
>> For simplicity, let's say I've been running the suite of performance
>> tests within a single interpreter - so I test one module thoroughly,
>> then move on to the next without exiting the interpreter.
>> 
>> I'm finding that if I prune the list of modules down to just the best
>> performers, I get pretty different results - what was best no longer
>> is.  This strikes me as strange.
> 
>> I'm about ready to rewrite things to run each individual test in a
>> fresh interpreter. But is there a better way?
> 
> You could run combinations of two modules in the same interpreter to
> see if there are specific modules that slow down the following module.
> If you can identify such modules you could then look into their code
> to try and find the cause of the slowdown.
> 
> Requires some work, but the results might be interesting to the
> greater public -- many real-world applications make do with a single
> interpreter ;)

I would add that your present results probably do reflect the real-world
better than a contrived, yet scientific and arguably more "accurate"
test.  This tells me that the variations you see are down in the noise,
and that any optimizations you may make to improve performance could be
lost in any given application.

Unless, of course, you're on an academic pursuit, in which case carry
on!

Dan


From breamoreboy at yahoo.co.uk  Sun Jan 25 11:30:30 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 25 Jan 2015 16:30:30 +0000
Subject: Benchmarking some modules - strange result
In-Reply-To: <CAGGBd_rSazrC4yAt+CebeuvCJYjZWOXohoZHgTUtfGNZZtr5Ww@mail.gmail.com>
References: <CAGGBd_rSazrC4yAt+CebeuvCJYjZWOXohoZHgTUtfGNZZtr5Ww@mail.gmail.com>
Message-ID: <ma35nf$ma2$1@ger.gmane.org>

On 25/01/2015 02:11, Dan Stromberg wrote:
> Hi folks.
>
> I've been benchmarking some python modules that are mostly variations
> on the same theme.
>
> For simplicity, let's say I've been running the suite of performance
> tests within a single interpreter - so I test one module thoroughly,
> then move on to the next without exiting the interpreter.
>
> I'm finding that if I prune the list of modules down to just the best
> performers, I get pretty different results - what was best no longer
> is.  This strikes me as strange.
>
> I'm forcing a garbage collection between tests with gc.collect(), but
> even that yields the oddball results.
>
> Is there something else I should do to restore the interpreter to a
> known-pristine state for the sake of such tests?
>
> BTW, there isn't much else going on on this computer, except some
> possible small cronjobs.
>
> I'm about ready to rewrite things to run each individual test in a
> fresh interpreter. But is there a better way?
>
> If I do the rewrite, I might run 1 run of module A, 1 run of module B,
> 1 run of module C, then another run of module A, another run of module
> B, and another run of module C - to spread any possible timing
> oddities more evenly.
>
> Thanks.
>

Are you aware of this code repository https://hg.python.org/benchmarks/ 
and the associated mailing list 
https://mail.python.org/mailman/listinfo/speed, also available as 
gmane.comp.python.speed ?  Maybe there's something there for all of us, 
maybe not, there's only one way to find out :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From marfig at gmail.com  Sun Jan 25 13:23:43 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sun, 25 Jan 2015 19:23:43 +0100
Subject: Object destruction delayed on interactive prompt
Message-ID: <MPG.2f2f52ffff24c09f98969c@nntp.aioe.org>

Consider the following class:

    class A:
        def __init__(self, value):
            self.value = value

        def __del__(self):
            print("'A' instance being collected...")

        def __repr__(self):
            return str(self.value)

If ran as a script, the destructor behavior works as expected:

    if __name__ == '__main__':
        x1 = A(12)
        print(x1)                   # __repr__()
        x1 = 2                      # __del__()
        print(x1)

But if I run it interactively, a weird behavior comes up:

    >>> x1 = A(12)
    >>> x1 = 'string'
        A instance being collected...    # __del__() as expected
    >>> x1 = A(12)				# Recreate x1
    >>> x1					# __repr__()
        12
    >>> x1 = 'string'                    # __del__() isn't executed!
    >>> x1                               # it is delayed until here
        A instance being collected...
        'string'

This is reproducible in IDLE and at the system command prompt. Is this a 
REPL specific behavior?


From marfig at gmail.com  Sun Jan 25 13:24:40 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sun, 25 Jan 2015 19:24:40 +0100
Subject: Object destruction delayed on interactive prompt
References: <MPG.2f2f52ffff24c09f98969c@nntp.aioe.org>
Message-ID: <MPG.2f2f5352e46ced5d98969d@nntp.aioe.org>

In article <MPG.2f2f52ffff24c09f98969c at nntp.aioe.org>, marfig at gmail.com 
says...
> [...]

Forgot to mention this is Python 3.4.2


From wxjmfauth at gmail.com  Sun Jan 25 13:57:02 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Sun, 25 Jan 2015 10:57:02 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <e072e82f-1faa-4be3-814f-9addaea971ef@googlegroups.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <9a6694a5-5774-415a-b28a-7a9425a9112a@googlegroups.com>
 <54c34e68$0$12976$c3e8da3$5496439d@news.astraweb.com>
 <e072e82f-1faa-4be3-814f-9addaea971ef@googlegroups.com>
Message-ID: <b02fae32-08b5-42c0-b275-f8be73b1b0ad@googlegroups.com>

Le dimanche 25 janvier 2015 00:20:30 UTC+1, Rick Johnson a ?crit?:

Do not complain too much.
These brave Python devs have already succeeded to
create an anti unicode product.





From ginolampascione at gmx.com  Sun Jan 25 14:03:49 2015
From: ginolampascione at gmx.com (CARMELO PIGNATRACOZZA DE ROSARIO ARGENTINA)
Date: Sun, 25 Jan 2015 11:03:49 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
References: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
Message-ID: <b9ca94ce-afc7-4dfa-a338-e84826fec953@googlegroups.com>

-- redacted --


From rantingrickjohnson at gmail.com  Sun Jan 25 14:12:08 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Sun, 25 Jan 2015 11:12:08 -0800 (PST)
Subject: Object destruction delayed on interactive prompt
In-Reply-To: <MPG.2f2f52ffff24c09f98969c@nntp.aioe.org>
References: <MPG.2f2f52ffff24c09f98969c@nntp.aioe.org>
Message-ID: <c4e237bf-ec49-499f-83be-b989613f6521@googlegroups.com>

__del__ is unreliable. But don't take my word, check out the doc.

https://docs.python.org/3.2/reference/datamodel.html#object.__del__


From python at mrabarnett.plus.com  Sun Jan 25 14:13:23 2015
From: python at mrabarnett.plus.com (MRAB)
Date: Sun, 25 Jan 2015 19:13:23 +0000
Subject: Object destruction delayed on interactive prompt
In-Reply-To: <MPG.2f2f52ffff24c09f98969c@nntp.aioe.org>
References: <MPG.2f2f52ffff24c09f98969c@nntp.aioe.org>
Message-ID: <54C54053.6070008@mrabarnett.plus.com>

On 2015-01-25 18:23, Mario Figueiredo wrote:
> Consider the following class:
>
>      class A:
>          def __init__(self, value):
>              self.value = value
>
>          def __del__(self):
>              print("'A' instance being collected...")
>
>          def __repr__(self):
>              return str(self.value)
>
> If ran as a script, the destructor behavior works as expected:
>
>      if __name__ == '__main__':
>          x1 = A(12)
>          print(x1)                   # __repr__()
>          x1 = 2                      # __del__()
>          print(x1)
>
> But if I run it interactively, a weird behavior comes up:
>
>      >>> x1 = A(12)
>      >>> x1 = 'string'
>          A instance being collected...    # __del__() as expected
>      >>> x1 = A(12)				# Recreate x1
>      >>> x1					# __repr__()
>          12
>      >>> x1 = 'string'                    # __del__() isn't executed!
>      >>> x1                               # it is delayed until here
>          A instance being collected...
>          'string'
>
> This is reproducible in IDLE and at the system command prompt. Is this a
> REPL specific behavior?
>
In the REPL, the result of an expression is bound to '_':

 >>> x1 = A(12)
 >>> x1 # _ will be bound to the result.
12
 >>> x1 = 'string'
 >>> # At this point, _ is still bound to the object.
 >>> 0 # This will bind _ to another object, so the previous object can 
be collected.
'A' instance being collected...
0



From marfig at gmail.com  Sun Jan 25 14:29:15 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Sun, 25 Jan 2015 20:29:15 +0100
Subject: Object destruction delayed on interactive prompt
References: <MPG.2f2f52ffff24c09f98969c@nntp.aioe.org>
 <mailman.18133.1422213206.18130.python-list@python.org>
Message-ID: <MPG.2f2f626013054d798969e@nntp.aioe.org>

In article <mailman.18133.1422213206.18130.python-list at python.org>, 
python at mrabarnett.plus.com says...
> In the REPL, the result of an expression is bound to '_':
> 
>  >>> x1 = A(12)
>  >>> x1 # _ will be bound to the result.
> 12
>  >>> x1 = 'string'
>  >>> # At this point, _ is still bound to the object.
>  >>> 0 # This will bind _ to another object, so the previous object can 
> be collected.
> 'A' instance being collected...
> 0

Aha! Thank you.


From dfnsonfsduifb at gmx.de  Sun Jan 25 15:15:47 2015
From: dfnsonfsduifb at gmx.de (Johannes Bauer)
Date: Sun, 25 Jan 2015 21:15:47 +0100
Subject: Idiomatic backtracking in Python
Message-ID: <ma3itj$ol6$1@news.albasani.net>

Hi folks,

I have a problem at hand that needs code for backtracking as a solution.
And I have no problem coding it, but I can't get rid of the feeling that
I'm always solving backtracking problems in a non-Pythonic
(non-idiomatic) way. So, I would like to ask if you have a Pythonic
approach to backtracking problems? If so, I'd love to hear your solutions!

Cheers,
Johannes

-- 
>> Wo hattest Du das Beben nochmal GENAU vorhergesagt?
> Zumindest nicht ?ffentlich!
Ah, der neueste und bis heute genialste Streich unsere gro?en
Kosmologen: Die Geheim-Vorhersage.
 - Karl Kaos ?ber R?diger Thomas in dsa <hidbv3$om2$1 at speranza.aioe.org>


From shalini.ravishankar at gmail.com  Sun Jan 25 15:23:12 2015
From: shalini.ravishankar at gmail.com (Shalini Ravishankar)
Date: Sun, 25 Jan 2015 12:23:12 -0800 (PST)
Subject: Problem while reading files from hdfs using python
Message-ID: <19c7923f-2f26-4752-ac2b-1b6dfc093631@googlegroups.com>

Hello Everyone,

I am trying to read(open) and write files in hdfs inside a python script. But having error. Can someone tell me what is wrong here.

Code (full): sample.py
    
    #!/usr/bin/python
    

    from subprocess import Popen, PIPE
    
    print "Before Loop"
    
    cat = Popen(["hadoop", "fs", "-cat", "./sample.txt"],
                stdout=PIPE)
    put = Popen(["hadoop", "fs", "-put", "-", "./modifiedfile.txt"],
                stdin=PIPE)
    for line in cat.stdout:
        line += "Blah"
        print line
        put.stdin.write(line)
    
    cat.stdout.close()
    cat.wait()
    put.stdin.close()
    put.wait()

When I execute : 

    hadoop jar /usr/local/hadoop/share/hadoop/tools/lib/hadoop-streaming-2.5.1.jar -file ./sample.py -mapper './sample.py' -input sample.txt -output fileRead

It executes properly I couldn't find the file which supposed to create in hdfs modifiedfile

And When I execute :

     hadoop fs -getmerge ./fileRead/ file.txt

Inside the file.txt, I got :

    Before Loop	
    Before Loop

Can someone please tell me what I am doing wrong here ?? I dont think it reads from the sample.txt

I would really appreciate the help.


--
Thanks & Regards,
Shalini Ravishankar.


From ian at feete.org  Sun Jan 25 15:51:03 2015
From: ian at feete.org (Ian Foote)
Date: Sun, 25 Jan 2015 20:51:03 +0000
Subject: Idiomatic backtracking in Python
In-Reply-To: <ma3itj$ol6$1@news.albasani.net>
References: <ma3itj$ol6$1@news.albasani.net>
Message-ID: <54C55737.5030008@feete.org>

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi,

I think a very idiomatic way to implement backtracking is using a
recursive generator (python 3):

def backtrack_solver(data=None):
    if data is None:
        yield from backtrack_solver(data=initial_data)

    if cannot_be_valid(data):
        return

    if matches_condition(data):
        yield data
        return

    for new_data in process(data):
        yield from backtrack_solver(new_data)

This generator will yield valid solutions to a suitably defined problem.

`initial_data`, `cannot_be_valid`, `matches_condition` and `process`
should be replaced with appropriate implementation for your problem.

For example, a sudoku solver could be fit to this by accepting a
partially solved grid as the `data` parameter.

`cannot_be_valid` would now detect grids that have, say, two `1`s in a
row or any other invalid grid state and exit.

`matches_condition` would detect a fully solved grid.

`process` would produce new grids with more cells filled in than the
current grid.

`initial_data` wouldn't be strictly necessary here, but you could use
it for an example grid. It could also be an empty grid, and the solver
would then yield all valid grids.

Regards,
Ian F

On 25/01/15 20:15, Johannes Bauer wrote:
> Hi folks,
> 
> I have a problem at hand that needs code for backtracking as a
> solution. And I have no problem coding it, but I can't get rid of
> the feeling that I'm always solving backtracking problems in a
> non-Pythonic (non-idiomatic) way. So, I would like to ask if you
> have a Pythonic approach to backtracking problems? If so, I'd love
> to hear your solutions!
> 
> Cheers, Johannes
> 

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From tjreedy at udel.edu  Sun Jan 25 16:35:48 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Sun, 25 Jan 2015 16:35:48 -0500
Subject: __bases__ misleading error message
In-Reply-To: <54c4dae1$0$13005$c3e8da3$5496439d@news.astraweb.com>
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
 <54c4606a$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2eecca37bc450998969a@nntp.aioe.org>
 <54c4dae1$0$13005$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <ma3njm$c1c$1@ger.gmane.org>

On 1/25/2015 7:00 AM, Steven D'Aprano wrote:

> What happens inside the dictionary? Dictionaries are "hash tables", so they
> are basically a big array of cells, and each cell is a pair of pointers,
> one for the key and one for the value:
>
>      [dictionary header]
>      [blank]
>      [blank]
>      [ptr to the string 'y', ptr to the int 42]

At the moment, for CPython, each entry has 3 items, with the first being 
the cached hash of the key.  Hash comparison is first used to test 
whether keys are equal.

   [hash('y'), ptr('y'), ptr(42)]

>      [blank]
>      [ptr to 'x', ptr to 23]
>      [blank]
>      [blank]
>      [blank]
>      [ptr to 'colour', ptr to 'red']
>      [blank]


As you say, these are implementation details.  CPython dicts for the 
instances of at least some classes have a different, specialized 
structure, with two arrays.

In the above, [blank] entries, which are about 1/2 to 2/3 of the 
entries, take the same space as real entries (12 to 24 bytes).  Raymond 
H. has proposed that the standard dict have two arrays like so:

1. the first array is a sparse array of indexes into the second array: 
[b, b, 2, b, 0, b, b, b, 1, b] (where b might be -1 interpreted as 
<blank>), using only as many bytes as needed for the maximum index.

2. the second array is a compact array of entries in insertion order, 
such as

     [hash, ptr to 'x', ptr to 23]
     [hash, ptr to 'colour', ptr to 'red']
     [hash, ptr to the string 'y', ptr to the int 42]

Iteration would use the compact array, making all dicts OrderedDicts. 
Pypy has already switched to this.  It seems that on modern processors 
with multilevel on-chip caches, the space reduction leads to cache-miss 
reductions that compensate for the indirection cost.


-- 
Terry Jan Reedy



From ben+python at benfinney.id.au  Sun Jan 25 19:32:08 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Mon, 26 Jan 2015 11:32:08 +1100
Subject: Idiomatic backtracking in Python
References: <ma3itj$ol6$1@news.albasani.net>
Message-ID: <8561bumlfb.fsf@benfinney.id.au>

Johannes Bauer <dfnsonfsduifb at gmx.de> writes:

> So, I would like to ask if you have a Pythonic approach to
> backtracking problems? If so, I'd love to hear your solutions!

I'm not aware of what the problem is. ?Back-tracking? doesn't have a
general meaning I recognise beyond random access into a data structure.
So a Python list is the obvious starting point.

Do you have a specific meaning of ?back-tracking? that implies
particular problems that are difficult to solve?

-- 
 \       ?The Vatican is not a state.? a state must have people. There |
  `\    are no Vaticanians.? No-one gets born in the Vatican except by |
_o__)        an unfortunate accident.? ?Geoffrey Robertson, 2010-09-18 |
Ben Finney



From python at mrabarnett.plus.com  Sun Jan 25 19:43:24 2015
From: python at mrabarnett.plus.com (MRAB)
Date: Mon, 26 Jan 2015 00:43:24 +0000
Subject: Idiomatic backtracking in Python
In-Reply-To: <8561bumlfb.fsf@benfinney.id.au>
References: <ma3itj$ol6$1@news.albasani.net> <8561bumlfb.fsf@benfinney.id.au>
Message-ID: <54C58DAC.3010401@mrabarnett.plus.com>

On 2015-01-26 00:32, Ben Finney wrote:
> Johannes Bauer <dfnsonfsduifb at gmx.de> writes:
>
>> So, I would like to ask if you have a Pythonic approach to
>> backtracking problems? If so, I'd love to hear your solutions!
>
> I'm not aware of what the problem is. ?Back-tracking? doesn't have a
> general meaning I recognise beyond random access into a data structure.
> So a Python list is the obvious starting point.
>
> Do you have a specific meaning of ?back-tracking? that implies
> particular problems that are difficult to solve?
>
I believe he's talking about trying different alternatives until one
works. You get it in matching regexes (well, when using the NFA
approach as used in the re module, Perl regexes, etc, anyway).



From yawar.amin at gmail.com  Sun Jan 25 20:26:53 2015
From: yawar.amin at gmail.com (Yawar Amin)
Date: Sun, 25 Jan 2015 17:26:53 -0800 (PST)
Subject: Alternative to multi-line lambdas: Assign-anywhere def statements
In-Reply-To: <54c470a9$0$12983$c3e8da3$5496439d@news.astraweb.com>
References: <CAPTjJmrAQgtauH74dwCzb_-6T09D0dLVkxiGrAxJMp_OOwgS0g@mail.gmail.com>
 <54C3EAD1.2010501@stoneleaf.us>
 <CAPTjJmohdQbK9_ikh8heaMRbpJ270UW6C1AE2oNVgV_4AoYfQg@mail.gmail.com>
 <mailman.18121.1422151185.18130.python-list@python.org>
 <4741da2c-8fc5-4c06-bc3a-cfadca890abf@googlegroups.com>
 <54c470a9$0$12983$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <566d71d9-3f89-4422-b454-77913b1b5e01@googlegroups.com>

Hi Steven,

On Saturday, January 24, 2015 at 11:27:33 PM UTC-5, Steven D'Aprano
wrote:
> [...]
> > Doesn't the traceback tell us exactly where the lambda was called
> > from?
> 
> Yes (assuming the source code is available, which it may not be), but

If the source code is not available, then you're equally unable to debug
a lambda function and a named function.

> even so, which is easier?
> 
> "Oh, the exception occurred in myfunc"
> 
> versus
> 
> "Hmmm, the exception occurred in a lambda, lets see now, that was
> called by "f", but f might have called seven different lambdas, which
> [...]

True, Python's current traceback reporting doesn't tell us the exact
column number on which the exception occurred. So for example with this:

    print((lambda: 1)(), (lambda: 1 / 0)())

You will get the following traceback:

    Traceback (most recent call last):
      File "test.py", line 3, in <module>
        print((lambda: 1)(), (lambda: 1 / 0)())
      File "test.py", line 3, in <lambda>
        print((lambda: 1)(), (lambda: 1 / 0)())
    ZeroDivisionError: integer division or modulo by zero

So the problem is there are two lambdas in line 3, so you need to
examine them both to figure out which one caused the exception. The
simple solution to this is to just put the lambdas on different lines:

    print(
      (lambda: 1)(),
      (lambda: 1 / 0)()
    )

Now you get a blindingly obvious traceback:

    Traceback (most recent call last):
      File "test.py", line 5, in <module>
        (lambda: 1 / 0)()
      File "test.py", line 5, in <lambda>
        (lambda: 1 / 0)()
    ZeroDivisionError: integer division or modulo by zero


> Using lambda is trading off convenience when writing the code for ease
> of debugging the code when a problem occurs. Whether that trade-off is
> worthwhile or not depends on factors such as how likely the lambda is
> to have a bug, how many of them there are, and whether or not there is
> uncertainty as to which one is called from where.

I feel like this whole 'debugging' argument is a red herring, because
you can have _many_ different expressions in a line of code all of which
could have potentially caused an exception you're trying to debug. For
example, dispensing with the lambdas:

    print(1, 1 / 0)

Error:

    Traceback (most recent call last):
      File "test.py", line 3, in <module>
        print(1, 1 / 0)
    ZeroDivisionError: integer division or modulo by zero

Again, it all comes down to Python just not telling you precisely where
the error occurred, and instead only giving you the general vicinity.
Again, this can be fixed simply by just putting the expressions on
different lines.

Regards,

Yawar


From marko at pacujo.net  Sun Jan 25 20:31:16 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Mon, 26 Jan 2015 03:31:16 +0200
Subject: Idiomatic backtracking in Python
References: <ma3itj$ol6$1@news.albasani.net>
 <mailman.18136.1422232323.18130.python-list@python.org>
Message-ID: <87bnlml44b.fsf@elektro.pacujo.net>

Ben Finney <ben+python at benfinney.id.au>:

> ?Back-tracking? doesn't have a general meaning I recognise beyond
> random access into a data structure.

Backtracking means the part of depth-first traversal where you retreat
to the parent node. If you implement your traversal with a recursive
function, backtracking means ? more or less ? a return from the
function.


Marko


From rosuav at gmail.com  Sun Jan 25 20:45:03 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 26 Jan 2015 12:45:03 +1100
Subject: Idiomatic backtracking in Python
In-Reply-To: <87bnlml44b.fsf@elektro.pacujo.net>
References: <ma3itj$ol6$1@news.albasani.net>
 <mailman.18136.1422232323.18130.python-list@python.org>
 <87bnlml44b.fsf@elektro.pacujo.net>
Message-ID: <CAPTjJmr5Bp7oi9mNg9TqGwkXng38SSik+q7xcWfHuRXjgP_fgg@mail.gmail.com>

On Mon, Jan 26, 2015 at 12:31 PM, Marko Rauhamaa <marko at pacujo.net> wrote:
> Backtracking means the part of depth-first traversal where you retreat
> to the parent node. If you implement your traversal with a recursive
> function, backtracking means ? more or less ? a return from the
> function.

But possibly you need to return from N levels, not just one. Imagine
you're traversing a directory tree using a simplistic recursive
algorithm:

def traverse(dir):
    for d in subdirs(dir): traverse(d)
    for f in files(dir):
        if file_size(f) > 1024*1024*1024: skip this entire branch of the tree

Obviously you have to define the branch somehow, but there are plenty
of times when you might want to break out of "everything up to here".
How do you define that? How do you return lots of levels all at once?
I remember facing this exact problem in trying to solve a particular
piece-layout puzzle; if I discovered an impossible situation, I could
actually discard at least two or three levels of recursion all at
once, because there's no way that the situation could become
un-impossible within those levels. Can't remember how I ended up
dealing with that... I think I got naughty and used a global variable.

ChrisA


From ian.g.kelly at gmail.com  Sun Jan 25 21:21:13 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Sun, 25 Jan 2015 19:21:13 -0700
Subject: __bases__ misleading error message
In-Reply-To: <ma3njm$c1c$1@ger.gmane.org>
References: <1a194e0a0b738d205de54180fa7@nntp.aioe.org>
 <54c39366$0$13006$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2e298c14dbed69989692@nntp.aioe.org>
 <54c4606a$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2eecca37bc450998969a@nntp.aioe.org>
 <54c4dae1$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <ma3njm$c1c$1@ger.gmane.org>
Message-ID: <CALwzidk+foTWr_-6ufUPfGfYqCBCbg_J9toJNHP75zAf9F8B3A@mail.gmail.com>

On Jan 25, 2015 2:37 PM, "Terry Reedy" <tjreedy at udel.edu> wrote:
> 2. the second array is a compact array of entries in insertion order,
such as
>
>     [hash, ptr to 'x', ptr to 23]
>     [hash, ptr to 'colour', ptr to 'red']
>     [hash, ptr to the string 'y', ptr to the int 42]
>
> Iteration would use the compact array, making all dicts OrderedDicts.
Pypy has already switched to this.  It seems that on modern processors with
multilevel on-chip caches, the space reduction leads to cache-miss
reductions that compensate for the indirection cost.

Deletion becomes O(n) though. Has there been any investigation into how
commonly deletion of keys is done?
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From rustompmody at gmail.com  Sun Jan 25 21:41:31 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Sun, 25 Jan 2015 18:41:31 -0800 (PST)
Subject: Idiomatic backtracking in Python
In-Reply-To: <mailman.18134.1422219082.18130.python-list@python.org>
References: <ma3itj$ol6$1@news.albasani.net>
 <mailman.18134.1422219082.18130.python-list@python.org>
Message-ID: <14b148fe-42ac-4239-8eb5-9fbc42f30392@googlegroups.com>

On Monday, January 26, 2015 at 2:21:34 AM UTC+5:30, Ian Foote wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Hi,
> 
> I think a very idiomatic way to implement backtracking is using a
> recursive generator (python 3):
> 
> def backtrack_solver(data=None):
>     if data is None:
>         yield from backtrack_solver(data=initial_data)
> 
>     if cannot_be_valid(data):
>         return
> 
>     if matches_condition(data):
>         yield data
>         return
> 
>     for new_data in process(data):
>         yield from backtrack_solver(new_data)
> 
> This generator will yield valid solutions to a suitably defined problem.
> 
> `initial_data`, `cannot_be_valid`, `matches_condition` and `process`
> should be replaced with appropriate implementation for your problem.
> 
> For example, a sudoku solver could be fit to this by accepting a
> partially solved grid as the `data` parameter.
> 
> `cannot_be_valid` would now detect grids that have, say, two `1`s in a
> row or any other invalid grid state and exit.
> 
> `matches_condition` would detect a fully solved grid.
> 
> `process` would produce new grids with more cells filled in than the
> current grid.
> 
> `initial_data` wouldn't be strictly necessary here, but you could use
> it for an example grid. It could also be an empty grid, and the solver
> would then yield all valid grids.
> 
> Regards,
> Ian F
> 
> On 25/01/15 20:15, Johannes Bauer wrote:
> > Hi folks,
> > 
> > I have a problem at hand that needs code for backtracking as a
> > solution. And I have no problem coding it, but I can't get rid of
> > the feeling that I'm always solving backtracking problems in a
> > non-Pythonic (non-idiomatic) way. So, I would like to ask if you
> > have a Pythonic approach to backtracking problems? If so, I'd love
> > to hear your solutions!
> > 
> > Cheers, Johannes

To add to Ian:

The classic way of doing it in a functional framework is called:
"Replace failure by list of successes"

https://rkrishnan.org/files/wadler-1985.pdf

The things that have to go into it are
1. Extensive use of list comprehensions
2. Lazy lists

Just change in the above 'list' to 'generator'
and more or less it should work in python

More or less that means when you have a comprehension
[expr for x in list2 for y in list2 etc]

change the '[]' to '()'
and recursively change the list1 list2 to gen1 gen2

Some nuisances that bug me (or I dont know how to handle):

1. Singleton
   [val] becomes (x for x in [val])  (Hoo Boy!)

   Or 
   def single_val(): yield val

2. Nice syntax like list +

Compare [1] + [2]
with

>>> from itertools import chain
>>> a = (x for x in [1])
>>> b = (x for x in [2])
>>> list(chain(a,b))
[1, 2]

Of course it looks worse because the (syntax) overhead of
jumping between lists and generators overwhelms in this trivial case


From steve+comp.lang.python at pearwood.info  Sun Jan 25 21:46:46 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Mon, 26 Jan 2015 13:46:46 +1100
Subject: Alternative to multi-line lambdas: Assign-anywhere def statements
References: <CAPTjJmrAQgtauH74dwCzb_-6T09D0dLVkxiGrAxJMp_OOwgS0g@mail.gmail.com>
 <54C3EAD1.2010501@stoneleaf.us>
 <CAPTjJmohdQbK9_ikh8heaMRbpJ270UW6C1AE2oNVgV_4AoYfQg@mail.gmail.com>
 <mailman.18121.1422151185.18130.python-list@python.org>
 <4741da2c-8fc5-4c06-bc3a-cfadca890abf@googlegroups.com>
 <54c470a9$0$12983$c3e8da3$5496439d@news.astraweb.com>
 <566d71d9-3f89-4422-b454-77913b1b5e01@googlegroups.com>
Message-ID: <54c5aa96$0$12983$c3e8da3$5496439d@news.astraweb.com>

Yawar Amin wrote:

> Hi Steven,
> 
> On Saturday, January 24, 2015 at 11:27:33 PM UTC-5, Steven D'Aprano
> wrote:
>> [...]
>> > Doesn't the traceback tell us exactly where the lambda was called
>> > from?
>> 
>> Yes (assuming the source code is available, which it may not be), but
> 
> If the source code is not available, then you're equally unable to debug
> a lambda function and a named function.

If source code to a library is unavailable, debugging is significantly more
difficult, but it may still be possible. At least in the sense that you can
identify the nature of the bug and develop a work-around in your own code.
Obviously there needs to be *some* source code for you to edit, otherwise
there's nothing for you to edit :-)

Even in the absence of source code, you may still be able to report a bug to
the application developer and show the full traceback. Even without source,
tracebacks show the names of functions, and lambdas all share the same
name:

[steve at ando ~]$ cat demo.py
def fail(x):
        f = lambda a: 1/a
        g = lambda a: f(a-1)
        return g(x)

print fail(1)
[steve at ando ~]$ python -m compileall demo.py
Compiling demo.py ...
[steve at ando ~]$ python demo.pyc
Traceback (most recent call last):
  File "demo.py", line 6, in <module>
    print fail(1)
  File "demo.py", line 4, in fail
    return g(x)
  File "demo.py", line 3, in <lambda>
    g = lambda a: f(a-1)
  File "demo.py", line 2, in <lambda>
    f = lambda a: 1/a
ZeroDivisionError: integer division or modulo by zero
[steve at ando ~]$ mv demo.py demo-save.py  # hide the source
[steve at ando ~]$ python demo.pyc
Traceback (most recent call last):
  File "demo.py", line 6, in <module>
  File "demo.py", line 4, in fail
  File "demo.py", line 3, in <lambda>
  File "demo.py", line 2, in <lambda>
ZeroDivisionError: integer division or modulo by zero


In this toy example, it is still easy to debug even without names. It's a
three line function, how hard could it be? :-) But that isn't always going
to be the case.



[...]
> True, Python's current traceback reporting doesn't tell us the exact
> column number on which the exception occurred. So for example with this:
[...]
> So the problem is there are two lambdas in line 3, so you need to
> examine them both to figure out which one caused the exception. The
> simple solution to this is to just put the lambdas on different lines:
> 
>     print(
>       (lambda: 1)(),
>       (lambda: 1 / 0)()
>     )
> 
> Now you get a blindingly obvious traceback:


It's blindingly obvious because it is trivial. You're still thinking about
the easy cases, not the hard cases:

py> def make_funcs():
...     closures = []
...     for i in range(5, -5, -1):
...         closures.append(lambda x, i=i: x/i)
...     return closures
...
py> results = [f(5) for f in make_funcs()]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 1, in <listcomp>
  File "<stdin>", line 4, in <lambda>
ZeroDivisionError: division by zero


That's still not a hard case, because all the closures have a very similar
form and it's easy to spot that one of them divides by zero. But it
demonstrates one way that line numbers alone don't help.

But do understand I'm not saying that lambdas cannot be debugged. I'm saying
that *function names are a useful debugging tool*, so if you take away the
function name that makes debugging just that little bit harder. Not
necessarily in every single case, and not necessarily hard to the point
that you spend days trying to track down the error, but hard enough in
enough circumstances that using lambda for arbitrarily complex functions
would be a bad idea. (The same applies to comprehensions: they should be
kept simple.) That shouldn't be controversial.



-- 
Steven



From dieter at handshake.de  Mon Jan 26 02:17:57 2015
From: dieter at handshake.de (dieter)
Date: Mon, 26 Jan 2015 08:17:57 +0100
Subject: Track down SIGABRT
References: <B967FFA3-810A-4C9F-A353-A3C5E8C9ED6B@ravnalaska.net>
 <7FF67692-9F7B-4EE1-AD9F-83DAC545A78A@mac.com>
 <mailman.17686.1421168721.18130.python-list@python.org>
 <87h9vuoae7.fsf@jester.gateway.pace.com>
 <16DE6703-A761-457E-A942-36C833E32884@ravnalaska.net>
Message-ID: <87k30a57tm.fsf@handshake.de>

Israel Brewster <israel at ravnalaska.net> writes:
> ...
> Running it through GDB didn't seem to give me much more information than that crash report - I can see that it is in thread 0, and the call stack is identical to what the crash report shows, but I can't see where in the python code it is.
> ...
> Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
> 0   libsystem_kernel.dylib        	0x98176be6 __select + 10
> 1   time.so                       	0x0052fdda 0x52f000 + 3546
> 2   org.python.python             	0x0007e90a PyCFunction_Call + 98
> 3   org.python.python             	0x000ccef4 PyEval_EvalFrameEx + 8182
> 4   org.python.python             	0x000caeb2 PyEval_EvalCodeEx + 1777

This tells you: the crash happens somewhere in a call to a function
defined in "time.so".
I suppose that all such functions are harmless in themselves.


I see two potential causes:

  *  a stack overflow
     some Python builds are made with quite a small thread runtime stack.
     However, you would usually get a "SIGSEGV" rather than
     a "SIGABRT".

  *  a bad pointer passed in to the function.
     Again, I would expect rather a "SIGSEGV" than a "SIGABRT" --
     but maybe "__select" has a special sanity check for its arguments
     and raises "SIGABRT" when the check fails.

In order to determine where in your Python code the problem happens,
you likely need a Python with debugging symbols (system installed
Python interpreters usually are "stripped", e.g. they no longer
have debugging symbols).

Python comes with GDB macros able to show you information
at the Python (rather than the C) level. Here (Ubuntu 12.4),
it is at "/usr/share/doc/python2.7/gdbinit.gz".
Those macros need debugging symbols.
Read the top of this file, for how to get those macros defined
in your GDB session.


I doubt that being able to relate the problem to code
at the Python level will help you much. Your "SIGABRT" problem
is likely not caused on the Python level (but at C level).

If it is not caused by a runtime stack overflow, the cause is likely
a memory corruption, made non locally (far away) in some C extension.
Using a tool to track down memory corruption might help you
(however, in my experience, it is usually a huge task).



From jpiitula at ling.helsinki.fi  Mon Jan 26 02:21:53 2015
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 26 Jan 2015 09:21:53 +0200
Subject: Idiomatic backtracking in Python
References: <ma3itj$ol6$1@news.albasani.net>
 <mailman.18134.1422219082.18130.python-list@python.org>
 <14b148fe-42ac-4239-8eb5-9fbc42f30392@googlegroups.com>
Message-ID: <qotppa2qa5q.fsf@ruuvi.it.helsinki.fi>

Rustom Mody writes:

> To add to Ian:
> 
> The classic way of doing it in a functional framework is called:
> "Replace failure by list of successes"
> 
> https://rkrishnan.org/files/wadler-1985.pdf
> 
> The things that have to go into it are
> 1. Extensive use of list comprehensions
> 2. Lazy lists
> 
> Just change in the above 'list' to 'generator'
> and more or less it should work in python
> 
> More or less that means when you have a comprehension
> [expr for x in list2 for y in list2 etc]
> 
> change the '[]' to '()'
> and recursively change the list1 list2 to gen1 gen2
> 
> Some nuisances that bug me (or I dont know how to handle):
> 
> 1. Singleton
>    [val] becomes (x for x in [val])  (Hoo Boy!)
> 
>    Or 
>    def single_val(): yield val

It's just one def:

def sing(*args):
   for arg in args:
       yield arg

Or not even that: iter((val,)).

But see below at the end.

> 2. Nice syntax like list +
> 
> Compare [1] + [2]
> with
> 
> >>> from itertools import chain
> >>> a = (x for x in [1])
> >>> b = (x for x in [2])
> >>> list(chain(a,b))
> [1, 2]
> 
> Of course it looks worse because the (syntax) overhead of jumping
> between lists and generators overwhelms in this trivial case

Yes, one wouldn't jump back and forth so much. Just collect the result
at the end.

>>> list(chain(sing(3,1,4), sing(1), sing(5,9,2,6)))
[3, 1, 4, 1, 5, 9, 2, 6]

>>> list(chain(sing(3,1,4,1), sing(), sing(5,9,2,6)))
[3, 1, 4, 1, 5, 9, 2, 6]

And it gets better: chain takes lists! And tuples! For those who like
their brackets round:

>>> tuple(chain((3,1,4,1), (), (5,9,2,6)))
(3, 1, 4, 1, 5, 9, 2, 6)

>>> set(chain((3,)))
{3}

>>> list(chain(()))
[]

So chain does it all.


From rustompmody at gmail.com  Mon Jan 26 02:28:09 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Sun, 25 Jan 2015 23:28:09 -0800 (PST)
Subject: Idiomatic backtracking in Python
In-Reply-To: <qotppa2qa5q.fsf@ruuvi.it.helsinki.fi>
References: <ma3itj$ol6$1@news.albasani.net>
 <mailman.18134.1422219082.18130.python-list@python.org>
 <14b148fe-42ac-4239-8eb5-9fbc42f30392@googlegroups.com>
 <qotppa2qa5q.fsf@ruuvi.it.helsinki.fi>
Message-ID: <fd7c6831-5510-4591-a393-14a3b4ec4100@googlegroups.com>

On Monday, January 26, 2015 at 12:52:04 PM UTC+5:30, Jussi Piitulainen wrote:
> Rustom Mody writes:
> 
> > To add to Ian:
> > 
> > The classic way of doing it in a functional framework is called:
> > "Replace failure by list of successes"
> > 
> > https://rkrishnan.org/files/wadler-1985.pdf
> > 
> > The things that have to go into it are
> > 1. Extensive use of list comprehensions
> > 2. Lazy lists
> > 
> > Just change in the above 'list' to 'generator'
> > and more or less it should work in python
> > 
> > More or less that means when you have a comprehension
> > [expr for x in list2 for y in list2 etc]
> > 
> > change the '[]' to '()'
> > and recursively change the list1 list2 to gen1 gen2
> > 
> > Some nuisances that bug me (or I dont know how to handle):
> > 
> > 1. Singleton
> >    [val] becomes (x for x in [val])  (Hoo Boy!)
> > 
> >    Or 
> >    def single_val(): yield val
> 
> It's just one def:
> 
> def sing(*args):
>    for arg in args:
>        yield arg
> 
> Or not even that: iter((val,)).


Sweet


> 
> But see below at the end.
> 
> > 2. Nice syntax like list +
> > 
> > Compare [1] + [2]
> > with
> > 
> > >>> from itertools import chain
> > >>> a = (x for x in [1])
> > >>> b = (x for x in [2])
> > >>> list(chain(a,b))
> > [1, 2]
> > 
> > Of course it looks worse because the (syntax) overhead of jumping
> > between lists and generators overwhelms in this trivial case
> 
> Yes, one wouldn't jump back and forth so much. Just collect the result
> at the end.
> 
> >>> list(chain(sing(3,1,4), sing(1), sing(5,9,2,6)))
> [3, 1, 4, 1, 5, 9, 2, 6]
> 
> >>> list(chain(sing(3,1,4,1), sing(), sing(5,9,2,6)))
> [3, 1, 4, 1, 5, 9, 2, 6]
> 
> And it gets better: chain takes lists! And tuples! For those who like
> their brackets round:
> 
> >>> tuple(chain((3,1,4,1), (), (5,9,2,6)))
> (3, 1, 4, 1, 5, 9, 2, 6)
> 
> >>> set(chain((3,)))
> {3}
> 
> >>> list(chain(()))
> []
> 
> So chain does it all.

Neat 
Thanks



From breamoreboy at yahoo.co.uk  Mon Jan 26 03:06:16 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 26 Jan 2015 08:06:16 +0000
Subject: Idiomatic backtracking in Python
In-Reply-To: <8561bumlfb.fsf@benfinney.id.au>
References: <ma3itj$ol6$1@news.albasani.net> <8561bumlfb.fsf@benfinney.id.au>
Message-ID: <ma4si1$vbf$1@ger.gmane.org>

On 26/01/2015 00:32, Ben Finney wrote:
> Johannes Bauer <dfnsonfsduifb at gmx.de> writes:
>
>> So, I would like to ask if you have a Pythonic approach to
>> backtracking problems? If so, I'd love to hear your solutions!
>
> I'm not aware of what the problem is. ?Back-tracking? doesn't have a
> general meaning I recognise beyond random access into a data structure.
> So a Python list is the obvious starting point.
>
> Do you have a specific meaning of ?back-tracking? that implies
> particular problems that are difficult to solve?
>

As good a definition here http://en.wikipedia.org/wiki/Backtracking as 
any.  As elsewhere in this thread it mentions sudoku.  To me this 
http://norvig.com/sudoku.html is a classic example of putting theory 
into practice.  Read and weep :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From stephane at wirtel.be  Mon Jan 26 08:14:24 2015
From: stephane at wirtel.be (=?utf-8?q?St=C3=A9phane?= Wirtel)
Date: Mon, 26 Jan 2015 14:14:24 +0100
Subject: PythonFOSDEM 2015 - Last news
Message-ID: <1AF942A6-E01E-4620-AA38-8A0E042061D2@wirtel.be>

Hi all,

This week-end is FOSDEM and especially the PythonFOSDEM 2015,

PythonFOSDEM will take place in Brussels, in Belgium, in Europe.

If you don't know FOSDEM, here is the site https://fosdem.org/2015/

About the PythonFOSDEM, the site http://www.python-fosdem.org/

The last blog post with some pictures of the last edition
http://blog.python-fosdem.org/post/109196659496/pythonfosdem-2015-last-news

The schedule:
	http://www.python-fosdem.org/#programme
	https://fosdem.org/2015/schedule/track/python/

If you don't know what to do this week-end, just take a plane or your 
car, you won't regret it.
Chocolate, Beers, Python developers, Plush snake, Shirts, Books, free 
eBooks,

If you don't know Brussels, this is the most beautiful place of Europe 
and maybe of the world.

Bye and See you there with the Python Community.

Cheers,

Stephane

--
St?phane Wirtel - http://wirtel.be - @matrixise


From nh.jones01 at gmail.com  Mon Jan 26 08:32:22 2015
From: nh.jones01 at gmail.com (Norah Jones)
Date: Mon, 26 Jan 2015 13:32:22 +0000
Subject: HTTP over Asynchronous AF_UNIX Socket in python
Message-ID: <abcd1234abc123ab12a0000074868000020000001052@gmail.com>

Hi, 

The problem description:

There are set of processes running on my system say `process_set_1`. Build a process agent which runs an `asynchronous` socket listening to incoming requests from process_set_1. Each process sends an `id`. The agent stores these ids in a dictionary and sends response that ur id has been accepted. Now agent process receives some data from another process (which is some sort of sister process for the agent). This data contains id along with a command which is to be sent by the agent to the process_set_1 through HTTP client over `AF_UNIX` socket, since each process in process_set_1 has a HTTP listening CLI. The process agent sends an HTTP request by recognizing id stored in dictionary to the process_set_1. A service running in the process_set_1 routes this HTTP command to the respective process.

Now my problem is the HTTP request which to be sent must go through AF_UNIX socket. I got this solution.

    class UnixStreamHTTPConnection(httplib.HTTPConnection):
    
        def __init__(self, path, host='localhost/rg_cli',port=None, strict=None,
                     timeout=None):
            httplib.HTTPConnection.__init__(self, host, port=port, strict=strict,
                                            timeout=timeout)
            self.path=path
    
        def connect(self):
            self.sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
            self.sock.connect(self.path)

But this cannot work since normal socket will not work and thus i thought of `asyncore` module in python. To use asyncore module again i will have to subclass asyncore.dispatcher. This class also contains connect() method.

Another problem is I don't know how asyncore module works and thus not able to find a way to mix the work of 1) listening forever, accept the connection, store id and the sock_fd. 
2) accept data from the process' agent sister process, retrieve the sock_fd by matching the id in the dictionary and send it through the AF_UNIX socket.

Please help since i have already spent 2 days digging it out. Sorry if could explain my problem very well.

Thanks,
Norah Jones




From andrew3 at r3dsolutions.com  Mon Jan 26 08:38:55 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Mon, 26 Jan 2015 05:38:55 -0800
Subject: Fwd: Re: Comparisons and sorting of a numeric class....
In-Reply-To: <54C6434E.1030101@r3dsolutions.com>
References: <54C6434E.1030101@r3dsolutions.com>
Message-ID: <54C6436F.8020906@r3dsolutions.com>




-------- Original Message --------
Subject: 	Re: Comparisons and sorting of a numeric class....
Date: 	Mon, 26 Jan 2015 05:38:22 -0800
From: 	Andrew Robinson <andrew3 at r3dsolutions.com>
To: 	Steven D'Aprano <steve+comp.lang.python at pearwood.info>



On 01/24/2015 12:27 AM, Steven D'Aprano wrote:
> Andrew Robinson wrote:
>
>> But let me explain a bit more why I'm picking on Python:  For even if we
>> set the electronic engineering concerns aside that I've raised (and they
>> are valid, as OOP is supposed to model reality, not reality be bent to
>> match OOP) -- People's facile explanations about why Python's version of
>> bool is the way it is -- still bothers me here in the python mail list
>> -- because people seem to have a very wrong idea about bool's nature as
>> a dualton being somehow justified solely by the fact that there are only
>> two values in Boolean logic;
> Nobody has suggested that except you.
Yes, they did 'suggest' it.
> Earlier I even stated that I didn't
> know GvR's motivation in making True and False singletons, but suggested
> that it might have been a matter of efficiency.
True... but you are not the only person on this list.

Although I seriously doubt that either efficiency, or memory
conservation plays a part in this in any meausrable manner.  eg: You
accused me of 'pre-optimizing' earlier, and if anything looks like a
pre-optimization, it's the bool itself because computers have tons of
memory now, and I seriously doubt modern Python versions can even run in
a small micro-controler; eg: without an almost complete rewrite of the
language....and as far as efficiency, I know speed won't change
significantly whether or not a singleton, or multiple instances are
allowed except under very unusual circumstances.  So, even now -- I have
no idea why Guido chose to make bool so restrictive other than because
he thought C++ was absolutely restrictive, when in fact C++'s type
system is more flexible than he seems to have noticed.

>> -- And I know
>> Charles bool didn't use singletons in his algebra,  -- just read his
>> work and you'll see he never mentions them or describes them, but he
>> does actually use dozens of instances of the True and False objects he
>> was talking about -- for the obvious reason that he would have needed
>> special mirrors, dichroic or partially silvered, to be even able to
>> attempt to make one instance of True written on paper show up in
>> multiple places; And that's silly to do when there's no compelling
>> reason to do it.
> In the words of physicist Wolfgang Pauli, that is not even wrong.
>
> http://en.wikipedia.org/wiki/Not_even_wrong
>
> I'm actually gobsmacked that you could seriously argue that because Boole
> wrote down true and false (using whatever notation he choose) more than
> once, that proves that they aren't singletons. That's as sensible as
> claiming that if I write your name down twice, you must be two people.
Clearly: Charles bool did not use singletons, and you are wasting your
breath splitting hairs that are moot.
>> Yet -- people here seem to want to insist that the bool type with only
>> two instances is some kind of pure re-creation of what Charles Bool
>> did -- when clearly it isn't.
> Nobody has argued that Boole (note the spelling of his name) considered True
> and False to be singletons. Being a mathematician, he probably considered
> that there is a single unique True value and a single unique False value,
> in the same way that there is a single unique value pi (3.1415...) and a
> single unique value 0.
The spelling caveat is great -- and in Python the object named in bool's
honor is spelled bool (lowercase too). ;)  another point about the
inconsistency of the object with the historical author, I just love it,
which is part of why I'm going to keep on spelling it like that!!!!  For
even the spelling, suggests Python is really acting like a lemming and
just doing bool because Guido though other lanugages do bool...   so
I'll just continue because it's fitting that anyone who mocks my use of
the mis-spelling bool also mock's Python's.

>
> But "the number of instances" and "singleton" are concepts from object
> oriented programming, which didn't exist when Boole was alive.
Yep -- I made that point myself in an earlier e-mail.  Do you feel
brilliant, or something, copying my remarks ?

>   It is not
> even wrong to ask the question whether Boole thought of true and false to
> be singleton objects. He no more had an opinion on that than Julius Caesar
> had an opinion on whether the Falkland Islands belong to the UK or
> Argentina.
Oooooh!  So you want people to think you commune with the dead, and know
he never thought about it alive and/or dead?  D'Aprano speaks
posthumously for Dr. bool ?

You're being very condescending and arrogant and arguing in pointless
circles!

I said, and I quote "He didn't use singletons in his algebra" -- if you
can show where he did, I'll retract my remark; otherwise -- you're
merely proving my point.

>> It's a amalgamation of enhancements such
>> as binary words instead of just True/False and many other things
>> (operators that work on words rather than single bits.).  So -- I don't
>> see that Python's implementation of Bool is justified by either a purist
>> appeal to Charles bool, or by ignoring pragmatic concerns that have been
>> attached to Bool's work for years by Electrical Engineers in order to
>> make it more useful for practical computer problems.  Yet these two
>> things are what this python list has sort of harped on.
> Python's bools are objects, and they represent Boolean values, not strings,
It's far more likely in my experience that an object in a computer *at
least* represents what can actually be found in the code of that object,
rather than trying to claim objects in python have nothing to do with
what is found in the object.  I *DO* know that the bool *object* in
python certainly does represent a string, in the repr() method; eg:
"True" or "False" strings to be precise.

So:  Where exactly is this boolean 'value' in the computer that you are
harping on, and what does it consist of ?  The moment you point out
where it is -- I will point out, that it is likely transmitted by wires
which were designed by engineers using HDL's, or else, you're going to
point to something containing a string, or an integer, but whatever it
is -- I know for sure it's not some mythical 'bool' in reality.

The bool values you seem to want to talk about exist only in your mind,
and you can't actually show them to me;  they aren't real objects in
Python or a computer.  Your whole argument is non-falsifiable and rather
pointless as far as I can tell.

> not lists, not floats, and not three-value or four-value logic values. They
> are designed for Boolean two-valued logic, like the bulk of programming
> languages, not for simulating hardware.
That's a non-sequitur, and downright lame.

I showed Ian a way to do what I wanted to do in C++, so the bulk of
programming languages is irrelevant as each has their own quirks and
work arounds; and you obviously don't know that most engineers use
programmable logic in their projects, now, so they use HDL's in
*synthesis* mode not just 'simulation'. The vast majority of all
hardware projects done today are built using this supposed 'niche' you
talk about;  I can, for example, build a complete web site using a
XILINX FPGA and a HDL language without ever using C/C++ or Python or
intel processor or any other dumbed down 'bool' based language you can
think of.  The difference is that HDL's are meant to ultimately
instantiate objects into hardware rather than create a software solution.

...snip...

>
> [...]
>> Where python is different from other languages regarding bool -- and
>> deserves a little extra picking on, is that Guido has imposed four
>> constraints simultaneously to bool which together cause a conflict
>> that I don't think (offhand) I've ever encountered in another language;
>> Definitely not in C/C++!
>>
>> The four things are: 1 -- he cut off subtyping and created no alternate
>> method of doing type checking of duck-types,
> The point of duck-typing is that you *don't* type check,

Gee... you are acting rather inconsistent for someone with so much
programming experience.
You do a duck type check by testing if it acts like a duck.... obviously!

But, I was also referring to how the built in Python type() function is
strict -- eg: a duck type "FAILS" a standard type check (in general).
There is no alternate way to get duck types to pass *existing* type()
checks -- and yes, Python DOES type() check in various places whether or
not I or you want it to! ; and other programmers can call type() in
their legacy code, too.

Hence, duck types often *don't work* because there is no way to
circumvent type() checks that already exist in the Python language, and
for this very reason a simple google search will reveal bug reports
where people are asking Guido to remove type checks altogether in
various places in python 3 precisely because duck types fail to work in
those places.  ( I wouldn't mind if they were gone. )

I really don't have time for the rest of your email; it's pointless...
A lemming is, as a lemming does...




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From a24061 at ducksburg.com  Mon Jan 26 08:43:18 2015
From: a24061 at ducksburg.com (Adam Funk)
Date: Mon, 26 Jan 2015 13:43:18 +0000
Subject: Why does argparse return None instead of [] if an append action
 isn't used?
References: <l265obxc6d.ln2@news.ducksburg.com>
 <mailman.17532.1420818709.18130.python-list@python.org>
Message-ID: <msshpbxjvv.ln2@news.ducksburg.com>

On 2015-01-09, Wolfgang Maier wrote:

> On 01/09/2015 03:44 PM, Adam Funk wrote:
>> I noticed in use that if an option with the 'append' action isn't
>> used, argparse assigns None to it rather than an empty list, &
>> confirmed this interactively:
>>
>> #v+
>>>>> import argparse
>>>>> parser = argparse.ArgumentParser()
>>>>> parser.add_argument('--foo', action='append')
>> _AppendAction(option_strings=['--foo'], dest='foo', nargs=None, const=None, default=None, type=None, choices=None, help=None, metavar=None)
>>>>> parser.add_argument('--bar', action='append')
>> _AppendAction(option_strings=['--bar'], dest='bar', nargs=None, const=None, default=None, type=None, choices=None, help=None, metavar=None)
>>>>> parser.parse_args('--foo 1 --foo 2'.split())
>> Namespace(bar=None, foo=['1', '2'])
>> #v-
>>
>
> Isn't that the exact behaviour documented here:
>
> https://docs.python.org/3/library/argparse.html#default
>
> where it says that the default for the default argument is None ?
>
> I think Skip is right: you should be able to just add
>
> default = []
>
> to your arguments in the add_argument call.

Yes, it works.


-- 
Master Foo said: "A man who mistakes secrets for knowledge is like
a man who, seeking light, hugs a candle so closely that he smothers
it and burns his hand."                            --- Eric Raymond


From a24061 at ducksburg.com  Mon Jan 26 08:43:36 2015
From: a24061 at ducksburg.com (Adam Funk)
Date: Mon, 26 Jan 2015 13:43:36 +0000
Subject: Why does argparse return None instead of [] if an append action
 isn't used?
References: <l265obxc6d.ln2@news.ducksburg.com>
 <mailman.17529.1420816664.18130.python-list@python.org>
Message-ID: <8tshpbxjvv.ln2@news.ducksburg.com>

On 2015-01-09, Ned Batchelder wrote:

> On 1/9/15 9:44 AM, Adam Funk wrote:
>> This makes it a bit more trouble to use:
>>
>>    if options.bar:
>>       for b in options:bar
>>          do_stuff(b)
>>
>> instead of
>>
>>    for b in options.bar
>>       do_stuff(b)
>
> This doesn't answer why the value defaults to None, and some people may 
> recoil at it, but I've used:
>
>      for b in options.bar or ():
>          do_stuff(b)

Do you mean "for b in options.bar or []:" ?


-- 
War is God's way of teaching Americans geography.
                                 [Ambrose Bierce]


From __peter__ at web.de  Mon Jan 26 09:04:51 2015
From: __peter__ at web.de (Peter Otten)
Date: Mon, 26 Jan 2015 15:04:51 +0100
Subject: Why does argparse return None instead of [] if an append action
 isn't used?
References: <l265obxc6d.ln2@news.ducksburg.com>
 <mailman.17529.1420816664.18130.python-list@python.org>
 <8tshpbxjvv.ln2@news.ducksburg.com>
Message-ID: <ma5hi4$si0$1@ger.gmane.org>

Adam Funk wrote:

> On 2015-01-09, Ned Batchelder wrote:
> 
>> On 1/9/15 9:44 AM, Adam Funk wrote:
>>> This makes it a bit more trouble to use:
>>>
>>>    if options.bar:
>>>       for b in options:bar
>>>          do_stuff(b)
>>>
>>> instead of
>>>
>>>    for b in options.bar
>>>       do_stuff(b)
>>
>> This doesn't answer why the value defaults to None, and some people may
>> recoil at it, but I've used:
>>
>>      for b in options.bar or ():
>>          do_stuff(b)
> 
> Do you mean "for b in options.bar or []:" ?

Doesn't matter; in the context of a for loop any empty iterable would do.



From marko at pacujo.net  Mon Jan 26 09:12:12 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Mon, 26 Jan 2015 16:12:12 +0200
Subject: HTTP over Asynchronous AF_UNIX Socket in python
References: <mailman.18146.1422279152.18130.python-list@python.org>
Message-ID: <87siexeimb.fsf@elektro.pacujo.net>

Norah Jones <nh.jones01 at gmail.com>:

> But this cannot work since normal socket will not work and thus i
> thought of `asyncore` module in python. To use asyncore module again i
> will have to subclass asyncore.dispatcher. This class also contains
> connect() method.
>
> Another problem is I don't know how asyncore module works and thus not
> able to find a way to mix the work of 1) listening forever, accept the
> connection, store id and the sock_fd.
> 2) accept data from the process' agent sister process, retrieve the
> sock_fd by matching the id in the dictionary and send it through the
> AF_UNIX socket.

Asyncore was a nice idea, but you shouldn't build anything on top of it.
The newest Python versions have moved to a scheme called asyncio. Its
programming model is a bit unconventional and hasn't won me over yet.

Personally, I have found select.epoll(EPOLLET) plus a timer
implementation enough of a framework for all of my async needs.

Then comes HTTP support. The stdlib networking facilities are great for
quick scripting, but not really compatible with the asynchronous
paradigm. I have coded my protocols by hand myself.


Marko


From wxjmfauth at gmail.com  Mon Jan 26 09:31:26 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Mon, 26 Jan 2015 06:31:26 -0800 (PST)
Subject: Formatting string with accented characters for printing
In-Reply-To: <mailman.17841.1421605741.18130.python-list@python.org>
References: <CAGAAoy3kyhwTexNNv3Bs0of=6h2dT6OD5kvZF-PUzauUCociQg@mail.gmail.com>
 <mailman.17841.1421605741.18130.python-list@python.org>
Message-ID: <a3cc60c7-ca6b-4c9a-a4a4-887b9cf34ecf@googlegroups.com>

Le dimanche 18 janvier 2015 19:29:12 UTC+1, Peter Otten a ?crit?:
> 
> The best approach is to convert your data to unicode as soon as you read it 
> and perform all string operations with unicode. This also avoids breaking 
> characters:
> 
> >>> print "M?resse"[:2]
> M?                                                                                                                                                    
> >>> print u"M?resse"[:2]
> M?
> 
> There are still problems (e. g. with narrow builds), and the best way to 
> avoid a few string-related inconviences is to switch to Python 3.

Well,

>>> print 'M?resse'
M?resse
>>> print u'M?resse'
M?resse
>>> print 'M?resse'[:2]
M?
>>> print u'M?resse'[:2]
M?
>>> sys.version
'2.7.6 (default, Nov 10 2013, 19:24:18) [MSC v.1500 32 bit (Intel)]'
>>>

jmf


From random832 at fastmail.us  Mon Jan 26 10:01:24 2015
From: random832 at fastmail.us (random832 at fastmail.us)
Date: Mon, 26 Jan 2015 10:01:24 -0500
Subject: Python is DOOMED! Again!
In-Reply-To: <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <1422284484.2032011.219005705.2D69F434@webmail.messagingengine.com>

On Thu, Jan 22, 2015, at 23:23, Steven D'Aprano wrote:
> Rick Johnson wrote:
> 
> > The solution is move the type
> > hinting syntax completely out of the source file and into
> > another file -- think of it as a "Python Type Hinting Header
> > File".
> 
> The 1970s called, they want their bad ideas back.
> 
> I can do no better than to quote from the Go FAQs:
> 
>     Dependency management is a big part of software development 
>     today but the ?header files? of languages in the C tradition 
>     are antithetical to clean dependency analysis?and fast 
>     compilation.

This is more along the lines of a lint library than a header file
(header files in the 1970s didn't even actually include function
signature information) - which did not even participate in compilation
at all.


From a24061 at ducksburg.com  Mon Jan 26 10:50:21 2015
From: a24061 at ducksburg.com (Adam Funk)
Date: Mon, 26 Jan 2015 15:50:21 +0000
Subject: Why does argparse return None instead of [] if an append action
 isn't used?
References: <l265obxc6d.ln2@news.ducksburg.com>
 <mailman.17529.1420816664.18130.python-list@python.org>
 <8tshpbxjvv.ln2@news.ducksburg.com>
 <mailman.18148.1422281105.18130.python-list@python.org>
Message-ID: <ta4ipbx9j3.ln2@news.ducksburg.com>

On 2015-01-26, Peter Otten wrote:

> Adam Funk wrote:
>
>> On 2015-01-09, Ned Batchelder wrote:
>> 
>>> On 1/9/15 9:44 AM, Adam Funk wrote:
>>>> This makes it a bit more trouble to use:
>>>>
>>>>    if options.bar:
>>>>       for b in options:bar
>>>>          do_stuff(b)
>>>>
>>>> instead of
>>>>
>>>>    for b in options.bar
>>>>       do_stuff(b)
>>>
>>> This doesn't answer why the value defaults to None, and some people may
>>> recoil at it, but I've used:
>>>
>>>      for b in options.bar or ():
>>>          do_stuff(b)
>> 
>> Do you mean "for b in options.bar or []:" ?
>
> Doesn't matter; in the context of a for loop any empty iterable would do.

Of course it would.  Doh!


-- 
A recent study conducted by Harvard University found that the average
American walks about 900 miles a year. Another study by the AMA found
that Americans drink, on average, 22 gallons of alcohol a year. This
means, on average, Americans get about 41 miles to the gallon.
                 http://www.cartalk.com/content/average-americans-mpg


From ian.g.kelly at gmail.com  Mon Jan 26 11:13:38 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 26 Jan 2015 09:13:38 -0700
Subject: Why does argparse return None instead of [] if an append action
 isn't used?
In-Reply-To: <ta4ipbx9j3.ln2@news.ducksburg.com>
References: <l265obxc6d.ln2@news.ducksburg.com>
 <mailman.17529.1420816664.18130.python-list@python.org>
 <8tshpbxjvv.ln2@news.ducksburg.com>
 <mailman.18148.1422281105.18130.python-list@python.org>
 <ta4ipbx9j3.ln2@news.ducksburg.com>
Message-ID: <CALwzidknU4WfAPJboBEcyP18EpbkS943gCj3H=osCYRaHX7_iA@mail.gmail.com>

On Mon, Jan 26, 2015 at 8:50 AM, Adam Funk <a24061 at ducksburg.com> wrote:
> On 2015-01-26, Peter Otten wrote:
>
>> Adam Funk wrote:
>>
>>> On 2015-01-09, Ned Batchelder wrote:
>>>>      for b in options.bar or ():
>>>>          do_stuff(b)
>>>
>>> Do you mean "for b in options.bar or []:" ?
>>
>> Doesn't matter; in the context of a for loop any empty iterable would do.
>
> Of course it would.  Doh!

Stylistically, I generally prefer the empty list for this. The empty
tuple might be a little faster since it's a singleton and doesn't need
to be constructed at runtime, but that's clearly a micro-optimization,
and I think the list more accurately conveys the intention of
"something to be iterated over". Although tuples are iterable, I don't
often use them for that purpose.


From jpiitula at ling.helsinki.fi  Mon Jan 26 11:29:19 2015
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 26 Jan 2015 18:29:19 +0200
Subject: Why does argparse return None instead of [] if an append action
 isn't used?
References: <l265obxc6d.ln2@news.ducksburg.com>
 <mailman.17529.1420816664.18130.python-list@python.org>
 <8tshpbxjvv.ln2@news.ducksburg.com>
 <mailman.18148.1422281105.18130.python-list@python.org>
 <ta4ipbx9j3.ln2@news.ducksburg.com>
 <mailman.18151.1422288861.18130.python-list@python.org>
Message-ID: <qotioft4iao.fsf@ruuvi.it.helsinki.fi>

Ian Kelly writes:
> On Mon, Jan 26, 2015 at 8:50 AM, Adam Funk wrote:
> > On 2015-01-26, Peter Otten wrote:
> >
> >> Adam Funk wrote:
> >>
> >>> On 2015-01-09, Ned Batchelder wrote:
> >>>>      for b in options.bar or ():
> >>>>          do_stuff(b)
> >>>
> >>> Do you mean "for b in options.bar or []:" ?
> >>
> >> Doesn't matter; in the context of a for loop any empty iterable
> >> would do.
> >
> > Of course it would.  Doh!
> 
> Stylistically, I generally prefer the empty list for this. The empty
> tuple might be a little faster since it's a singleton and doesn't
> need to be constructed at runtime, but that's clearly a
> micro-optimization, and I think the list more accurately conveys the
> intention of "something to be iterated over". Although tuples are
> iterable, I don't often use them for that purpose.

I've used tuples to convey the intention of immutability, as opposed
to using lists. For all I know, collecting a generator (from groupby)
into a tuple might be slower than collecting it into a list. I have no
intention to measure this. The programs have been fast enough for me.


From breamoreboy at yahoo.co.uk  Mon Jan 26 11:31:55 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 26 Jan 2015 16:31:55 +0000
Subject: Fwd: Re: Comparisons and sorting of a numeric class....
In-Reply-To: <54C6436F.8020906@r3dsolutions.com>
References: <54C6434E.1030101@r3dsolutions.com>
 <54C6436F.8020906@r3dsolutions.com>
Message-ID: <ma5q64$jnm$1@ger.gmane.org>

On 26/01/2015 13:38, Andrew Robinson wrote:
>

*plonk*

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From bc at freeuk.com  Mon Jan 26 12:00:22 2015
From: bc at freeuk.com (BartC)
Date: Mon, 26 Jan 2015 17:00:22 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <54c2299d$0$13005$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17973.1421939508.18130.python-list@python.org>
 <54c2299d$0$13005$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <Houxw.308955$FO6.44943@fx33.am4>


[Reposting. First attempt went direct to poster, perhaps via email, not 
sure why as I don't have a button to do that. If this does the same then 
please ignore.]
On 23/01/2015 10:59, Steven D'Aprano wrote:
 > Chris Angelico wrote:
 >
 >> On Fri, Jan 23, 2015 at 1:16 AM, Steven D'Aprano
 >> <steve+comp.lang.python at pearwood.info> wrote:
 >>> Mario Figueiredo wrote:
 >>>
 >>>> def handle_employees(emp: Union[Employee, Sequence[Employee]], raise:
 >>>> Union[float, Sequence[float]]) -> Union[Employee, Sequence[Employee],
 >>>> None]:
 >>>
 >>> Using
 >>> floats for money is Just Wrong and anyone who does so should have their
 >>> licence to program taken away.
 >>
 >> But using a float to specify a percentage raise that an employee (or
 >> class of employees) gets would be reasonable.
 >
 > I don't think that a raise of 0.10000000000000001 (10%),
 > 0.035000000000000003 (3.5%) or 0.070000000000000007 (7%) is quite what
 > people intended.

It seems they are getting a bigger raise than they expected in each 
case. So why complain?

But in practice they will never see that billionth of a cent extra; they 
will get the same amount as they would if floating point wasn't used.

And, how is the increase determined? It could well be the result of some 
complex calculation performed in floating point, which then has to be 
converted to ... BTW how *do* you represent a raise of 10% exactly if 
not with binary floating point?

-- 
Bartc





From breamoreboy at yahoo.co.uk  Mon Jan 26 12:18:03 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 26 Jan 2015 17:18:03 +0000
Subject: Why does argparse return None instead of [] if an append action
 isn't used?
In-Reply-To: <qotioft4iao.fsf@ruuvi.it.helsinki.fi>
References: <l265obxc6d.ln2@news.ducksburg.com>
 <mailman.17529.1420816664.18130.python-list@python.org>
 <8tshpbxjvv.ln2@news.ducksburg.com>
 <mailman.18148.1422281105.18130.python-list@python.org>
 <ta4ipbx9j3.ln2@news.ducksburg.com>
 <mailman.18151.1422288861.18130.python-list@python.org>
 <qotioft4iao.fsf@ruuvi.it.helsinki.fi>
Message-ID: <ma5ssj$ars$1@ger.gmane.org>

On 26/01/2015 16:29, Jussi Piitulainen wrote:
>
> I've used tuples to convey the intention of immutability, as opposed
> to using lists. For all I know, collecting a generator (from groupby)
> into a tuple might be slower than collecting it into a list. I have no
> intention to measure this. The programs have been fast enough for me.
>

IIRC, and probably from this list, creating tuples is way faster than 
creating lists, but accessing items is slower.  Can anybody confirm this 
for us?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From torriem at gmail.com  Mon Jan 26 12:42:40 2015
From: torriem at gmail.com (Michael Torrie)
Date: Mon, 26 Jan 2015 10:42:40 -0700
Subject: HTTP over Asynchronous AF_UNIX Socket in python
In-Reply-To: <abcd1234abc123ab12a0000074868000020000001052@gmail.com>
References: <abcd1234abc123ab12a0000074868000020000001052@gmail.com>
Message-ID: <54C67C90.2070105@gmail.com>

On 01/26/2015 06:32 AM, Norah Jones wrote:
> Now my problem is the HTTP request which to be sent must go through
> AF_UNIX socket. 

The Python Twisted framework may be of use to you.  It's got a very
steep learning curve, but it's fairly easy to change the underlying byte
transport for any protocol they have implemented. In fact in the Twisted
docs, they show a web client accessing an HTTP server over a unix socket
(scroll down to the bottom of the page):

http://twisted.readthedocs.org/en/latest/web/howto/client.html

They show a client connecting to a Docker server which is speaking HTTP
over a unix socket.

Twisted is very powerful and flexible, and event-driven.


From sohcahtoa82 at gmail.com  Mon Jan 26 13:13:34 2015
From: sohcahtoa82 at gmail.com (sohcahtoa82 at gmail.com)
Date: Mon, 26 Jan 2015 10:13:34 -0800 (PST)
Subject: Python simple Code
In-Reply-To: <4e283f62-0b6a-4ef7-a784-b9b3da73f510@googlegroups.com>
References: <4e283f62-0b6a-4ef7-a784-b9b3da73f510@googlegroups.com>
Message-ID: <60668bfd-6a6a-47fb-8a9f-7e1256f3bd76@googlegroups.com>

On Saturday, January 24, 2015 at 4:16:27 PM UTC-8, Salem Alqahtani wrote:
> Hi Guys,
> 
> I just joined the group and I hope that I can help and be active.
> 
> I have a question about python. I wrote a code on python 2.7 and I want to choose from the list of names that I provide n!. I execute the code but the result or output is the numbers. I want the people names are the result.
> 
> 
> Sincerely
> 
> import sys
> import array
> a=['salem','Ali','sultan']
> m = len(a)
> def Factorials(m):
>     if m == 0:
>         return 1
>     else:
>         print m
>         return m * Factorials(m-1)
> def output():
>     print a
> def main():
>     print Factorials(m)
>     output()
> main()

Your English is a bit rough, but from what I'm understanding, the output you're TRYING to get is:

salem
Ali
sultan

If that's the case, then why do you have functions using factorials?  It sounds like you really have no idea what you're doing and just blindly copied some other code with zero understanding of it.


From ian.g.kelly at gmail.com  Mon Jan 26 13:23:34 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 26 Jan 2015 11:23:34 -0700
Subject: Why does argparse return None instead of [] if an append action
 isn't used?
In-Reply-To: <ma5ssj$ars$1@ger.gmane.org>
References: <l265obxc6d.ln2@news.ducksburg.com>
 <mailman.17529.1420816664.18130.python-list@python.org>
 <8tshpbxjvv.ln2@news.ducksburg.com>
 <mailman.18148.1422281105.18130.python-list@python.org>
 <ta4ipbx9j3.ln2@news.ducksburg.com>
 <mailman.18151.1422288861.18130.python-list@python.org>
 <qotioft4iao.fsf@ruuvi.it.helsinki.fi> <ma5ssj$ars$1@ger.gmane.org>
Message-ID: <CALwzid=rzENxp3GHQbcu5WrnFesEJQFD==DDfrDC=EcX4=_WjQ@mail.gmail.com>

On Mon, Jan 26, 2015 at 10:18 AM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> IIRC, and probably from this list, creating tuples is way faster than
> creating lists, but accessing items is slower.  Can anybody confirm this for
> us?

The first seems to be true as long as the tuples are small.

$ python3 -m timeit 't = (1000, 2000, 3000)'
100000000 loops, best of 3: 0.0147 usec per loop
$ python3 -m timeit 't = [1000, 2000, 3000]'
10000000 loops, best of 3: 0.0678 usec per loop
$ python3 -m timeit 't = tuple(range(10000))'
10000 loops, best of 3: 183 usec per loop
$ python3 -m timeit 't = list(range(10000))'
10000 loops, best of 3: 174 usec per loop
$ python3 -m timeit 't = tuple(range(10000000))'
10 loops, best of 3: 323 msec per loop
$ python3 -m timeit 't = list(range(10000000))'
10 loops, best of 3: 306 msec per loop

This is probably a result of the use of freelists to avoid
reallocating the tuple objects, though. I don't see any substantial
difference in access time:

$ python3 -m timeit -s 't = tuple(range(10000))' 't[5000]'
10000000 loops, best of 3: 0.0316 usec per loop
$ python3 -m timeit -s 't = list(range(10000))' 't[5000]'
10000000 loops, best of 3: 0.0318 usec per loop
$ python3 -m timeit -s 't = tuple(range(10000))' 'for x in t: pass'
10000 loops, best of 3: 112 usec per loop
$ python3 -m timeit -s 't = list(range(10000))' 'for x in t: pass'
10000 loops, best of 3: 113 usec per loop


From ian.g.kelly at gmail.com  Mon Jan 26 13:26:33 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 26 Jan 2015 11:26:33 -0700
Subject: Why does argparse return None instead of [] if an append action
 isn't used?
In-Reply-To: <CALwzid=rzENxp3GHQbcu5WrnFesEJQFD==DDfrDC=EcX4=_WjQ@mail.gmail.com>
References: <l265obxc6d.ln2@news.ducksburg.com>
 <mailman.17529.1420816664.18130.python-list@python.org>
 <8tshpbxjvv.ln2@news.ducksburg.com>
 <mailman.18148.1422281105.18130.python-list@python.org>
 <ta4ipbx9j3.ln2@news.ducksburg.com>
 <mailman.18151.1422288861.18130.python-list@python.org>
 <qotioft4iao.fsf@ruuvi.it.helsinki.fi> <ma5ssj$ars$1@ger.gmane.org>
 <CALwzid=rzENxp3GHQbcu5WrnFesEJQFD==DDfrDC=EcX4=_WjQ@mail.gmail.com>
Message-ID: <CALwzidkTTk9Z0CBEKDpxjPCw_uePgczhYbaLH725+c2ERem6mQ@mail.gmail.com>

On Mon, Jan 26, 2015 at 11:23 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> $ python3 -m timeit 't = (1000, 2000, 3000)'
> 100000000 loops, best of 3: 0.0147 usec per loop
> $ python3 -m timeit 't = [1000, 2000, 3000]'
> 10000000 loops, best of 3: 0.0678 usec per loop
> $ python3 -m timeit 't = tuple(range(10000))'
> 10000 loops, best of 3: 183 usec per loop
> $ python3 -m timeit 't = list(range(10000))'
> 10000 loops, best of 3: 174 usec per loop
> $ python3 -m timeit 't = tuple(range(10000000))'
> 10 loops, best of 3: 323 msec per loop
> $ python3 -m timeit 't = list(range(10000000))'
> 10 loops, best of 3: 306 msec per loop
>
> This is probably a result of the use of freelists to avoid
> reallocating the tuple objects, though. I don't see any substantial
> difference in access time:

Whoops. Actually it's a result of the 3-element tuple being a constant
in the code object. If we use the constructor, the difference mostly
goes away.

$ python3 -m timeit 't = tuple(range(1000, 4000, 1000))'
1000000 loops, best of 3: 0.559 usec per loop
$ python3 -m timeit 't = list(range(1000, 4000, 1000))'
1000000 loops, best of 3: 0.585 usec per loop


From varun7rs at gmail.com  Mon Jan 26 14:52:00 2015
From: varun7rs at gmail.com (varun7rs at gmail.com)
Date: Mon, 26 Jan 2015 11:52:00 -0800 (PST)
Subject: Running a .py file iteratively at the terminal
Message-ID: <bea3815c-7a64-417a-959c-9408581a643e@googlegroups.com>

Hello Everyone,

I am running a python script as of now and I have to change three global values repeatedly. I'm tired of doing this manually. SO, I was wondering if there is a way to run a python command repeatedly. In my case, the command would be

srva at hades:~$ python NFV_v3_7_10_14.py -l log --lp --xml eu_v3_14_1_15.xml

Everytime I run this, I get a log file with the results. The main file is the NFV_v3....py. These are the values I intend to change iteratively and then run the command in the terminal. 
dataplane_latencybound = 200 # The delay bounds are in milli seconds
controlplane_latencybound1 = 200 # The delay bounds are in milli seconds

So, in every iteration, I would like to increase it from 0 in steps of 10 till 200. And after doing so, I'd like to run the command. But, I'm unaware of doing this using a single script. I hope some of you experts over there could help me in this issue. It can be a huge timesaver.


Thanks a lot guys
Varun RS


From tundra at tundraware.com  Mon Jan 26 15:18:40 2015
From: tundra at tundraware.com (Tim Daneliuk)
Date: Mon, 26 Jan 2015 14:18:40 -0600
Subject: What killed Smalltalk could kill Python
In-Reply-To: <mailman.18066.1422053863.18130.python-list@python.org>
References: <54bfd513$0$12978$c3e8da3$5496439d@news.astraweb.com>
 <spp5pb-0tt1.ln1@ozzie.tundraware.com>
 <mailman.17932.1421884530.18130.python-list@python.org>
 <54C2D058.8060809@tundraware.com>
 <mailman.18066.1422053863.18130.python-list@python.org>
Message-ID: <02kipb-eav2.ln1@ozzie.tundraware.com>

On 01/23/2015 04:57 PM, Chris Angelico wrote:
> On Sat, Jan 24, 2015 at 9:51 AM, Tim Daneliuk <tundra at tundraware.com> wrote:
>> On 01/21/2015 05:55 PM, Chris Angelico wrote:
>>> On Thu, Jan 22, 2015 at 10:37 AM, Tim Daneliuk <tundra at tundraware.com> wrote:
>>>> I find these kinds of discussions sort of silly.  Once there is a critical
>>>> mass of installed base, no language EVER dies.
>>>
>>> Not sure about that. Back in the 1990s, I wrote most of my code in
>>> REXX, either command-line or using a GUI toolkit like VX-REXX. Where's
>>> REXX today? Well, let's see. It's still the native-ish language of
>>> OS/2. Where's OS/2 today? Left behind. REXX has no Unicode support (it
>>> does, however, support DBCS - useful, no?), no inbuilt networking
>>> support (there are third-party TCP/IP socket libraries for OS/2 REXX,
>>> but I don't know that other REXX implementations have socket services;
>>> and that's just basic BSD sockets, no higher-level protocol handling
>>> at all), etc, etc. Sure, it's not technically dead... but is anyone
>>> developing the language further? I don't think so. Is new REXX code
>>> being written? Not a lot. Yet when OS/2 was more popular, REXX
>>> definitely had its installed base. It was the one obvious scripting
>>> language for any OS/2 program. Languages can definitely die, or at
>>> least be so left behind that they may as well be dead.
>>>
>>> ChrisA
>>>
>>
>> Rexx is still well used on mainframes.
> 
> Oh, is it? Cool! Maybe some day I'll be interviewing for a job, and
> they'll ask if I know REXX.. and I'll actually be able to say yes. :)
> 
> ChrisA
> 

Let me first note for the record that I make my living on *NIX type
systems.  So, my comments below are not bound to my personal technical
religion ...


I work in and among some of the larger corporations on the planet and I
have a little secret for you:  Mainframes are NOT going away wholesale.
As the population of mainframe-savvy staff dwindles into retirement,
one of the hottest tickets you're going to see in the next 20 years
is people who can do that work.  It's so bad, that IBM themselves are
working to train the next generation of MVS systems programmers, and
the like.

And no, you can't just replace mainframes with open systems equivalents.
There are likely hundreds of millions of lines of COBOL and assembler
code that cannot just be ported over to a new platform and language.
Why?  Because there is an ecosystem of support in the mainframe world
that is utterly absent in the *NIX/Windoze world.   This includes things
especially like CICS, IMS (ask Caterpillar if they'll stop using it ;),
DB2 and so forth.

So, yes, if you're mainframe savvy, you may have a nice consulting career
in your old age :)

-- 
----------------------------------------------------------------------------
Tim Daneliuk     tundra at tundraware.com
PGP Key:         http://www.tundraware.com/PGP/



From andrew3 at r3dsolutions.com  Mon Jan 26 15:28:41 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Mon, 26 Jan 2015 12:28:41 -0800
Subject: Fwd: Re: Comparisons and sorting of a numeric class....
In-Reply-To: <ma5q64$jnm$1@ger.gmane.org>
References: <54C6434E.1030101@r3dsolutions.com>
 <54C6436F.8020906@r3dsolutions.com> <ma5q64$jnm$1@ger.gmane.org>
Message-ID: <54C6A379.10706@r3dsolutions.com>

Hi Mark !
I hope you are well, and haven't been injured falling out of your chair 
laughing.
There are probably 12 to 14 emails that I haven't been able to read in 
my inbox from the python list on the subject of this 'drivel', because I 
have a real life besides the semi-comedy act that goes on here.  I 
seriously doubt I will ever read them all...

On 01/26/2015 08:31 AM, Mark Lawrence wrote:
> On 26/01/2015 13:38, Andrew Robinson wrote:
>>
>
> *plonk*
>

Ah well, now that I have actually bothered to read your three replies, I 
suppose the most surprising part of your emails is this:

-My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

You do realize that such a statement actually encourages more drivel ? :D
Cheers.



From breamoreboy at yahoo.co.uk  Mon Jan 26 15:30:42 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Mon, 26 Jan 2015 20:30:42 +0000
Subject: Running a .py file iteratively at the terminal
In-Reply-To: <bea3815c-7a64-417a-959c-9408581a643e@googlegroups.com>
References: <bea3815c-7a64-417a-959c-9408581a643e@googlegroups.com>
Message-ID: <ma685r$ibo$1@ger.gmane.org>

On 26/01/2015 19:52, varun7rs at gmail.com wrote:
> Hello Everyone,
>
> I am running a python script as of now and I have to change three global values repeatedly. I'm tired of doing this manually. SO, I was wondering if there is a way to run a python command repeatedly. In my case, the command would be
>
> srva at hades:~$ python NFV_v3_7_10_14.py -l log --lp --xml eu_v3_14_1_15.xml
>
> Everytime I run this, I get a log file with the results. The main file is the NFV_v3....py. These are the values I intend to change iteratively and then run the command in the terminal.
> dataplane_latencybound = 200 # The delay bounds are in milli seconds
> controlplane_latencybound1 = 200 # The delay bounds are in milli seconds
>
> So, in every iteration, I would like to increase it from 0 in steps of 10 till 200. And after doing so, I'd like to run the command. But, I'm unaware of doing this using a single script. I hope some of you experts over there could help me in this issue. It can be a huge timesaver.
>
>
> Thanks a lot guys
> Varun RS
>

I think you need this:-

dataplane_latencybound in range(0, 205, 10):
     doSomething(dataplane_latencybound)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From varun7rs at gmail.com  Mon Jan 26 16:10:22 2015
From: varun7rs at gmail.com (varun7rs at gmail.com)
Date: Mon, 26 Jan 2015 13:10:22 -0800 (PST)
Subject: Running a .py file iteratively at the terminal
In-Reply-To: <mailman.18158.1422304262.18130.python-list@python.org>
References: <bea3815c-7a64-417a-959c-9408581a643e@googlegroups.com>
 <mailman.18158.1422304262.18130.python-list@python.org>
Message-ID: <6e21583e-8c62-413f-b54a-1e7ffaab9fd4@googlegroups.com>

Thanks a lot Mark but that would be a bit trivial. How can I run the same file multiple times? Or if I need to run two commands: 
srva at hades:~$ python NFV_nw_eu_v3_14_1_15.py --output eu_v3_14_1_15 --demand demands_v3_21_1_15.xml --xml nobel-eu.xml
srva at hades:~$ python NFV_v3_7_10_14.py -l log --lp --xml eu_v3_14_1_15.xml 

repeatedly, how can I do that? Can I write a script to perform this function?If so, can you please help me with it?
The first command generates an output file eu_v3 and the second file feeds it to the solver. This is what I intend to do multiple times. I hope I have explained it this time in a much better way. I'm sorry English is my second language and I have some problems in expressing myself at times.

Thank You



From pkeogh at compusoftcs.com  Mon Jan 26 16:30:48 2015
From: pkeogh at compusoftcs.com (Philip Keogh)
Date: Mon, 26 Jan 2015 13:30:48 -0800 (PST)
Subject: Running a .py file iteratively at the terminal
In-Reply-To: <6e21583e-8c62-413f-b54a-1e7ffaab9fd4@googlegroups.com>
References: <bea3815c-7a64-417a-959c-9408581a643e@googlegroups.com>
 <mailman.18158.1422304262.18130.python-list@python.org>
 <6e21583e-8c62-413f-b54a-1e7ffaab9fd4@googlegroups.com>
Message-ID: <alpine.DEB.2.11.1501261328100.12714@raven.philkeogh.com>

On Mon, 26 Jan 2015, varun7rs at gmail.com wrote:
> Thanks a lot Mark but that would be a bit trivial. How can I run the
> same file multiple times? Or if I need to run two commands:
> srva at hades:~$ python NFV_nw_eu_v3_14_1_15.py --output eu_v3_14_1_15
> --demand demands_v3_21_1_15.xml --xml nobel-eu.xml
>?srva at hades:~$ python NFV_v3_7_10_14.py -l log --lp --xml eu_v3_14_1_15.xml 
> repeatedly, how can I do that? Can I write a script to perform this
> function?If so, can you please help me with it?  The first command
> generates an output file eu_v3 and the second file feeds it to the
> solver. This is what I intend to do multiple times. I hope I have
> explained it this time in a much better way. I'm sorry English is my
> second language and I have some problems in expressing myself at
> times.
> 
> Thank You
> 

Have you read about Bash shell brace expansion, or a one-liner loop? A
simple wrapper script could easily accomplish what you seem to be
attempting to do.

For more, see:
http://tldp.org/LDP/Bash-Beginners-Guide/html/sect_03_04.html
http://www.linuxjournal.com/content/bash-brace-expansion
http://wiki.bash-hackers.org/syntax/expansion/brace
http://tldp.org/LDP/abs/html/loops1.html

From ian.g.kelly at gmail.com  Mon Jan 26 17:22:44 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 26 Jan 2015 15:22:44 -0700
Subject: Fwd: Re: Comparisons and sorting of a numeric class....
In-Reply-To: <54C6436F.8020906@r3dsolutions.com>
References: <54C6434E.1030101@r3dsolutions.com>
 <54C6436F.8020906@r3dsolutions.com>
Message-ID: <CALwzid=DNqDn6MGY6G4sqKvE0gnXbJQQDe5rZShNqNk2iN6srQ@mail.gmail.com>

On Jan 26, 2015 6:42 AM, "Andrew Robinson" <andrew3 at r3dsolutions.com> wrote:
> ...

If you're going to descend into insults and name-calling, then I'm not
going to waste any more of my time on this thread. The restriction on
inheriting from bool isn't likely to change. There have been several
suggestions as to how you can do what you want. I recommend you pick one
and get on with it.
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From cs at zip.com.au  Mon Jan 26 17:35:03 2015
From: cs at zip.com.au (Cameron Simpson)
Date: Tue, 27 Jan 2015 09:35:03 +1100
Subject: Running a .py file iteratively at the terminal
In-Reply-To: <6e21583e-8c62-413f-b54a-1e7ffaab9fd4@googlegroups.com>
References: <6e21583e-8c62-413f-b54a-1e7ffaab9fd4@googlegroups.com>
Message-ID: <20150126223503.GA91282@cskk.homeip.net>

On 26Jan2015 13:10, varun7rs at gmail.com <varun7rs at gmail.com> wrote:
>Thanks a lot Mark but that would be a bit trivial. How can I run the same file multiple times? Or if I need to run two commands:
>srva at hades:~$ python NFV_nw_eu_v3_14_1_15.py --output eu_v3_14_1_15 --demand demands_v3_21_1_15.xml --xml nobel-eu.xml
>srva at hades:~$ python NFV_v3_7_10_14.py -l log --lp --xml eu_v3_14_1_15.xml
>
>repeatedly, how can I do that? Can I write a script to perform this function?If so, can you please help me with it?
>The first command generates an output file eu_v3 and the second file feeds it to the solver. This is what I intend to do multiple times. I hope I have explained it this time in a much better way. I'm sorry English is my second language and I have some problems in expressing myself at times.

Certainly you can script it. Write a tiny shell script (named "mygensolve.sh" 
for the sake of example).  Example (untested):

  #!/bin/sh
  python NFV_nw_eu_v3_14_1_15.py --output eu_v3_14_1_15 --demand demands_v3_21_1_15.xml --xml nobel-eu.xml
  python NFV_v3_7_10_14.py -l log --lp --xml eu_v3_14_1_15.xml

Either make it executable ("chmod +rx mygensolve.sh") and run it like this:

  ./mygensolve.sh

or don't bother, and run it in an analogous fashion to your python commands:

  sh mygensolve.sh

There are multiple paths forward from here if you have many runs with filenames 
which can be enurated somehow.

Cheers,
Cameron Simpson <cs at zip.com.au>

The top three answers:  Yes I *am* going to a fire!
                        Oh! We're using *kilometers* per hour now.
                        I have to go that fast to get back to my own time.
- Peter Harper <bo165 at FreeNet.Carleton.CA>


From andrew3 at r3dsolutions.com  Mon Jan 26 18:47:09 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Mon, 26 Jan 2015 15:47:09 -0800
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <20150115095452.072d5763@rg.highlandtechnology.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
 <CALwzidn4t_mVvtUjucKwPLzeq5pgFdYDBLjePMeuEEB7gTvKCQ@mail.gmail.com>
 <54B72D32.3090209@r3dsolutions.com>
 <CALwzidmn-WJVMxXmRK=dSw0vWoBLf=rZ-6VhXinQhfn3BjF=TQ@mail.gmail.com>
 <mailman.17743.1421306724.18130.python-list@python.org>
 <20150115095452.072d5763@rg.highlandtechnology.com>
Message-ID: <54C6D1FD.6070901@r3dsolutions.com>

Hi, Rob.
Sorry I'm so slow in getting back to you.... there's too much to read 
and I can't catch up with the backlog.  But I wanted to reply to you, at 
least as I think you made some very good points that make more sense to 
me than other people's replies.

On 01/15/2015 09:54 AM, Rob Gaddi wrote:
> On Wed, 14 Jan 2015 23:23:54 -0800
> Andrew Robinson <andrew3 at r3dsolutions.com> wrote:
>
>>> Boolean algebra has two values: true and false, or 1 and 0, or humpty
>>> and dumpty, or whatever you like to call them.
>> You're speaking to an Electrical engineer.  I know there are 10 kinds of
>> people, those who know binary and those who don't.  But you're way off
>> base if you think most industrial quality code for manipulating boolean
>> logic uses (or even can be restricted to use) only two values and still
>> accomplish their tasks correctly and within a finite amount of time.
>>
> [snip]
>
> Absolutely it does and can.  You store anything that's non-boolean in a
> non-boolean value, and keep it as fuzzy as you like.  But at the end of
> the day, an if statement has no "kinda".  You do, or you don't.  1 or
> 0.  And so you must ultimately resolve to a Boolean decision.

Yes -- at the *point* of decision; a logic expression always collapses 
to a True or False value.
metastability must always resolve to a final value, or else the system 
will malfunction.
(Although cache branch prediction can choose to take both paths, one of 
them eventually gets flushed).
That's the same in digital circuitry as well,  even with uncertainty 
meta information appended to it.

>
> You have to ask
>
> 	if x = '1'
> or
> 	if (x = '1') or (x = 'H')
>
> Because you are comparing one value of an enumerated type against
> others, the result of that '=' operation being, in fact, a boolean,
> defined again on the range (true, false).
That's fine, too.   An enumerated type is still a semantic subtype, if 
not a formal one recognized by type().
So -- I don't see that you are arguing the two types must be 
semantically distinct until the if statement is actually executed, at 
which point a true/false decision must be made.  I totally agree, 
digital systems must make a final decision at some point.

Your example, here, BTW: is almost exactly what I was talking about in 
the original few posts of the thread;  Eg: a way to comparing the 
uncertainty value returned by a float's subtype's compare -- against an 
enumerated bool meta-type to resolve that value to a final True or False 
for an if statement.

>
>> [snip]
>>
>> We've discovered that we live in a quantum-mechanical universe -- yet
>> people still don't grasp the pragmatic issue that basic logic can be
>> indeterminate at least some of the time ?!
>>
> But actions can't be. You're not asking the software about it's
> feelings, you're telling it to follow a defined sequence of
> instructions.  Do this, or don't do this.

Right!
And, in quantum mechanics -- a wave packet 'collapses' to one and only 
one final decision.
So, I agree with you; and let me get your opinion:

I admit, there can be good reasons to prevent direct subtyping; I know, 
for example, that in C++ no base class is allowed to be subtyped -- but 
not because of OOP concerns or ideology about bool; I'm fairly sure the 
reason had something to do with difficulties in implementing base class 
overloading in the compiler due to compile time binding issues.

But that's useless reasoning with an interpreter like Python which 
*already* allows subtyping of at least some base classes and does 
runtime type() tests instead of compile time tests.

So: The major question I have been asking about is 'when' must the 
decision be made, and 'why' (besides oversight / copying other 
languages) is the a bool variable/object in Python designed in such a 
way as to force the decision to be made early, rather than late -- and 
prevent bool from carrying extended information about the bool itself; 
eg: meta information -- so that the final decision can be delayed until 
an 'if' statement is actually used, and the context is known:

eg:

x = a > b  # x is an uncertain compare that generates meta data along 
with a boolean True or False.
# this value 'x' can be used in two ways:

if x > bool_meta_threshold:  # if statement's branch chosen by meta data.
if x:  # If statement's branch chosen by default/base bool value 
contained in x, meta data is ignored.

>
>> I don't know what you mean about composition vs. sub-classing.
>> Would you care to show an example of how it would solve the problem and
>> still allow hierarchical sorting ?
>>
>> I don't see how you can get pre-existing python functions (like sort,
>> max, and min) to accept a complex bool value and have that value
>> automatically revert to a True or False in an intelligent manner without
>> overloading the operators defined in some class -- somewhere -- to
>> operate on the data the class contains.
>>
>> How do you intend to achieve that with this -- composition -- thing you
>> mentioned ?
>>
>>
> You'd do it something like this.
>
> class _clogic(object):
> 	"""Represents 'continuous' logic.  For any given instance,
> there is a threshold value between 0 and 1 that delineates True from
> False, with 0 being entirely False and 1 being entirely True.
> 	"""
> 	
> 	def __init__(self, value, threshold=0.5):
> 		self.value = value
> 		self.threshold = threshold
> 		
> 	def __bool__(self):
> 		return value > threshold
> 	__nonzero__ = __bool__
> 	
> 	def __eq__(self, other):
> 		if other in (True, False):
> 			return bool(self) == other
> 			
> 		try:
> 			return self.value == other.value
> 		except AttributeError:
> 			return self.value == other
> 		
> 	def __and__(self, other):
> 		return self.__class__(
> 			min(self.value, other.value),
> 			self.threshold)
>
> 	def __or__(self, other):
> 		return self.__class__(
> 			max(self.value, other.value),
> 			self.threshold)
>
> No need to subclass bool, you just use the __bool__ (or __nonzero__)
> methods to say "Alright, well when you do finally have to make a
> decision on this thing, here's how you make it.  And obviously, you can
> add on as many additional data members to carry additional information
> as your heart desires.
>

Hmmm....  That's not much different than the tuple object I made as a 
container and which Ian complained about.  In fact, you did overload the 
comparison operators, just like I did...

Let's see: Ian first complained that I wasn't subclassing in one 
example, and then he next complained that he thought I was subclassing  
*too quickly*  (like he forgot that I didn't subclass before) because of 
something to do with 'bool' -- and then he mentioned I wasn't using 
composition....

But now --I wonder why it didn't click with him that I avoided 
subclassing bool in my tuple example (at all)  -- because I was clearly 
making a general purpose container (composition pattern) to hold a bool 
and uncertainty value.

So -- I really don't think there is anything wrong with what I already 
did, except perhaps the name of the class was misleading; for it is 
really capable of being general purpose.... not just 'bool'...

In any event, thanks for the example; but it still leaves me with the 
distinct feeling that I'm damned if I do -- and damned if I don't...

LOL.



From steve+comp.lang.python at pearwood.info  Mon Jan 26 19:11:45 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 27 Jan 2015 11:11:45 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
Message-ID: <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>

random832 at fastmail.us wrote:

> On Thu, Jan 22, 2015, at 23:23, Steven D'Aprano wrote:
>> Rick Johnson wrote:
>> 
>> > The solution is move the type
>> > hinting syntax completely out of the source file and into
>> > another file -- think of it as a "Python Type Hinting Header
>> > File".
>> 
>> The 1970s called, they want their bad ideas back.
>> 
>> I can do no better than to quote from the Go FAQs:
>> 
>>     Dependency management is a big part of software development
>>     today but the ?header files? of languages in the C tradition
>>     are antithetical to clean dependency analysis?and fast
>>     compilation.
> 
> This is more along the lines of a lint library than a header file

Stub files are a second-rate solution for the problem of annotating
functions where you are unable (or unwilling) to annotate the source code
directly. They suffer from similar problems:

- you have to manage the stub file independently of the source 
  code it belongs with

- type information is about as far away from the variable as it
  is possible to get (a completely different file!)

- lexical analysis has to look for twice as many files (it has to 
  hit the hard drive for a stub file before looking at the source),
  and we know from importing that file system access is a 
  significant and expensive part of the process.

But, when the first-rate solution cannot be used, a second-rate solution is
better than nothing.


> (header files in the 1970s didn't even actually include function
> signature information) - which did not even participate in compilation
> at all.

If C compilers didn't use the header files, what were they for?



-- 
Steven



From steve+comp.lang.python at pearwood.info  Mon Jan 26 19:22:39 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 27 Jan 2015 11:22:39 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17951.1421906568.18130.python-list@python.org>
 <54c0a571$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f2aced5243efbfb989684@nntp.aioe.org>
 <54c1063c$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17973.1421939508.18130.python-list@python.org>
 <54c2299d$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <Houxw.308955$FO6.44943@fx33.am4>
Message-ID: <54c6da50$0$12993$c3e8da3$5496439d@news.astraweb.com>

BartC wrote:

> how do you represent a raise of 10% exactly if
> not with binary floating point?


In Python today, the best solution is probably to use Decimals:

from decimal import Decimal
raise = Decimal("0.1")


But the traditional solution is to track money in cents, or a fixed fraction
of a cent, using integers, and do everything in integer maths. That has the
disadvantage that division always truncates, but if you care about that you
can easily write your own division-with-round-to-nearest function.

Or use Decimal, which handles rounding correctly and flexibly.


-- 
Steven



From dan at tombstonezero.net  Mon Jan 26 20:09:23 2015
From: dan at tombstonezero.net (Dan Sommers)
Date: Tue, 27 Jan 2015 01:09:23 +0000 (UTC)
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <ma6og2$hb9$1@dont-email.me>

On Tue, 27 Jan 2015 11:11:45 +1100, Steven D'Aprano wrote:

> random832 at fastmail.us wrote:

>> (header files in the 1970s didn't even actually include function
>> signature information) - which did not even participate in
>> compilation at all.

> If C compilers didn't use the header files, what were they for?

The compiler did use the header files, but only for functions' return
types and other non-function-signature things (like macros and type
definitions).

Dan


From rantingrickjohnson at gmail.com  Mon Jan 26 20:10:18 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Mon, 26 Jan 2015 17:10:18 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <ca841d92-09c6-4735-a63a-16bb806e7155@googlegroups.com>

On Monday, January 26, 2015 at 6:12:00 PM UTC-6, Steven D'Aprano wrote:

> Stub files are a second-rate solution for the problem of
> annotating functions where you are unable (or unwilling)
> to annotate the source code directly. They suffer from
> similar problems:
>
> - you have to manage the stub file independently of the
> source code it belongs with
>
> - type information is about as far away from the variable as it
>   is possible to get (a completely different file!)
>
> - lexical analysis has to look for twice as many files (it has to
>   hit the hard drive for a stub file before looking at the source),
>   and we know from importing that file system access is a
>   significant and expensive part of the process.

Funny how your example logically leads to the solution of
your own "partisan problem".

At an early stage in the design process, most wise designers
would realize that: since stub files are optional, and
therefore searching for stub files *EVERY TIME* Python is
reading a script is superfluous, then the solution is to
require a declaration in every file that wants typehinting.
In other words, put the onerous on the "typehint author" by
requiring a "typehint declaration" at the top of every file
that has a corresponding typehints stub.

    usestypehints scriptA.typehints

Of course, there are much better alternatives than to
introduce *another* keyword. Shebangs, strings, whatever....
So don't take my example too literally!

> But, when the first-rate solution cannot be used, a
> second-rate solution is better than nothing.

Your synthetic "first rate vs second rate" dichotomy is
nothing more than a highly subjective and one sided
interpretation meant to paint the opposition as wrong without
offering any real evidence of "wrongfulness". Are you
attempting to polarize this issue? And if you are, what
possible good could come from injecting emotion into a
technical debate?

To find truths one must remain open to new ideas, *only*
follow logical paths, and *defiantly* reject the corrupting
influence of emotion. Does impartiality mean *anything* to
you? Have you ever wondered why lady justice wears a
blindfold?





From andrew3 at r3dsolutions.com  Mon Jan 26 20:10:31 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Mon, 26 Jan 2015 17:10:31 -0800
Subject: Fwd: Re: Comparisons and sorting of a numeric class....
In-Reply-To: <CALwzid=DNqDn6MGY6G4sqKvE0gnXbJQQDe5rZShNqNk2iN6srQ@mail.gmail.com>
References: <54C6434E.1030101@r3dsolutions.com>
 <54C6436F.8020906@r3dsolutions.com>
 <CALwzid=DNqDn6MGY6G4sqKvE0gnXbJQQDe5rZShNqNk2iN6srQ@mail.gmail.com>
Message-ID: <54C6E587.1040409@r3dsolutions.com>

On 01/26/2015 02:22 PM, Ian Kelly wrote:
>
>
> On Jan 26, 2015 6:42 AM, "Andrew Robinson" <andrew3 at r3dsolutions.com 
> <mailto:andrew3 at r3dsolutions.com>> wrote:
> > ...
>
> If you're going to descend into insults and name-calling, then I'm not 
> going to waste any more of my time on this thread.
>

I don't believe I've actually, intentionally, insulted you.  That's 
generally not in my nature, although annoyance sometimes comes out.

If my response to D'Aprano's abrasive remarks upset you -- well, sorry.  
It honestly wasn't aimed at you and it wasn't derogatory name calling.  
eg:  If you mean 'bool', instead of 'Boole' that's just because Python 
does it.

> The restriction on inheriting from bool isn't likely to change. There 
> have been several suggestions as to how you can do what you want. I 
> recommend you pick one and get on with it.
>
>
>
FYI:  I already have implemented the code twice, so there's no need to 
continue the conversation for my sake.
I got 'on' with it a long time ago; but thanks for the advice for what 
it's worth.

I hope you enjoyed seeing a C++ type cast of a non bool type into a bool 
that can be used as a bool at leisure, although if you've already stated 
your pleasure or displeasure -- it may take me a while to find the email 
in the backlog so don't feel pressure to repeat yourself.

--Cheers.

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From ian.g.kelly at gmail.com  Mon Jan 26 20:50:07 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Mon, 26 Jan 2015 18:50:07 -0700
Subject: Comparisons and sorting of a numeric class....
In-Reply-To: <54C6D1FD.6070901@r3dsolutions.com>
References: <54ABB88A.7070504@r3dsolutions.com> <54ABC52A.1050507@davea.name>
 <54ABE383.3020801@r3dsolutions.com>
 <CAPTjJmpktyHfghEr+cjPrhso7JgB4VfS4=5Gdi95gT0aFbSYGA@mail.gmail.com>
 <54AC97D9.4010504@r3dsolutions.com>
 <CAPTjJmooTK_+HVoeyeSrqBHN1=YjRYQ2kfDyQtL9JoA9SbTqsQ@mail.gmail.com>
 <54ACAA04.60801@r3dsolutions.com> <54ADC99F.3020405@stoneleaf.us>
 <54B44A64.7010105@r3dsolutions.com>
 <CAPTjJmr0Bqcyj=VBADVSthSZ+pYMXQeNC-j8qLC2xHAVLUmcgA@mail.gmail.com>
 <mailman.17650.1421114374.18130.python-list@python.org>
 <54b4aded$0$2738$c3e8da3$76491128@news.astraweb.com>
 <54B5B486.7080406@r3dsolutions.com>
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 <54B72D32.3090209@r3dsolutions.com>
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 <mailman.17743.1421306724.18130.python-list@python.org>
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Message-ID: <CALwzidnwQqp=ZjkCXevFVX39jbhYyht2gHHm3E5ffkL2b-+rtA@mail.gmail.com>

On Mon, Jan 26, 2015 at 4:47 PM, Andrew Robinson
<andrew3 at r3dsolutions.com> wrote:
> Hmmm....  That's not much different than the tuple object I made as a
> container and which Ian complained about.  In fact, you did overload the
> comparison operators, just like I did...

Yeah, I know I said I was done with this thread, but since you call me
out by name I'll take a moment to respond.

> Let's see: Ian first complained that I wasn't subclassing in one example,

No. What I suggested was that for Python 2 you should explicitly name
a base class of object, i.e. the base class of *everything*. That's
not "you should use subclassing here", but rather "here's a tip for
writing good, Pythonic code".

> and then he next complained that he thought I was subclassing  *too quickly*
> (like he forgot that I didn't subclass before) because of something to do
> with 'bool' -- and then he mentioned I wasn't using composition....

I actually wrote about your tuple subclass "This seems fine," so don't
try to spin my words into something that they aren't. My criticism was
centered on your needless subclassing of tuple (nothing to do with
'bool'), resulting in a boolean class that supports nonsensical
operations like:

>>> len(MostlyFalse)
2

and even:

>>> isinstance(MostlyFalse, Sequence)
True

You may also notice that Rob's example which you compare to your own
doesn't do this.

> But now --I wonder why it didn't click with him that I avoided subclassing
> bool in my tuple example (at all)  -- because I was clearly making a general
> purpose container (composition pattern) to hold a bool and uncertainty
> value.

This is not an example of composition. By subclassing tuple, you are
effectively declaring that your boolean type IS a type of tuple.
Instead of aggressively and arrogantly defending poor code, why don't
you take my criticism as the learning opportunity that it was offered
as? Here would be a good place to start:

http://stackoverflow.com/questions/49002/prefer-composition-over-inheritance


From rantingrickjohnson at gmail.com  Mon Jan 26 22:26:13 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Mon, 26 Jan 2015 19:26:13 -0800 (PST)
Subject: Python simple Code
In-Reply-To: <ma1dtf$v4t$1@dont-email.me>
References: <4e283f62-0b6a-4ef7-a784-b9b3da73f510@googlegroups.com>
 <ma1dtf$v4t$1@dont-email.me>
Message-ID: <30fc6832-6407-42d3-9448-650fcdb65be7@googlegroups.com>

On Saturday, January 24, 2015 at 6:38:50 PM UTC-6, Denis McMahon wrote:

> Observations:
> 
> a) There is no need to import array, you are only using a list.

I'm just pondering here... (and pinky, i'm looking at you!),
but there "may" be a good excuse for "import array". I have a
feeling it's merely an artifact. Maybe the OP began his
script with a Python array, then realizing he needed a mixed-
type container, began using list and forgot to edit his
imports. So yes: superfluous, yet forgivable.

*HOWEVER* I cannot forgive someone for creating a function that
merely prints a global variable! WTH???

@OP: Why did you create the "output" function?



From moonlight06082013 at gmail.com  Tue Jan 27 00:17:40 2015
From: moonlight06082013 at gmail.com (Rehab Habeeb)
Date: Tue, 27 Jan 2015 08:17:40 +0300
Subject: unicode question
Message-ID: <CAA3NwWquCX54YBh15Kd_ncOtpe49nJyF_wRqEeBL6nCY0Py7Pg@mail.gmail.com>

Hi there python staff
does python support arabic language for texts ? and what to do if it
support it?
i wrote hello in Arabic using codeskulptor and the powershell just for
testing and the same error appeared( a sytanx error in unicode)!!
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From rosuav at gmail.com  Tue Jan 27 00:26:01 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 27 Jan 2015 16:26:01 +1100
Subject: unicode question
In-Reply-To: <CAA3NwWquCX54YBh15Kd_ncOtpe49nJyF_wRqEeBL6nCY0Py7Pg@mail.gmail.com>
References: <CAA3NwWquCX54YBh15Kd_ncOtpe49nJyF_wRqEeBL6nCY0Py7Pg@mail.gmail.com>
Message-ID: <CAPTjJmpfkgZmkPxi3revmR-URq+e0FDhx4H6EFhuJokBQtrb4Q@mail.gmail.com>

On Tue, Jan 27, 2015 at 4:17 PM, Rehab Habeeb
<moonlight06082013 at gmail.com> wrote:
> Hi there python staff
> does python support arabic language for texts ? and what to do if it support
> it?
> i wrote hello in Arabic using codeskulptor and the powershell just for
> testing and the same error appeared( a sytanx error in unicode)!!

If you're using Python 3, you have very good support for non-ASCII
text, including Arabic. In Python 2, you can work with Unicode data,
but your variable/function names all have to be in ASCII.

What was your code, and what was the error? Copy and paste them into
the email, and we'll be better able to help you.

ChrisA


From steve at pearwood.info  Tue Jan 27 01:32:02 2015
From: steve at pearwood.info (Steven D'Aprano)
Date: 27 Jan 2015 06:32:02 GMT
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <ca841d92-09c6-4735-a63a-16bb806e7155@googlegroups.com>
Message-ID: <54c730e2$0$2738$c3e8da3$76491128@news.astraweb.com>

On Mon, 26 Jan 2015 17:10:18 -0800, Rick Johnson wrote:

> On Monday, January 26, 2015 at 6:12:00 PM UTC-6, Steven D'Aprano wrote:
> 
>> Stub files are a second-rate solution for the problem of annotating
>> functions where you are unable (or unwilling) to annotate the source
>> code directly. They suffer from similar problems:
>>
>> - you have to manage the stub file independently of the source code it
>>   belongs with
>>
>> - type information is about as far away from the variable as it
>>   is possible to get (a completely different file!)
>>
>> - lexical analysis has to look for twice as many files (it has to
>>   hit the hard drive for a stub file before looking at the source), and
>>   we know from importing that file system access is a significant and
>>   expensive part of the process.
> 
> Funny how your example logically leads to the solution of your own
> "partisan problem".
> 
> At an early stage in the design process, most wise designers would
> realize that: since stub files are optional, and therefore searching for
> stub files *EVERY TIME* Python is reading a script is superfluous, then
> the solution is to require a declaration in every file that wants
> typehinting. In other words, put the onerous on the "typehint author" by
> requiring a "typehint declaration" at the top of every file that has a
> corresponding typehints stub.

Unfortunately that doesn't work. Stubs will be needed for extension 
modules written in C (or some other language), or built-in modules such 
as sys (which are built into the interpreter). So modules which will need 
your declaration won't have anywhere to put it!

Likewise for byte-code only libraries (no source code distributed, just 
the .pyc files).

And it does nothing to solve the problem that the type declaration is as 
far away from the parameters as it is possible to be.


[...]
>> But, when the first-rate solution cannot be used, a second-rate
>> solution is better than nothing.
> 
> Your synthetic "first rate vs second rate" dichotomy 

I'm sure that there are worse solutions that stub/header files. But 
splitting information about a single function over two files is by any 
standard sub-optimal.


> is nothing more
> than a highly subjective and one sided interpretation 

Just because I have considered and rejected your solution doesn't mean I 
haven't given it the thought it deserves.

Rick, I'll admit that I was being a smart arse with my quip about the 
seventies wanting their bad ideas back. A separate header file is a 
reasonable solution to the problem of type hinting when you cannot or 
will not annotate the actual source. That makes it "bad" merely in a 
relative sense: it has serious disadvantages compared to in-place 
annotations, but it is still a workable solution when you can't annotate 
the source.

Analogy: a spoon makes a really poor knife, but if you have nothing else 
on hand, you can cut vegetables and even the softer cuts of meat using 
the side of a spoon.


> meant to paint the
> opposition as wrong without offering any real evidence of
> "wrongfulness". 

Rick, you just quoted me giving three reasons why stub files are less 
suitable than in-place annotations. How can you justify claiming that I'm 
not giving evidence of wrongfulness?


-- 
Steven


From steve+comp.lang.python at pearwood.info  Tue Jan 27 01:36:43 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 27 Jan 2015 17:36:43 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <ma6og2$hb9$1@dont-email.me>
Message-ID: <54c731fc$0$2910$c3e8da3$76491128@news.astraweb.com>

Dan Sommers wrote:

> On Tue, 27 Jan 2015 11:11:45 +1100, Steven D'Aprano wrote:
> 
>> random832 at fastmail.us wrote:
> 
>>> (header files in the 1970s didn't even actually include function
>>> signature information) - which did not even participate in
>>> compilation at all.
> 
>> If C compilers didn't use the header files, what were they for?
> 
> The compiler did use the header files, but only for functions' return
> types and other non-function-signature things (like macros and type
> definitions).

I consider return type to be part of the function signature. The signature 
of a function is the parameters it accepts and the result it returns.



--
Steve



From rosuav at gmail.com  Tue Jan 27 02:59:42 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 27 Jan 2015 18:59:42 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <54c731fc$0$2910$c3e8da3$76491128@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <ma6og2$hb9$1@dont-email.me>
 <54c731fc$0$2910$c3e8da3$76491128@news.astraweb.com>
Message-ID: <CAPTjJmqG4P07OS0pCnFJOxjOPp9jmNv3JJQ1GVJZCcdZYu6+=A@mail.gmail.com>

On Tue, Jan 27, 2015 at 5:36 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> I consider return type to be part of the function signature. The signature
> of a function is the parameters it accepts and the result it returns.

It is, but there are times when it isn't significant. For instance,
C++ overloaded functions are distinguished by their function
signatures, but *not* including the return values (nor several other
aspects).

ChrisA


From steve+comp.lang.python at pearwood.info  Tue Jan 27 03:03:11 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Tue, 27 Jan 2015 19:03:11 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <ma6og2$hb9$1@dont-email.me>
 <54c731fc$0$2910$c3e8da3$76491128@news.astraweb.com>
 <mailman.18165.1422345585.18130.python-list@python.org>
Message-ID: <54c74640$0$12980$c3e8da3$5496439d@news.astraweb.com>

Chris Angelico wrote:

> On Tue, Jan 27, 2015 at 5:36 PM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> I consider return type to be part of the function signature. The
>> signature of a function is the parameters it accepts and the result it
>> returns.
> 
> It is, but there are times when it isn't significant. For instance,
> C++ overloaded functions are distinguished by their function
> signatures, but *not* including the return values (nor several other
> aspects).

C++ is an unholy abomination unto Nuggan :-)


-- 
Steve



From morristurnies at yahoo.com  Tue Jan 27 04:46:31 2015
From: morristurnies at yahoo.com (morristurnies)
Date: Tue, 27 Jan 2015 01:46:31 -0800 (PST)
Subject: aging Products And skin care products
Message-ID: <1422351991685-5084350.post@n6.nabble.com>

Belladerm all your skin's brands Skin Care Tips products. You will likely
realize that these items are mostly filled up with chemicals and
dysfunctional water-content. Using compounds to your skin could worsen it
and make it dried or cause it make oils to compensate for the dryness. These
products you are utilizing on your skin to enhance your appearance may
really be making things worse. If you utilize makeup, read the brands of the
products you utilize and eliminate any powder- based makeup since your pores
can clog.

Belladerm is a wholesome quite essential to achieve a wholesome looking
skin. Contain plenty of vegetables and fruits in to your diet menu. Also,
take multivitamins over a regular schedule. Try to avoid fried and fatty
food as much as possible. Create a regular exercise regime to naturally
cleanse the human body. Aside for these tips, increase your water
absorption. Water is among the finest ingredients for the skin. Avoid
dehydration causing elements including coffee and liquor.

http://www.alrastc.net/belladerm-skincare/



--
View this message in context: http://python.6.x6.nabble.com/aging-Products-And-skin-care-products-tp5084350.html
Sent from the Python - python-list mailing list archive at Nabble.com.


From greg.ewing at canterbury.ac.nz  Tue Jan 27 05:04:27 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Tue, 27 Jan 2015 23:04:27 +1300
Subject: Fwd: Re: Comparisons and sorting of a numeric class....
In-Reply-To: <mailman.18147.1422279623.18130.python-list@python.org>
References: <54C6434E.1030101@r3dsolutions.com>
 <mailman.18147.1422279623.18130.python-list@python.org>
Message-ID: <cip65eFah5qU1@mid.individual.net>

Andrew Robinson wrote:

> The spelling caveat is great -- and in Python the object named in bool's 
> honor is spelled bool (lowercase too). ;)

That doesn't change the fact that the man was called
George Boole (not Charles!). If you're going to refer
to him by name, it's only courteous to make some effort
to get it right.

http://en.wikipedia.org/wiki/George_Boole

-- 
Greg


From bronger at physik.rwth-aachen.de  Tue Jan 27 07:32:06 2015
From: bronger at physik.rwth-aachen.de (Torsten Bronger)
Date: Tue, 27 Jan 2015 13:32:06 +0100
Subject: ANN: JuliaBase -- LIMS for specimen-based research published as open
 source
Message-ID: <87386w4d6h.fsf@physik.rwth-aachen.de>

We are proud to announce that our in-house samples database solution
is now published as open source software (AGPL).  It is a
Python/Django-based framework for creating Web databases for
samples.  So far, it is used successfully by four in-house
departments.

For all the details and a demo, visit <http://www.juliabase.org>.

The highlights include:

- maximal flexibility for being adapted perfectly to your production and
  measurement setups, and to your workflows; (that's the reason why it is a
  programming framework rather than a turnkey application)
- keeps track of samples across sample splits
- support for pre-evaluating raw data and creating plots
- arbitrarily complex searches made easy, e.g. ?find all samples with infrared
  measurements, deposited together with a sample on glass substrate with a
  conductivity greater than 10^-6 S/cm; oh yes, and only from this year and
  made by John?
- export to spreadsheets
- automatic lab notebooks
- server interaction with other programs through an HTTP/JSON interface

JuliaBase's sources include an "example institute" that programmers
can use as a starting point.

-- 
Torsten Bronger    Jabber ID: torsten.bronger at jabber.rwth-aachen.de
                                  or http://bronger-jmp.appspot.com


From sjmsoft at gmail.com  Tue Jan 27 07:48:47 2015
From: sjmsoft at gmail.com (sjmsoft at gmail.com)
Date: Tue, 27 Jan 2015 04:48:47 -0800 (PST)
Subject: Idiomatic backtracking in Python
In-Reply-To: <ma3itj$ol6$1@news.albasani.net>
References: <ma3itj$ol6$1@news.albasani.net>
Message-ID: <2a14a0cf-0768-40d6-b005-f04fdb49f61a@googlegroups.com>

On Sunday, January 25, 2015 at 4:15:58 PM UTC-4, Johannes Bauer wrote:
> Hi folks,
> 
> I have a problem at hand that needs code for backtracking as a solution.
> And I have no problem coding it, but I can't get rid of the feeling that
> I'm always solving backtracking problems in a non-Pythonic
> (non-idiomatic) way. So, I would like to ask if you have a Pythonic
> approach to backtracking problems? If so, I'd love to hear your solutions!

When I think of backtracking, I think of Prolog (to which backtracking is central).  You could use PySWIP to run SWI-Prolog from your Python program.  Not idiomatic Python backtracking, of course, but it would get the job done, and Prolog's backtracking is reliable and well-described.  It would help if you already know a bit of Prolog or are keen to learn.

Cheers,
  Steve J. Martin




From ndbecker2 at gmail.com  Tue Jan 27 08:15:12 2015
From: ndbecker2 at gmail.com (Neal Becker)
Date: Tue, 27 Jan 2015 08:15:12 -0500
Subject: Is there a more elegant way to spell this?
Message-ID: <ma8311$q4c$1@ger.gmane.org>

Is there a more elegant way to spell this?

for x in [_ for _ in seq if some_predicate]:


-- 
-- Those who don't understand recursion are doomed to repeat it



From kwpolska at gmail.com  Tue Jan 27 08:20:10 2015
From: kwpolska at gmail.com (Chris Warrick)
Date: Tue, 27 Jan 2015 14:20:10 +0100
Subject: Is there a more elegant way to spell this?
In-Reply-To: <ma8311$q4c$1@ger.gmane.org>
References: <ma8311$q4c$1@ger.gmane.org>
Message-ID: <CAMw+j7LiZjeQP-UR+sryTWL0xQ3XuH6n6UzJ_1Zjq2WV2HRgrA@mail.gmail.com>

On Jan 27, 2015 2:16 PM, "Neal Becker" <ndbecker2 at gmail.com> wrote:
>
> Is there a more elegant way to spell this?
>
> for x in [_ for _ in seq if some_predicate]:

for x in seq:
    if some_predicate:
        do_something_to(x)

-- 
Chris Warrick <https://chriswarrick.com/>
Sent from my Galaxy S3.
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From jeanmichel at sequans.com  Tue Jan 27 08:35:33 2015
From: jeanmichel at sequans.com (Jean-Michel Pichavant)
Date: Tue, 27 Jan 2015 14:35:33 +0100 (CET)
Subject: Is there a more elegant way to spell this?
In-Reply-To: <ma8311$q4c$1@ger.gmane.org>
Message-ID: <1364207052.11341325.1422365733563.JavaMail.root@sequans.com>

----- Original Message -----
> From: "Neal Becker" <ndbecker2 at gmail.com>
> To: python-list at python.org
> Sent: Tuesday, 27 January, 2015 2:15:12 PM
> Subject: Is there a more elegant way to spell this?
> 
> Is there a more elegant way to spell this?
> 
> for x in [_ for _ in seq if some_predicate]:

You could use a generator expression

for x in (_ for _ in seq if some_predicate):

This is very similar but it prevents python from creating a new list.


JM



-- IMPORTANT NOTICE: 

The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

From rustompmody at gmail.com  Tue Jan 27 09:08:29 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Tue, 27 Jan 2015 06:08:29 -0800 (PST)
Subject: Is there a more elegant way to spell this?
In-Reply-To: <mailman.18170.1422364524.18130.python-list@python.org>
References: <mailman.18170.1422364524.18130.python-list@python.org>
Message-ID: <93753e86-165b-4e46-a0bd-4e4a419d68d9@googlegroups.com>

On Tuesday, January 27, 2015 at 6:45:41 PM UTC+5:30, Neal Becker wrote:
> Is there a more elegant way to spell this?
> 
> for x in [_ for _ in seq if some_predicate]:

Depends on what follows the ':'

In the trivial case all thats outside the comprehension can be dropped:

>>> [x for x in [y for y in range(10) if y % 2 == 0]]
[0, 2, 4, 6, 8]
>>> [y for y in range(10) if y % 2 == 0]
[0, 2, 4, 6, 8]
>>> 

Or

>>> [x*x for x in [y for y in range(10) if y % 2 == 0]]
[0, 4, 16, 36, 64]
>>> [y*y for y in range(10) if y % 2 == 0]
[0, 4, 16, 36, 64]
>>> 
> 
> 
> -- 
> -- Those who don't understand recursion are doomed to repeat it

Ha!


From jpiitula at ling.helsinki.fi  Tue Jan 27 09:25:21 2015
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 27 Jan 2015 16:25:21 +0200
Subject: Is there a more elegant way to spell this?
References: <mailman.18170.1422364524.18130.python-list@python.org>
Message-ID: <qot7fw8s3la.fsf@ruuvi.it.helsinki.fi>

Neal Becker writes:

> Is there a more elegant way to spell this?
> 
> for x in [_ for _ in seq if some_predicate]:

If you mean some_predicate(_), then possibly this.

for x in filter(some_predicate, seq):
   handle(x)

If you mean literally some_predicate, then perhaps this.

if some_predicate:
   for x in seq:
      handle(x)

Unless you also have in mind an interesting arrangement where
some_predicate might change during the loop, like this.

for x in [_ for _ in seq if some_predicate]:
    ...
    some_predicate = fubar(x)
    ...

Then I have nothing to say.


From ndbecker2 at gmail.com  Tue Jan 27 09:37:49 2015
From: ndbecker2 at gmail.com (Neal Becker)
Date: Tue, 27 Jan 2015 09:37:49 -0500
Subject: Is there a more elegant way to spell this?
References: <mailman.18170.1422364524.18130.python-list@python.org>
 <qot7fw8s3la.fsf@ruuvi.it.helsinki.fi>
Message-ID: <ma87ru$e21$1@ger.gmane.org>

Jussi Piitulainen wrote:

> Neal Becker writes:
> 
>> Is there a more elegant way to spell this?
>> 
>> for x in [_ for _ in seq if some_predicate]:
> 
> If you mean some_predicate(_), then possibly this.
> 
> for x in filter(some_predicate, seq):
>    handle(x)
> 

I like this best, except probably even better:

for x in ifilter (some_predicate, seq):



From jpiitula at ling.helsinki.fi  Tue Jan 27 09:47:34 2015
From: jpiitula at ling.helsinki.fi (Jussi Piitulainen)
Date: 27 Jan 2015 16:47:34 +0200
Subject: Is there a more elegant way to spell this?
References: <mailman.18170.1422364524.18130.python-list@python.org>
 <qot7fw8s3la.fsf@ruuvi.it.helsinki.fi>
 <mailman.18173.1422369489.18130.python-list@python.org>
Message-ID: <qot386ws2k9.fsf@ruuvi.it.helsinki.fi>

Neal Becker writes:
> Jussi Piitulainen wrote:
> > Neal Becker writes:
> > 
> >> Is there a more elegant way to spell this?
> >> 
> >> for x in [_ for _ in seq if some_predicate]:
> > 
> > If you mean some_predicate(_), then possibly this.
> > 
> > for x in filter(some_predicate, seq):
> >    handle(x)
> > 
> 
> I like this best, except probably even better:
> 
> for x in ifilter (some_predicate, seq):

That's in Python 2 and in itertools, I think. In Python 3, filter is a
built-in and returns a filter object.

>>> f = filter(None, map(int, '102030'))
>>> f
<filter object at 0x217d9d0>
>>> next(f)
1
>>> list(f)
[2, 3]
>>> list(f)
[]
>>> 


From rustompmody at gmail.com  Tue Jan 27 10:09:57 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Tue, 27 Jan 2015 07:09:57 -0800 (PST)
Subject: kivy: python on android
Message-ID: <739cbaf5-4868-49c6-ad34-ca3976c9b40a@googlegroups.com>

Following some posts here I thought I'd try python on android via kivy.

Followed the tutorials -- involved a couple of GBs(!!) of downloads
using something called buildozer

Finally got a hello world running on a phone -- Yay!

Now when I try to go from hello world to something a more (kivy-examples run
nicely on ubuntu), buildozer starts downloading those GBs again!!

Does anyone have a clue on where I am clueless?


From random832 at fastmail.us  Tue Jan 27 11:13:10 2015
From: random832 at fastmail.us (random832 at fastmail.us)
Date: Tue, 27 Jan 2015 11:13:10 -0500
Subject: unicode question
In-Reply-To: <CAA3NwWquCX54YBh15Kd_ncOtpe49nJyF_wRqEeBL6nCY0Py7Pg@mail.gmail.com>
References: <CAA3NwWquCX54YBh15Kd_ncOtpe49nJyF_wRqEeBL6nCY0Py7Pg@mail.gmail.com>
Message-ID: <1422375190.3245500.219555521.5C80989C@webmail.messagingengine.com>

On Tue, Jan 27, 2015, at 00:17, Rehab Habeeb wrote:
> Hi there python staff
> does python support arabic language for texts ? and what to do if it
> support it?
> i wrote hello in Arabic using codeskulptor and the powershell just for
> testing and the same error appeared( a sytanx error in unicode)!!

Python itself supports arabic just fine, but the MS Windows console in
general, and Python's implementation of it in particular, have poor
support for many aspects of unicode, so it's important to define exactly
what you are trying to do.


From johnnybureddu at gmx.com  Tue Jan 27 11:39:08 2015
From: johnnybureddu at gmx.com (REVOLUCION!)
Date: Tue, 27 Jan 2015 08:39:08 -0800 (PST)
Subject: -- redacted --
Message-ID: <35861325-94c1-418c-ab89-e4ea967431da@googlegroups.com>

-- redacted --


From breamoreboy at yahoo.co.uk  Tue Jan 27 12:25:42 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Tue, 27 Jan 2015 17:25:42 +0000
Subject: unicode question
In-Reply-To: <1422375190.3245500.219555521.5C80989C@webmail.messagingengine.com>
References: <CAA3NwWquCX54YBh15Kd_ncOtpe49nJyF_wRqEeBL6nCY0Py7Pg@mail.gmail.com>
 <1422375190.3245500.219555521.5C80989C@webmail.messagingengine.com>
Message-ID: <ma8hmv$97q$1@ger.gmane.org>

On 27/01/2015 16:13, random832 at fastmail.us wrote:
> On Tue, Jan 27, 2015, at 00:17, Rehab Habeeb wrote:
>> Hi there python staff
>> does python support arabic language for texts ? and what to do if it
>> support it?
>> i wrote hello in Arabic using codeskulptor and the powershell just for
>> testing and the same error appeared( a sytanx error in unicode)!!
>
> Python itself supports arabic just fine, but the MS Windows console in
> general, and Python's implementation of it in particular, have poor
> support for many aspects of unicode, so it's important to define exactly
> what you are trying to do.
>

People might find this http://bugs.python.org/issue1602 and hence this 
https://github.com/Drekin/win-unicode-console useful.  The latter is 
available on pypi.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From random832 at fastmail.us  Tue Jan 27 12:26:07 2015
From: random832 at fastmail.us (random832 at fastmail.us)
Date: Tue, 27 Jan 2015 12:26:07 -0500
Subject: Python is DOOMED! Again!
In-Reply-To: <54c731fc$0$2910$c3e8da3$76491128@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <ma6og2$hb9$1@dont-email.me>
 <54c731fc$0$2910$c3e8da3$76491128@news.astraweb.com>
Message-ID: <1422379567.3283901.219591285.7786A63A@webmail.messagingengine.com>

On Tue, Jan 27, 2015, at 01:36, Steven D'Aprano wrote:
> I consider return type to be part of the function signature. The
> signature 
> of a function is the parameters it accepts and the result it returns.

It's part of it, but not the whole of it, and early C compilers had no
information about the parameters except from the call site itself. You
could even call the same function multiple different ways (this was
later formalized with variadic functions).


From random832 at fastmail.us  Tue Jan 27 12:35:38 2015
From: random832 at fastmail.us (random832 at fastmail.us)
Date: Tue, 27 Jan 2015 12:35:38 -0500
Subject: Python is DOOMED! Again!
In-Reply-To: <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <1422380138.3205000.219592229.70468DB8@webmail.messagingengine.com>

On Mon, Jan 26, 2015, at 19:11, Steven D'Aprano wrote:
> > (header files in the 1970s didn't even actually include function
> > signature information) - which did not even participate in compilation
> > at all.
> 
> If C compilers didn't use the header files, what were they for?

My sentence may have been phrased in a confusing way. C compilers did
use the header files, and the header files did not include _most_
function signature information (they only included the return type of
functions whose return type was not int. Any function not declared was
assumed to return int). Lint libraries did contain function signature
information, and were not used for compilation (but rather only for
running lint).

The void type didn't exist either - a function with no declared return
type could either return int or return nothing at all. A call site
attempting to use the value of such a function would get whatever
arbitrary value was in r0. Lint libraries also included return
statements for such functions to determine if they returned values or
not.

Here is an example of a lint library:
http://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/lib/llib-lc

Here is stdio.h from the same era.
http://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/include/stdio.h

Headers also would often not include function declarations even for
functions that did have non-int return types. For example, time.h had no
function declarations despite many of the time library functions
returning pointers, it only contained the definition of struct tm. There
was no stdlib.h at all - you were expected to declare e.g. "char
*malloc();" yourself if you needed it.


From random832 at fastmail.us  Tue Jan 27 12:37:06 2015
From: random832 at fastmail.us (random832 at fastmail.us)
Date: Tue, 27 Jan 2015 12:37:06 -0500
Subject: Python is DOOMED! Again!
In-Reply-To: <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <1422380226.3205759.219596437.64022321@webmail.messagingengine.com>

On Mon, Jan 26, 2015, at 19:11, Steven D'Aprano wrote:
> random832 at fastmail.us wrote:
> - lexical analysis has to look for twice as many files (it has to 
>   hit the hard drive for a stub file before looking at the source),
>   and we know from importing that file system access is a 
>   significant and expensive part of the process.

The idea is that the type hinting files would not participate in
execution at all, only static analysis, so the interpreter doesn't need
to look for these things at all, it only needs to ignore them.


From breamoreboy at yahoo.co.uk  Tue Jan 27 12:40:32 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Tue, 27 Jan 2015 17:40:32 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <1422379567.3283901.219591285.7786A63A@webmail.messagingengine.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <ma6og2$hb9$1@dont-email.me>
 <54c731fc$0$2910$c3e8da3$76491128@news.astraweb.com>
 <1422379567.3283901.219591285.7786A63A@webmail.messagingengine.com>
Message-ID: <ma8iip$qea$1@ger.gmane.org>

On 27/01/2015 17:26, random832 at fastmail.us wrote:
> On Tue, Jan 27, 2015, at 01:36, Steven D'Aprano wrote:
>> I consider return type to be part of the function signature. The
>> signature
>> of a function is the parameters it accepts and the result it returns.
>
> It's part of it, but not the whole of it, and early C compilers had no
> information about the parameters except from the call site itself. You
> could even call the same function multiple different ways (this was
> later formalized with variadic functions).
>

Back to that old Whitesmith's compiler.  It's certainly very interesting 
to see what the assembler looks like when you forget the ampersand, the 
compiler doesn't throw an error, and so the entire structure instead of 
a single pointer gets passed into your function.  Not so much passed by 
value, or reference, or object, but complete foul up :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rgaddi at technologyhighland.invalid  Tue Jan 27 12:49:11 2015
From: rgaddi at technologyhighland.invalid (Rob Gaddi)
Date: Tue, 27 Jan 2015 09:49:11 -0800
Subject: Is there a more elegant way to spell this?
References: <ma8311$q4c$1@ger.gmane.org>
 <mailman.18171.1422364818.18130.python-list@python.org>
Message-ID: <20150127094911.236b6e6d@rg.highlandtechnology.com>

On Tue, 27 Jan 2015 14:20:10 +0100
Chris Warrick <kwpolska at gmail.com> wrote:

> On Jan 27, 2015 2:16 PM, "Neal Becker" <ndbecker2 at gmail.com> wrote:
> >
> > Is there a more elegant way to spell this?
> >
> > for x in [_ for _ in seq if some_predicate]:
> 
> for x in seq:
>     if some_predicate:
>         do_something_to(x)
> 
> -- 
> Chris Warrick <https://chriswarrick.com/>
> Sent from my Galaxy S3.
> 
Or the somewhat less indenty

for x in seq:
    if not some_predicate: continue
    do_something_to(x)

-- 
Rob Gaddi, Highland Technology -- www.highlandtechnology.com
Email address domain is currently out of order.  See above to fix.


From marfig at gmail.com  Tue Jan 27 12:59:10 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Tue, 27 Jan 2015 18:59:10 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
Message-ID: <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>

In article <mailman.18178.1422380228.18130.python-list at python.org>, 
random832 at fastmail.us says...
> 
> On Mon, Jan 26, 2015, at 19:11, Steven D'Aprano wrote:
> > random832 at fastmail.us wrote:
> > - lexical analysis has to look for twice as many files (it has to 
> >   hit the hard drive for a stub file before looking at the source),
> >   and we know from importing that file system access is a 
> >   significant and expensive part of the process.
> 
> The idea is that the type hinting files would not participate in
> execution at all, only static analysis, so the interpreter doesn't need
> to look for these things at all, it only needs to ignore them.

Like Steven, I do not agree with the idea of adding files for the 
purposes of static analysis. But you make an important point.

Static analysis cannot and should not clutter executable code. Static 
analysis doesn't require code execution. The Python interpreter doesn't 
need to be called in. It is for this reason that it makes absolutely no 
sense to for type hints to be mixed with our code. Let them reside in 
comments, docstrings, external files, whatever. But never in our code.

I'm actually baffled that PEP 484 came into existence, let alone it 
having any kind of supporter. Here we have a syntax that even requires 
changes to the interpreter so it can safely ignore all the type hinting 
clutter that is going to be added by anyone wanting to perform static 
analysis.

And we should also be careful around the argument that type hints are 
optional.

An optional feature says nothing of its requirements. The requirements 
for PEP 484 are heavy. Not only will they force an update to the 
interpreter, but will also force many users to reformate their function 
headers in order for them to become bareable to the eye. In fact, no 
longer will you look at function definitions like you did before.

And an optional feature says nothing of its usage patterns. Type hints 
may be optional, but they may become a requirement for many projects. In 
fact, the more complex your project, the more likely you are of wanting 
to perform static analysis. It's not because type hints are optional 
that I have some kind of choice about the matter. I may force myself, or 
be forced, to use them. And if that is the case, I would rather prefer 
having a syntax that doesn't clutter my ezxecutable code.


From marfig at gmail.com  Tue Jan 27 13:05:50 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Tue, 27 Jan 2015 19:05:50 +0100
Subject: Is there a more elegant way to spell this?
References: <mailman.18170.1422364524.18130.python-list@python.org>
 <qot7fw8s3la.fsf@ruuvi.it.helsinki.fi>
Message-ID: <MPG.2f31f1c4a200b3239896a0@nntp.aioe.org>

In article <qot7fw8s3la.fsf at ruuvi.it.helsinki.fi>, 
jpiitula at ling.helsinki.fi says...
> 
> If you mean literally some_predicate, then perhaps this.
> 
> if some_predicate:
>    for x in seq:
>       handle(x)
> 

Careful. See Chris Warrick answer for the correct position of the 'if' 
statement.


From random832 at fastmail.us  Tue Jan 27 13:07:21 2015
From: random832 at fastmail.us (random832 at fastmail.us)
Date: Tue, 27 Jan 2015 13:07:21 -0500
Subject: unicode question
In-Reply-To: <ma8hmv$97q$1@ger.gmane.org>
References: <CAA3NwWquCX54YBh15Kd_ncOtpe49nJyF_wRqEeBL6nCY0Py7Pg@mail.gmail.com>
 <1422375190.3245500.219555521.5C80989C@webmail.messagingengine.com>
 <ma8hmv$97q$1@ger.gmane.org>
Message-ID: <1422382041.3305848.219610121.0D631297@webmail.messagingengine.com>

On Tue, Jan 27, 2015, at 12:25, Mark Lawrence wrote:
> People might find this http://bugs.python.org/issue1602 and hence this 
> https://github.com/Drekin/win-unicode-console useful.  The latter is 
> available on pypi.

However, Arabic is one of those scripts that runs up against the real
limitations of the windows console. At least on non-Arabic versions of
Windows, you'll just get a sequence of boxes, and it won't do any
bidirectional processing either. I have no idea what, if anything, it
would do differently on Arabic versions of Windows.


From random832 at fastmail.us  Tue Jan 27 13:13:39 2015
From: random832 at fastmail.us (random832 at fastmail.us)
Date: Tue, 27 Jan 2015 13:13:39 -0500
Subject: Is there a more elegant way to spell this?
In-Reply-To: <MPG.2f31f1c4a200b3239896a0@nntp.aioe.org>
References: <mailman.18170.1422364524.18130.python-list@python.org>
 <qot7fw8s3la.fsf@ruuvi.it.helsinki.fi>
 <MPG.2f31f1c4a200b3239896a0@nntp.aioe.org>
Message-ID: <1422382419.788815.219612865.60921FC7@webmail.messagingengine.com>

On Tue, Jan 27, 2015, at 13:05, Mario Figueiredo wrote:
> In article <qot7fw8s3la.fsf at ruuvi.it.helsinki.fi>, 
> jpiitula at ling.helsinki.fi says...
> > 
> > If you mean literally some_predicate, then perhaps this.
> > 
> > if some_predicate:
> >    for x in seq:
> >       handle(x)
> > 
> 
> Careful. See Chris Warrick answer for the correct position of the 'if' 
> statement.

I think by "if you mean literally some_predicate" he was taking
some_predicate as a variable [rather than an expression] that does not
change during the loop. That'd be a silly thing to do in the originally
posted code, though, since it'd be easier to do "[] if not
some_predicate else [...]"


From ndbecker2 at gmail.com  Tue Jan 27 13:25:54 2015
From: ndbecker2 at gmail.com (Neal Becker)
Date: Tue, 27 Jan 2015 13:25:54 -0500
Subject: Is there a more elegant way to spell this?
References: <mailman.18170.1422364524.18130.python-list@python.org>
 <qot7fw8s3la.fsf@ruuvi.it.helsinki.fi>
Message-ID: <ma8l7i$d9l$1@ger.gmane.org>

Jussi Piitulainen wrote:

> Neal Becker writes:
> 
>> Is there a more elegant way to spell this?
>> 
>> for x in [_ for _ in seq if some_predicate]:
> 
> If you mean some_predicate(_), then possibly this.
> 
> for x in filter(some_predicate, seq):
>    handle(x)
> 
> If you mean literally some_predicate, then perhaps this.
> 
> if some_predicate:
>    for x in seq:
>       handle(x)
> 
> Unless you also have in mind an interesting arrangement where
> some_predicate might change during the loop, like this.
> 
> for x in [_ for _ in seq if some_predicate]:
>     ...
>     some_predicate = fubar(x)
>     ...
> 
> Then I have nothing to say.


To clarify, I meant some_predicate(_), and then ifilter looks like a nice 
solution.

-- 
-- Those who don't understand recursion are doomed to repeat it



From emile at fenx.com  Tue Jan 27 13:27:32 2015
From: emile at fenx.com (Emile van Sebille)
Date: Tue, 27 Jan 2015 10:27:32 -0800
Subject: Is there a more elegant way to spell this?
In-Reply-To: <20150127094911.236b6e6d@rg.highlandtechnology.com>
References: <ma8311$q4c$1@ger.gmane.org>
 <mailman.18171.1422364818.18130.python-list@python.org>
 <20150127094911.236b6e6d@rg.highlandtechnology.com>
Message-ID: <ma8lat$els$1@ger.gmane.org>

On 1/27/2015 9:49 AM, Rob Gaddi wrote:
> Or the somewhat less indenty
>
> for x in seq:
>      if not some_predicate: continue
>      do_something_to(x)
>


... or shorter and equally less indenty


for x in seq:
     if some_predicate: do_something_to(x)



From john_ladasky at sbcglobal.net  Tue Jan 27 14:16:16 2015
From: john_ladasky at sbcglobal.net (John Ladasky)
Date: Tue, 27 Jan 2015 11:16:16 -0800 (PST)
Subject: Formatting string with accented characters for printing
In-Reply-To: <mailman.17838.1421604508.18130.python-list@python.org>
References: <mailman.17838.1421604508.18130.python-list@python.org>
Message-ID: <bace8bc5-c8af-4d9a-b43e-c78044560dd7@googlegroups.com>

Jerry,

I can tell from your code that you are using Python 2.  If you are a new Python programmer, and you do not HAVE to use Python 2, use Python 3 instead.

In Python 3, text objects are something called "Unicode" rather than just sequences of bytes.  Unicode makes it much easier to handle characters which are not part of the English alphabet.


From marfig at gmail.com  Tue Jan 27 15:12:24 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Tue, 27 Jan 2015 21:12:24 +0100
Subject: An object is an instance (or not)?
Message-ID: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>

This is a follow up from a previous discussion in which it is argued 
that the following code produces the correct error message terminology, 
considering that in Python an object is also an instance.

    >>> class Sub:
    >>>     pass
    
    >>> foo = Sub()
    >>> foo.__bases__
    [...]
    AttributeError: 'Sub' object has no attribute '__bases__'

I'm making this into a new thread, because the particular discussion of 
whether an object is an instance in Python seems more interesting than 
discussing whether that error message should be changed or not.

Here's another example where the terminology keeps indicating that in 
Python an object is an instance:

    >>> class Sub:
	    pass

    >>> x = Sub()
    >>> x
    <__main__.Sub object at 0x02631690>

The problem is that I personally cannot agree with this terminology and 
I would like to hear arguments that could convince me to adopt the 
Python way. But before your replies, here's my argumentation:

An instance IS an object. On that we can agree. After all, everything in 
Python is an object. Even classes are. We can even pass them as function 
arguments:

    >>> class Sub:
	    pass

    >>> def show(aClass):
	    print(type(aClass))
	
    >>> show(Sub)
    <class 'type'>

The problem is that an object isn't always an instance. The word 
instance in OOP has a very formal meaning. In programming languages in 
which the classes aren't fully realized objects, it is ok to speak of 
'instance' and 'object' interchangeably. But even then, sometimes the 
term 'object instance' is preferred, as a way to separate these 
'instances' from other variable instances that may not be created from 
class definitions (e.g. C++ built-in types).

The fact that in Python classes are objects, should not just eliminate 
this distinction. The OOP terminology should exist beyond the language 
implementing it. It facilitates discourse and helps transmiting concepts 
when describing your ideas to another programmer. And because in python, 
classes are of the type 'type' and they exist as fully realized objects, 
is no excuse to make a distinction between them and their own fully 
realized instances. The language implementation details should not exist 
as a way for us to freely reformulate long standing terms.

Because, from my own study of Python, I've came to realize that the 
distinction between objects and instances of objects actually exists. In 
Python, class objects cannot participate in OOP, only their instances. 
This is why I say that even in Python, where a class is an object, an 
object is not always an instance. The language itself forces that 
distinction.

...

I don't think that any of this is reason enough to rewrite error 
messages in Python. Seems unnecessary. What I'm arguing thought is that 
error messages in Python cannot become the source of new terminology. 
The language itself implements a very clear distinction between class 
objects and their instances. And it is thus wrong of us to say that 
Object = Instance. At least from an OOP perspective.


From ethan at stoneleaf.us  Tue Jan 27 15:36:29 2015
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 27 Jan 2015 12:36:29 -0800
Subject: An object is an instance (or not)?
In-Reply-To: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
Message-ID: <54C7F6CD.2080303@stoneleaf.us>

On 01/27/2015 12:12 PM, Mario Figueiredo wrote:
>
> Because, from my own study of Python, I've came to realize that the 
> distinction between objects and instances of objects actually exists. In 
> Python, class objects cannot participate in OOP, only their instances. 

I haven't followed the other thread.  Can you give an example of this?  Because I have a counter-example ready:  the new
Enum data type, which uses a metaclass to treat the class just like any other instance of a normal class:

  list(MyEnum)  # fails on a regular class

  for enum in MyEnum: # fails on a regular class

  MyEnum['EnumName']  # fails on a regular class

--
~Ethan~

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From rosuav at gmail.com  Tue Jan 27 15:40:28 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 28 Jan 2015 07:40:28 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
Message-ID: <CAPTjJmp33D7pwrVvrGUGL8HUQZ+s77rn8R749zJefzr+CkTGSg@mail.gmail.com>

On Wed, Jan 28, 2015 at 4:59 AM, Mario Figueiredo <marfig at gmail.com> wrote:
> An optional feature says nothing of its requirements. The requirements
> for PEP 484 are heavy. Not only will they force an update to the
> interpreter, but will also force many users to reformate their function
> headers in order for them to become bareable to the eye. In fact, no
> longer will you look at function definitions like you did before.

What updates are needed to the interpreter?

https://www.python.org/dev/peps/pep-3107/

Already happened, long ago.

ChrisA


From andre.roberge at gmail.com  Tue Jan 27 15:50:05 2015
From: andre.roberge at gmail.com (=?ISO-8859-1?Q?Andr=E9_Roberge?=)
Date: Tue, 27 Jan 2015 12:50:05 -0800 (PST)
Subject: An object is an instance (or not)?
In-Reply-To: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
Message-ID: <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>

On Tuesday, 27 January 2015 16:12:47 UTC-4, Mario Figueiredo  wrote:
> This is a follow up from a previous discussion in which it is argued 
> that the following code produces the correct error message terminology, 
> considering that in Python an object is also an instance.
> 
>     >>> class Sub:
>     >>>     pass
>     
>     >>> foo = Sub()
>     >>> foo.__bases__
>     [...]
>     AttributeError: 'Sub' object has no attribute '__bases__'
> 
> I'm making this into a new thread, because the particular discussion of 
> whether an object is an instance in Python seems more interesting than 
> discussing whether that error message should be changed or not.
> 
> Here's another example where the terminology keeps indicating that in 
> Python an object is an instance:
> 
>     >>> class Sub:
> 	    pass
> 
>     >>> x = Sub()
>     >>> x
>     <__main__.Sub object at 0x02631690>
> 
> The problem is that I personally cannot agree with this terminology and 
> I would like to hear arguments that could convince me to adopt the 
> Python way. But before your replies, here's my argumentation:
> 
> An instance IS an object. On that we can agree. After all, everything in 
> Python is an object. Even classes are. We can even pass them as function 
> arguments:
> 
>     >>> class Sub:
> 	    pass
> 
>     >>> def show(aClass):
> 	    print(type(aClass))
> 	
>     >>> show(Sub)
>     <class 'type'>
> 
> The problem is that an object isn't always an instance. The word 
> instance in OOP has a very formal meaning. In programming languages in 
> which the classes aren't fully realized objects, it is ok to speak of 
> 'instance' and 'object' interchangeably. But even then, sometimes the 
> term 'object instance' is preferred, as a way to separate these 
> 'instances' from other variable instances that may not be created from 
> class definitions (e.g. C++ built-in types).
> 
> The fact that in Python classes are objects, should not just eliminate 
> this distinction. The OOP terminology should exist beyond the language 
> implementing it. It facilitates discourse and helps transmiting concepts 
> when describing your ideas to another programmer. And because in python, 
> classes are of the type 'type' and they exist as fully realized objects, 
> is no excuse to make a distinction between them and their own fully 
> realized instances. The language implementation details should not exist 
> as a way for us to freely reformulate long standing terms.
> 
> Because, from my own study of Python, I've came to realize that the 
> distinction between objects and instances of objects actually exists. In 
> Python, class objects cannot participate in OOP, only their instances. 
> This is why I say that even in Python, where a class is an object, an 
> object is not always an instance. The language itself forces that 
> distinction.
> 
> ...
> 
> I don't think that any of this is reason enough to rewrite error 
> messages in Python. Seems unnecessary. What I'm arguing thought is that 
> error messages in Python cannot become the source of new terminology. 
> The language itself implements a very clear distinction between class 
> objects and their instances. And it is thus wrong of us to say that 
> Object = Instance. At least from an OOP perspective.

You keep writing "an object is not an instance", making statements such as "the terminology keeps indicating that in Python an object is an instance" and yet, none of the examples you show from Python (tracebacks or repr outputs) include the word "instance".   

To phrase it differently: all the examples of output from Python that you show use the word "object" and not the word "instance".  Yet **you** claim that "Python" states that objects are instances ....    Can you point out at least one example where "Python" wrongly use the word instance instead of object?


From marfig at gmail.com  Tue Jan 27 15:58:05 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Tue, 27 Jan 2015 21:58:05 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <mailman.18185.1422391238.18130.python-list@python.org>
Message-ID: <MPG.2f321a3382f9c42d9896a2@nntp.aioe.org>

In article <mailman.18185.1422391238.18130.python-list at python.org>, 
rosuav at gmail.com says...
> 
> On Wed, Jan 28, 2015 at 4:59 AM, Mario Figueiredo <marfig at gmail.com> wrote:
> > An optional feature says nothing of its requirements. The requirements
> > for PEP 484 are heavy. Not only will they force an update to the
> > interpreter, but will also force many users to reformate their function
> > headers in order for them to become bareable to the eye. In fact, no
> > longer will you look at function definitions like you did before.
> 
> What updates are needed to the interpreter?
> 
> https://www.python.org/dev/peps/pep-3107/
> 
> Already happened, long ago.

I wasn't aware the interpreter was already able to parse PEP 484. Thank 
you. Strike that phrase of that paragraph.

But what a royal mess!

Looking at PEP 3107, i'm left wondering: what if I have for instance 
already annotated my functions for parameter marshalling, following the 
syntax expected of that specific library, and now I want to annotate 
them for type hinting for the purposes of static analysis?


From marfig at gmail.com  Tue Jan 27 16:06:30 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Tue, 27 Jan 2015 22:06:30 +0100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
Message-ID: <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>

In article <80a9f882-6b13-45a7-b514-8c47b3a4c37d at googlegroups.com>, 
andre.roberge at gmail.com says...
> 
> You keep writing "an object is not an instance", making statements
> such as "the terminology keeps indicating that in Python an object is 
> an instance" and yet, none of the examples you show from Python
> (tracebacks or repr outputs) include the word "instance".   

I think you misread my argument. Look at the first example on my post, 
or follow the discussion on "__bases__ misleading error message" here on 
the newsgroups.

That error message has me start that thread arguing that the error is 
misleading because the Sub object does have the __bases__ attribute. 
It's the Sub instance object that does not have it.

Some of the answers that were given argued that in Python object = 
instance.

> Yet
> **you** claim that "Python" states that objects are instances ....

That is no my claim. I said that much. You should probably read my post 
more carefully.


From rosuav at gmail.com  Tue Jan 27 16:08:43 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 28 Jan 2015 08:08:43 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <MPG.2f321a3382f9c42d9896a2@nntp.aioe.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <mailman.18185.1422391238.18130.python-list@python.org>
 <MPG.2f321a3382f9c42d9896a2@nntp.aioe.org>
Message-ID: <CAPTjJmrh_fxuYbXqZyhttsNCc5vC4J9CaO6co_cfeoeQpNf+NA@mail.gmail.com>

On Wed, Jan 28, 2015 at 7:58 AM, Mario Figueiredo <marfig at gmail.com> wrote:
> Looking at PEP 3107, i'm left wondering: what if I have for instance
> already annotated my functions for parameter marshalling, following the
> syntax expected of that specific library, and now I want to annotate
> them for type hinting for the purposes of static analysis?

This is the kind of argument that keeps on coming up. Everyone has a
"What if" scenario about function annotations... and almost nobody
actually has a codebase that uses them. It's equivalent to asking:
"What if I already used docstrings to control URL routing, and now I
want to use them for function documentation?". Well, simple. You move
your other-use-of-annotations out to something else (probably a
decorator) before you add type hints. Until that time, you're welcome
to continue using annotations for something other than type hinting;
you just can't do both at once on the same function.

ChrisA


From marfig at gmail.com  Tue Jan 27 16:19:56 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Tue, 27 Jan 2015 22:19:56 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <mailman.18185.1422391238.18130.python-list@python.org>
 <MPG.2f321a3382f9c42d9896a2@nntp.aioe.org>
 <mailman.18186.1422392925.18130.python-list@python.org>
Message-ID: <MPG.2f321f4b69ff42fe9896a4@nntp.aioe.org>

In article <mailman.18186.1422392925.18130.python-list at python.org>, 
rosuav at gmail.com says...
> 
> On Wed, Jan 28, 2015 at 7:58 AM, Mario Figueiredo <marfig at gmail.com> wrote:
> > Looking at PEP 3107, i'm left wondering: what if I have for instance
> > already annotated my functions for parameter marshalling, following the
> > syntax expected of that specific library, and now I want to annotate
> > them for type hinting for the purposes of static analysis?
> 
> This is the kind of argument that keeps on coming up. Everyone has a
> "What if" scenario about function annotations... and almost nobody
> actually has a codebase that uses them. It's equivalent to asking:
> "What if I already used docstrings to control URL routing, and now I
> want to use them for function documentation?". Well, simple. You move
> your other-use-of-annotations out to something else (probably a
> decorator) before you add type hints. Until that time, you're welcome
> to continue using annotations for something other than type hinting;
> you just can't do both at once on the same function.
> 
> ChrisA

I'm sorry Chris. But that's a weak argument and you know it. If I use 
those decorators inside properly formated docstrings, I can do both 
things, and more! And I don't have to  move anything anywhere. 

    def func(a, b, c):
    """
    This function does something very interesting and returns a surprise
    :a: an integer, also known as whole number (lies!)
    :b: a float on a string so it can't escape
    :c: an unicode string with some bad language

    @typehint@ some crazy syntax for static analysis
    @marshallib@ more crazy syntax for the marshall lib
    @anotherlib@ Whoohoo! a 3rd annotation for another lib
    """

Are you telling me this is not a viable alternative. That somehow we 
should ignore the possibility of potentially different annotations 
having to coexist on a project? C'mon!


From rosuav at gmail.com  Tue Jan 27 16:24:06 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 28 Jan 2015 08:24:06 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <MPG.2f321f4b69ff42fe9896a4@nntp.aioe.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <mailman.18185.1422391238.18130.python-list@python.org>
 <MPG.2f321a3382f9c42d9896a2@nntp.aioe.org>
 <mailman.18186.1422392925.18130.python-list@python.org>
 <MPG.2f321f4b69ff42fe9896a4@nntp.aioe.org>
Message-ID: <CAPTjJmo4KjtSJEzjMyG2DEiCz3kk8K+DqLZAvV-Skm==S9BiyQ@mail.gmail.com>

On Wed, Jan 28, 2015 at 8:19 AM, Mario Figueiredo <marfig at gmail.com> wrote:
>     @typehint@ some crazy syntax for static analysis
>     @marshallib@ more crazy syntax for the marshall lib
>     @anotherlib@ Whoohoo! a 3rd annotation for another lib
>     """
>
> Are you telling me this is not a viable alternative. That somehow we
> should ignore the possibility of potentially different annotations
> having to coexist on a project? C'mon!

Sure you can! But this is *itself* a weak argument, unless you
actually have a codebase that uses it. YAGNI comes to mind. When do
you actually need to annotate with multiple styles like this, and
should everyone pay the price (the disconnect from from the function
name) even though this is almost never needed?

ChrisA


From marfig at gmail.com  Tue Jan 27 16:35:07 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Tue, 27 Jan 2015 22:35:07 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <mailman.18185.1422391238.18130.python-list@python.org>
 <MPG.2f321a3382f9c42d9896a2@nntp.aioe.org>
 <mailman.18186.1422392925.18130.python-list@python.org>
 <MPG.2f321f4b69ff42fe9896a4@nntp.aioe.org>
 <mailman.18187.1422393854.18130.python-list@python.org>
Message-ID: <MPG.2f3222dbf8501a419896a5@nntp.aioe.org>

In article <mailman.18187.1422393854.18130.python-list at python.org>, 
rosuav at gmail.com says...
> 
> Sure you can! But this is *itself* a weak argument, unless you
> actually have a codebase that uses it.

Wait. Are you saying that unless I show you a codebase that requires 
marshalling and static analysis, you will ignore the fact that a 
project, no matter its size, may require more than one annotation type?

In other words, lets suggest function annotations as a restrictive 
feature, instead of a feature that can adapt to more than one use case.

> YAGNI comes to mind. When do
> you actually need to annotate with multiple styles like this, and
> should everyone pay the price (the disconnect from from the function
> name) even though this is almost never needed?

That is your price. My price is seeing my executable code cluttered with 
static fluff. Very pythonesc, I suppose...


From andre.roberge at gmail.com  Tue Jan 27 16:38:12 2015
From: andre.roberge at gmail.com (=?ISO-8859-1?Q?Andr=E9_Roberge?=)
Date: Tue, 27 Jan 2015 13:38:12 -0800 (PST)
Subject: An object is an instance (or not)?
In-Reply-To: <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
Message-ID: <a771f6f2-9aa3-44ca-9f87-88a984c7c27e@googlegroups.com>

On Tuesday, 27 January 2015 17:06:50 UTC-4, Mario Figueiredo  wrote:
> In article <80a9f882-6b13-45a7-b514-8c47b3a4c37d at googlegroups.com>, 
> andre.roberge at gmail.com says...
> > 
> > You keep writing "an object is not an instance", making statements
> > such as "the terminology keeps indicating that in Python an object is 
> > an instance" and yet, none of the examples you show from Python
> > (tracebacks or repr outputs) include the word "instance".   
> 
> I think you misread my argument. Look at the first example on my post, 
> or follow the discussion on "__bases__ misleading error message" here on 
> the newsgroups.


> 
> That error message has me start that thread arguing that the error is 
> misleading because the Sub object does have the __bases__ attribute. 
> It's the Sub instance object that does not have it.
> 

To use the word object to describe an instance is perfectly appropriate. Your claims imply the the opposite is happening.

> Some of the answers that were given argued that in Python object = 
> instance.
> 
> > Yet
> > **you** claim that "Python" states that objects are instances ....
> 
> That is no my claim. I said that much. You should probably read my post 
> more carefully.

I read your post carefully: not once did I see an output from Python using the word "instance".


>From your post:

==== Python's output ======
    AttributeError: 'Sub' object has no attribute '__bases__' 
=============================
Python uses the word "object, not "instance".



++++++ your words +++++++++++

Here's another example where the terminology keeps indicating that in 
Python an object is an instance: 
++++++++++++++++++++++++++++++

==========Python's output ===============
    <__main__.Sub object at 0x02631690> 
=======================================
Python uses the word "object, not "instance", contrary to what you wrote.



+++++++++++ your words ++++++++++++++

The problem is that an object isn't always an instance. 
+++++++++++++++++++++++++++++++++++++


++++++++++++ your words ++++++++++++

What I'm arguing thought is that 
error messages in Python cannot become the source of new terminology. 
++++++++++++++++++++++++++++++++

Not a single output from Python uses the word instance.

It is appropriate to refer to an instance as an object.  It might not be appropriate to refer to an object as an instance ... but Python does not do so as your explicit examples demonstrate, and contrary to your claim.

A.R.




From marfig at gmail.com  Tue Jan 27 16:39:21 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Tue, 27 Jan 2015 22:39:21 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <mailman.18185.1422391238.18130.python-list@python.org>
 <MPG.2f321a3382f9c42d9896a2@nntp.aioe.org>
 <mailman.18186.1422392925.18130.python-list@python.org>
 <MPG.2f321f4b69ff42fe9896a4@nntp.aioe.org>
 <mailman.18187.1422393854.18130.python-list@python.org>
 <MPG.2f3222dbf8501a419896a5@nntp.aioe.org>
Message-ID: <MPG.2f3223d5959d93b9896a6@nntp.aioe.org>

I can now start to understand the criticism of how Python is evolving 
coming from many corners, either long term python educators like Mark 
Lutz.




From marfig at gmail.com  Tue Jan 27 16:43:21 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Tue, 27 Jan 2015 22:43:21 +0100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <a771f6f2-9aa3-44ca-9f87-88a984c7c27e@googlegroups.com>
Message-ID: <MPG.2f3224d1997790e19896a7@nntp.aioe.org>

In article <a771f6f2-9aa3-44ca-9f87-88a984c7c27e at googlegroups.com>, 
andre.roberge at gmail.com says...
> 
> It is appropriate to refer to an instance as an object.  It might not 
> be appropriate to refer to an object as an instance ... but Python
> does not do so as your explicit examples demonstrate, and contrary to 
> your claim.

I'll try one more time: It - Is - Not - My - Claim.

It is the claim of a few users in here that replied to that thread.


From andre.roberge at gmail.com  Tue Jan 27 16:49:01 2015
From: andre.roberge at gmail.com (=?ISO-8859-1?Q?Andr=E9_Roberge?=)
Date: Tue, 27 Jan 2015 13:49:01 -0800 (PST)
Subject: An object is an instance (or not)?
In-Reply-To: <MPG.2f3224d1997790e19896a7@nntp.aioe.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <a771f6f2-9aa3-44ca-9f87-88a984c7c27e@googlegroups.com>
 <MPG.2f3224d1997790e19896a7@nntp.aioe.org>
Message-ID: <9a2cf6ca-2eb8-4a87-9e83-e87d90d5fe42@googlegroups.com>

On Tuesday, 27 January 2015 17:43:38 UTC-4, Mario Figueiredo  wrote:
> In article <a771f6f2-9aa3-44ca-9f87-88a984c7c27e at googlegroups.com>, 
> andre.roberge at gmail.com says...
> > 
> > It is appropriate to refer to an instance as an object.  It might not 
> > be appropriate to refer to an object as an instance ... but Python
> > does not do so as your explicit examples demonstrate, and contrary to 
> > your claim.
> 
> I'll try one more time: It - Is - Not - My - Claim.
> 
> It is the claim of a few users in here that replied to that thread.

At the very beginning of the first message I replied to, you wrote:

**This is a follow up from a previous discussion in which it is argued 
that the following code produces the correct error message terminology **

I pointed out to you that the word object WAS used correctly: hence, the correct terminology was used in that error message.

You are just wasting people's time.


From rosuav at gmail.com  Tue Jan 27 16:53:14 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 28 Jan 2015 08:53:14 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <MPG.2f3222dbf8501a419896a5@nntp.aioe.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <mailman.18185.1422391238.18130.python-list@python.org>
 <MPG.2f321a3382f9c42d9896a2@nntp.aioe.org>
 <mailman.18186.1422392925.18130.python-list@python.org>
 <MPG.2f321f4b69ff42fe9896a4@nntp.aioe.org>
 <mailman.18187.1422393854.18130.python-list@python.org>
 <MPG.2f3222dbf8501a419896a5@nntp.aioe.org>
Message-ID: <CAPTjJmqScWH2PLRChQYt4adRNA2xmw1F8scHTm_qCOCiyjD5Jg@mail.gmail.com>

On Wed, Jan 28, 2015 at 8:35 AM, Mario Figueiredo <marfig at gmail.com> wrote:
> In other words, lets suggest function annotations as a restrictive
> feature, instead of a feature that can adapt to more than one use case.

PEP 3107 made a feature that can adapt to more than one use case. It's
been years now, and the use-cases originally suggested are the only
ones actually seen in the wild. Apparently nobody has actually come up
with a need for the flexibility.

ChrisA


From marfig at gmail.com  Tue Jan 27 16:58:20 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Tue, 27 Jan 2015 22:58:20 +0100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <a771f6f2-9aa3-44ca-9f87-88a984c7c27e@googlegroups.com>
 <MPG.2f3224d1997790e19896a7@nntp.aioe.org>
 <9a2cf6ca-2eb8-4a87-9e83-e87d90d5fe42@googlegroups.com>
Message-ID: <MPG.2f322851e6cf90ad9896a8@nntp.aioe.org>

In article <9a2cf6ca-2eb8-4a87-9e83-e87d90d5fe42 at googlegroups.com>, 
andre.roberge at gmail.com says...
> 
> **This is a follow up from a previous discussion in which it is argued 
> that the following code produces the correct error message terminology **
> 
> I pointed out to you that the word object WAS used correctly: hence, the correct terminology was used in that error message.
> 
> You are just wasting people's time.

That is just rude!

I'm still trying to understand what is the problem you are having with 
my post. Have you followed the previous thread? Is there anything you 
are not understanding?

People were saying to me that in Python object = instance. I'm trying to 
argue why I believe it isn't and asking for arguments to convince me 
otherwise.

And that's the best you can do?

Python does imply that an object is an instance, btw. It is why I got 
that answer from more than one person. Or so they say.

By referring to an instance of Sub as "Sub object", there's an implicit 
affirmation that an object is an instance.

Bye.


From ben+python at benfinney.id.au  Tue Jan 27 17:32:09 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Wed, 28 Jan 2015 09:32:09 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <a771f6f2-9aa3-44ca-9f87-88a984c7c27e@googlegroups.com>
 <MPG.2f3224d1997790e19896a7@nntp.aioe.org>
 <9a2cf6ca-2eb8-4a87-9e83-e87d90d5fe42@googlegroups.com>
 <MPG.2f322851e6cf90ad9896a8@nntp.aioe.org>
Message-ID: <85mw53lus6.fsf@benfinney.id.au>

Mario Figueiredo <marfig at gmail.com> writes:

> People were saying to me that in Python object = instance. I'm trying
> to argue why I believe it isn't and asking for arguments to convince
> me otherwise.

In Python:

* Every value is an object.

* Every object is an instance of some class.

* To say ?object? is uproblematic for values in Python, because the
  programming term ?object? doesn't imply anything about classes.

* To say ?instance? implies a specific relationship to some particular
  class; in programming terminology (because in English generally) an
  instance is so called only because it is an instance of some specific
  class.

> By referring to an instance of Sub as "Sub object", there's an
> implicit affirmation that an object is an instance.

Correct. That raises a fourth point:

* In the distant past of Python, some objects were not instances of any
  class; the terminology in the documentation and messages shows some
  confusing legacies from that ancient time.

The phrasing ?'Foo' object? is ambiguous in a way that ?'Foo' instance?
would not be. I agree with others that changing the message to refer to
?'Foo' instance? would be an improvement.

-- 
 \         ?Pinky, are you pondering what I'm pondering?? ?I think so, |
  `\    Brain, but I find scratching just makes it worse.? ?_Pinky and |
_o__)                                                       The Brain_ |
Ben Finney



From breamoreboy at yahoo.co.uk  Tue Jan 27 18:12:20 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Tue, 27 Jan 2015 23:12:20 +0000
Subject: An object is an instance (or not)?
In-Reply-To: <MPG.2f322851e6cf90ad9896a8@nntp.aioe.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <a771f6f2-9aa3-44ca-9f87-88a984c7c27e@googlegroups.com>
 <MPG.2f3224d1997790e19896a7@nntp.aioe.org>
 <9a2cf6ca-2eb8-4a87-9e83-e87d90d5fe42@googlegroups.com>
 <MPG.2f322851e6cf90ad9896a8@nntp.aioe.org>
Message-ID: <ma960t$g1m$1@ger.gmane.org>

On 27/01/2015 21:58, Mario Figueiredo wrote:
> In article <9a2cf6ca-2eb8-4a87-9e83-e87d90d5fe42 at googlegroups.com>,
> andre.roberge at gmail.com says...
>>
>> **This is a follow up from a previous discussion in which it is argued
>> that the following code produces the correct error message terminology **
>>
>> I pointed out to you that the word object WAS used correctly: hence, the correct terminology was used in that error message.
>>
>> You are just wasting people's time.
>
> That is just rude!
>
> I'm still trying to understand what is the problem you are having with
> my post. Have you followed the previous thread? Is there anything you
> are not understanding?
>
> People were saying to me that in Python object = instance. I'm trying to
> argue why I believe it isn't and asking for arguments to convince me
> otherwise.
>
> And that's the best you can do?
>
> Python does imply that an object is an instance, btw. It is why I got
> that answer from more than one person. Or so they say.
>
> By referring to an instance of Sub as "Sub object", there's an implicit
> affirmation that an object is an instance.
>
> Bye.
>

Mario and Andre, when you have to write code to meet the deadline to get 
the stage payment, does either of your bosses really care whether or not 
you are dealing with an object, an instance, or a piece of dead meat 
dropped by the neighbour's cat?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From ned at nedbatchelder.com  Tue Jan 27 18:22:00 2015
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Tue, 27 Jan 2015 18:22:00 -0500
Subject: An object is an instance (or not)?
In-Reply-To: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
Message-ID: <ma96io$ovh$1@ger.gmane.org>

On 1/27/15 3:12 PM, Mario Figueiredo wrote:
> This is a follow up from a previous discussion in which it is argued
> that the following code produces the correct error message terminology,
> considering that in Python an object is also an instance.

I don't know what the difference is between "object" and "instance".  An 
object is an instance of a class.  The two words are interchangeable as 
far as I know.

> An instance IS an object. On that we can agree. After all, everything in
> Python is an object. Even classes are. We can even pass them as function
> arguments:
>
>      >>> class Sub:
> 	    pass
>
>      >>> def show(aClass):
> 	    print(type(aClass))
> 	
>      >>> show(Sub)
>      <class 'type'>
>
> The problem is that an object isn't always an instance. The word
> instance in OOP has a very formal meaning.

A common mistake is to believe that "OOP" is a well-defined term.  It's 
not it's a collection of ideas that are expressed slightly differently 
in each language.

> In programming languages in
> which the classes aren't fully realized objects, it is ok to speak of
> 'instance' and 'object' interchangeably.

I don't know what a "not fully realized object" is.

> But even then, sometimes the
> term 'object instance' is preferred, as a way to separate these
> 'instances' from other variable instances that may not be created from
> class definitions (e.g. C++ built-in types).
>
> The fact that in Python classes are objects, should not just eliminate
> this distinction. The OOP terminology should exist beyond the language
> implementing it. It facilitates discourse and helps transmiting concepts
> when describing your ideas to another programmer. And because in python,
> classes are of the type 'type' and they exist as fully realized objects,
> is no excuse to make a distinction between them and their own fully
> realized instances. The language implementation details should not exist
> as a way for us to freely reformulate long standing terms.
>
> Because, from my own study of Python, I've came to realize that the
> distinction between objects and instances of objects actually exists. In
> Python, class objects cannot participate in OOP, only their instances.

What does "participate in OOP" mean?

> This is why I say that even in Python, where a class is an object, an
> object is not always an instance. The language itself forces that
> distinction.

-- 
Ned Batchelder, http://nedbatchelder.com



From salem055 at gmail.com  Tue Jan 27 18:22:01 2015
From: salem055 at gmail.com (Salem Alqahtani)
Date: Tue, 27 Jan 2015 15:22:01 -0800 (PST)
Subject: Python simple Code
In-Reply-To: <4e283f62-0b6a-4ef7-a784-b9b3da73f510@googlegroups.com>
References: <4e283f62-0b6a-4ef7-a784-b9b3da73f510@googlegroups.com>
Message-ID: <0514aac8-943b-4ecc-9ebb-91dd9b58c0f1@googlegroups.com>

On Saturday, January 24, 2015 at 7:16:27 PM UTC-5, Salem Alqahtani wrote:
> Hi Guys,
> 
> I just joined the group and I hope that I can help and be active.
> 
> I have a question about python. I wrote a code on python 2.7 and I want to choose from the list of names that I provide n!. I execute the code but the result or output is the numbers. I want the people names are the result.
> 
> 
> Sincerely
> 
> import sys
> import array
> a=['salem','Ali','sultan']
> m = len(a)
> def Factorials(m):
>     if m == 0:
>         return 1
>     else:
>         print m
>         return m * Factorials(m-1)
> def output():
>     print a
> def main():
>     print Factorials(m)
>     output()
> main()

Hi Guys,

I appreciate your answers and the output that I am expected from my simple code is the following:

['salem','Ali','sultan']
['salem','sultan','Ali']
['Ali','sultan','salem']
['Ali','salem','sultan']
['sultan','Ali','salem']
['sultan','salem','sultan']

the 3 * 2 * 1 is 6 but I do not looking for this output.  

Sincerely


From ben+python at benfinney.id.au  Tue Jan 27 18:39:53 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Wed, 28 Jan 2015 10:39:53 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <ma96io$ovh$1@ger.gmane.org>
Message-ID: <857fw7lrna.fsf@benfinney.id.au>

Ned Batchelder <ned at nedbatchelder.com> writes:

> On 1/27/15 3:12 PM, Mario Figueiredo wrote:
> > This is a follow up from a previous discussion in which it is argued
> > that the following code produces the correct error message terminology,
> > considering that in Python an object is also an instance.
>
> I don't know what the difference is between "object" and "instance".
> An object is an instance of a class.  The two words are
> interchangeable as far as I know.

Not in English grammar, IMO. To say ?foo is an instance? implies the
sentence isn't finished; the term ?instance? only makes sense in the
context of a relationship to some class. To say ?foo is an object?
doesn't have that implication.

> A common mistake is to believe that "OOP" is a well-defined term.
> It's not it's a collection of ideas that are expressed slightly
> differently in each language.

Right. The common meaning of ?object? shared by all OOP systems is
surprisingly small.

Many OOP systems do not use classes (e.g. JavaScript) and are no less
object-oriented for that. In such a system it would be true to say ?foo
is an object, but is not an instance of anything?.

> > Because, from my own study of Python, I've came to realize that the
> > distinction between objects and instances of objects actually
> > exists. In Python, class objects cannot participate in OOP, only
> > their instances.
>
> What does "participate in OOP" mean?

To the extent I understand (and I'm confused on what that might mean as
you are), I think it's plainly false.

In Python, every class is an object. Every class has the full range of
behaviour that we expect of objects. A class just has the additional
feature that it can be instantiated.

> > This is why I say that even in Python, where a class is an object,
> > an object is not always an instance. The language itself forces that
> > distinction.

You have not, to my knowledge, shown any object (in Python 2.2 or later)
which is not an instance of some class. Python objects are always an
instance of some specific class.

-- 
 \     ?Books and opinions, no matter from whom they came, if they are |
  `\     in opposition to human rights, are nothing but dead letters.? |
_o__)                                                  ?Ernestine Rose |
Ben Finney



From rosuav at gmail.com  Tue Jan 27 18:42:22 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 28 Jan 2015 10:42:22 +1100
Subject: An object is an instance (or not)?
In-Reply-To: <ma96io$ovh$1@ger.gmane.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <ma96io$ovh$1@ger.gmane.org>
Message-ID: <CAPTjJmr1nW=kbiRZyYaEkCSSqmb-QOLYnwmohMmMmgoQkM_Ehw@mail.gmail.com>

On Wed, Jan 28, 2015 at 10:22 AM, Ned Batchelder <ned at nedbatchelder.com> wrote:
> I don't know what the difference is between "object" and "instance".  An
> object is an instance of a class.  The two words are interchangeable as far
> as I know.

My understanding is that "instance" is meaningless unless followed by
"of". That is to say, 123.45 is an object, and it is an instance *of*
the 'float' class. Everything in Python is an instance *of something*,
so in a sense, you can say that everything is an instance, but that's
like saying that everything has a color. Sure it does, but you need to
be more specific.

ChrisA


From ian.g.kelly at gmail.com  Tue Jan 27 18:50:14 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Tue, 27 Jan 2015 16:50:14 -0700
Subject: Python simple Code
In-Reply-To: <0514aac8-943b-4ecc-9ebb-91dd9b58c0f1@googlegroups.com>
References: <4e283f62-0b6a-4ef7-a784-b9b3da73f510@googlegroups.com>
 <0514aac8-943b-4ecc-9ebb-91dd9b58c0f1@googlegroups.com>
Message-ID: <CALwzidkVCjt86YayXbNeMzVtZ7xVcp4-y8a-4D0dSMwbYb8N0Q@mail.gmail.com>

On Tue, Jan 27, 2015 at 4:22 PM, Salem Alqahtani <salem055 at gmail.com> wrote:
> I appreciate your answers and the output that I am expected from my simple code is the following:
>
> ['salem','Ali','sultan']
> ['salem','sultan','Ali']
> ['Ali','sultan','salem']
> ['Ali','salem','sultan']
> ['sultan','Ali','salem']
> ['sultan','salem','sultan']
>
> the 3 * 2 * 1 is 6 but I do not looking for this output.

>>> from itertools import permutations
>>> a = ['salem', 'Ali', 'sultan']
>>> for p in permutations(a):
...   print(list(p))
...
['salem', 'Ali', 'sultan']
['salem', 'sultan', 'Ali']
['Ali', 'salem', 'sultan']
['Ali', 'sultan', 'salem']
['sultan', 'salem', 'Ali']
['sultan', 'Ali', 'salem']


From marfig at gmail.com  Tue Jan 27 19:17:31 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Wed, 28 Jan 2015 01:17:31 +0100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
Message-ID: <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>

In article <mailman.18191.1422400930.18130.python-list at python.org>, 
ned at nedbatchelder.com says...
> 
> A common mistake is to believe that "OOP" is a well-defined term.  It's 
> not it's a collection of ideas that are expressed slightly differently 
> in each language.

A common mistake is thinking just because OOP has different 
implementations, it doesn't have a cohesive set of well described rules 
and its own well defined terminology.

> I don't know what a "not fully realized object" is.

A fully realized object, in an object oriented paradigm, is an object 
containing or pointing to data and the methods to act on that data. It's 
an instance of a class.

A *not* fully realized object is possible in Python, since Classes are 
first-class objects, despite not being able to participate in OOP.

> 
> What does "participate in OOP" mean?

Means the object is capable of participating in inheritance and/or 
polymorphism. An instance of an object is capable of doing so, per its 
class definitions. Whereas a Python class object is not.

    >>> class Master:
            def func(self):
                pass

    >>> class Sub(Master):
            pass

    >>> Sub.func()
    TypeError: func() missing 1 required positional argument: 'self'

But somehow I think you knew the answer to all these questions and were 
instead being snarky.


From invalid at invalid.invalid  Tue Jan 27 19:23:37 2015
From: invalid at invalid.invalid (Grant Edwards)
Date: Wed, 28 Jan 2015 00:23:37 +0000 (UTC)
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
Message-ID: <ma9a68$ieo$1@reader1.panix.com>

On 2015-01-27, Ned Batchelder <ned at nedbatchelder.com> wrote:
> On 1/27/15 3:12 PM, Mario Figueiredo wrote:
>> This is a follow up from a previous discussion in which it is argued
>> that the following code produces the correct error message terminology,
>> considering that in Python an object is also an instance.
>
> I don't know what the difference is between "object" and "instance".  An 
> object is an instance of a class.  The two words are interchangeable as 
> far as I know.

They are interchangable in recent versions of Python.

--
Grant


From marfig at gmail.com  Tue Jan 27 19:24:22 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Wed, 28 Jan 2015 01:24:22 +0100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <ma96io$ovh$1@ger.gmane.org>
 <mailman.18192.1422401989.18130.python-list@python.org>
Message-ID: <MPG.2f324a8a8df0eba19896aa@nntp.aioe.org>

In article <mailman.18192.1422401989.18130.python-list at python.org>, 
ben+python at benfinney.id.au says...
> > > This is why I say that even in Python, where a class is an object,
> > > an object is not always an instance. The language itself forces that
> > > distinction.
> 
> You have not, to my knowledge, shown any object (in Python 2.2 or later)
> which is not an instance of some class. Python objects are always an
> instance of some specific class.

It is true that a class object is an instance of 'type'. But this is a 
special type (can't avoid the pun). A class object is not an instance of 
the type it implements. That is what I mean by an object that isn't an 
instance.

In other words, the object know as "Sub class" is not an instance 
object. True, it is an instance of the object 'type'.


From rosuav at gmail.com  Tue Jan 27 19:30:32 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 28 Jan 2015 11:30:32 +1100
Subject: An object is an instance (or not)?
In-Reply-To: <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
Message-ID: <CAPTjJmoswoQfUX-9rOyHg1CJCMoJ0QN7bB76H2Df6YTd-yn5ZA@mail.gmail.com>

On Wed, Jan 28, 2015 at 11:17 AM, Mario Figueiredo <marfig at gmail.com> wrote:
> Means the object is capable of participating in inheritance and/or
> polymorphism. An instance of an object is capable of doing so, per its
> class definitions. Whereas a Python class object is not.
>
>     >>> class Master:
>             def func(self):
>                 pass
>
>     >>> class Sub(Master):
>             pass
>
>     >>> Sub.func()
>     TypeError: func() missing 1 required positional argument: 'self'
>
> But somehow I think you knew the answer to all these questions and were
> instead being snarky.

I have no idea what you're proving here. You just showed that the
class has a function attached to it, and you didn't provide enough
arguments to it. And types have their own set of attributes and
methods:

>>> dir(type)
['__abstractmethods__', '__base__', '__bases__', '__basicsize__',
'__call__', '__class__', '__delattr__', '__dict__', '__dictoffset__',
'__dir__', '__doc__', '__eq__', '__flags__', '__format__', '__ge__',
'__getattribute__', '__gt__', '__hash__', '__init__',
'__instancecheck__', '__itemsize__', '__le__', '__lt__', '__module__',
'__mro__', '__name__', '__ne__', '__new__', '__prepare__',
'__qualname__', '__reduce__', '__reduce_ex__', '__repr__',
'__setattr__', '__sizeof__', '__str__', '__subclasscheck__',
'__subclasses__', '__subclasshook__', '__text_signature__',
'__weakrefoffset__', 'mro']

Most of those are inherited from object, but some aren't.

What are you demonstrating?

ChrisA


From marfig at gmail.com  Tue Jan 27 19:31:06 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Wed, 28 Jan 2015 01:31:06 +0100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <ma96io$ovh$1@ger.gmane.org>
 <mailman.18193.1422402146.18130.python-list@python.org>
Message-ID: <MPG.2f324c19ac737fdc9896ab@nntp.aioe.org>

In article <mailman.18193.1422402146.18130.python-list at python.org>, 
rosuav at gmail.com says...
> 
> On Wed, Jan 28, 2015 at 10:22 AM, Ned Batchelder <ned at nedbatchelder.com> wrote:
> > I don't know what the difference is between "object" and "instance".  An
> > object is an instance of a class.  The two words are interchangeable as far
> > as I know.
> 
> My understanding is that "instance" is meaningless unless followed by
> "of". That is to say, 123.45 is an object, and it is an instance *of*
> the 'float' class. Everything in Python is an instance *of something*,
> so in a sense, you can say that everything is an instance, but that's
> like saying that everything has a color. Sure it does, but you need to
> be more specific.
> 

In programming languages in which class definitions aren't first-class 
objects, the terms are in fact used interchangeably. And rightly so, 
because an object is in fact always an instance of some class.

Python and a few other languages implement class definitions as first-
class objects. In this case, the distinction between an object and an 
instance is actually an implementation detail and comes with its own 
semantics. This is why I object to the notion that in Python object = 
instance.



From marfig at gmail.com  Tue Jan 27 19:35:07 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Wed, 28 Jan 2015 01:35:07 +0100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
 <mailman.18195.1422405040.18130.python-list@python.org>
Message-ID: <MPG.2f324d0d46ba9afc9896ac@nntp.aioe.org>

In article <mailman.18195.1422405040.18130.python-list at python.org>, 
rosuav at gmail.com says...
> 
> On Wed, Jan 28, 2015 at 11:17 AM, Mario Figueiredo <marfig at gmail.com> wrote:
> > Means the object is capable of participating in inheritance and/or
> > polymorphism. An instance of an object is capable of doing so, per its
> > class definitions. Whereas a Python class object is not.
> >
> >     >>> class Master:
> >             def func(self):
> >                 pass
> >
> >     >>> class Sub(Master):
> >             pass
> >
> >     >>> Sub.func()
> >     TypeError: func() missing 1 required positional argument: 'self'
> >
> I have no idea what you're proving here. You just showed that the
> class has a function attached to it, and you didn't provide enough
> arguments to it. And types have their own set of attributes and
> methods:
> 

I admit it was a contrived example. I couldn't think of a way to 
demonstrate that a class object does not participate in its own 
inheritance rules. Only instances of it can.


From marfig at gmail.com  Tue Jan 27 19:52:57 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Wed, 28 Jan 2015 01:52:57 +0100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <a771f6f2-9aa3-44ca-9f87-88a984c7c27e@googlegroups.com>
 <MPG.2f3224d1997790e19896a7@nntp.aioe.org>
 <9a2cf6ca-2eb8-4a87-9e83-e87d90d5fe42@googlegroups.com>
 <MPG.2f322851e6cf90ad9896a8@nntp.aioe.org>
 <mailman.18190.1422400358.18130.python-list@python.org>
Message-ID: <MPG.2f32513a4d0addbf9896ad@nntp.aioe.org>

In article <mailman.18190.1422400358.18130.python-list at python.org>, 
breamoreboy at yahoo.co.uk says...
> 
> Mario and Andre, when you have to write code to meet the deadline to get 
> the stage payment, does either of your bosses really care whether or not 
> you are dealing with an object, an instance, or a piece of dead meat 
> dropped by the neighbour's cat?

That is valuable input. You don't care how a type or an instance of a 
type differ. Should be intersting to ask you to make a Cat object. I 
wonder if you are not going to ask if they mean a class or an instance 
of that class.

Anyways, more to the point, this is simply a debate on language and how 
to express Python concepts. If that bothers you, I'll take note.


From steve+comp.lang.python at pearwood.info  Tue Jan 27 19:55:58 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 28 Jan 2015 11:55:58 +1100
Subject: Is there a more elegant way to spell this?
References: <mailman.18170.1422364524.18130.python-list@python.org>
Message-ID: <54c8339f$0$13008$c3e8da3$5496439d@news.astraweb.com>

Neal Becker wrote:

> Is there a more elegant way to spell this?
> 
> for x in [_ for _ in seq if some_predicate]:

Don't use _ as the loop variable here.

There are three common conventions for _ and this is none of them:


(1) n the interactive interpreter _ is used for the result of the last
expression:

py> 1+2
3
py> _ * 2
6

(2) In locale-aware applications, _ is apparently used as a function for
localising text into the user's native language.

(3) _ is also commonly used as a "don't care" variable name:

a, _, b, _ = get_four_items()  # but I only care about two of them


So in a loop, you would only use _ as the loop variable when you don't use
the loop variable, e.g.:

[random.random() for _ in range(10)]


Of course, a convention is just a convention, not a law, you can ignore such
conventions if you insist. But conventions make it easier and quicker to
understand code, not just for others, but for yourself as well.


-- 
Steven



From ben+python at benfinney.id.au  Tue Jan 27 20:00:58 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Wed, 28 Jan 2015 12:00:58 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <ma96io$ovh$1@ger.gmane.org>
 <mailman.18192.1422401989.18130.python-list@python.org>
 <MPG.2f324a8a8df0eba19896aa@nntp.aioe.org>
Message-ID: <85386vlnw5.fsf@benfinney.id.au>

Mario Figueiredo <marfig at gmail.com> writes:

> It is true that a class object is an instance of 'type'. But this is a
> special type (can't avoid the pun).

Nevertheless it is a class, and can do everything that classes do.

And every class is an object, and can do everything that objects do.

You seem to agree with those, so please stop claiming that classes are
not objects. Python classes are always objects, and always have been.

> A class object is not an instance of the type it implements.

You keep introducing hurdles that are irrelevant. Yes, a class is not an
instance of itself. That doesn't impact the fact a class is an object.

> That is what I mean by an object that isn't an instance.

That's incoherent. It's an instance of a class, and simultaneously is
not an instance?

> In other words, the object know as "Sub class" is not an instance 
> object. True, it is an instance of the object 'type'.

You've tied yourself in knots with concepts that are not coherent, and
even if they were do not appear to be relevant to Python.

-- 
 \      ?Very few things happen at the right time, and the rest do not |
  `\     happen at all. The conscientious historian will correct these |
_o__)                          defects.? ?Mark Twain, _A Horse's Tale_ |
Ben Finney



From steve+comp.lang.python at pearwood.info  Tue Jan 27 20:09:43 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 28 Jan 2015 12:09:43 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
Message-ID: <54c836d9$0$12980$c3e8da3$5496439d@news.astraweb.com>

random832 at fastmail.us wrote:

> On Mon, Jan 26, 2015, at 19:11, Steven D'Aprano wrote:
>> random832 at fastmail.us wrote:
>> - lexical analysis has to look for twice as many files (it has to
>>   hit the hard drive for a stub file before looking at the source),
>>   and we know from importing that file system access is a
>>   significant and expensive part of the process.
> 
> The idea is that the type hinting files would not participate in
> execution at all, only static analysis, so the interpreter doesn't need
> to look for these things at all, it only needs to ignore them.

Yes, but the *type-checker* needs to look for all those files, which slows
the type-checker down.

My estimate of time savings, plucked completely from thin air, is that
type-checkers will save around 5% time by not using a separate stub file.
(Anyone actually using MyPy care to measure it?)

Of course, that will differ according to circumstances: a stub file on a
slow CD/DVD media mounted over the network will be much more expensive than
a stub file on a RAM disk or SSD drive.

Regardless of exactly how much more expensive it is, two sets of file I/O by
definition will be more expensive than one set of file I/O.

But really, this is the minor point against header files. The icing on the
cake, not the cake itself. The big reason for avoiding them is dependency
management and the splitting of information about a single thing into two
files.


-- 
Steven



From marfig at gmail.com  Tue Jan 27 20:14:06 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Wed, 28 Jan 2015 02:14:06 +0100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <ma96io$ovh$1@ger.gmane.org>
 <mailman.18192.1422401989.18130.python-list@python.org>
 <MPG.2f324a8a8df0eba19896aa@nntp.aioe.org>
 <mailman.18196.1422406856.18130.python-list@python.org>
Message-ID: <MPG.2f3256323b56435c9896ae@nntp.aioe.org>

In article <mailman.18196.1422406856.18130.python-list at python.org>, 
ben+python at benfinney.id.au says...
> 
> Mario Figueiredo <marfig at gmail.com> writes:
> 
> > It is true that a class object is an instance of 'type'. But this is a
> > special type (can't avoid the pun).
> 
> Nevertheless it is a class, and can do everything that classes do.
> 
> And every class is an object, and can do everything that objects do.
> 
> You seem to agree with those, so please stop claiming that classes are
> not objects. Python classes are always objects, and always have been.
> 
> > A class object is not an instance of the type it implements.
> 
> You keep introducing hurdles that are irrelevant. Yes, a class is not an
> instance of itself. That doesn't impact the fact a class is an object.
> 
> > That is what I mean by an object that isn't an instance.
> 
> That's incoherent. It's an instance of a class, and simultaneously is
> not an instance?
> 
> > In other words, the object know as "Sub class" is not an instance 
> > object. True, it is an instance of the object 'type'.
> 
> You've tied yourself in knots with concepts that are not coherent, and
> even if they were do not appear to be relevant to Python.

Very well. I'm failing at putting my point across. I will not discuss 
this further.


From marfig at gmail.com  Tue Jan 27 20:19:03 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Wed, 28 Jan 2015 02:19:03 +0100
Subject: Is there a more elegant way to spell this?
References: <mailman.18170.1422364524.18130.python-list@python.org>
 <54c8339f$0$13008$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <MPG.2f3257584e3201d69896af@nntp.aioe.org>

In article <54c8339f$0$13008$c3e8da3$5496439d at news.astraweb.com>, 
steve+comp.lang.python at pearwood.info says...
> (3) _ is also commonly used as a "don't care" variable name:
> 
> a, _, b, _ = get_four_items()  # but I only care about two of them
> 

According to the following link, it is actually a double underscore:
http://docs.python-guide.org/en/latest/writing/style/#idioms


From steve+comp.lang.python at pearwood.info  Tue Jan 27 20:26:11 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 28 Jan 2015 12:26:11 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
Message-ID: <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>

Mario Figueiredo wrote:

> Static analysis cannot and should not clutter executable code.

(1) It isn't clutter. The human reader uses that information as well as the
compiler, interpreter, type-checker, IDE, text editor, correctness tester,
etc.

(2) Algol, Ada, Boo, C, C#, C++, Cobol, Cobra, D, F#, Fantom, Fortran, Go,
Haskell, Java, Julia, Kotlin, Oberon, Pascal, Rust, Scala and dozens
(hundreds?) of other languages disagree with you.



> Let [type-hints] reside in comments, docstrings, external files, whatever.

Didn't you criticise the use of type-hints in comments earlier? Or am I
confusing you with somebody else?



> I'm actually baffled that PEP 484 came into existence, let alone it 
> having any kind of supporter. Here we have a syntax that even requires 
> changes to the interpreter so it can safely ignore all the type hinting 
> clutter that is going to be added by anyone wanting to perform static 
> analysis.

That *absolutely is not true*. I don't know where you get this from.

Python 3 has supported function annotations for over five years now. The
only change required with PEP 484 is to give those annotations a standard
meaning and encourage people to use them for type-checking instead of
whatever other uses they have or haven't (mostly haven't) thought of.



> The requirements 
> for PEP 484 are heavy. Not only will they force an update to the 
> interpreter, but will also force many users to reformate their function 
> headers in order for them to become bareable to the eye. In fact, no 
> longer will you look at function definitions like you did before.

Again, this is wrong. PEP 484 requires *no* update to the interpreter. It
adds a single library file to the standard library, but use of that is
optional. It requires *nobody* to rewrite or reformate their function
headers. The only people who will do so are those who want to run
type-checkers which support type-hints.



-- 
Steven



From ben+python at benfinney.id.au  Tue Jan 27 20:29:18 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Wed, 28 Jan 2015 12:29:18 +1100
Subject: Is there a more elegant way to spell this?
References: <mailman.18170.1422364524.18130.python-list@python.org>
 <54c8339f$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3257584e3201d69896af@nntp.aioe.org>
Message-ID: <85y4onk80h.fsf@benfinney.id.au>

Mario Figueiredo <marfig at gmail.com> writes:

> In article <54c8339f$0$13008$c3e8da3$5496439d at news.astraweb.com>, 
> steve+comp.lang.python at pearwood.info says...
> > (3) _ is also commonly used as a "don't care" variable name:
> > 
> > a, _, b, _ = get_four_items()  # but I only care about two of them
> > 
>
> According to the following link, it is actually a double underscore:
> http://docs.python-guide.org/en/latest/writing/style/#idioms

More accurately (and as acknowledged in that guide), a single underscore
*is* a common name for a ?don't care? name, but is better avoided for
that purpose because it's also commonly used for other purposes.

In other words: That guide is correct in its admonition, but that
doesn't challenge what Steven said about common usage.

-- 
 \       ?My business is to teach my aspirations to conform themselves |
  `\              to fact, not to try and make facts harmonise with my |
_o__)                   aspirations.? ?Thomas Henry Huxley, 1860-09-23 |
Ben Finney



From salem055 at gmail.com  Tue Jan 27 20:35:49 2015
From: salem055 at gmail.com (Salem Alqahtani)
Date: Tue, 27 Jan 2015 17:35:49 -0800 (PST)
Subject: Python simple Code
In-Reply-To: <mailman.18194.1422402657.18130.python-list@python.org>
References: <4e283f62-0b6a-4ef7-a784-b9b3da73f510@googlegroups.com>
 <0514aac8-943b-4ecc-9ebb-91dd9b58c0f1@googlegroups.com>
 <mailman.18194.1422402657.18130.python-list@python.org>
Message-ID: <ccd28f7f-b129-4f9c-a59c-000e50995fff@googlegroups.com>

On Tuesday, January 27, 2015 at 6:51:10 PM UTC-5, Ian wrote:
> On Tue, Jan 27, 2015 at 4:22 PM, Salem Alqahtani <salem055 at gmail.com> wrote:
> > I appreciate your answers and the output that I am expected from my simple code is the following:
> >
> > ['salem','Ali','sultan']
> > ['salem','sultan','Ali']
> > ['Ali','sultan','salem']
> > ['Ali','salem','sultan']
> > ['sultan','Ali','salem']
> > ['sultan','salem','sultan']
> >
> > the 3 * 2 * 1 is 6 but I do not looking for this output.
> 
> >>> from itertools import permutations
> >>> a = ['salem', 'Ali', 'sultan']
> >>> for p in permutations(a):
> ...   print(list(p))
> ...
> ['salem', 'Ali', 'sultan']
> ['salem', 'sultan', 'Ali']
> ['Ali', 'salem', 'sultan']
> ['Ali', 'sultan', 'salem']
> ['sultan', 'salem', 'Ali']
> ['sultan', 'Ali', 'salem']

Thank you so much


From steve+comp.lang.python at pearwood.info  Tue Jan 27 21:05:49 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 28 Jan 2015 13:05:49 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <mailman.18185.1422391238.18130.python-list@python.org>
 <MPG.2f321a3382f9c42d9896a2@nntp.aioe.org>
Message-ID: <54c843fe$0$12984$c3e8da3$5496439d@news.astraweb.com>

Mario Figueiredo wrote:

> Looking at PEP 3107, i'm left wondering: what if I have for instance
> already annotated my functions for parameter marshalling, following the
> syntax expected of that specific library, and now I want to annotate
> them for type hinting for the purposes of static analysis?

You cannot simultaneously follow two competing standards.

If you have a library that expects annotations to represent (let's say)
parameter marshalling, and another library that expects annotations to
represent documentation, and a third library that expects annotations to
represent hyperlinks to external resources, and a fourth that expects them
to be used for range checking, would you expect to be able to use all four
competing and incompatible uses of annotations in the same function at the
same time? Or even any two such libraries at the same time?

Of course not. At best, each library will ignore annotations that it doesn't
understand. Possibly they will print warnings, or raise exceptions, and
force you to choose between them. At worst, the libraries will misinterpret
the annotation and do the wrong thing, with consequences ranging from
annoying to disastrous. But unless all four libraries are designed from the
start to cooperate, you cannot expect them to cooperate.

Why should type hints be held to a higher (and impossible) standard?

If you use annotations for some other purposes, your choices post-PEP 484
will become:

- Do absolutely nothing different, and your annotations will continue to
work exactly as they currently do. You're not currently running a
type-checker which expects annotations to be type-hints, so you merely
continue *not running* such a type-checker.

Or, if you decide that you do want to run a type-checker:

- Find a type-checker that doesn't use annotations, and use whatever rules
it uses. I believe some linters (obiwan comes to mind?) may use type hints
in docstrings to do simple type checking. Find such a tool, or write your
own, and use it.

- Find a type-checker which can cooperatively interoperate with your
existing use of annotations, if such a thing exists. Feel free to write one
if you wish, or pony up the money to pay somebody else to do so.

- Use a stub file, and a type-checker which will ignore the annotations and
use the stub file instead.

- Give up on your dream of lexical analysis of Python. You can't have
everything, and your Python experience will be just like 2014 all over
again.

- Give up on your current use of annotations, and replace them with
type-hints.

- Change to some other language that does everything you want, and re-write
your entire application in this new language.

- Stamp your feet and hold your breath until you collapse and see if that
helps. (It probably won't, but my two year old nephew[1] thinks it does.)

PEP 484 gives you many choices, starting with "do absolutely nothing, and
absolutely nothing will change".





[1] Actually, that's a gross slander. For somebody right in the middle of
the terrible twos, he's relatively sweet natured and well behaved.

-- 
Steven



From rustompmody at gmail.com  Tue Jan 27 21:11:08 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Tue, 27 Jan 2015 18:11:08 -0800 (PST)
Subject: An object is an instance (or not)?
In-Reply-To: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
Message-ID: <9a470405-d22d-448b-83ff-93fccd92bea6@googlegroups.com>

On Wednesday, January 28, 2015 at 1:42:47 AM UTC+5:30, Mario Figueiredo wrote:
> This is a follow up from a previous discussion in which it is argued 
> that the following code produces the correct error message terminology, 
> considering that in Python an object is also an instance.
> 
>     >>> class Sub:
>     >>>     pass
>     
>     >>> foo = Sub()
>     >>> foo.__bases__
>     [...]
>     AttributeError: 'Sub' object has no attribute '__bases__'
> 
> I'm making this into a new thread, because the particular discussion of 
> whether an object is an instance in Python seems more interesting than 
> discussing whether that error message should be changed or not.
> 
> Here's another example where the terminology keeps indicating that in 
> Python an object is an instance:
> 
>     >>> class Sub:
> 	    pass
> 
>     >>> x = Sub()
>     >>> x
>     <__main__.Sub object at 0x02631690>
> 
> The problem is that I personally cannot agree with this terminology and 
> I would like to hear arguments that could convince me to adopt the 
> Python way. But before your replies, here's my argumentation:
> 
> An instance IS an object. On that we can agree. After all, everything in 
> Python is an object. Even classes are. We can even pass them as function 
> arguments:
> 
>     >>> class Sub:
> 	    pass
> 
>     >>> def show(aClass):
> 	    print(type(aClass))
> 	
>     >>> show(Sub)
>     <class 'type'>
> 
> The problem is that an object isn't always an instance. The word 
> instance in OOP has a very formal meaning. In programming languages in 
> which the classes aren't fully realized objects, it is ok to speak of 
> 'instance' and 'object' interchangeably. But even then, sometimes the 
> term 'object instance' is preferred, as a way to separate these 
> 'instances' from other variable instances that may not be created from 
> class definitions (e.g. C++ built-in types).
> 
> The fact that in Python classes are objects, should not just eliminate 
> this distinction. The OOP terminology should exist beyond the language 
> implementing it. It facilitates discourse and helps transmiting concepts 
> when describing your ideas to another programmer. And because in python, 
> classes are of the type 'type' and they exist as fully realized objects, 
> is no excuse to make a distinction between them and their own fully 
> realized instances. The language implementation details should not exist 
> as a way for us to freely reformulate long standing terms.
> 
> Because, from my own study of Python, I've came to realize that the 
> distinction between objects and instances of objects actually exists. In 
> Python, class objects cannot participate in OOP, only their instances. 
> This is why I say that even in Python, where a class is an object, an 
> object is not always an instance. The language itself forces that 
> distinction.
> 
> ...
> 
> I don't think that any of this is reason enough to rewrite error 
> messages in Python. Seems unnecessary. What I'm arguing thought is that 
> error messages in Python cannot become the source of new terminology. 
> The language itself implements a very clear distinction between class 
> objects and their instances. And it is thus wrong of us to say that 
> Object = Instance. At least from an OOP perspective.

The issue (as I see it) is primarily with English - in particular the word 
'is', technically called copula:
https://en.wikipedia.org/wiki/Copula_%28linguistics%29

Is is(!) used in 3 ways that can get mutually incompatible:
Predication: The sky is blue
Identity: Two plus three is five [Notice how you've used '=' above]
Belonging: (OOP isa relation): Cat is a mammal

Some people have found this (mis|over)use of 'is' so problematic that they have 
suggested to doctor English to not use is as far as possible:
https://en.wikipedia.org/wiki/E-Prime


From ian.g.kelly at gmail.com  Tue Jan 27 21:15:57 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Tue, 27 Jan 2015 19:15:57 -0700
Subject: An object is an instance (or not)?
In-Reply-To: <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
Message-ID: <CALwzidn9XBgUc0YA1H=WN-+vN_zz9nmGhENjEEzp_Q-FDtpoLg@mail.gmail.com>

On Tue, Jan 27, 2015 at 5:17 PM, Mario Figueiredo <marfig at gmail.com> wrote:
> In article <mailman.18191.1422400930.18130.python-list at python.org>,
> ned at nedbatchelder.com says...
>> What does "participate in OOP" mean?
>
> Means the object is capable of participating in inheritance and/or
> polymorphism. An instance of an object is capable of doing so, per its
> class definitions. Whereas a Python class object is not.

Python class objects are capable of doing both these things.

>     >>> class Master:
>             def func(self):
>                 pass
>
>     >>> class Sub(Master):
>             pass
>
>     >>> Sub.func()
>     TypeError: func() missing 1 required positional argument: 'self'

You get the same result by calling Master.func(), so I don't see how
this is a counter-example. Anyway, here is how class objects
participate in inheritance:

class BaseMetaClass(type):
    def func(cls):
        return 42

class DerivedMetaClass(BaseMetaClass):
    pass

class DerivedClass(metaclass=DerivedMetaClass):
    pass

>>> isinstance(DerivedClass, BaseMetaClass)
True
>>> print(DerivedClass.func())
42

Note that this is exactly the same way that non-class objects
participate in inheritance. Instances don't simply inherit from other
instances. Rather, the class of the instance inherits from other
classes and provides methods to the instances. And that's what happens
here: the class's meta class inherits from another, and the method it
defines is callable on the instance.


From steve+comp.lang.python at pearwood.info  Tue Jan 27 21:16:30 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 28 Jan 2015 13:16:30 +1100
Subject: Is there a more elegant way to spell this?
References: <mailman.18170.1422364524.18130.python-list@python.org>
 <54c8339f$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3257584e3201d69896af@nntp.aioe.org>
Message-ID: <54c8467e$0$13013$c3e8da3$5496439d@news.astraweb.com>

Mario Figueiredo wrote:

> In article <54c8339f$0$13008$c3e8da3$5496439d at news.astraweb.com>,
> steve+comp.lang.python at pearwood.info says...
>> (3) _ is also commonly used as a "don't care" variable name:
>> 
>> a, _, b, _ = get_four_items()  # but I only care about two of them
>> 
> 
> According to the following link, it is actually a double underscore:
> http://docs.python-guide.org/en/latest/writing/style/#idioms

That's third-party documentation, not official, and I strongly disagree with
a couple of those recommendations. But this specific one seems reasonable
enough.


-- 
Steven



From ned at nedbatchelder.com  Tue Jan 27 21:21:15 2015
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Tue, 27 Jan 2015 21:21:15 -0500
Subject: An object is an instance (or not)?
In-Reply-To: <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
Message-ID: <ma9h2s$pcc$1@ger.gmane.org>

On 1/27/15 7:17 PM, Mario Figueiredo wrote:
> In article <mailman.18191.1422400930.18130.python-list at python.org>,
> ned at nedbatchelder.com says...
>>
>> A common mistake is to believe that "OOP" is a well-defined term.  It's
>> not it's a collection of ideas that are expressed slightly differently
>> in each language.
>
> A common mistake is thinking just because OOP has different
> implementations, it doesn't have a cohesive set of well described rules
> and its own well defined terminology.

I know you think that it has well described rules and terminology.  But 
take a look at this discussion, and maybe realize that the terms are not 
as well-defined, or certainly not as widely accepted as you think.

Do you have a reference that defines these terms?

>
>> I don't know what a "not fully realized object" is.
>
> A fully realized object, in an object oriented paradigm, is an object
> containing or pointing to data and the methods to act on that data. It's
> an instance of a class.
>
> A *not* fully realized object is possible in Python, since Classes are
> first-class objects, despite not being able to participate in OOP.
>>
>> What does "participate in OOP" mean?
>
> Means the object is capable of participating in inheritance and/or
> polymorphism. An instance of an object is capable of doing so, per its
> class definitions. Whereas a Python class object is not.
>
>      >>> class Master:
>              def func(self):
>                  pass
>
>      >>> class Sub(Master):
>              pass
>
>      >>> Sub.func()
>      TypeError: func() missing 1 required positional argument: 'self'


> But somehow I think you knew the answer to all these questions and were
> instead being snarky.

I am not being snarky, I'm trying to understand where our mutual 
incomprehension lies.


-- 
Ned Batchelder, http://nedbatchelder.com



From rustompmody at gmail.com  Tue Jan 27 21:52:50 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Tue, 27 Jan 2015 18:52:50 -0800 (PST)
Subject: An object is an instance (or not)?
In-Reply-To: <mailman.18199.1422411685.18130.python-list@python.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
 <mailman.18199.1422411685.18130.python-list@python.org>
Message-ID: <f326fdf5-a044-438e-b54f-e75d814fe7be@googlegroups.com>

On Wednesday, January 28, 2015 at 7:55:12 AM UTC+5:30, Ned Batchelder wrote:
> On 1/27/15 7:17 PM, Mario Figueiredo wrote:
> > Ned Batchelder says...
> >>
> >> A common mistake is to believe that "OOP" is a well-defined term.  It's
> >> not it's a collection of ideas that are expressed slightly differently
> >> in each language.
> >
> > A common mistake is thinking just because OOP has different
> > implementations, it doesn't have a cohesive set of well described rules
> > and its own well defined terminology.
> 
> I know you think that it has well described rules and terminology.  But 
> take a look at this discussion, and maybe realize that the terms are not 
> as well-defined, or certainly not as widely accepted as you think.

I'd go a step or two further than that.

Here's a discussion almost isomorphic [including Ned's futile attempts at
inducing sanity] to this one from a few years ago
https://groups.google.com/d/msg/comp.lang.python/y6mnzDeEsRU/Wvpo4mJ-a2gJ
[And others by that same OP - Mark Janssen - zipher]?

And there's the recent one (2 because of thread breaking) on
<<Comparisons and sorting of a numeric class>>

To me all these suggest that OOP as a philosophy pickles the brain.
And violently passionate adherence to the philosophy conduces to madness.

[Reminded of a quote I saw on the scheme mailing list:
OOP is the phlogiston theory of CS
]

====================
? To those who suffer violent allergic reactions on seeing ...groups.google... the numbering of the official archive is so fluid that even
google (search engine!) is getting confused and pointing to broken links


From denismfmcmahon at gmail.com  Tue Jan 27 22:15:32 2015
From: denismfmcmahon at gmail.com (Denis McMahon)
Date: Wed, 28 Jan 2015 03:15:32 +0000 (UTC)
Subject: Python simple Code
References: <4e283f62-0b6a-4ef7-a784-b9b3da73f510@googlegroups.com>
 <0514aac8-943b-4ecc-9ebb-91dd9b58c0f1@googlegroups.com>
Message-ID: <ma9k8k$v9f$1@dont-email.me>

On Tue, 27 Jan 2015 15:22:01 -0800, Salem Alqahtani wrote:

> I appreciate your answers and the output that I am expected from my
> simple code is the following:
> 
> ['salem','Ali','sultan']
> ['salem','sultan','Ali']
> ['Ali','sultan','salem']
> ['Ali','salem','sultan']
> ['sultan','Ali','salem']
> ['sultan','salem','sultan']

A long way to do this is as follows (you've already been shown the short 
way using permutations)

words = ['salem','Ali','sultan']

for a in words:
    for b in words:
         if b != a:
              for c in words:
                  if c != a:
                      if c != b:
                          print [a, b, c]

Not quite so long:

words = ['salem','Ali','sultan']

for a in words:
    for b in [x for x in words if x != a]:
        for c in [x for x in words if x != a and x != b]:
            print [a, b, c]

Observe that neither of these scale as elegantly as the permutations 
example already given.

-- 
Denis McMahon, denismfmcmahon at gmail.com


From wuwei23 at gmail.com  Tue Jan 27 23:44:10 2015
From: wuwei23 at gmail.com (alex23)
Date: Wed, 28 Jan 2015 14:44:10 +1000
Subject: An object is an instance (or not)?
In-Reply-To: <MPG.2f324d0d46ba9afc9896ac@nntp.aioe.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
 <mailman.18195.1422405040.18130.python-list@python.org>
 <MPG.2f324d0d46ba9afc9896ac@nntp.aioe.org>
Message-ID: <ma9pen$8ds$1@dont-email.me>

On 28/01/2015 10:35 AM, Mario Figueiredo wrote:
> I admit it was a contrived example. I couldn't think of a way to
> demonstrate that a class object does not participate in its own
> inheritance rules. Only instances of it can.

A class object isn't an instance of itself, it's an instance of the 
Class (to be extact, 'type') class. Method dispatching will also 
traverse the base classes when refering to the class object, too:

     >>> class Master:
     ...     @classmethod
     ...     def func(cls):
     ...         return cls
     ...
     >>> class Sub(Master):
     ...     pass
     ...
     >>> type(Sub)
     <class 'type'>
     >>> Sub.func()
     <class '__main__.Sub'>





From wuwei23 at gmail.com  Tue Jan 27 23:47:56 2015
From: wuwei23 at gmail.com (alex23)
Date: Wed, 28 Jan 2015 14:47:56 +1000
Subject: An object is an instance (or not)?
In-Reply-To: <MPG.2f324a8a8df0eba19896aa@nntp.aioe.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <ma96io$ovh$1@ger.gmane.org>
 <mailman.18192.1422401989.18130.python-list@python.org>
 <MPG.2f324a8a8df0eba19896aa@nntp.aioe.org>
Message-ID: <ma9pkr$8ds$2@dont-email.me>

On 28/01/2015 10:24 AM, Mario Figueiredo wrote:
> In other words, the object know as "Sub class" is not an instance
> object. True, it is an instance of the object 'type'.

     >>> class Foo:
     ...     pass
     ...
     >>> isinstance(Foo, type)
     True
     >>> isinstance(Foo, object)
     True

A class is an object that is an instance of the class type. I'm still 
failing to see what distinction you're trying to make here.


From rustompmody at gmail.com  Wed Jan 28 00:23:06 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Tue, 27 Jan 2015 21:23:06 -0800 (PST)
Subject: An object is an instance (or not)?
In-Reply-To: <ma9pkr$8ds$2@dont-email.me>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <ma96io$ovh$1@ger.gmane.org>
 <mailman.18192.1422401989.18130.python-list@python.org>
 <MPG.2f324a8a8df0eba19896aa@nntp.aioe.org>
 <ma9pkr$8ds$2@dont-email.me>
Message-ID: <83792681-c60d-4465-8d7d-77bab09686dd@googlegroups.com>

On Wednesday, January 28, 2015 at 10:18:07 AM UTC+5:30, alex23 wrote:
> On 28/01/2015 10:24 AM, Mario Figueiredo wrote:
> > In other words, the object know as "Sub class" is not an instance
> > object. True, it is an instance of the object 'type'.
> 
>      >>> class Foo:
>      ...     pass
>      ...
>      >>> isinstance(Foo, type)
>      True
>      >>> isinstance(Foo, object)
>      True
> 
> A class is an object that is an instance of the class type. I'm still 
> failing to see what distinction you're trying to make here.

Confusion is not disallowed is it ;-)
Maybe some diagrams will help. Something like
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.50.631&rep=rep1&type=pdf
pic on page 7 particularly the distinction between the arrows and the dotted arrows


From marko at pacujo.net  Wed Jan 28 00:25:20 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Wed, 28 Jan 2015 07:25:20 +0200
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <a771f6f2-9aa3-44ca-9f87-88a984c7c27e@googlegroups.com>
 <MPG.2f3224d1997790e19896a7@nntp.aioe.org>
 <9a2cf6ca-2eb8-4a87-9e83-e87d90d5fe42@googlegroups.com>
 <MPG.2f322851e6cf90ad9896a8@nntp.aioe.org>
 <mailman.18190.1422400358.18130.python-list@python.org>
 <MPG.2f32513a4d0addbf9896ad@nntp.aioe.org>
Message-ID: <877fw7jx33.fsf@elektro.pacujo.net>

Mario Figueiredo <marfig at gmail.com>:

> That is valuable input. You don't care how a type or an instance of a
> type differ. Should be intersting to ask you to make a Cat object. I
> wonder if you are not going to ask if they mean a class or an instance
> of that class.
>
> Anyways, more to the point, this is simply a debate on language and how 
> to express Python concepts. If that bothers you, I'll take note.

Python itself has answers to your questions:

   >>> isinstance(3, int)
   True
   >>> isinstance("3", int)
   False
   >>> isinstance(int, type)
   True
   >>> isinstance(type, int)
   False
   >>> isinstance(type, type)
   True
   >>> isinstance(3, type)
   False
   >>> isinstance(int, 3)
   Traceback (most recent call last):
     File "<stdin>", line 1, in <module>
   TypeError: isinstance() arg 2 must be a type or tuple of types
   >>> isinstance(3, object)
   True
   >>> isinstance("3", object)
   True
   >>> isinstance(int, object)
   True
   >>> isinstance(type, object)
   True
   >>> isinstance(object, object)
   True


Marko


From random832 at fastmail.us  Wed Jan 28 00:37:46 2015
From: random832 at fastmail.us (random832 at fastmail.us)
Date: Wed, 28 Jan 2015 00:37:46 -0500
Subject: An object is an instance (or not)?
In-Reply-To: <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
Message-ID: <1422423466.366357.219840709.1CB2D6D1@webmail.messagingengine.com>

On Tue, Jan 27, 2015, at 16:06, Mario Figueiredo wrote:
> That error message has me start that thread arguing that the error is 
> misleading because the Sub object does have the __bases__ attribute. 
> It's the Sub instance object that does not have it.

What do you think "Sub object" means?

Sub itself is not a Sub object, it is a type object. "instance" is
implicit in the phrase "foo object".


From jeanpierreda at gmail.com  Wed Jan 28 00:43:52 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Tue, 27 Jan 2015 21:43:52 -0800
Subject: An object is an instance (or not)?
In-Reply-To: <1422423466.366357.219840709.1CB2D6D1@webmail.messagingengine.com>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <1422423466.366357.219840709.1CB2D6D1@webmail.messagingengine.com>
Message-ID: <CABicbJKM9xZmT+L4b=WxqXUpT60yS3sZGS56VzKt_NrZNaXbrg@mail.gmail.com>

On Tue, Jan 27, 2015 at 9:37 PM,  <random832 at fastmail.us> wrote:
> On Tue, Jan 27, 2015, at 16:06, Mario Figueiredo wrote:
>> That error message has me start that thread arguing that the error is
>> misleading because the Sub object does have the __bases__ attribute.
>> It's the Sub instance object that does not have it.
>
> What do you think "Sub object" means?
>
> Sub itself is not a Sub object, it is a type object. "instance" is
> implicit in the phrase "foo object".

Yes. Unfortunately, it's still not really completely clear. "Sub
instance" would avoid this confusion for everyone.

I think the only reason to avoid "instance" in the past would have
been the old-style object confusion, as Ben Finney pointed out. (BTW I
agree with literally every single thing he said in this thread, it's
really amazing.)

-- Devin


From random832 at fastmail.us  Wed Jan 28 00:44:47 2015
From: random832 at fastmail.us (random832 at fastmail.us)
Date: Wed, 28 Jan 2015 00:44:47 -0500
Subject: An object is an instance (or not)?
In-Reply-To: <ma9pkr$8ds$2@dont-email.me>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <ma96io$ovh$1@ger.gmane.org>
 <mailman.18192.1422401989.18130.python-list@python.org>
 <MPG.2f324a8a8df0eba19896aa@nntp.aioe.org> <ma9pkr$8ds$2@dont-email.me>
Message-ID: <1422423887.367928.219842465.7175FB29@webmail.messagingengine.com>

On Tue, Jan 27, 2015, at 23:47, alex23 wrote:
> On 28/01/2015 10:24 AM, Mario Figueiredo wrote:
> > In other words, the object know as "Sub class" is not an instance
> > object. True, it is an instance of the object 'type'.
> 
>      >>> class Foo:
>      ...     pass
>      ...
>      >>> isinstance(Foo, type)
>      True
>      >>> isinstance(Foo, object)
>      True
> 
> A class is an object that is an instance of the class type. I'm still 
> failing to see what distinction you're trying to make here.

I think his objection is to the use of the phrase "'Sub' object" to
refer only to instances of the Sub type, when 'Sub' is the name of the
type object itself and therefore (he thinks) "'Sub' object" should refer
to it instead. (I can only assume he wants "'x' object" for x = Sub().)


From rustompmody at gmail.com  Wed Jan 28 00:53:50 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Tue, 27 Jan 2015 21:53:50 -0800 (PST)
Subject: An object is an instance (or not)?
In-Reply-To: <877fw7jx33.fsf@elektro.pacujo.net>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <a771f6f2-9aa3-44ca-9f87-88a984c7c27e@googlegroups.com>
 <MPG.2f3224d1997790e19896a7@nntp.aioe.org>
 <9a2cf6ca-2eb8-4a87-9e83-e87d90d5fe42@googlegroups.com>
 <MPG.2f322851e6cf90ad9896a8@nntp.aioe.org>
 <mailman.18190.1422400358.18130.python-list@python.org>
 <MPG.2f32513a4d0addbf9896ad@nntp.aioe.org> <877fw7jx33.fsf@elektro.pacujo.net>
Message-ID: <9010c34b-2b2e-4cff-86c1-a45fc6ef61a1@googlegroups.com>

On Wednesday, January 28, 2015 at 10:55:32 AM UTC+5:30, Marko Rauhamaa wrote:
> Python itself has answers to your questions:
> 
>    >>> isinstance(3, int)
>    True
>    >>> isinstance("3", int)
>    False
>    >>> isinstance(int, type)
>    True
>    >>> isinstance(type, int)
>    False
>    >>> isinstance(type, type)
>    True
>    >>> isinstance(3, type)
>    False
>    >>> isinstance(int, 3)
>    Traceback (most recent call last):
>      File "<stdin>", line 1, in <module>
>    TypeError: isinstance() arg 2 must be a type or tuple of types
>    >>> isinstance(3, object)
>    True
>    >>> isinstance("3", object)
>    True
>    >>> isinstance(int, object)
>    True
>    >>> isinstance(type, object)
>    True
>    >>> isinstance(object, object)
>    True
> 
> 
> Marko


neat
Maybe add also

>>> isinstance(type,object)
True
>>> isinstance(object,object)
True
>>> issubclass(object,type)
False
>>> issubclass(type,object)
True
>>> isinstance(object,type)
True
>>> issubclass(int,object)
True


From breamoreboy at yahoo.co.uk  Wed Jan 28 00:57:57 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Wed, 28 Jan 2015 05:57:57 +0000
Subject: An object is an instance (or not)?
In-Reply-To: <MPG.2f32513a4d0addbf9896ad@nntp.aioe.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <a771f6f2-9aa3-44ca-9f87-88a984c7c27e@googlegroups.com>
 <MPG.2f3224d1997790e19896a7@nntp.aioe.org>
 <9a2cf6ca-2eb8-4a87-9e83-e87d90d5fe42@googlegroups.com>
 <MPG.2f322851e6cf90ad9896a8@nntp.aioe.org>
 <mailman.18190.1422400358.18130.python-list@python.org>
 <MPG.2f32513a4d0addbf9896ad@nntp.aioe.org>
Message-ID: <ma9tpe$ken$1@ger.gmane.org>

On 28/01/2015 00:52, Mario Figueiredo wrote:
> In article <mailman.18190.1422400358.18130.python-list at python.org>,
> breamoreboy at yahoo.co.uk says...
>>
>> Mario and Andre, when you have to write code to meet the deadline to get
>> the stage payment, does either of your bosses really care whether or not
>> you are dealing with an object, an instance, or a piece of dead meat
>> dropped by the neighbour's cat?
>
> That is valuable input. You don't care how a type or an instance of a
> type differ. Should be intersting to ask you to make a Cat object. I
> wonder if you are not going to ask if they mean a class or an instance
> of that class.
>
> Anyways, more to the point, this is simply a debate on language and how
> to express Python concepts. If that bothers you, I'll take note.
>

The thing that bothers me is that many people, some of them with maybe 
20 years of Python experience, have repeatedly stated Python concepts 
with respect to the terms class, instance and object.  Instead of 
accepting their knowledge of the language and gracefully stepping back, 
you've carried on until the twist of knots would make any boy scout proud.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From random832 at fastmail.us  Wed Jan 28 01:01:08 2015
From: random832 at fastmail.us (random832 at fastmail.us)
Date: Wed, 28 Jan 2015 01:01:08 -0500
Subject: An object is an instance (or not)?
In-Reply-To: <CABicbJKM9xZmT+L4b=WxqXUpT60yS3sZGS56VzKt_NrZNaXbrg@mail.gmail.com>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <1422423466.366357.219840709.1CB2D6D1@webmail.messagingengine.com>
 <CABicbJKM9xZmT+L4b=WxqXUpT60yS3sZGS56VzKt_NrZNaXbrg@mail.gmail.com>
Message-ID: <1422424868.372353.219845333.5C2DDFCF@webmail.messagingengine.com>

On Wed, Jan 28, 2015, at 00:43, Devin Jeanpierre wrote:
> On Tue, Jan 27, 2015 at 9:37 PM,  <random832 at fastmail.us> wrote:
> > Sub itself is not a Sub object, it is a type object. "instance" is
> > implicit in the phrase "foo object".
> 
> Yes. Unfortunately, it's still not really completely clear. "Sub
> instance" would avoid this confusion for everyone.

It really is completely clear. Nobody is confused but you.


From rustompmody at gmail.com  Wed Jan 28 01:22:46 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Tue, 27 Jan 2015 22:22:46 -0800 (PST)
Subject: An object is an instance (or not)?
In-Reply-To: <mailman.18204.1422424871.18130.python-list@python.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <1422423466.366357.219840709.1CB2D6D1@webmail.messagingengine.com>
 <CABicbJKM9xZmT+L4b=WxqXUpT60yS3sZGS56VzKt_NrZNaXbrg@mail.gmail.com>
 <mailman.18204.1422424871.18130.python-list@python.org>
Message-ID: <d7d48e3b-c278-40f7-b13f-ee7ac968a6f1@googlegroups.com>

On Wednesday, January 28, 2015 at 11:31:46 AM UTC+5:30, random wrote:
> On Wed, Jan 28, 2015, at 00:43, Devin Jeanpierre wrote:
> > On Tue, Jan 27, 2015 at 9:37 PM,  random832 wrote:
> > > Sub itself is not a Sub object, it is a type object. "instance" is
> > > implicit in the phrase "foo object".
> > 
> > Yes. Unfortunately, it's still not really completely clear. "Sub
> > instance" would avoid this confusion for everyone.
> 
> It really is completely clear. Nobody is confused but you.

I think I can count 4 people
OP trying to show the confusion (maybe confusedly)
Ben agreeing that some terminology could be straightened out
Devin agreeing with Ben
Me(Rusi): Prefer a not so cavalier adjective-noun equivalencing


From ben+python at benfinney.id.au  Wed Jan 28 01:59:50 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Wed, 28 Jan 2015 17:59:50 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <1422423466.366357.219840709.1CB2D6D1@webmail.messagingengine.com>
 <CABicbJKM9xZmT+L4b=WxqXUpT60yS3sZGS56VzKt_NrZNaXbrg@mail.gmail.com>
 <1422424868.372353.219845333.5C2DDFCF@webmail.messagingengine.com>
Message-ID: <85r3ufjspl.fsf@benfinney.id.au>

random832 at fastmail.us writes:

> On Wed, Jan 28, 2015, at 00:43, Devin Jeanpierre wrote:
> > On Tue, Jan 27, 2015 at 9:37 PM,  <random832 at fastmail.us> wrote:
> > > Sub itself is not a Sub object, it is a type object. "instance" is
> > > implicit in the phrase "foo object".
> > 
> > Yes. Unfortunately, it's still not really completely clear. "Sub
> > instance" would avoid this confusion for everyone.
>
> It really is completely clear. Nobody is confused but you.

You have no justification to claim that, and it's hostile and dismissive
to claim it so assertively.

I'll freely admit to finding ?'Foo' object? ambiguous. It can reasonably
be interpreted to mean either ?a 'Foo' object? (? ?an object of class
'Foo'?), or ?the 'Foo' object? (? ?the object referred to by the name
'Foo'?). The error message which inspired this thread needs improvement,
as I've said already.

Let's not dismiss anyone's experience without good reason.

-- 
 \     ?When people believe that they have absolute knowledge, with no |
  `\     test in reality, this [the Auschwitz crematorium] is how they |
_o__)             behave.? ?Jacob Bronowski, _The Ascent of Man_, 1973 |
Ben Finney



From ben+python at benfinney.id.au  Wed Jan 28 02:03:12 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Wed, 28 Jan 2015 18:03:12 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <1422423466.366357.219840709.1CB2D6D1@webmail.messagingengine.com>
 <CABicbJKM9xZmT+L4b=WxqXUpT60yS3sZGS56VzKt_NrZNaXbrg@mail.gmail.com>
 <mailman.18204.1422424871.18130.python-list@python.org>
 <d7d48e3b-c278-40f7-b13f-ee7ac968a6f1@googlegroups.com>
Message-ID: <85mw53jsjz.fsf@benfinney.id.au>

Rustom Mody <rustompmody at gmail.com> writes:

> Me(Rusi): Prefer a not so cavalier adjective-noun equivalencing

I can sympathise with that preference. It really is a lost cause,
though; the English language just works that way.

We use nouns as verbs, nouns as modifiers, adjectives as nouns; and
rather than wish it were not so, we must to take care to express
ourselves to avoid unintended ambiguity ? especially in writing. And
*especially* in writing terse formal error messages.

The English language is imperfect, but it's what we have. Live with it.

-- 
 \      ?The manager has personally passed all the water served here.? |
  `\                                                  ?hotel, Acapulco |
_o__)                                                                  |
Ben Finney



From greg.ewing at canterbury.ac.nz  Wed Jan 28 02:21:12 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Wed, 28 Jan 2015 20:21:12 +1300
Subject: An object is an instance (or not)?
In-Reply-To: <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
Message-ID: <cirgvaFtgueU1@mid.individual.net>

Mario Figueiredo wrote:
> That error message has me start that thread arguing that the error is 
> misleading because the Sub object does have the __bases__ attribute. 
> It's the Sub instance object that does not have it.
> 
> Some of the answers that were given argued that in Python object = 
> instance.

No, they pointed out that *in that particular sentence* the
word "object" was being used in a way that's more or less
synonymous with "instance".

But that doesn't mean the two words are perfectly
interchangeable in all English sentences. Sometimes one
is better than the other.

I prefer to use the word "instance" when I'm talking about
an instance *of* something, e.g. "an instance of Foo" or
"a Foo instance". If I'm not mentioning a class, I just
use the word "object".

So I would argue that "Sub instance has no attribute..."
is a marginally clearer way to word that message.

Which means, I think, that I'm more or less agreeing with
you, but *not* because of objects not always being instances
in Python. On the contrary, it's precisely because all
objects *are* instances that using the word "instance"
on its own in place of "object" is pointless -- it
doesn't convey any extra information.

-- 
Greg


From tjreedy at udel.edu  Wed Jan 28 02:21:39 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Wed, 28 Jan 2015 02:21:39 -0500
Subject: unicode question
In-Reply-To: <CAA3NwWquCX54YBh15Kd_ncOtpe49nJyF_wRqEeBL6nCY0Py7Pg@mail.gmail.com>
References: <CAA3NwWquCX54YBh15Kd_ncOtpe49nJyF_wRqEeBL6nCY0Py7Pg@mail.gmail.com>
Message-ID: <maa2m6$u45$1@ger.gmane.org>

On 1/27/2015 12:17 AM, Rehab Habeeb wrote:
> Hi there python staff
> does python support arabic language for texts ? and what to do if it
> support it?
> i wrote hello in Arabic using codeskulptor and the powershell just for
> testing and the same error appeared( a sytanx error in unicode)!!

I do not know how complete the support is, but this is copied from 
3.4.2, which uses tcl/tk 8.6.
 >>> t = "???????"
 >>> for c in t: print(c)  # Prints rightmost char above first
?
?
?
?
?
?
?

The following StackOverflow question and response indicate that there 
may b more issue, but it was asked before tcl/tk 8.6 was available, so 
the answer may be partially obsolete.


-- 
Terry Jan Reedy




From ben+python at benfinney.id.au  Wed Jan 28 02:48:24 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Wed, 28 Jan 2015 18:48:24 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <1422423466.366357.219840709.1CB2D6D1@webmail.messagingengine.com>
 <CABicbJKM9xZmT+L4b=WxqXUpT60yS3sZGS56VzKt_NrZNaXbrg@mail.gmail.com>
Message-ID: <85iofrjqgn.fsf@benfinney.id.au>

Devin Jeanpierre <jeanpierreda at gmail.com> writes:

> [?] as Ben Finney pointed out. (BTW I agree with literally every
> single thing he said in this thread, it's really amazing.)

Hmm, writing that doesn't annoy somebody is not worth writing [0].

It shouldn't annoy *everyone* though, so I'm glad to know you can agree
with me this time :-)


[0] often attributed to Kingley Amis, as ?If you can't annoy somebody,
there's little point in writing.? though I can't find the source for
that aphorism.

-- 
 \     ?Facts are stubborn things; and whatever may be our wishes, our |
  `\   inclinations, or the dictates of our passion, they cannot alter |
_o__)        the state of facts and evidence.? ?John Adams, 1770-12-04 |
Ben Finney



From steve+comp.lang.python at pearwood.info  Wed Jan 28 02:55:42 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 28 Jan 2015 18:55:42 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <a771f6f2-9aa3-44ca-9f87-88a984c7c27e@googlegroups.com>
 <MPG.2f3224d1997790e19896a7@nntp.aioe.org>
 <9a2cf6ca-2eb8-4a87-9e83-e87d90d5fe42@googlegroups.com>
 <MPG.2f322851e6cf90ad9896a8@nntp.aioe.org>
 <mailman.18189.1422397927.18130.python-list@python.org>
Message-ID: <54c89600$0$12902$c3e8da3$5496439d@news.astraweb.com>

Ben Finney wrote:

> * In the distant past of Python, some objects were not instances of any
> class; the terminology in the documentation and messages shows some
> confusing legacies from that ancient time.


I presume you are referring to the type/class distinction?

That is, in Python 1.5 (for example), the *instance* 23 was an instance of 
the *type* int but not of any class, as classes (created with the "class" 
keyword) were distinct from types.

If you mean something else, can you explain please?


-- 
Steve



From fetchinson at googlemail.com  Wed Jan 28 03:01:46 2015
From: fetchinson at googlemail.com (Fetchinson .)
Date: Wed, 28 Jan 2015 09:01:46 +0100
Subject: python on mobile mailing list
Message-ID: <CADjSo4Sw002qQ3Z8b++OkEXY7TFwTW9mPQWKXCGMEq6vdMzW9Q@mail.gmail.com>

Hi all, the mobile-sig mailing list is alive:

https://mail.python.org/pipermail/mobile-sig/2015-January/thread.html

If you are interested in python on smart phones that's the place to go!

Cheers,
Daniel


-- 
Psss, psss, put it down! - http://www.cafepress.com/putitdown


From marfig at gmail.com  Wed Jan 28 03:32:51 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Wed, 28 Jan 2015 09:32:51 +0100
Subject: Is there a more elegant way to spell this?
References: <mailman.18170.1422364524.18130.python-list@python.org>
 <54c8339f$0$13008$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3257584e3201d69896af@nntp.aioe.org>
 <mailman.18197.1422408555.18130.python-list@python.org>
Message-ID: <MPG.2f32bd1e986d67d99896b0@nntp.aioe.org>

In article <mailman.18197.1422408555.18130.python-list at python.org>, 
ben+python at benfinney.id.au says...
> 
> More accurately (and as acknowledged in that guide), a single underscore
> *is* a common name for a ?don't care? name, but is better avoided for
> that purpose because it's also commonly used for other purposes.
> 
> In other words: That guide is correct in its admonition, but that
> doesn't challenge what Steven said about common usage.

I was not trying to challenge his assertion. Only adding more 
information to it.


From steve+comp.lang.python at pearwood.info  Wed Jan 28 03:45:57 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 28 Jan 2015 19:45:57 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <mailman.18200.1422423469.18130.python-list@python.org>
Message-ID: <54c8a1c6$0$12906$c3e8da3$5496439d@news.astraweb.com>

random832 at fastmail.us wrote:

> On Tue, Jan 27, 2015, at 16:06, Mario Figueiredo wrote:
>> That error message has me start that thread arguing that the error is
>> misleading because the Sub object does have the __bases__ attribute.
>> It's the Sub instance object that does not have it.
> 
> What do you think "Sub object" means?

I think it means the Sub class, which is an object. And Python 3.3 agrees 
with me:

py> class Sub(object):
...     pass
... 
py> isinstance(Sub, object)
True

Sub is also an instance of type. And object is an instance of type, type is 
an instance of object, and type is a subclass of object. But object is not a 
subclass of type. However it is an instance of type. Are we confused yet?

There is a sense, taken from Java in particular, that "object" is synonymous 
for "instance". For example, Oracle's documentation for classes says:

"A class contains constructors that are invoked to create objects from the 
class blueprint."

http://docs.oracle.com/javase/tutorial/java/javaOO/constructors.html

But you won't find any Java documentation referring to the class itself as 
an object. Java has no metaclasses, classes are not instances of a 
metaclass, and so classes are never instances. Classes are classes, objects 
are instances of a class, and that is all there is to it.

But in Python, "object" and "instance" are more ambiguous, thanks to 
metaclasses. Instances of a metaclass are classes, hence classes are 
instances as well as classes:

py> isinstance(Sub, type)
True

Sub is an instance of the class "type". And because classes themselves are 
first-class (ha ha!) values, like ints, strings, lists etc., classes are 
objects.

All classes (in Python 3) are instances of a class (the metaclass), but not 
all instances are classes.

Obviously this is rather confusing, but fortunately metaclasses (other than 
type itself) are rare, so *most of the time* we can get away with Java-like 
terminology, and pretend that classes are distinct from instances rather 
than being just another kind of instance (of the metaclass).

But what we cannot do is pretend that "object" means instance, because all 
classes are objects. Alas, habits from other languages leak in, and the 
Javaesque terminology "Foo object" meaning an instance of Foo sometimes gets 
used, even though "Foo object" should refer to the object called Foo, namely 
the class object itself.

The unfortunate ambiguity is that sometimes "Foo object" gets used to mean 
Foo, and other times it gets used to me some instance of Foo. We say:

"the None object has no state"

and

"the function requires an int object as argument".



> Sub itself is not a Sub object,

Sub itself is not *a* Sub object, it is *the* Sub object, just as 42 is 
*the* object with type int and value forty-two.


> it is a type object. "instance" is
> implicit in the phrase "foo object".

Alas, classes *are* instances, of their metaclass, so "Sub object" could 
refer to an instance of Sub (using the Javaesque terminology) or Sub itself 
(using more Pythonistic terminology).



-- 
Steven



From steve+comp.lang.python at pearwood.info  Wed Jan 28 03:48:23 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 28 Jan 2015 19:48:23 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <1422423466.366357.219840709.1CB2D6D1@webmail.messagingengine.com>
 <CABicbJKM9xZmT+L4b=WxqXUpT60yS3sZGS56VzKt_NrZNaXbrg@mail.gmail.com>
 <mailman.18204.1422424871.18130.python-list@python.org>
Message-ID: <54c8a257$0$12906$c3e8da3$5496439d@news.astraweb.com>

random832 at fastmail.us wrote:

> On Wed, Jan 28, 2015, at 00:43, Devin Jeanpierre wrote:
>> On Tue, Jan 27, 2015 at 9:37 PM,  <random832 at fastmail.us> wrote:
>> > Sub itself is not a Sub object, it is a type object. "instance" is
>> > implicit in the phrase "foo object".
>> 
>> Yes. Unfortunately, it's still not really completely clear. "Sub
>> instance" would avoid this confusion for everyone.
> 
> It really is completely clear. Nobody is confused but you.

Ironically, your denial of a pretty clear case of ambiguity demonstrates 
that if anyone is confused, it is you.

In an earlier thread, Mario demonstrated an obvious example of confusing 
error message due to the object/instance ambiguity, where the error message 
states that Sub doesn't have a method when it actually does. It is an 
*instance of Sub*, not the Sub object itself, which lacks the method.


-- 
Steve



From steve+comp.lang.python at pearwood.info  Wed Jan 28 04:09:35 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 28 Jan 2015 20:09:35 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <ma96io$ovh$1@ger.gmane.org>
 <mailman.18192.1422401989.18130.python-list@python.org>
Message-ID: <54c8a752$0$11125$c3e8da3@news.astraweb.com>

Ben Finney wrote:

> Ned Batchelder <ned at nedbatchelder.com> writes:
> 
>> On 1/27/15 3:12 PM, Mario Figueiredo wrote:
>> > This is a follow up from a previous discussion in which it is argued
>> > that the following code produces the correct error message terminology,
>> > considering that in Python an object is also an instance.
>>
>> I don't know what the difference is between "object" and "instance".
>> An object is an instance of a class.  The two words are
>> interchangeable as far as I know.
> 
> Not in English grammar, IMO. To say ?foo is an instance? implies the
> sentence isn't finished; the term ?instance? only makes sense in the
> context of a relationship to some class. To say ?foo is an object?
> doesn't have that implication.

I'm sure that there is a grammatical term for this, but I don't know it. 
Regardless of the terminology though, "foo is an instance" is a complete 
sentence fragment:

"foo is an instance" (of some unspecified class)

is the same grammatical construct as:

"George is a soldier" (of some unspecified army)
"Pluto is a cartoon animal" (of some unspecified species)
"Bearhugger's Old Peculiar is a drink" (of some unspecified type)
"Herbie is a car" (of some unspecified make and model)

etc. In Java, the term "object" as a synonym for "instance" is unambiguous, 
because in Java all classes are subclasses of Object, and no classes are 
themselves instances of a class. But that's not the case with Python.


>> A common mistake is to believe that "OOP" is a well-defined term.
>> It's not it's a collection of ideas that are expressed slightly
>> differently in each language.
> 
> Right. The common meaning of ?object? shared by all OOP systems is
> surprisingly small.

Agreed. There really is no widespread agreement on what OOP means 
*precisely*. Wikipedia states:

"Attempts to find a consensus definition or theory behind objects have not 
proven very successful" and there is little agreement of the fundamental 
features of OOP:

http://en.wikipedia.org/wiki/Object-
oriented_programming#Fundamental_features_and_concepts


[...] 
> In Python, every class is an object. Every class has the full range of
> behaviour that we expect of objects. A class just has the additional
> feature that it can be instantiated.

We can also define an "is-a" relationship between classes and their 
instances:

[1, 2, "spam"] is-a list;

but not list is-a [1, 2, "spam"]


However, in Python that breaks down at the very bottom of the inheritance 
hierarchy, thanks to the circular relationship between type and object:

py> isinstance(type, object)
True
py> isinstance(object, type)
True

type is-a object
object is-a type



-- 
Steve



From steve+comp.lang.python at pearwood.info  Wed Jan 28 04:16:46 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 28 Jan 2015 20:16:46 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
 <mailman.18199.1422411685.18130.python-list@python.org>
Message-ID: <54c8a8fe$0$11125$c3e8da3@news.astraweb.com>

Ned Batchelder wrote:

> Do you have a reference that defines these terms?

*A* reference is not sufficient. It has to be a reference which all other 
references agree with.

I'll be kind, and lower the requirement to one where *the majority* of other 
references agree. The OP still won't find one :-)

Or perhaps that should be a sad face smiley :-( How much time we would all 
save if academics and language designers would only stick to a single 
consistent terminology across all languages.


-- 
Steven



From steve+comp.lang.python at pearwood.info  Wed Jan 28 04:17:33 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 28 Jan 2015 20:17:33 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <ma96io$ovh$1@ger.gmane.org>
 <mailman.18192.1422401989.18130.python-list@python.org>
 <MPG.2f324a8a8df0eba19896aa@nntp.aioe.org>
Message-ID: <54c8a92d$0$11125$c3e8da3@news.astraweb.com>

Mario Figueiredo wrote:

> In other words, the object know as "Sub class" is not an instance
> object. True, it is an instance of the object 'type'.


Can you not see the contradiction there?

The object known as 42 is not an instance object. True, it is an instance of 
the object "int".

Er, then surely that means that 42 *is* an instance object?

I agree that in *common situations*, it is useful to pretend that Python is 
like Java, and draw a distinction between classes and instances. I don't 
think it is useful to deny that classes are instances.

The discussion depends on context, in the same way that depending on context 
sometimes it is useful to include Homo sapiens in the group "Animals" and 
sometimes not:

"Sit up straight and stop eating like an animal!"

"Like all animals, human beings rely on the environment for their survival."


-- 
Steve



From steve+comp.lang.python at pearwood.info  Wed Jan 28 04:21:08 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 28 Jan 2015 20:21:08 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <ma96io$ovh$1@ger.gmane.org>
 <mailman.18192.1422401989.18130.python-list@python.org>
 <MPG.2f324a8a8df0eba19896aa@nntp.aioe.org> <ma9pkr$8ds$2@dont-email.me>
 <mailman.18202.1422423889.18130.python-list@python.org>
Message-ID: <54c8aa04$0$11125$c3e8da3@news.astraweb.com>

random832 at fastmail.us wrote:

> I think his objection is to the use of the phrase "'Sub' object" to
> refer only to instances of the Sub type, when 'Sub' is the name of the
> type object itself and therefore (he thinks) "'Sub' object" should refer
> to it instead. (I can only assume he wants "'x' object" for x = Sub().)


Yes, that's exactly what Mario asked for in the original thread that started 
this. Sadly Python cannot do this.

But the docs could consistently use "class" or "type" to refer to classes 
and types (in Python 3, they are the same thing), and "instance" to refer to 
instances which are not classes, and "object" to refer to both.

And then I would be sooooooo happyyyyyy :-)


-- 
Steve



From steve+comp.lang.python at pearwood.info  Wed Jan 28 04:28:14 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 28 Jan 2015 20:28:14 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
Message-ID: <54c8abaf$0$11125$c3e8da3@news.astraweb.com>

Mario Figueiredo wrote:

> In article <mailman.18191.1422400930.18130.python-list at python.org>,
> ned at nedbatchelder.com says...
>> 
>> A common mistake is to believe that "OOP" is a well-defined term.  It's
>> not it's a collection of ideas that are expressed slightly differently
>> in each language.
> 
> A common mistake is thinking just because OOP has different
> implementations, it doesn't have a cohesive set of well described rules
> and its own well defined terminology.

Alas, this is not a mistake. As I posted in a reply to Ben, OOP does not 
have a cohesive set of rules and well-defined terminology.


>> I don't know what a "not fully realized object" is.
> 
> A fully realized object, in an object oriented paradigm, is an object
> containing or pointing to data and the methods to act on that data. It's
> an instance of a class.

In Python, classes meet that definition too. A class in Python is a value 
which can contain data (or point to data), and it has methods which act on 
that data. Classes in Python themselves have a class, which we call the 
metaclass, and classes inherit behaviour from their class just as integer 
instances inherit behaviour from their class, int.


> A *not* fully realized object is possible in Python, since Classes are
> first-class objects, despite not being able to participate in OOP.
> 
>> 
>> What does "participate in OOP" mean?
> 
> Means the object is capable of participating in inheritance and/or
> polymorphism. An instance of an object is capable of doing so, per its
> class definitions. Whereas a Python class object is not.

Class objects are capable of participating in inheritance. A class can have 
multiple metaclasses. They can even have multiple inheritance of 
metaclasses.

I'm not sure what relevance polymorphism has.



-- 
Steven



From wxjmfauth at gmail.com  Wed Jan 28 04:58:28 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Wed, 28 Jan 2015 01:58:28 -0800 (PST)
Subject: unicode question
In-Reply-To: <mailman.18207.1422429712.18130.python-list@python.org>
References: <CAA3NwWquCX54YBh15Kd_ncOtpe49nJyF_wRqEeBL6nCY0Py7Pg@mail.gmail.com>
 <mailman.18207.1422429712.18130.python-list@python.org>
Message-ID: <2aabb47c-f222-4d67-99e1-450f2afefaa6@googlegroups.com>

One way is to work with Py32 and a dedicated Qt widget.
Arabic, Farsi (Persian), Urdu, ... scripts are far beyond
my knowledge. In my "unicode plain text" editor, I have no
problem to blindly cut/copy/past works coming for a TeX unicode
engine or entering these chars from the keyboard.
Now it is no more working properly when it works!

For a serious work and from what I know on that
precise field, c# is very valuable solution.
On the Apple side, zero experience.

jmf

PS The latest tcl (or Py implementation) is broken
on the side of Latin chars!


From rosuav at gmail.com  Wed Jan 28 05:01:06 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 28 Jan 2015 21:01:06 +1100
Subject: An object is an instance (or not)?
In-Reply-To: <54c8a8fe$0$11125$c3e8da3@news.astraweb.com>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
 <mailman.18199.1422411685.18130.python-list@python.org>
 <54c8a8fe$0$11125$c3e8da3@news.astraweb.com>
Message-ID: <CAPTjJmrPXXptRLTv36c=3iXh0-nPWzj4Wk9yhmzQ=93MFmxo7A@mail.gmail.com>

On Wed, Jan 28, 2015 at 8:16 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Or perhaps that should be a sad face smiley :-( How much time we would all
> save if academics and language designers would only stick to a single
> consistent terminology across all languages.

That's like wishing that every human spoke the same language, instead
of having English, French, Italian, Polish, Serbian, Korean, and a
host of others. The problem isn't the languages; the variety of
languages reflects a variety of concepts being communicated, and to
unify the languages spoken would entail dispensing with that variety.

The terminology isn't consistent because there are myriad variations
between the concepts. Is it useful to talk about "multiple
inheritance" as a concept? I believe I've yet to meet two distinct
languages that have identical MI semantics. Does each language need
its own word for that term so we don't have any sort of
inconsistencies? Or do all languages have to implement the exact same
functionality?

ChrisA


From al.basili at gmail.com  Wed Jan 28 05:12:02 2015
From: al.basili at gmail.com (alb)
Date: 28 Jan 2015 10:12:02 GMT
Subject: parsing tree from excel sheet
Message-ID: <cirqviF15qtU1@mid.individual.net>

Hi everyone,

I've a document structure which is extremely simple and represented on a 
spreadsheet in the following way (a made up example):

subsystem | chapter | section | subsection | subsubsec |
    A     |         |         |            |           |
          | func0   |         |            |           |
          |         |interface|            |           |
          |         |latency  |            |           |
          |         |priority |            |           |
          | func1   |         |            |           |
          |         |interface|            |           |
          |         |latency  |            |           |
          |         |priority |            |           |
          |         |depend   |            |           |
          |         |         | variables  |           |
          |         |         |            | static    |
          |         |         |            | global    |
          |         |         | functions  |           |
          |         |         |            | internal  |
          |         |         |            | external  |

And I'd like to get a tree like this:

    A
    +-------> func0
    |           +---> interface
    |           +---> latency
    |           \---> priority
    \-------> func1
                +---> interface
                +---> latency
                +---> priority
                \---> depend
                         +---> variables
                         |         +---> static
                         |         \---> local
                         \---> functions
                                   +---> internal
                                   \---> external

I know about the xlrd module to get data from excel and I'm also aware 
about the ETE toolkit (which is more specific for bioinformatics, but I 
guess can suitable fill the need).

Does anyone recommend any other path other than scripting through these 
two modules?

Is there any more suitable module/example/project out there that would 
achieve the same result?

The reason for parsing is because the need behind is to create documents 
edited in excel but typeset in LaTeX, therefore my script will spill out 
\chapter, \section and so forth based on the tree structure.

Every node will have some text and some images with a very light markup 
like mediawiki that I can easily convert into latex.

Hope I've not been too confusing.
Thanks for any pointer/suggestion/comment.

Al

p.s.: I'm not extremely proficient in python, actually I'm just starting 
with it!

-- 
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?


From greg.ewing at canterbury.ac.nz  Wed Jan 28 05:33:26 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Wed, 28 Jan 2015 23:33:26 +1300
Subject: An object is an instance (or not)?
In-Reply-To: <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
Message-ID: <cirs7pF1tdrU1@mid.individual.net>

Mario Figueiredo wrote:
> An instance of an object is capable of doing so, per its 
> class definitions. Whereas a Python class object is not.
> 
>     >>> class Master:
>             def func(self):
>                 pass
> 
>     >>> class Sub(Master):
>             pass
> 
>     >>> Sub.func()
>     TypeError: func() missing 1 required positional argument: 'self'

But Sub is not an *instance* of Master here, it's
a *subclass* of Master, which is quite a different
thing:

 >>> Sub.__class__
<class 'type'>

To make Sub be an *instance* of Master, you need to
do this. (NOTE: This is Python 3 syntax; the same
thing can be done in Python 2, but the syntax is
slightly different.)

 >>> class Master(type):
...  def func(self):
...   print("func of", self, "called")
...
 >>> class Sub(metaclass = Master):
...  pass
...
 >>> Sub.__class__
<class '__main__.Master'>
 >>> Sub.func()
func of <class '__main__.Sub'> called

So, you see, Python classes *can* participate in OOP
just as fully as any other object. You just need to
know how to do it correctly.

-- 
Greg


From greg.ewing at canterbury.ac.nz  Wed Jan 28 05:33:43 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Wed, 28 Jan 2015 23:33:43 +1300
Subject: An object is an instance (or not)?
In-Reply-To: <MPG.2f324d0d46ba9afc9896ac@nntp.aioe.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
 <mailman.18195.1422405040.18130.python-list@python.org>
 <MPG.2f324d0d46ba9afc9896ac@nntp.aioe.org>
Message-ID: <cirs87F1tdrU2@mid.individual.net>

Mario Figueiredo wrote:
> I couldn't think of a way to 
> demonstrate that a class object does not participate in its own 
> inheritance rules. Only instances of it can.

I think I may see where your reasoning is going astray.
You think that an instance "inherits" methods from its
class in the same way that a subclass inherits methods
from its base class.

But thinking of the instance-class relationship as
an inheritance relationship is misleading. It's more
accurate to say that a class *defines* the methods
that its instances have. The class inherits methods
from its base class, but those methods still apply to
instances of the class, not the class itself.

That doesn't mean the class itself can't be given
methods, though. The methods of the class are defined
by its metaclass, and the metaclass inherits methods
from *its* base class, etc.

Here's a diagram:

+------+                  +------------+
| type |                  | base class |
+------+                  +------------+
    ^                           ^
    | subclass of               | subclass of
    |                           |
+-----------+              +-------+              +----------+
| metaclass |<-------------| class |<-------------| instance |
+-----------+  instance of +-------+  instance of +----------+

It should be clear from this that the relationship
between an instance and its class is exactly the same
as that between a class and its metaclass, including
inheritance relationships.

The diagram can be extended indefinitely far to the
left -- the metaclass could be an instance of a
meta-metaclass, etc. (Although there's an old standing
joke in the Python world that metaclasses make your
head explode, so I hate to think what a meta-metaclass
would do -- probably take out a whole floor of the
office building you work in. Meta-meta-metaclasses are
right out.)

-- 
Greg


From marfig at gmail.com  Wed Jan 28 05:48:28 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Wed, 28 Jan 2015 11:48:28 +0100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <a771f6f2-9aa3-44ca-9f87-88a984c7c27e@googlegroups.com>
 <MPG.2f3224d1997790e19896a7@nntp.aioe.org>
 <9a2cf6ca-2eb8-4a87-9e83-e87d90d5fe42@googlegroups.com>
 <MPG.2f322851e6cf90ad9896a8@nntp.aioe.org>
 <mailman.18190.1422400358.18130.python-list@python.org>
 <MPG.2f32513a4d0addbf9896ad@nntp.aioe.org>
 <mailman.18203.1422424695.18130.python-list@python.org>
Message-ID: <MPG.2f32dcd13b4e4a519896b1@nntp.aioe.org>

In article <mailman.18203.1422424695.18130.python-list at python.org>, 
breamoreboy at yahoo.co.uk says...
> 
> The thing that bothers me is that many people, some of them with maybe 
> 20 years of Python experience, have repeatedly stated Python concepts 
> with respect to the terms class, instance and object.  Instead of 
> accepting their knowledge of the language and gracefully stepping back, 
> you've carried on until the twist of knots would make any boy scout proud.

Condescending much?

I'm not one to lower to arguments from authority. Sorry. Never have, 
never will. Neither I adopt such attitude on those programming languages 
in which I am myself an authoritative source. I respect knowledge as 
anyone else. But I also specifically asked for arguments that could show 
me the Python way. I have a desire to understand. It's not just a matter 
of accepting the word of someone who is more experienced than me. That 
does not do any good to anyone. I'm not trying to change anything, 
neither I'm a OOP fanatic like some tried to accuse me. I'm just trying 
to understand. Do *you* understand that?

I may have sounded ignorant to you. It's something I cannot avoid, 
because while I try to argue this issue, I do it from the position of 
someone who is still learning the Python language syntax and semantics. 
But I'm much more than what you may think. And I would like to be 
treated with a little more respect. Like you I'm a software developer 
and, probably like you, I have decades of software development as a 
profession on my back.

But some of the arguments in here (and yours too) have done very little 
to help me understand the language semantics on this particular issue. 
Purportedly, or perhaps innocently due to my clumsiness, some folks in 
here argue with little more than "but a class object is an instance of 
'type'". They choose to ignore that class objects are clearly a special 
type of object unlike the instances they help define. Like in so many 
debates, there's unfortunately always a desire to ignore or avoid other 
side that is arguing with us.

Thankfully, I am now starting to understand the semantics. Folks like 
Ben, Steven or Ian (apologies to a couple others I am missing. Can't 
remember your names and having an hard time looking through past posts) 
have helped tremendously by leaving smugness aside, adopting an 
educational attitude towards a clearly confused person, and -- I would 
wager -- understanding that I'm asking questions, not trying to set new 
ways.

Don't feel so bothered by my person, sir. Just ignore me if that makes 
you feel better.


From David.Aldrich at EMEA.NEC.COM  Wed Jan 28 06:10:54 2015
From: David.Aldrich at EMEA.NEC.COM (David Aldrich)
Date: Wed, 28 Jan 2015 11:10:54 +0000
Subject: Beginner question - class definition error
Message-ID: <41302A7145AC054FA7A96CFD03835A0A0B918B97@EX10MBX02.EU.NEC.COM>

Hi

I am just getting started with Python 3.3.3 and Kivy 1.8.

I am using the Kivy  development environment on Windows (open a command prompt and call kivy.bat).

With this minimal code:

import kivy
kivy.require('1.8.0')

from kivy.app import App
from kivy.uix.label import Label

class MyApp(App):
  def build(self):
    return Label(text='Hello World')

  if __name__ == '__main__':
    MyApp().run()

I get this error when I run it:

C:\>python MinimalApplication.py
[INFO              ] Kivy v1.8.0
[INFO              ] [Logger      ] Record log in <snip>
[INFO              ] [Factory     ] 157 symbols loaded
[DEBUG          ] [Cache       ] register <kv.lang> with limit=None, timeout=Nones
[DEBUG          ] [Cache       ] register <kv.image> with limit=None, timeout=60s
[DEBUG          ] [Cache       ] register <kv.atlas> with limit=None, timeout=Nones
[INFO              ] [Image       ] Providers: img_tex, img_dds, img_pygame, img_gif (img_pil ignored)
[DEBUG          ] [Cache       ] register <kv.texture> with limit=1000, timeout=60s
[DEBUG          ] [Cache       ] register <kv.shader> with limit=1000, timeout=3600s
[INFO              ] [Text        ] Provider: pygame
 Traceback (most recent call last):
   File "MinimalApplication.py", line 7, in <module>
     class MyApp(App):
   File "MinimalApplication.py", line 12, in MyApp
     MyApp().run()
 NameError: name 'MyApp' is not defined

How can I fix this please?

Best regards

David



From ben+python at benfinney.id.au  Wed Jan 28 06:20:36 2015
From: ben+python at benfinney.id.au (Ben Finney)
Date: Wed, 28 Jan 2015 22:20:36 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <a771f6f2-9aa3-44ca-9f87-88a984c7c27e@googlegroups.com>
 <MPG.2f3224d1997790e19896a7@nntp.aioe.org>
 <9a2cf6ca-2eb8-4a87-9e83-e87d90d5fe42@googlegroups.com>
 <MPG.2f322851e6cf90ad9896a8@nntp.aioe.org>
 <mailman.18189.1422397927.18130.python-list@python.org>
 <54c89600$0$12902$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <85egqfjgmz.fsf@benfinney.id.au>

Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:

> Ben Finney wrote:
>
> > * In the distant past of Python, some objects were not instances of any
> > class; the terminology in the documentation and messages shows some
> > confusing legacies from that ancient time.
>
>
> I presume you are referring to the type/class distinction?
>
> That is, in Python 1.5 (for example), the *instance* 23 was an
> instance of the *type* int but not of any class, as classes (created
> with the "class" keyword) were distinct from types.

That's what I was referring to, yes.

All ancient history now. In all current versions of Python, every type
is a class and every class is a type, and every type is an object and
every class is an object, and every object is an instance of a class and
is an instance of a type (and you are me and all are we together).

-- 
 \          ?I like to reminisce with people I don't know. Granted, it |
  `\                                     takes longer.? ?Steven Wright |
_o__)                                                                  |
Ben Finney



From steve+comp.lang.python at pearwood.info  Wed Jan 28 06:52:46 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Wed, 28 Jan 2015 22:52:46 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
 <mailman.18195.1422405040.18130.python-list@python.org>
 <MPG.2f324d0d46ba9afc9896ac@nntp.aioe.org> <cirs87F1tdrU2@mid.individual.net>
Message-ID: <54c8cd8f$0$12975$c3e8da3$5496439d@news.astraweb.com>

Gregory Ewing wrote:

> Mario Figueiredo wrote:
>> I couldn't think of a way to
>> demonstrate that a class object does not participate in its own
>> inheritance rules. Only instances of it can.
> 
> I think I may see where your reasoning is going astray.
> You think that an instance "inherits" methods from its
> class in the same way that a subclass inherits methods
> from its base class.

In fairness, "inherit" is standard terminology for the way instances get
their behaviour from their class.

Also, you can override methods *on the instance*:


py> class Parrot(object):
...     def talk(self):
...             print("Polly wants a cracker!")
...
py> polly = Parrot()
py> polly.talk()
Polly wants a cracker!
py> from types import MethodType
py> polly.talk = MethodType(
...     lambda self: print("Polly wants a spam sandwich!"), polly)
py> polly.talk()
Polly wants a spam sandwich!



> But thinking of the instance-class relationship as
> an inheritance relationship is misleading. It's more
> accurate to say that a class *defines* the methods
> that its instances have. The class inherits methods
> from its base class, but those methods still apply to
> instances of the class, not the class itself.

I won't speak for other OOP models, but I don't think that is true in
Python. In Python, obj.talk performs the following (grossly simplified)
process:

* search the instance for an attribute "talk"
* search the class
* search all the base classes
* fail

(simplified because I have ignored the roles of __getattr__ and
__getattribute__, of metaclasses, and the descriptor protocol)


That's more or less the same as what happens whether obj is a class object
or a non-class object. I don't know what attribute lookup *literally* uses
the exact same code for looking up attributes on an instance or a class,
but it wouldn't surprise me if it does.


> That doesn't mean the class itself can't be given
> methods, though. The methods of the class are defined
> by its metaclass, and the metaclass inherits methods
> from *its* base class, etc.


The normal way of giving a class methods that are callable from the class is
to define them on the class with the classmethod or staticmethod
decorators. Using a metaclass is usually overkill :-)



> Here's a diagram:
> 
> +------+                  +------------+
> | type |                  | base class |
> +------+                  +------------+
>     ^                           ^
>     | subclass of               | subclass of
>     |                           |
> +-----------+              +-------+              +----------+
> | metaclass |<-------------| class |<-------------| instance |
> +-----------+  instance of +-------+  instance of +----------+
> 
> It should be clear from this that the relationship
> between an instance and its class is exactly the same
> as that between a class and its metaclass, including
> inheritance relationships.
> 
> The diagram can be extended indefinitely far to the
> left -- the metaclass could be an instance of a
> meta-metaclass, etc. (Although there's an old standing
> joke in the Python world that metaclasses make your
> head explode, so I hate to think what a meta-metaclass
> would do -- probably take out a whole floor of the
> office building you work in. Meta-meta-metaclasses are
> right out.)

An early essay on Python metaclasses was subtitled "The Killer-Joke". 




-- 
Steven



From python at mrabarnett.plus.com  Wed Jan 28 07:13:50 2015
From: python at mrabarnett.plus.com (MRAB)
Date: Wed, 28 Jan 2015 12:13:50 +0000
Subject: Beginner question - class definition error
In-Reply-To: <41302A7145AC054FA7A96CFD03835A0A0B918B97@EX10MBX02.EU.NEC.COM>
References: <41302A7145AC054FA7A96CFD03835A0A0B918B97@EX10MBX02.EU.NEC.COM>
Message-ID: <54C8D27E.2080907@mrabarnett.plus.com>

On 2015-01-28 11:10, David Aldrich wrote:
> Hi
>
> I am just getting started with Python 3.3.3 and Kivy 1.8.
>
> I am using the Kivy  development environment on Windows (open a command prompt and call kivy.bat).
>
> With this minimal code:
>
> import kivy
> kivy.require('1.8.0')
>
> from kivy.app import App
> from kivy.uix.label import Label
>
> class MyApp(App):
>    def build(self):
>      return Label(text='Hello World')
>
>    if __name__ == '__main__':
>      MyApp().run()
>
> I get this error when I run it:
>
> C:\>python MinimalApplication.py
> [INFO              ] Kivy v1.8.0
> [INFO              ] [Logger      ] Record log in <snip>
> [INFO              ] [Factory     ] 157 symbols loaded
> [DEBUG          ] [Cache       ] register <kv.lang> with limit=None, timeout=Nones
> [DEBUG          ] [Cache       ] register <kv.image> with limit=None, timeout=60s
> [DEBUG          ] [Cache       ] register <kv.atlas> with limit=None, timeout=Nones
> [INFO              ] [Image       ] Providers: img_tex, img_dds, img_pygame, img_gif (img_pil ignored)
> [DEBUG          ] [Cache       ] register <kv.texture> with limit=1000, timeout=60s
> [DEBUG          ] [Cache       ] register <kv.shader> with limit=1000, timeout=3600s
> [INFO              ] [Text        ] Provider: pygame
>   Traceback (most recent call last):
>     File "MinimalApplication.py", line 7, in <module>
>       class MyApp(App):
>     File "MinimalApplication.py", line 12, in MyApp
>       MyApp().run()
>   NameError: name 'MyApp' is not defined
>
> How can I fix this please?
>
Unindent the 'if' statement. Currently, it's indented inside the class
definition, so MyApp isn't defined yet.



From David.Aldrich at EMEA.NEC.COM  Wed Jan 28 07:43:30 2015
From: David.Aldrich at EMEA.NEC.COM (David Aldrich)
Date: Wed, 28 Jan 2015 12:43:30 +0000
Subject: Beginner question - class definition error
In-Reply-To: <54C8D27E.2080907@mrabarnett.plus.com>
References: <41302A7145AC054FA7A96CFD03835A0A0B918B97@EX10MBX02.EU.NEC.COM>
 <54C8D27E.2080907@mrabarnett.plus.com>
Message-ID: <41302A7145AC054FA7A96CFD03835A0A0B918C3C@EX10MBX02.EU.NEC.COM>

> Unindent the 'if' statement. Currently, it's indented inside the class
> definition, so MyApp isn't defined yet.

Thanks very much. That fixed it.

Best regards

David


From andres.riancho at gmail.com  Wed Jan 28 08:07:44 2015
From: andres.riancho at gmail.com (Andres Riancho)
Date: Wed, 28 Jan 2015 10:07:44 -0300
Subject: multiprocessing module backport from 3 to 2.7 - spawn feature
Message-ID: <CA+1Rt66fb5zFwKiBG=tkHzURfiYFX_xKo=XxUKvWO4CdySX0_Q@mail.gmail.com>

List,

I've been searching around for a multiprocessing module backport from
3 to 2.7.x and the closest thing I've found was celery's billiard [0]
which seems to be a work in progress.

The feature I'm specially interested in is the ability to spawn
processes [1] instead of forking, which is not present in the 2.7
version of the module.

Anyone knows about a working backport of the multiprocessing 3k module?

[0] https://github.com/celery/billiard
[1] https://docs.python.org/3.4/library/multiprocessing.html#multiprocessing.set_start_method

Regards,
-- 
Andr?s Riancho
Project Leader at w3af - http://w3af.org/
Web Application Attack and Audit Framework
Twitter: @w3af
GPG: 0x93C344F3


From lucaberto at libero.it  Wed Jan 28 08:22:18 2015
From: lucaberto at libero.it (luca72)
Date: Wed, 28 Jan 2015 05:22:18 -0800 (PST)
Subject: write file to a server
Message-ID: <6b5943a2-ab9d-4949-bfbe-7671740bb9fb@googlegroups.com>

Hello i'm under windows, i have to write a file from my computer to a local server like taht "\\DOCUMENTALE\my_folder\".
How i have to proceed ?

Thanks 


From ginobusciarello at outlook.com  Wed Jan 28 08:38:20 2015
From: ginobusciarello at outlook.com (Dieffe)
Date: Wed, 28 Jan 2015 05:38:20 -0800 (PST)
Subject: -- redacted --
Message-ID: <9ea713a4-3e21-4522-b751-5d896c5ea31e@googlegroups.com>

-- redacted --


From python at mrabarnett.plus.com  Wed Jan 28 08:38:27 2015
From: python at mrabarnett.plus.com (MRAB)
Date: Wed, 28 Jan 2015 13:38:27 +0000
Subject: write file to a server
In-Reply-To: <6b5943a2-ab9d-4949-bfbe-7671740bb9fb@googlegroups.com>
References: <6b5943a2-ab9d-4949-bfbe-7671740bb9fb@googlegroups.com>
Message-ID: <54C8E653.3070908@mrabarnett.plus.com>

On 2015-01-28 13:22, luca72 wrote:
> Hello i'm under windows, i have to write a file from my computer to a
> local server like taht "\\DOCUMENTALE\my_folder\".
> How i have to proceed ?
>
That's a path to a folder that just happens to be on another computer on 
your network. Treat it the same way you would for a 'local' folder,
eg "C:\my_folder".



From ginobusciarello at outlook.com  Wed Jan 28 08:38:53 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Wed, 28 Jan 2015 05:38:53 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <35861325-94c1-418c-ab89-e4ea967431da@googlegroups.com>
References: <35861325-94c1-418c-ab89-e4ea967431da@googlegroups.com>
Message-ID: <a841a48c-a26f-4ebe-a0fd-6f5e00af491a@googlegroups.com>

-- redacted --


From ginobusciarello at outlook.com  Wed Jan 28 08:39:18 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Wed, 28 Jan 2015 05:39:18 -0800 (PST)
Subject: -- redacted --
Message-ID: <642cec20-f6d1-4443-af37-150b51eaa3c2@googlegroups.com>

-- redacted --


From ginobusciarello at outlook.com  Wed Jan 28 08:39:43 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Wed, 28 Jan 2015 05:39:43 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
References: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
Message-ID: <648d2578-50ff-4322-a141-3a03ae0f8a67@googlegroups.com>

-- redacted --


From cousinstanley at gmail.com  Wed Jan 28 08:59:49 2015
From: cousinstanley at gmail.com (Cousin Stanley)
Date: Wed, 28 Jan 2015 06:59:49 -0700
Subject: Beginner question - class definition error
References: <mailman.18213.1422446683.18130.python-list@python.org>
Message-ID: <maapvn$ilb$1@dont-email.me>


> from kivy.app import App
> from kivy.uix.label import Label
> 
> class MyApp(App):
>   def build(self):
>     return Label(text='Hello World')
> 
>   if __name__ == '__main__':
>     MyApp().run()
>
> ....
>
> I get this error when I run it:
> ....
>
> Traceback (most recent call last):
>   File "MinimalApplication.py", line 7, in <module>
>     class MyApp(App):
>   File "MinimalApplication.py", line 12, in MyApp
>     MyApp().run()
> NameError: name 'MyApp' is not defined
>
> How can I fix this please?
 
  Try removing beginning indentation 
  from ....

    if __name__ == '__main__': 
  
if __name__ == '__main__':


-- 
Stanley C. Kitching
Human Being
Phoenix, Arizona


From jesseporeddu at aim.com  Wed Jan 28 09:00:41 2015
From: jesseporeddu at aim.com (VOGLIAMO RENZUSCONI IN GALERA!)
Date: Wed, 28 Jan 2015 06:00:41 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <35861325-94c1-418c-ab89-e4ea967431da@googlegroups.com>
References: <35861325-94c1-418c-ab89-e4ea967431da@googlegroups.com>
Message-ID: <16c1abb5-4fee-46e9-81ef-161191428c76@googlegroups.com>

-- redacted --


From __peter__ at web.de  Wed Jan 28 09:08:00 2015
From: __peter__ at web.de (Peter Otten)
Date: Wed, 28 Jan 2015 15:08 +0100
Subject: parsing tree from excel sheet
References: <cirqviF15qtU1@mid.individual.net>
Message-ID: <maaqg1$hk9$1@ger.gmane.org>

alb wrote:

> Hi everyone,
> 
> I've a document structure which is extremely simple and represented on a
> spreadsheet in the following way (a made up example):
> 
> subsystem | chapter | section | subsection | subsubsec |
>     A     |         |         |            |           |
>           | func0   |         |            |           |
>           |         |interface|            |           |
>           |         |latency  |            |           |
>           |         |priority |            |           |
>           | func1   |         |            |           |
>           |         |interface|            |           |
>           |         |latency  |            |           |
>           |         |priority |            |           |
>           |         |depend   |            |           |
>           |         |         | variables  |           |
>           |         |         |            | static    |
>           |         |         |            | global    |
>           |         |         | functions  |           |
>           |         |         |            | internal  |
>           |         |         |            | external  |
> 
> And I'd like to get a tree like this:
> 
>     A
>     +-------> func0
>     |           +---> interface
>     |           +---> latency
>     |           \---> priority
>     \-------> func1
>                 +---> interface
>                 +---> latency
>                 +---> priority
>                 \---> depend
>                          +---> variables
>                          |         +---> static
>                          |         \---> local
>                          \---> functions
>                                    +---> internal
>                                    \---> external
> 
> I know about the xlrd module to get data from excel and I'm also aware
> about the ETE toolkit (which is more specific for bioinformatics, but I
> guess can suitable fill the need).
> 
> Does anyone recommend any other path other than scripting through these
> two modules?
> 
> Is there any more suitable module/example/project out there that would
> achieve the same result?
> 
> The reason for parsing is because the need behind is to create documents
> edited in excel but typeset in LaTeX, therefore my script will spill out
> \chapter, \section and so forth based on the tree structure.
> 
> Every node will have some text and some images with a very light markup
> like mediawiki that I can easily convert into latex.
> 
> Hope I've not been too confusing.
> Thanks for any pointer/suggestion/comment.
> 
> Al
> 
> p.s.: I'm not extremely proficient in python, actually I'm just starting
> with it!

You can save the excel sheet as csv so that you an use the csv module which 
may be easier to use than xlrd. The rest should be doable by hand. Here's 
what I hacked together:

$ cat parse_column_tree.py
import csv

def column_index(row):
    for result, cell in enumerate(row, 0):
        if cell:
            return result
    raise ValueError


class Node:
    def __init__(self, name, level):
        self.name = name
        self.level = level
        self.children = []

    def append(self, child):
        self.children.append(child)

    def __str__(self):
        return "\%s{%s}" % (self.level, self.name)

    def show(self):
        yield [self.name]
        for i, child in enumerate(self.children):
            lastchild = i == len(self.children)-1
            first = True
            for c in child.show():
                if first:
                    yield ["\---> " if lastchild else "+---> "] + c
                    first = False
                else:
                    yield ["      " if lastchild else "|     "] + c
    def show2(self):
        yield str(self)
        for child in self.children:
            yield from child.show2()

def show(root):
    for row in root.show():
        print("".join(row))

def show2(root):
    for line in root.show2():
        print(line)

def read_tree(rows, levelnames):
    root = Node("#ROOT", "#ROOT")
    old_level = 0
    stack = [root]
    for i, row in enumerate(rows, 1):

        new_level = column_index(row)
        node = Node(row[new_level], levelnames[new_level])

        if new_level == old_level:
            stack[-1].append(node)
        elif new_level > old_level:
            if new_level - old_level != 1:
                raise ValueError

            stack.append(stack[-1].children[-1])
            stack[-1].append(node)
            old_level = new_level
        else:
            while new_level < old_level:
                stack.pop(-1)
                old_level -= 1
            stack[-1].append(node)
    return root

def main():
    import argparse
    parser = argparse.ArgumentParser()
    parser.add_argument("infile")
    parser.add_argument("--latex", action="store_true")

    args = parser.parse_args()

    with open(args.infile) as f:
        rows = csv.reader(f)
        levelnames = next(rows) # skip header
        tree = read_tree(rows, levelnames)

        show_tree = show2 if args.latex else show
        for node in tree.children:
            show_tree(node)
            print("")

if __name__ == "__main__":
    main()
$ cat data.csv
subsystem,chapter,section,subsection,subsubsec,
A,,,,,
,func0,,,,
,,interface,,,
,,latency,,,
,,priority,,,
,func1,,,,
,,interface,,,
,,latency,,,
,,priority,,,
,,depend,,,
,,,variables,,
,,,,static,
,,,,global,
,,,functions,,
,,,,internal,
,,,,external,
$ python3 parse_column_tree.py data.csv
A
+---> func0
|     +---> interface
|     +---> latency
|     \---> priority
\---> func1
      +---> interface
      +---> latency
      +---> priority
      \---> depend
            +---> variables
            |     +---> static
            |     \---> global
            \---> functions
                  +---> internal
                  \---> external

$ python3 parse_column_tree.py data.csv --latex
\subsystem{A}
\chapter{func0}
\section{interface}
\section{latency}
\section{priority}
\chapter{func1}
\section{interface}
\section{latency}
\section{priority}
\section{depend}
\subsection{variables}
\subsubsec{static}
\subsubsec{global}
\subsection{functions}
\subsubsec{internal}
\subsubsec{external}








From skip.montanaro at gmail.com  Wed Jan 28 09:10:42 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Wed, 28 Jan 2015 08:10:42 -0600
Subject: Python is DOOMED! Again!
In-Reply-To: <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CANc-5Uz+1X1r4cUYacV5Ck6i--u+s9rzeaX7-CGk+H4fKRbP9g@mail.gmail.com>

On Tue, Jan 27, 2015 at 7:26 PM, Steven D'Aprano <
steve+comp.lang.python at pearwood.info> wrote:

> (2) Algol, Ada, Boo, C, C#, C++, Cobol, Cobra, D, F#, Fantom, Fortran, Go,
> Haskell, Java, Julia, Kotlin, Oberon, Pascal, Rust, Scala and dozens
> (hundreds?) of other languages disagree with you.
>

Well, sure. But that's always been one of the nice things about Python,
less visual clutter. While I understand where all the type hinting activity
is coming from (and accept it as inevitable), I'm also sympathetic to
Mario's perspective.

Python-1.5-anyone?-ly, y'rs,

Skip
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From rosuav at gmail.com  Wed Jan 28 09:12:15 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 29 Jan 2015 01:12:15 +1100
Subject: write file to a server
In-Reply-To: <54C8E653.3070908@mrabarnett.plus.com>
References: <6b5943a2-ab9d-4949-bfbe-7671740bb9fb@googlegroups.com>
 <54C8E653.3070908@mrabarnett.plus.com>
Message-ID: <CAPTjJmqjgdymGsSZ-6ce14TwOD3UwMEMVepLjPFbhzNg4_wffg@mail.gmail.com>

On Thu, Jan 29, 2015 at 12:38 AM, MRAB <python at mrabarnett.plus.com> wrote:
> On 2015-01-28 13:22, luca72 wrote:
>>
>> Hello i'm under windows, i have to write a file from my computer to a
>> local server like taht "\\DOCUMENTALE\my_folder\".
>> How i have to proceed ?
>>
> That's a path to a folder that just happens to be on another computer on
> your network. Treat it the same way you would for a 'local' folder,
> eg "C:\my_folder".

And if you've done that and it isn't working, one likely cause is that
Windows uses backslashes in path names, but Python string literals
treat backslashes specially. Use a raw string literal:

path = r"\\DOCUMENTALE\my_folder\some_file_name"
with open(path, "wb") as f:
    ... write to file ...

If you have other problems, the best thing to do is to post your code
and the exact output it produces, especially if that's a traceback.
Those are incredibly helpful.

ChrisA


From python.list at tim.thechases.com  Wed Jan 28 09:13:46 2015
From: python.list at tim.thechases.com (Tim Chase)
Date: Wed, 28 Jan 2015 08:13:46 -0600
Subject: parsing tree from excel sheet
In-Reply-To: <cirqviF15qtU1@mid.individual.net>
References: <cirqviF15qtU1@mid.individual.net>
Message-ID: <20150128081346.01b45a48@bigbox.christie.dr>

On 2015-01-28 10:12, alb wrote:
> I've a document structure which is extremely simple and represented
> on a spreadsheet in the following way (a made up example):
> 
> subsystem | chapter | section | subsection | subsubsec |
>     A     |         |         |            |           |
>           | func0   |         |            |           |
>           |         |interface|            |           |
>           |         |latency  |            |           |
>           |         |priority |            |           |
>           | func1   |         |            |           |
>           |         |interface|            |           |
>           |         |latency  |            |           |
>           |         |priority |            |           |
> 
> And I'd like to get a tree like this:
> 
>     A
>     +-------> func0
>     |           +---> interface
>     |           +---> latency
>     |           \---> priority
>     \-------> func1
>                 +---> interface
>                 +---> latency
>                 +---> priority
> 
> I know about the xlrd module to get data from excel

If I have to get my code to read Excel files, xlrd is usually my
first and only stop.

> Does anyone recommend any other path other than scripting through
> these two modules?

Well, if you export from Excel as CSV, you can use the "csv" module
in the standard library.  This is actually my preferred route because
it prevents people (coughclientscough) from messing up the CSV file
with formatting, joined cells, and other weirdnesses that can choke
my utilities.

> Is there any more suitable module/example/project out there that
> would achieve the same result?

I don't believe there's anything that will natively do the work for
you.  Additionally, you'd have to clarify what should happen if two
rows in the same section had different sub-trees but the same
content/name.  Based on your use-case (LaTex export using these as
headers) I suspect you'd want a warning so you can repair the input
and re-run.  But it would be possible to default to either keeping or
squashing the duplicates.

> p.s.: I'm not extremely proficient in python, actually I'm just
> starting with it!

Well, you've come to the right place. Most of us are pretty fond of
Python here. :-)

-tkc






From al.basili at gmail.com  Wed Jan 28 09:27:38 2015
From: al.basili at gmail.com (alb)
Date: 28 Jan 2015 14:27:38 GMT
Subject: parsing tree from excel sheet
References: <cirqviF15qtU1@mid.individual.net>
 <mailman.18217.1422454096.18130.python-list@python.org>
Message-ID: <cis9uqF5ddpU1@mid.individual.net>

Hi Peter,

Peter Otten <__peter__ at web.de> wrote:
[]
> You can save the excel sheet as csv so that you an use the csv module which 
> may be easier to use than xlrd. The rest should be doable by hand. Here's 
> what I hacked together:
> 
> $ cat parse_column_tree.py
> import csv
> 
> def column_index(row):
>    for result, cell in enumerate(row, 0):
>        if cell:
>            return result
>    raise ValueError
> 
> 
> class Node:
>    def __init__(self, name, level):
>        self.name = name
>        self.level = level
>        self.children = []
> 
>    def append(self, child):
>        self.children.append(child)
> 
>    def __str__(self):
>        return "\%s{%s}" % (self.level, self.name)
> 
>    def show(self):
>        yield [self.name]
>        for i, child in enumerate(self.children):
>            lastchild = i == len(self.children)-1
>            first = True
>            for c in child.show():
>                if first:
>                    yield ["\---> " if lastchild else "+---> "] + c
>                    first = False
>                else:
>                    yield ["      " if lastchild else "|     "] + c
>    def show2(self):
>        yield str(self)
>        for child in self.children:
>            yield from child.show2()
> 
> def show(root):
>    for row in root.show():
>        print("".join(row))
> 
> def show2(root):
>    for line in root.show2():
>        print(line)
> 
> def read_tree(rows, levelnames):
>    root = Node("#ROOT", "#ROOT")
>    old_level = 0
>    stack = [root]
>    for i, row in enumerate(rows, 1):
> 
>        new_level = column_index(row)
>        node = Node(row[new_level], levelnames[new_level])
> 
>        if new_level == old_level:
>            stack[-1].append(node)
>        elif new_level > old_level:
>            if new_level - old_level != 1:
>                raise ValueError
> 
>            stack.append(stack[-1].children[-1])
>            stack[-1].append(node)
>            old_level = new_level
>        else:
>            while new_level < old_level:
>                stack.pop(-1)
>                old_level -= 1
>            stack[-1].append(node)
>    return root
> 
> def main():
>    import argparse
>    parser = argparse.ArgumentParser()
>    parser.add_argument("infile")
>    parser.add_argument("--latex", action="store_true")
> 
>    args = parser.parse_args()
> 
>    with open(args.infile) as f:
>        rows = csv.reader(f)
>        levelnames = next(rows) # skip header
>        tree = read_tree(rows, levelnames)
> 
>        show_tree = show2 if args.latex else show
>        for node in tree.children:
>            show_tree(node)
>            print("")
> 
> if __name__ == "__main__":
>    main()
> $ cat data.csv
> subsystem,chapter,section,subsection,subsubsec,
> A,,,,,
> ,func0,,,,
> ,,interface,,,
> ,,latency,,,
> ,,priority,,,
> ,func1,,,,
> ,,interface,,,
> ,,latency,,,
> ,,priority,,,
> ,,depend,,,
> ,,,variables,,
> ,,,,static,
> ,,,,global,
> ,,,functions,,
> ,,,,internal,
> ,,,,external,
> $ python3 parse_column_tree.py data.csv
> A
> +---> func0
> |     +---> interface
> |     +---> latency
> |     \---> priority
> \---> func1
>      +---> interface
>      +---> latency
>      +---> priority
>      \---> depend
>            +---> variables
>            |     +---> static
>            |     \---> global
>            \---> functions
>                  +---> internal
>                  \---> external
> 
> $ python3 parse_column_tree.py data.csv --latex
> \subsystem{A}
> \chapter{func0}
> \section{interface}
> \section{latency}
> \section{priority}
> \chapter{func1}
> \section{interface}
> \section{latency}
> \section{priority}
> \section{depend}
> \subsection{variables}
> \subsubsec{static}
> \subsubsec{global}
> \subsection{functions}
> \subsubsec{internal}
> \subsubsec{external}

WOW! I didn't really want someone else to write what I needed but thanks 
a lot! That's a lot of food to digest in a single byte, so I'll first 
play a bit with it (hopefully understanding what is doing) and then come 
back with comments.

I really appreciated your time and effort.

Al


From marfig at gmail.com  Wed Jan 28 10:04:18 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Wed, 28 Jan 2015 16:04:18 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>

In article <54c83ab4$0$12982$c3e8da3$5496439d at news.astraweb.com>, 
steve+comp.lang.python at pearwood.info says...
> 
> Mario Figueiredo wrote:
> 
> > Static analysis cannot and should not clutter executable code.
> 
> (1) It isn't clutter. The human reader uses that information as well as the
> compiler, interpreter, type-checker, IDE, text editor, correctness tester,
> etc.
> 
> (2) Algol, Ada, Boo, C, C#, C++, Cobol, Cobra, D, F#, Fantom, Fortran, Go,
> Haskell, Java, Julia, Kotlin, Oberon, Pascal, Rust, Scala and dozens
> (hundreds?) of other languages disagree with you.
> 

Sorry. Somehow I missed this post. Only realized now from the Skip 
answer.

This is simply not true!

For most of the strongly typed languages (e.g. static typed languages) 
in that list -- C, C++, C# and Scala, the ones I know best from that 
list -- require little to no annotations in the code (and certainly no 
new explicit function or class based syntax) in order for static 
analysers to perform their thing, except perhaps on the most exotic 
static analysers. 

Being a strongly typed language, there is no need for added information 
in the function signatures. From that list you can safely exclude all 
strongly-typed languages.

For dynamically typed languages, what I have seen being implemented on 
almost all cases is doc-like features for type annotation. Of the list 
you provide (few there are dynamically typed, btw) Julia is the one I 
know of. Julia implements a similar type annotation to type annotations 
in Python. In fact I see a lot of Julia in PEP 484. But with different 
objectives:

    function add(a::Int, b::Int)
        a + b
    end  

Here the :: annotation is meant to attribute a type in an otherwise 
dynamically typed language and that function signature is executed at 
runtime with all the implications of a statically typed signature.

Static analysis in Julia admitedly can only be performed if those 
annotations are present, and of the entire list you provide this is the 
only example language that more closely matches your argument. The 
others simply are not true.

But in any case, in Julia type annotations, contrary to Python, are 
evaluated at runtime. It then makes all sense for them to coexist with 
the language syntax.


From wxjmfauth at gmail.com  Wed Jan 28 10:40:25 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Wed, 28 Jan 2015 07:40:25 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
Message-ID: <bb056488-5ebb-485a-8ecb-77b7d3836806@googlegroups.com>

Le mercredi 28 janvier 2015 16:04:35 UTC+1, Mario Figueiredo a ?crit?:
> In article <54c83ab4$0$12982$c3e8da3$5496439d at news.astraweb.com>, 
> steve+comp.lang.python at pearwood.info says...
> > 
> > Mario Figueiredo wrote:
> > 
> > > Static analysis cannot and should not clutter executable code.
> > 
> > (1) It isn't clutter. The human reader uses that information as well as the
> > compiler, interpreter, type-checker, IDE, text editor, correctness tester,
> > etc.
> > 
> > (2) Algol, Ada, Boo, C, C#, C++, Cobol, Cobra, D, F#, Fantom, Fortran, Go,
> > Haskell, Java, Julia, Kotlin, Oberon, Pascal, Rust, Scala and dozens
> > (hundreds?) of other languages disagree with you.
> > 
> 
> Sorry. Somehow I missed this post. Only realized now from the Skip 
> answer.
> 
> This is simply not true!
> 
> For most of the strongly typed languages (e.g. static typed languages) 
> in that list -- C, C++, C# and Scala, the ones I know best from that 
> list -- require little to no annotations in the code (and certainly no 
> new explicit function or class based syntax) in order for static 
> analysers to perform their thing, except perhaps on the most exotic 
> static analysers. 
> 
> Being a strongly typed language, there is no need for added information 
> in the function signatures. From that list you can safely exclude all 
> strongly-typed languages.
> 
> For dynamically typed languages, what I have seen being implemented on 
> almost all cases is doc-like features for type annotation. Of the list 
> you provide (few there are dynamically typed, btw) Julia is the one I 
> know of. Julia implements a similar type annotation to type annotations 
> in Python. In fact I see a lot of Julia in PEP 484. But with different 
> objectives:
> 
>     function add(a::Int, b::Int)
>         a + b
>     end  
> 
> Here the :: annotation is meant to attribute a type in an otherwise 
> dynamically typed language and that function signature is executed at 
> runtime with all the implications of a statically typed signature.
> 
> Static analysis in Julia admitedly can only be performed if those 
> annotations are present, and of the entire list you provide this is the 
> only example language that more closely matches your argument. The 
> others simply are not true.
> 
> But in any case, in Julia type annotations, contrary to Python, are 
> evaluated at runtime. It then makes all sense for them to coexist with 
> the language syntax.

I toyed with Julia (0.3.0rc3) only to see what this language
has to offer on the side of Unicode. A very good
suprise.

Contrary to Python, it works.

jmf



From stephen.boulet at gmail.com  Wed Jan 28 10:50:12 2015
From: stephen.boulet at gmail.com (stephen.boulet at gmail.com)
Date: Wed, 28 Jan 2015 07:50:12 -0800 (PST)
Subject: Open file in default app and exit in Windows
Message-ID: <4d9b197a-5682-4218-8b7c-88abeb879fb4@googlegroups.com>

I am using the following to open a file in its default application in Windows 7:

from subprocess import call

filename = 'my file.csv'
call('"%s"' % filename, shell=True)

This still leaves a python process hanging around until the launched app is closed. Any idea how to get around?


From mail at timgolden.me.uk  Wed Jan 28 11:07:04 2015
From: mail at timgolden.me.uk (Tim Golden)
Date: Wed, 28 Jan 2015 16:07:04 +0000
Subject: Open file in default app and exit in Windows
In-Reply-To: <4d9b197a-5682-4218-8b7c-88abeb879fb4@googlegroups.com>
References: <4d9b197a-5682-4218-8b7c-88abeb879fb4@googlegroups.com>
Message-ID: <54C90928.6000509@timgolden.me.uk>

On 28/01/2015 15:50, stephen.boulet at gmail.com wrote:
> I am using the following to open a file in its default application in
> Windows 7:
> 
> from subprocess import call
> 
> filename = 'my file.csv' call('"%s"' % filename, shell=True)
> 
> This still leaves a python process hanging around until the launched
> app is closed. Any idea how to get around?
> 

This is somewhat clumsy. The built-in way is:

import os
os.startfile("my file.csv")

TJG


From python.list at tim.thechases.com  Wed Jan 28 11:11:12 2015
From: python.list at tim.thechases.com (Tim Chase)
Date: Wed, 28 Jan 2015 10:11:12 -0600
Subject: Open file in default app and exit in Windows
In-Reply-To: <4d9b197a-5682-4218-8b7c-88abeb879fb4@googlegroups.com>
References: <4d9b197a-5682-4218-8b7c-88abeb879fb4@googlegroups.com>
Message-ID: <20150128101112.688bbe1e@bigbox.christie.dr>

On 2015-01-28 07:50, stephen.boulet at gmail.com wrote:
> I am using the following to open a file in its default application
> in Windows 7:
> 
> from subprocess import call
> 
> filename = 'my file.csv'
> call('"%s"' % filename, shell=True)

You can try

  import os
  filename = 'my file.csv'
  os.startfile(filename)

which works on Windows systems.  For other platforms, you'd have to
manually spawn either "open" on Macs or "xdg-open" on Linux.  Not
sure if there's a similar application on the BSDs.

-tkc





From stephen.boulet at gmail.com  Wed Jan 28 11:14:26 2015
From: stephen.boulet at gmail.com (stephen.boulet at gmail.com)
Date: Wed, 28 Jan 2015 08:14:26 -0800 (PST)
Subject: Open file in default app and exit in Windows
In-Reply-To: <mailman.18221.1422461233.18130.python-list@python.org>
References: <4d9b197a-5682-4218-8b7c-88abeb879fb4@googlegroups.com>
 <mailman.18221.1422461233.18130.python-list@python.org>
Message-ID: <01314ca6-3669-47d8-bc8f-4071af287c06@googlegroups.com>

On Wednesday, January 28, 2015 at 10:07:25 AM UTC-6, Tim Golden wrote:
> On 28/01/2015 15:50, stephen... at gmail.com wrote wrote:
> > I am using the following to open a file in its default application in
> > Windows 7:
> > 
> > from subprocess import call
> > 
> > filename = 'my file.csv' call('"%s"' % filename, shell=True)
> > 
> > This still leaves a python process hanging around until the launched
> > app is closed. Any idea how to get around?
> > 
> 
> This is somewhat clumsy. The built-in way is:
> 
> import os
> os.startfile("my file.csv")
> 
> TJG

Thank you. That is what I was looking for.


From peter.neumaier at gmail.com  Wed Jan 28 11:36:45 2015
From: peter.neumaier at gmail.com (peter.neumaier at gmail.com)
Date: Wed, 28 Jan 2015 08:36:45 -0800 (PST)
Subject: SUBMIT "ACCEPT" button - Python - beautifulsoap
Message-ID: <2cf53399-6eee-44a7-bdb7-ecb3675c0fed@googlegroups.com>

I am totally new to Python and please accept my apologies upfront for potential newbie errors. I am trying to parse a 'simple' web page: http://flow.gassco.no/

When opening the page first time in my browser I need to confirm T&C with an accept button. After accepting T&C I would like to scrape some data from that follow up page. It appears that when opening in a browser directly http://flow.gassco.no/acceptDisclaimer I would get around that T&C.
But not when I open the URL via beautifulsoap

My parsing/scraping tool is implemented in bs, but I fail to parse the content as I am not getting around T&C. When printing "response.text" from BS, I get below code. How do I get around this form for accepting terms & conditions so that I can parse/scrape data from that page?

Here is what I am doing:

#!/usr/bin/env python 
import requests 
import bs4 
index_url='http://flow.gassco.no/acceptDisclaimer'

def get_video_page_urls(): 
response = requests.get(index_url) 
soup = bs4.BeautifulSoup(response.text) 
return soup 
print(get_video_page_urls()) 

++++

PRINTOUT from response.text:

   <form action="acceptDisclaimer" method="get">
     <input class="accept" type="submit" value="Accept"/>
     <input class="decline" name="decline" onclick="window.location ='http://www.gassco.no'" type="button" value="Decline"/>
     </form></div></div></div></div></div>

    <script type="text/javascript">
    var _gaq = _gaq || [];
    _gaq.push(['_setAccount', 'UA-30727768-1']);
    _gaq.push(['_trackPageview']);

    (function() {
        var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
        ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
        var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
    })();

</script>


From random832 at fastmail.us  Wed Jan 28 12:08:34 2015
From: random832 at fastmail.us (random832 at fastmail.us)
Date: Wed, 28 Jan 2015 12:08:34 -0500
Subject: An object is an instance (or not)?
In-Reply-To: <85r3ufjspl.fsf@benfinney.id.au>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <1422423466.366357.219840709.1CB2D6D1@webmail.messagingengine.com>
 <CABicbJKM9xZmT+L4b=WxqXUpT60yS3sZGS56VzKt_NrZNaXbrg@mail.gmail.com>
 <1422424868.372353.219845333.5C2DDFCF@webmail.messagingengine.com>
 <85r3ufjspl.fsf@benfinney.id.au>
Message-ID: <1422464914.320696.220077169.5FAC6DC7@webmail.messagingengine.com>

On Wed, Jan 28, 2015, at 01:59, Ben Finney wrote:
> You have no justification to claim that, and it's hostile and dismissive
> to claim it so assertively.

Sorry about that - I was tired and had just read through the whole
thread at once.

> I'll freely admit to finding ?'Foo' object? ambiguous. It can reasonably
> be interpreted to mean either ?a 'Foo' object? (? ?an object of class
> 'Foo'?), or ?the 'Foo' object? (? ?the object referred to by the name
> 'Foo'?). The error message which inspired this thread needs improvement,
> as I've said already.

Most objects do not have an idea of their name, though. Assigning an
object to a new name doesn't change the object, either.


From ian.g.kelly at gmail.com  Wed Jan 28 12:33:49 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 28 Jan 2015 10:33:49 -0700
Subject: Python is DOOMED! Again!
In-Reply-To: <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
Message-ID: <CALwzidmBmB2qB7UqfqdsAgdk7+XdsN67oPSE8R3XPtS5893xNg@mail.gmail.com>

On Wed, Jan 28, 2015 at 8:04 AM, Mario Figueiredo <marfig at gmail.com> wrote:
> In article <54c83ab4$0$12982$c3e8da3$5496439d at news.astraweb.com>,
> steve+comp.lang.python at pearwood.info says...
>>
>> Mario Figueiredo wrote:
>>
>> > Static analysis cannot and should not clutter executable code.
>>
>> (1) It isn't clutter. The human reader uses that information as well as the
>> compiler, interpreter, type-checker, IDE, text editor, correctness tester,
>> etc.
>>
>> (2) Algol, Ada, Boo, C, C#, C++, Cobol, Cobra, D, F#, Fantom, Fortran, Go,
>> Haskell, Java, Julia, Kotlin, Oberon, Pascal, Rust, Scala and dozens
>> (hundreds?) of other languages disagree with you.
>>
>
> Sorry. Somehow I missed this post. Only realized now from the Skip
> answer.
>
> This is simply not true!
>
> For most of the strongly typed languages (e.g. static typed languages)

Python is a strongly typed language. It checks types at runtime and
does little implicit type conversion. Strong != static.

> in that list -- C, C++, C# and Scala, the ones I know best from that
> list -- require little to no annotations in the code (and certainly no
> new explicit function or class based syntax) in order for static
> analysers to perform their thing, except perhaps on the most exotic
> static analysers.

The languages you cite don't require extra type annotations because
they already have the types in the function signatures. Here's an
example function signature in Scala:

    def addInt( a:Int, b:Int ) : Int

How is that significantly different from a Python function that uses
the proposed annotations?


From johnnybureddu at gmx.com  Wed Jan 28 12:38:04 2015
From: johnnybureddu at gmx.com (REVOLUCION!)
Date: Wed, 28 Jan 2015 09:38:04 -0800 (PST)
Subject: -- redacted --
Message-ID: <6a5767b4-ef13-4ee8-8f57-3964b109ca79@googlegroups.com>

-- redacted --


From johnnybureddu at gmx.com  Wed Jan 28 12:42:27 2015
From: johnnybureddu at gmx.com (REVOLUCION!)
Date: Wed, 28 Jan 2015 09:42:27 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <35861325-94c1-418c-ab89-e4ea967431da@googlegroups.com>
References: <35861325-94c1-418c-ab89-e4ea967431da@googlegroups.com>
Message-ID: <e4b0c246-e807-4011-9d98-0aa5fbca1a5f@googlegroups.com>

-- redacted --


From zoneofbattle at yahoo.com  Wed Jan 28 12:44:52 2015
From: zoneofbattle at yahoo.com (Alex Potapenko)
Date: Wed, 28 Jan 2015 17:44:52 +0000 (UTC)
Subject: Python on armv7l router: C++ exceptions issue
Message-ID: <1074278333.1184248.1422467092765.JavaMail.yahoo@mail.yahoo.com>

I run Python on an arm-brcm-linux-uclibcgnueabi router. Python was cross-compiled using hndtools-arm-linux-2.6.36-uclibc-4.5.3 toolchain. While trying to use deluge, I realised that there's something wrong with handling C++ exceptions in C++ extension modules: they're not being caught at all. I tested whether C++ exception handling works on my system in general, and concluded it does work fine. I then wrote a simple C++ extension module with a try-catch block in the init function, that has a "throw 1" in the try section and a "catch (...)" section (see module.cpp), and I got "terminate called after throwing an instance of 'int'" when trying to load the module. Tested this with Python 2.7.9 and 3.4.2, however I had similar issues with other versions, such as 2.7.3 and 2.6.9.
Does anyone happen to know what I can try here? Any help is greatly appreciated!


Thanks in advance,
Alex
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From breamoreboy at yahoo.co.uk  Wed Jan 28 13:05:27 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Wed, 28 Jan 2015 18:05:27 +0000
Subject: write file to a server
In-Reply-To: <CAPTjJmqjgdymGsSZ-6ce14TwOD3UwMEMVepLjPFbhzNg4_wffg@mail.gmail.com>
References: <6b5943a2-ab9d-4949-bfbe-7671740bb9fb@googlegroups.com>
 <54C8E653.3070908@mrabarnett.plus.com>
 <CAPTjJmqjgdymGsSZ-6ce14TwOD3UwMEMVepLjPFbhzNg4_wffg@mail.gmail.com>
Message-ID: <mab8dg$6f4$1@ger.gmane.org>

On 28/01/2015 14:12, Chris Angelico wrote:
> On Thu, Jan 29, 2015 at 12:38 AM, MRAB <python at mrabarnett.plus.com> wrote:
>> On 2015-01-28 13:22, luca72 wrote:
>>>
>>> Hello i'm under windows, i have to write a file from my computer to a
>>> local server like taht "\\DOCUMENTALE\my_folder\".
>>> How i have to proceed ?
>>>
>> That's a path to a folder that just happens to be on another computer on
>> your network. Treat it the same way you would for a 'local' folder,
>> eg "C:\my_folder".
>
> And if you've done that and it isn't working, one likely cause is that
> Windows uses backslashes in path names, but Python string literals
> treat backslashes specially. Use a raw string literal:
>
> path = r"\\DOCUMENTALE\my_folder\some_file_name"
> with open(path, "wb") as f:
>      ... write to file ...
>
> If you have other problems, the best thing to do is to post your code
> and the exact output it produces, especially if that's a traceback.
> Those are incredibly helpful.
>
> ChrisA
>

Windows will accept forward slashes in path names.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From skip.montanaro at gmail.com  Wed Jan 28 13:06:51 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Wed, 28 Jan 2015 12:06:51 -0600
Subject: multiprocessing module backport from 3 to 2.7 - spawn feature
In-Reply-To: <CA+1Rt66fb5zFwKiBG=tkHzURfiYFX_xKo=XxUKvWO4CdySX0_Q@mail.gmail.com>
References: <CA+1Rt66fb5zFwKiBG=tkHzURfiYFX_xKo=XxUKvWO4CdySX0_Q@mail.gmail.com>
Message-ID: <CANc-5UyZZNkTjrVUt1M2zAUCeJGr_RffXcO_E4FiY5gZhSOD1A@mail.gmail.com>

On Wed, Jan 28, 2015 at 7:07 AM, Andres Riancho <andres.riancho at gmail.com>
wrote:

> The feature I'm specially interested in is the ability to spawn
> processes [1] instead of forking, which is not present in the 2.7
> version of the module.
>

Can you explain what you see as the difference between "spawn" and "fork"
in this context? Are you using Windows perhaps? I don't know anything
obviously different between the two terms on Unix systems.

Skip
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From n.poppelier at xs4all.nl  Wed Jan 28 13:09:53 2015
From: n.poppelier at xs4all.nl (n.poppelier at xs4all.nl)
Date: Wed, 28 Jan 2015 10:09:53 -0800 (PST)
Subject: ANN: unpyc3 - a python bytecode decompiler for Python3
In-Reply-To: <mailman.1084.1315945219.27778.python-list@python.org>
References: <mailman.1084.1315945219.27778.python-list@python.org>
Message-ID: <3dcc2862-bdd6-4a2a-8edb-1a9d51df26b3@googlegroups.com>

Last night I accidentally deleted a group of *.py files (stupid-stupid-stupid!). 

Thanks to unpyc3 I have reconstructed all but one of them so far from the *.pyc files that were in the directory __pycache__. Many thanks!!!

-- Nico


From breamoreboy at yahoo.co.uk  Wed Jan 28 13:16:56 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Wed, 28 Jan 2015 18:16:56 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
Message-ID: <mab931$qqu$1@ger.gmane.org>

On 28/01/2015 15:04, Mario Figueiredo wrote:
> In article <54c83ab4$0$12982$c3e8da3$5496439d at news.astraweb.com>,
> steve+comp.lang.python at pearwood.info says...
>>
>> Mario Figueiredo wrote:
>>
>>> Static analysis cannot and should not clutter executable code.
>>
>> (1) It isn't clutter. The human reader uses that information as well as the
>> compiler, interpreter, type-checker, IDE, text editor, correctness tester,
>> etc.
>>
>> (2) Algol, Ada, Boo, C, C#, C++, Cobol, Cobra, D, F#, Fantom, Fortran, Go,
>> Haskell, Java, Julia, Kotlin, Oberon, Pascal, Rust, Scala and dozens
>> (hundreds?) of other languages disagree with you.
>>
>
> Sorry. Somehow I missed this post. Only realized now from the Skip
> answer.
>
> This is simply not true!
>
> For most of the strongly typed languages (e.g. static typed languages)
> in that list -- C, C++, C# and Scala, the ones I know best from that
> list -- require little to no annotations in the code (and certainly no
> new explicit function or class based syntax) in order for static
> analysers to perform their thing, except perhaps on the most exotic
> static analysers.

C and C++ are weakly and statically typed languages.  Python is a 
strongly and dynamically typed language.  Therefore anything following 
based on the above paragraph alone is wrong.

>
> Being a strongly typed language, there is no need for added information
> in the function signatures. From that list you can safely exclude all
> strongly-typed languages.
>
> For dynamically typed languages, what I have seen being implemented on
> almost all cases is doc-like features for type annotation. Of the list
> you provide (few there are dynamically typed, btw) Julia is the one I
> know of. Julia implements a similar type annotation to type annotations
> in Python. In fact I see a lot of Julia in PEP 484. But with different
> objectives:
>
>      function add(a::Int, b::Int)
>          a + b
>      end
>
> Here the :: annotation is meant to attribute a type in an otherwise
> dynamically typed language and that function signature is executed at
> runtime with all the implications of a statically typed signature.
>
> Static analysis in Julia admitedly can only be performed if those
> annotations are present, and of the entire list you provide this is the
> only example language that more closely matches your argument. The
> others simply are not true.
>
> But in any case, in Julia type annotations, contrary to Python, are
> evaluated at runtime. It then makes all sense for them to coexist with
> the language syntax.
>


-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From skip.montanaro at gmail.com  Wed Jan 28 13:34:03 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Wed, 28 Jan 2015 12:34:03 -0600
Subject: Python is DOOMED! Again!
In-Reply-To: <mab931$qqu$1@ger.gmane.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
 <mab931$qqu$1@ger.gmane.org>
Message-ID: <CANc-5Uwh72C9erBoQJh=k6BQQgFBfVzruyeSJK_mNdCFGHhgTA@mail.gmail.com>

On Wed, Jan 28, 2015 at 12:16 PM, Mark Lawrence <breamoreboy at yahoo.co.uk>
wrote:

> C and C++ are weakly and statically typed languages.  Python is a strongly
> and dynamically typed language.


Feel free to edit this Google spreadsheet:
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From skip.montanaro at gmail.com  Wed Jan 28 13:36:20 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Wed, 28 Jan 2015 12:36:20 -0600
Subject: Python is DOOMED! Again!
In-Reply-To: <CANc-5Uwh72C9erBoQJh=k6BQQgFBfVzruyeSJK_mNdCFGHhgTA@mail.gmail.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
 <mab931$qqu$1@ger.gmane.org>
 <CANc-5Uwh72C9erBoQJh=k6BQQgFBfVzruyeSJK_mNdCFGHhgTA@mail.gmail.com>
Message-ID: <CANc-5UxDZF0MhFWjMopPq6sdzzG9svocaRtKZHDwJ8NQxFx9pw@mail.gmail.com>

On Wed, Jan 28, 2015 at 12:34 PM, Skip Montanaro
<skip.montanaro at gmail.com> wrote:
>
>
> On Wed, Jan 28, 2015 at 12:16 PM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
>>
>> C and C++ are weakly and statically typed languages.  Python is a strongly and dynamically typed language.
>
>
> Feel free to edit this Google spreadsheet:

Man, sometimes Gmail makes me mad... Ctlr-V shouldn't send. Of course,
sending is bound to Shift-Ctrl-V. Sometimes Gmail gets confused or
doesn't get the "he let up on the shift key" memo. Or maybe I'm a
spaz. At any rate, here's the link:

http://preview.tinyurl.com/kcrcq4y

Feel free to modify the spreadsheet. Should be open for anyone to edit.

Skip


From jeanpierreda at gmail.com  Wed Jan 28 13:42:16 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Wed, 28 Jan 2015 10:42:16 -0800
Subject: ANN: unpyc3 - a python bytecode decompiler for Python3
In-Reply-To: <3dcc2862-bdd6-4a2a-8edb-1a9d51df26b3@googlegroups.com>
References: <mailman.1084.1315945219.27778.python-list@python.org>
 <3dcc2862-bdd6-4a2a-8edb-1a9d51df26b3@googlegroups.com>
Message-ID: <CABicbJKNs7uAWVBUSX6BV3OQJKJ5zTvmfOxHAucsH=VNJ5CfXw@mail.gmail.com>

FWIW I put all my source code inside Dropbox so that even things I
haven't yet committed/pushed to Bitbucket/Github are backed up. So far
it's worked really well, despite using Dropbox on both Windows and
Linux. (See also: Google Drive, etc.)

(Free) Dropbox has a 30 day recovery time limit, and I think Google
Drive has a trash bin, as well as a 29 day recovery for emptied trash
items.

That said, hindsight is easier than foresight. I'm glad you were able
to recover your files!

-- Devin

On Wed, Jan 28, 2015 at 10:09 AM,  <n.poppelier at xs4all.nl> wrote:
> Last night I accidentally deleted a group of *.py files (stupid-stupid-stupid!).
>
> Thanks to unpyc3 I have reconstructed all but one of them so far from the *.pyc files that were in the directory __pycache__. Many thanks!!!
>
> -- Nico
> --
> https://mail.python.org/mailman/listinfo/python-list


From ckaynor at zindagigames.com  Wed Jan 28 13:47:26 2015
From: ckaynor at zindagigames.com (Chris Kaynor)
Date: Wed, 28 Jan 2015 10:47:26 -0800
Subject: ANN: unpyc3 - a python bytecode decompiler for Python3
In-Reply-To: <CABicbJKNs7uAWVBUSX6BV3OQJKJ5zTvmfOxHAucsH=VNJ5CfXw@mail.gmail.com>
References: <mailman.1084.1315945219.27778.python-list@python.org>
 <3dcc2862-bdd6-4a2a-8edb-1a9d51df26b3@googlegroups.com>
 <CABicbJKNs7uAWVBUSX6BV3OQJKJ5zTvmfOxHAucsH=VNJ5CfXw@mail.gmail.com>
Message-ID: <CALvWhxuLSx-x8uMYTQyX5iHNpz38M7uOq+qTiibYrTmgmR33Sw@mail.gmail.com>

On Wed, Jan 28, 2015 at 10:42 AM, Devin Jeanpierre
<jeanpierreda at gmail.com> wrote:
> FWIW I put all my source code inside Dropbox so that even things I
> haven't yet committed/pushed to Bitbucket/Github are backed up. So far
> it's worked really well, despite using Dropbox on both Windows and
> Linux. (See also: Google Drive, etc.)
>
> (Free) Dropbox has a 30 day recovery time limit, and I think Google
> Drive has a trash bin, as well as a 29 day recovery for emptied trash
> items.
>
> That said, hindsight is easier than foresight. I'm glad you were able
> to recover your files!

I use Google Drive for it for all the stuff I do at home, and use SVN
for all my personal projects, with the SVN depots also in Drive. The
combination works well for me, I can transfer between my desktop and
laptop freely, and have full revision history for debugging issues.

>
> -- Devin
>
> On Wed, Jan 28, 2015 at 10:09 AM,  <n.poppelier at xs4all.nl> wrote:
>> Last night I accidentally deleted a group of *.py files (stupid-stupid-stupid!).
>>
>> Thanks to unpyc3 I have reconstructed all but one of them so far from the *.pyc files that were in the directory __pycache__. Many thanks!!!
>>
>> -- Nico


From chat2jesse at gmail.com  Wed Jan 28 13:53:43 2015
From: chat2jesse at gmail.com (jesse)
Date: Wed, 28 Jan 2015 10:53:43 -0800
Subject: why zip64_limit defined as 1<<31 -1?
Message-ID: <CAE6kErhvOus7igddqKMLaJ=NdqNT9b=EUfuPVk0NAH-5U0PiNA@mail.gmail.com>

should not it be 1<<32 -1(4g)?

normal zip archive format should be able to support 4g file.

thanks
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From andres.riancho at gmail.com  Wed Jan 28 14:04:29 2015
From: andres.riancho at gmail.com (Andres Riancho)
Date: Wed, 28 Jan 2015 16:04:29 -0300
Subject: multiprocessing module backport from 3 to 2.7 - spawn feature
In-Reply-To: <CANc-5UyZZNkTjrVUt1M2zAUCeJGr_RffXcO_E4FiY5gZhSOD1A@mail.gmail.com>
References: <CA+1Rt66fb5zFwKiBG=tkHzURfiYFX_xKo=XxUKvWO4CdySX0_Q@mail.gmail.com>
 <CANc-5UyZZNkTjrVUt1M2zAUCeJGr_RffXcO_E4FiY5gZhSOD1A@mail.gmail.com>
Message-ID: <CA+1Rt67KWpmqw_iLfu+0qYs9QGRvXjPA76FhJQ4mpWpOtz6eVA@mail.gmail.com>

On Wed, Jan 28, 2015 at 3:06 PM, Skip Montanaro
<skip.montanaro at gmail.com> wrote:
>
> On Wed, Jan 28, 2015 at 7:07 AM, Andres Riancho <andres.riancho at gmail.com>
> wrote:
>>
>> The feature I'm specially interested in is the ability to spawn
>> processes [1] instead of forking, which is not present in the 2.7
>> version of the module.
>
>
> Can you explain what you see as the difference between "spawn" and "fork" in
> this context?

Well, fork is a system call [0] where a process creates a copy of
itself, usually using COW [1]. This copy receives a new process ID and
is slightly dependent on the parent: they share the same address
space.

Spawn, and I took that from the multiprocessing 3 documentation, will
create a new process without using fork(). This means that no memory
is shared between the MainProcess and the spawn'ed sub-process created
by multiprocessing.

My goal is to prevent dead-locks and other issues [2][3] which come
from forking a multithreaded program (situation I'm in right now).

[0] https://en.wikipedia.org/wiki/Fork_%28system_call%29
[1] https://en.wikipedia.org/wiki/Copy-on-write
[2] See "Note that safely forking a multithreaded process is
problematic." at
https://docs.python.org/3.4/library/multiprocessing.html#multiprocessing.set_start_method
[3] http://www.linuxprogrammingblog.com/threads-and-fork-think-twice-before-using-them

> Are you using Windows perhaps? I don't know anything obviously
> different between the two terms on Unix systems.

Nope, I'm on linux

> Skip
>



-- 
Andr?s Riancho
Project Leader at w3af - http://w3af.org/
Web Application Attack and Audit Framework
Twitter: @w3af
GPG: 0x93C344F3


From lazar.michael22 at gmail.com  Wed Jan 28 15:19:55 2015
From: lazar.michael22 at gmail.com (lazar.michael22 at gmail.com)
Date: Wed, 28 Jan 2015 12:19:55 -0800 (PST)
Subject: SUBMIT "ACCEPT" button - Python - beautifulsoap
In-Reply-To: <2cf53399-6eee-44a7-bdb7-ecb3675c0fed@googlegroups.com>
References: <2cf53399-6eee-44a7-bdb7-ecb3675c0fed@googlegroups.com>
Message-ID: <2df43584-d719-409e-a033-744f059344c7@googlegroups.com>

On Wednesday, January 28, 2015 at 8:36:59 AM UTC-8, peter.n... at gmail.com wrote:
> I am totally new to Python and please accept my apologies upfront for potential newbie errors. I am trying to parse a 'simple' web page: http://flow.gassco.no/
> 
> When opening the page first time in my browser I need to confirm T&C with an accept button. After accepting T&C I would like to scrape some data from that follow up page. It appears that when opening in a browser directly http://flow.gassco.no/acceptDisclaimer I would get around that T&C.
> But not when I open the URL via beautifulsoap
> 
> My parsing/scraping tool is implemented in bs, but I fail to parse the content as I am not getting around T&C. When printing "response.text" from BS, I get below code. How do I get around this form for accepting terms & conditions so that I can parse/scrape data from that page?
> 
> Here is what I am doing:
> 
> #!/usr/bin/env python 
> import requests 
> import bs4 
> index_url='http://flow.gassco.no/acceptDisclaimer'
> 
> def get_video_page_urls(): 
> response = requests.get(index_url) 
> soup = bs4.BeautifulSoup(response.text) 
> return soup 
> print(get_video_page_urls()) 
> 
> ++++
> 
> PRINTOUT from response.text:
> 
>    <form action="acceptDisclaimer" method="get">
>      <input class="accept" type="submit" value="Accept"/>
>      <input class="decline" name="decline" onclick="window.location ='http://www.gassco.no'" type="button" value="Decline"/>
>      </form></div></div></div></div></div>
> 
>     <script type="text/javascript">
>     var _gaq = _gaq || [];
>     _gaq.push(['_setAccount', 'UA-30727768-1']);
>     _gaq.push(['_trackPageview']);
> 
>     (function() {
>         var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
>         ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
>         var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
>     })();
> 
> </script>

Try clearing your browser cookies and then reopening the page, it should spit you back to the TOC screen. 

You can use the Session class to keep track of your cookies between requests:

with requests.Session() as s:

    # Request sessionid cookie and store it in the current session
    response = s.get('http://flow.gassco.no')
    
    # Subsequent gets will now include the session cookie 
    response = s.get('http://flow.gassco.no/acceptDisclaimer')

A good place to start when debugging something like this is to open up the developer tools in your browser (F12 in chrome/firefox) and observe the GET requests that get sent out as you click on different buttons.


From jeanpierreda at gmail.com  Wed Jan 28 15:50:50 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Wed, 28 Jan 2015 12:50:50 -0800
Subject: multiprocessing module backport from 3 to 2.7 - spawn feature
In-Reply-To: <CANc-5UyZZNkTjrVUt1M2zAUCeJGr_RffXcO_E4FiY5gZhSOD1A@mail.gmail.com>
References: <CA+1Rt66fb5zFwKiBG=tkHzURfiYFX_xKo=XxUKvWO4CdySX0_Q@mail.gmail.com>
 <CANc-5UyZZNkTjrVUt1M2zAUCeJGr_RffXcO_E4FiY5gZhSOD1A@mail.gmail.com>
Message-ID: <CABicbJKj+NdoYs1fMGE--coVKiOfMkz8YMp3BrZuXd41KF14mg@mail.gmail.com>

On Wed, Jan 28, 2015 at 10:06 AM, Skip Montanaro
<skip.montanaro at gmail.com> wrote:
> On Wed, Jan 28, 2015 at 7:07 AM, Andres Riancho <andres.riancho at gmail.com>
> wrote:
>> The feature I'm specially interested in is the ability to spawn
>> processes [1] instead of forking, which is not present in the 2.7
>> version of the module.
>
> Can you explain what you see as the difference between "spawn" and "fork" in
> this context? Are you using Windows perhaps? I don't know anything obviously
> different between the two terms on Unix systems.

On Unix, if you fork without exec*, and had threads open, threads
abruptly terminate, resulting in completely broken mutex state etc.,
which leads to deadlocks or worse if you try to acquire resources in
the forked child process. So in such circumstances, multiprocessing
(in 2.7) is not a viable option. But 3.x adds a feature, "spawn", that
lets you fork+exec instead of just forking.

I too would be interested in such a backport. I considered writing
one, but haven't had a strong enough need yet.

-- Devin


From rosuav at gmail.com  Wed Jan 28 16:36:48 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 29 Jan 2015 08:36:48 +1100
Subject: why zip64_limit defined as 1<<31 -1?
In-Reply-To: <CAE6kErhvOus7igddqKMLaJ=NdqNT9b=EUfuPVk0NAH-5U0PiNA@mail.gmail.com>
References: <CAE6kErhvOus7igddqKMLaJ=NdqNT9b=EUfuPVk0NAH-5U0PiNA@mail.gmail.com>
Message-ID: <CAPTjJmqBumcD_xWLBkxP1PxgaDixqWj-+Ra8vrSO50KsyWNbxA@mail.gmail.com>

On Thu, Jan 29, 2015 at 5:53 AM, jesse <chat2jesse at gmail.com> wrote:
> should not it be 1<<32 -1(4g)?
>
> normal zip archive format should be able to support 4g file.
>
> thanks

1<<31-1 is the limit for a signed 32-bit integer. You'd have to look
into the details of the zip file format to see whether that's the
official limit or not; it might simply be that some (un)archivers have
problems with >2GB files, even if the official stance is that it's
unsigned.

ChrisA


From rosuav at gmail.com  Wed Jan 28 16:38:43 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 29 Jan 2015 08:38:43 +1100
Subject: write file to a server
In-Reply-To: <mab8dg$6f4$1@ger.gmane.org>
References: <6b5943a2-ab9d-4949-bfbe-7671740bb9fb@googlegroups.com>
 <54C8E653.3070908@mrabarnett.plus.com>
 <CAPTjJmqjgdymGsSZ-6ce14TwOD3UwMEMVepLjPFbhzNg4_wffg@mail.gmail.com>
 <mab8dg$6f4$1@ger.gmane.org>
Message-ID: <CAPTjJmq9cBu2ppheTVeFgKHpKbyG_62HCBx2uYFE1o+qiM_ZYg@mail.gmail.com>

On Thu, Jan 29, 2015 at 5:05 AM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> Windows will accept forward slashes in path names.

Normally, yes. Does that work for UNC names too?
//server/share/pathname ? In any case, that's an alternative solution
to the same problem.

ChrisA


From rosuav at gmail.com  Wed Jan 28 16:40:32 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 29 Jan 2015 08:40:32 +1100
Subject: ANN: unpyc3 - a python bytecode decompiler for Python3
In-Reply-To: <CALvWhxuLSx-x8uMYTQyX5iHNpz38M7uOq+qTiibYrTmgmR33Sw@mail.gmail.com>
References: <mailman.1084.1315945219.27778.python-list@python.org>
 <3dcc2862-bdd6-4a2a-8edb-1a9d51df26b3@googlegroups.com>
 <CABicbJKNs7uAWVBUSX6BV3OQJKJ5zTvmfOxHAucsH=VNJ5CfXw@mail.gmail.com>
 <CALvWhxuLSx-x8uMYTQyX5iHNpz38M7uOq+qTiibYrTmgmR33Sw@mail.gmail.com>
Message-ID: <CAPTjJmqu9TqFK4uQaw+s-cuTMaJoatXRQ7iLsTch9aNDUfjnWw@mail.gmail.com>

On Thu, Jan 29, 2015 at 5:47 AM, Chris Kaynor <ckaynor at zindagigames.com> wrote:
> I use Google Drive for it for all the stuff I do at home, and use SVN
> for all my personal projects, with the SVN depots also in Drive. The
> combination works well for me, I can transfer between my desktop and
> laptop freely, and have full revision history for debugging issues.

I just do everything in git, no need for either Drive or something as
old as SVN. Much easier. :)

Using a more modern source control system (I'd normally recommend
people use either git or Mercurial, though there are a few others that
are also viable) saves you the trouble of "oops, I'm offline and can't
reach the Subversion server" and other issues.

ChrisA


From ian.g.kelly at gmail.com  Wed Jan 28 16:50:15 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Wed, 28 Jan 2015 14:50:15 -0700
Subject: why zip64_limit defined as 1<<31 -1?
In-Reply-To: <CAE6kErhvOus7igddqKMLaJ=NdqNT9b=EUfuPVk0NAH-5U0PiNA@mail.gmail.com>
References: <CAE6kErhvOus7igddqKMLaJ=NdqNT9b=EUfuPVk0NAH-5U0PiNA@mail.gmail.com>
Message-ID: <CALwzid=DNGy9k+Z-ni5O3k8hiZ5pZmcRG_paMCasvZW3ZZG1Fg@mail.gmail.com>

On Wed, Jan 28, 2015 at 11:53 AM, jesse <chat2jesse at gmail.com> wrote:
> should not it be 1<<32 -1(4g)?
>
> normal zip archive format should be able to support 4g file.

Bugs can be filed at http://bugs.python.org/


From jeanpierreda at gmail.com  Wed Jan 28 16:52:27 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Wed, 28 Jan 2015 13:52:27 -0800
Subject: ANN: unpyc3 - a python bytecode decompiler for Python3
In-Reply-To: <CAPTjJmqu9TqFK4uQaw+s-cuTMaJoatXRQ7iLsTch9aNDUfjnWw@mail.gmail.com>
References: <mailman.1084.1315945219.27778.python-list@python.org>
 <3dcc2862-bdd6-4a2a-8edb-1a9d51df26b3@googlegroups.com>
 <CABicbJKNs7uAWVBUSX6BV3OQJKJ5zTvmfOxHAucsH=VNJ5CfXw@mail.gmail.com>
 <CALvWhxuLSx-x8uMYTQyX5iHNpz38M7uOq+qTiibYrTmgmR33Sw@mail.gmail.com>
 <CAPTjJmqu9TqFK4uQaw+s-cuTMaJoatXRQ7iLsTch9aNDUfjnWw@mail.gmail.com>
Message-ID: <CABicbJLEk3rhUd_8xRVZ59+wyuMrrVin9fOXhysjPxzoh86CKg@mail.gmail.com>

On Wed, Jan 28, 2015 at 1:40 PM, Chris Angelico <rosuav at gmail.com> wrote:
> On Thu, Jan 29, 2015 at 5:47 AM, Chris Kaynor <ckaynor at zindagigames.com> wrote:
>> I use Google Drive for it for all the stuff I do at home, and use SVN
>> for all my personal projects, with the SVN depots also in Drive. The
>> combination works well for me, I can transfer between my desktop and
>> laptop freely, and have full revision history for debugging issues.
>
> I just do everything in git, no need for either Drive or something as
> old as SVN. Much easier. :)

Git doesn't help if you lose your files in between commits, or if you
lose the entire directory between pushes.

-- Devin


From rosuav at gmail.com  Wed Jan 28 17:02:31 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 29 Jan 2015 09:02:31 +1100
Subject: ANN: unpyc3 - a python bytecode decompiler for Python3
In-Reply-To: <CABicbJLEk3rhUd_8xRVZ59+wyuMrrVin9fOXhysjPxzoh86CKg@mail.gmail.com>
References: <mailman.1084.1315945219.27778.python-list@python.org>
 <3dcc2862-bdd6-4a2a-8edb-1a9d51df26b3@googlegroups.com>
 <CABicbJKNs7uAWVBUSX6BV3OQJKJ5zTvmfOxHAucsH=VNJ5CfXw@mail.gmail.com>
 <CALvWhxuLSx-x8uMYTQyX5iHNpz38M7uOq+qTiibYrTmgmR33Sw@mail.gmail.com>
 <CAPTjJmqu9TqFK4uQaw+s-cuTMaJoatXRQ7iLsTch9aNDUfjnWw@mail.gmail.com>
 <CABicbJLEk3rhUd_8xRVZ59+wyuMrrVin9fOXhysjPxzoh86CKg@mail.gmail.com>
Message-ID: <CAPTjJmp+uG6hnz6_S8b5wBLd3Sggw2F-W5Nvyc1=ikutHuHOpg@mail.gmail.com>

On Thu, Jan 29, 2015 at 8:52 AM, Devin Jeanpierre
<jeanpierreda at gmail.com> wrote:
> Git doesn't help if you lose your files in between commits, or if you
> lose the entire directory between pushes.

So you commit often and push immediately. Solved.

ChrisA


From fomcl at yahoo.com  Wed Jan 28 17:17:02 2015
From: fomcl at yahoo.com (Albert-Jan Roskam)
Date: Wed, 28 Jan 2015 14:17:02 -0800
Subject: unicode question
Message-ID: <1422483422.18222.BPMail_high_carrier@web163802.mail.gq1.yahoo.com>


----------------------------
On Wed, Jan 28, 2015 8:21 AM CET Terry Reedy wrote:

>On 1/27/2015 12:17 AM, Rehab Habeeb wrote:
>> Hi there python staff
>> does python support arabic language for texts ? and what to do if it
>> support it?
>> i wrote hello in Arabic using codeskulptor and the powershell just for
>> testing and the same error appeared( a sytanx error in unicode)!!
>
>I do not know how complete the support is, but this is copied from 3.4.2, which uses tcl/tk 8.6.
>>> t = "???????"
>>> for c in t: print(c)  # Prints rightmost char above first
>?
>?
>?
>?
>?
>?
>?

Wow, I never knew this was so clever. Is that with or without an RTL marker?


>The following StackOverflow question and response indicate that there may b more issue, but it was asked before tcl/tk 8.6 was available, so the answer may be partially obsolete.
>
>
>-- Terry Jan Reedy
>
>
>-- https://mail.python.org/mailman/listinfo/python-list



From jeanpierreda at gmail.com  Wed Jan 28 18:01:43 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Wed, 28 Jan 2015 15:01:43 -0800
Subject: ANN: unpyc3 - a python bytecode decompiler for Python3
In-Reply-To: <CAPTjJmp+uG6hnz6_S8b5wBLd3Sggw2F-W5Nvyc1=ikutHuHOpg@mail.gmail.com>
References: <mailman.1084.1315945219.27778.python-list@python.org>
 <3dcc2862-bdd6-4a2a-8edb-1a9d51df26b3@googlegroups.com>
 <CABicbJKNs7uAWVBUSX6BV3OQJKJ5zTvmfOxHAucsH=VNJ5CfXw@mail.gmail.com>
 <CALvWhxuLSx-x8uMYTQyX5iHNpz38M7uOq+qTiibYrTmgmR33Sw@mail.gmail.com>
 <CAPTjJmqu9TqFK4uQaw+s-cuTMaJoatXRQ7iLsTch9aNDUfjnWw@mail.gmail.com>
 <CABicbJLEk3rhUd_8xRVZ59+wyuMrrVin9fOXhysjPxzoh86CKg@mail.gmail.com>
 <CAPTjJmp+uG6hnz6_S8b5wBLd3Sggw2F-W5Nvyc1=ikutHuHOpg@mail.gmail.com>
Message-ID: <CABicbJJ7HhPJE68eJgaNKN7wAyXTSij4oZYTRB7T+tz9Txnz3w@mail.gmail.com>

I distrust any backup strategy that requires explicit action by the
user. I've seen users fail too often. (Including myself.)

-- Devin

On Wed, Jan 28, 2015 at 2:02 PM, Chris Angelico <rosuav at gmail.com> wrote:
> On Thu, Jan 29, 2015 at 8:52 AM, Devin Jeanpierre
> <jeanpierreda at gmail.com> wrote:
>> Git doesn't help if you lose your files in between commits, or if you
>> lose the entire directory between pushes.
>
> So you commit often and push immediately. Solved.
>
> ChrisA
> --
> https://mail.python.org/mailman/listinfo/python-list


From ckaynor at zindagigames.com  Wed Jan 28 18:12:40 2015
From: ckaynor at zindagigames.com (Chris Kaynor)
Date: Wed, 28 Jan 2015 15:12:40 -0800
Subject: ANN: unpyc3 - a python bytecode decompiler for Python3
In-Reply-To: <CABicbJJ7HhPJE68eJgaNKN7wAyXTSij4oZYTRB7T+tz9Txnz3w@mail.gmail.com>
References: <mailman.1084.1315945219.27778.python-list@python.org>
 <3dcc2862-bdd6-4a2a-8edb-1a9d51df26b3@googlegroups.com>
 <CABicbJKNs7uAWVBUSX6BV3OQJKJ5zTvmfOxHAucsH=VNJ5CfXw@mail.gmail.com>
 <CALvWhxuLSx-x8uMYTQyX5iHNpz38M7uOq+qTiibYrTmgmR33Sw@mail.gmail.com>
 <CAPTjJmqu9TqFK4uQaw+s-cuTMaJoatXRQ7iLsTch9aNDUfjnWw@mail.gmail.com>
 <CABicbJLEk3rhUd_8xRVZ59+wyuMrrVin9fOXhysjPxzoh86CKg@mail.gmail.com>
 <CAPTjJmp+uG6hnz6_S8b5wBLd3Sggw2F-W5Nvyc1=ikutHuHOpg@mail.gmail.com>
 <CABicbJJ7HhPJE68eJgaNKN7wAyXTSij4oZYTRB7T+tz9Txnz3w@mail.gmail.com>
Message-ID: <CALvWhxvao6G0H3OjgPqqd-d6Qc0U1k6W8WHdipVPV0EUts9Nnw@mail.gmail.com>

On Wed, Jan 28, 2015 at 3:01 PM, Devin Jeanpierre
<jeanpierreda at gmail.com> wrote:
> On Wed, Jan 28, 2015 at 2:02 PM, Chris Angelico <rosuav at gmail.com> wrote:
>> On Thu, Jan 29, 2015 at 8:52 AM, Devin Jeanpierre
>> <jeanpierreda at gmail.com> wrote:
>>> Git doesn't help if you lose your files in between commits, or if you
>>> lose the entire directory between pushes.
>>
>> So you commit often and push immediately. Solved.
> I distrust any backup strategy that requires explicit action by the
> user. I've seen users fail too often. (Including myself.)

That tends to be my opinion and experience as well :)

And that is where Drive is quite nice: its an automatic backup to an
off-site backup that requires no user action. Having some form of
source control is still needed however, as you don't get all the nice
history with Drive, and don't have the atomic updates - typically,
every save will be uploaded, even if that change itself will break
everything as you haven't made the required changes to other files.

Chris K


From sohcahtoa82 at gmail.com  Wed Jan 28 18:44:47 2015
From: sohcahtoa82 at gmail.com (sohcahtoa82 at gmail.com)
Date: Wed, 28 Jan 2015 15:44:47 -0800 (PST)
Subject: ANN: unpyc3 - a python bytecode decompiler for Python3
In-Reply-To: <mailman.18248.1422486781.18130.python-list@python.org>
References: <mailman.1084.1315945219.27778.python-list@python.org>
 <3dcc2862-bdd6-4a2a-8edb-1a9d51df26b3@googlegroups.com>
 <CABicbJKNs7uAWVBUSX6BV3OQJKJ5zTvmfOxHAucsH=VNJ5CfXw@mail.gmail.com>
 <CALvWhxuLSx-x8uMYTQyX5iHNpz38M7uOq+qTiibYrTmgmR33Sw@mail.gmail.com>
 <CAPTjJmqu9TqFK4uQaw+s-cuTMaJoatXRQ7iLsTch9aNDUfjnWw@mail.gmail.com>
 <CABicbJLEk3rhUd_8xRVZ59+wyuMrrVin9fOXhysjPxzoh86CKg@mail.gmail.com>
 <CAPTjJmp+uG6hnz6_S8b5wBLd3Sggw2F-W5Nvyc1=ikutHuHOpg@mail.gmail.com>
 <CABicbJJ7HhPJE68eJgaNKN7wAyXTSij4oZYTRB7T+tz9Txnz3w@mail.gmail.com>
 <mailman.18248.1422486781.18130.python-list@python.org>
Message-ID: <925339b3-11e9-45b8-a5bb-e0bdf66fbba5@googlegroups.com>

On Wednesday, January 28, 2015 at 3:13:36 PM UTC-8, Chris Kaynor wrote:
> On Wed, Jan 28, 2015 at 3:01 PM, Devin Jeanpierre
> <jeanpierreda at gmail.com> wrote:
> > On Wed, Jan 28, 2015 at 2:02 PM, Chris Angelico <rosuav at gmail.com> wrote:
> >> On Thu, Jan 29, 2015 at 8:52 AM, Devin Jeanpierre
> >> <jeanpierreda at gmail.com> wrote:
> >>> Git doesn't help if you lose your files in between commits, or if you
> >>> lose the entire directory between pushes.
> >>
> >> So you commit often and push immediately. Solved.
> > I distrust any backup strategy that requires explicit action by the
> > user. I've seen users fail too often. (Including myself.)
> 
> That tends to be my opinion and experience as well :)
> 
> And that is where Drive is quite nice: its an automatic backup to an
> off-site backup that requires no user action. Having some form of
> source control is still needed however, as you don't get all the nice
> history with Drive, and don't have the atomic updates - typically,
> every save will be uploaded, even if that change itself will break
> everything as you haven't made the required changes to other files.
> 
> Chris K

I'd definitely store all of my programming projects in a Google Drive if I wasn't already using Dropbox.

I recently finished my CS degree, and I had more than one professor say that they won't take "My computer crashed and I lost everything!" as an excuse for not being able to turn in homework.  Dropbox and Google Drive are both free, easy to use, and will keep several versions of your files so you can even use the excuse that your most recent save got corrupted.

Also, it was really nice to easily be able to save my work on my laptop, finish it on my desktop, and then print it from a school computer without dealing with a thumb drive.


From steve+comp.lang.python at pearwood.info  Wed Jan 28 19:29:57 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 29 Jan 2015 11:29:57 +1100
Subject: ANN: unpyc3 - a python bytecode decompiler for Python3
References: <mailman.1084.1315945219.27778.python-list@python.org>
 <3dcc2862-bdd6-4a2a-8edb-1a9d51df26b3@googlegroups.com>
 <CABicbJKNs7uAWVBUSX6BV3OQJKJ5zTvmfOxHAucsH=VNJ5CfXw@mail.gmail.com>
 <CALvWhxuLSx-x8uMYTQyX5iHNpz38M7uOq+qTiibYrTmgmR33Sw@mail.gmail.com>
 <CAPTjJmqu9TqFK4uQaw+s-cuTMaJoatXRQ7iLsTch9aNDUfjnWw@mail.gmail.com>
 <CABicbJLEk3rhUd_8xRVZ59+wyuMrrVin9fOXhysjPxzoh86CKg@mail.gmail.com>
 <CAPTjJmp+uG6hnz6_S8b5wBLd3Sggw2F-W5Nvyc1=ikutHuHOpg@mail.gmail.com>
 <CABicbJJ7HhPJE68eJgaNKN7wAyXTSij4oZYTRB7T+tz9Txnz3w@mail.gmail.com>
 <mailman.18248.1422486781.18130.python-list@python.org>
 <925339b3-11e9-45b8-a5bb-e0bdf66fbba5@googlegroups.com>
Message-ID: <54c97f06$0$12982$c3e8da3$5496439d@news.astraweb.com>

sohcahtoa82 at gmail.com wrote:

> I recently finished my CS degree, and I had more than one professor say
> that they won't take "My computer crashed and I lost everything!" as an
> excuse for not being able to turn in homework. ?

How about "My computer crashed and died and now I can't get to Dropbox to
access my files"?

"My computer got infected by ransomware which encrypted all my data files
and blocks access to Dropbox."

"One of my housemates torrented a Linux tarball, and the MPAA wrongly
identified it as a movie file. Purely on their say-so, my ISP disabled my
account and banned me from the Internet. But all is not lost, if I move 45
miles away, I can sign up with a different ISP!"

"Some dude I've never seen before gate-crashed our party and was smoking
pot, and the police raided us and seized my computer and everybody's
phones. My lawyer tells me the raid was illegal and if spend two or three
hundred thousand dollars in legal fees, I'll probably be able to get my
computer back within eight years or so."

"My dog ate my USB stick."

:-)




-- 
Steven



From steve+comp.lang.python at pearwood.info  Wed Jan 28 19:34:47 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 29 Jan 2015 11:34:47 +1100
Subject: ANN: unpyc3 - a python bytecode decompiler for Python3
References: <mailman.1084.1315945219.27778.python-list@python.org>
 <3dcc2862-bdd6-4a2a-8edb-1a9d51df26b3@googlegroups.com>
 <CABicbJKNs7uAWVBUSX6BV3OQJKJ5zTvmfOxHAucsH=VNJ5CfXw@mail.gmail.com>
 <CALvWhxuLSx-x8uMYTQyX5iHNpz38M7uOq+qTiibYrTmgmR33Sw@mail.gmail.com>
 <CAPTjJmqu9TqFK4uQaw+s-cuTMaJoatXRQ7iLsTch9aNDUfjnWw@mail.gmail.com>
 <mailman.18244.1422481989.18130.python-list@python.org>
Message-ID: <54c98027$0$12982$c3e8da3$5496439d@news.astraweb.com>

Devin Jeanpierre wrote:

> On Wed, Jan 28, 2015 at 1:40 PM, Chris Angelico <rosuav at gmail.com> wrote:
>> On Thu, Jan 29, 2015 at 5:47 AM, Chris Kaynor <ckaynor at zindagigames.com>
>> wrote:
>>> I use Google Drive for it for all the stuff I do at home, and use SVN
>>> for all my personal projects, with the SVN depots also in Drive. The
>>> combination works well for me, I can transfer between my desktop and
>>> laptop freely, and have full revision history for debugging issues.
>>
>> I just do everything in git, no need for either Drive or something as
>> old as SVN. Much easier. :)
> 
> Git doesn't help if you lose your files in between commits, 

Sure it does? You just lose the changes made since the previous commit, but
that's no different from restoring from backup. The restored file is only
as up to date as the last time a backup was taken.


> or if you 
> lose the entire directory between pushes.

Then restore from wherever you are pushing to.

But as Devin says, any backup strategy that requires the user to make a
backup is untrustworthy. I'm hoping that the next generation of DVCSs will
support continuous commits, the next generation of editors support
continuous saves, and the only time you need interact with the editor
(apart from, you know, actual editing) is to tell it "start a new branch
now".



-- 
Steven



From steve+comp.lang.python at pearwood.info  Wed Jan 28 19:37:32 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 29 Jan 2015 11:37:32 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
 <mailman.18224.1422466472.18130.python-list@python.org>
Message-ID: <54c980cd$0$12981$c3e8da3$5496439d@news.astraweb.com>

Ian Kelly wrote:

> On Wed, Jan 28, 2015 at 8:04 AM, Mario Figueiredo <marfig at gmail.com>
> wrote:
>> In article <54c83ab4$0$12982$c3e8da3$5496439d at news.astraweb.com>,
>> steve+comp.lang.python at pearwood.info says...
>>>
>>> Mario Figueiredo wrote:
>>>
>>> > Static analysis cannot and should not clutter executable code.
>>>
>>> (1) It isn't clutter. The human reader uses that information as well as
>>> the compiler, interpreter, type-checker, IDE, text editor, correctness
>>> tester, etc.
>>>
>>> (2) Algol, Ada, Boo, C, C#, C++, Cobol, Cobra, D, F#, Fantom, Fortran,
>>> Go, Haskell, Java, Julia, Kotlin, Oberon, Pascal, Rust, Scala and dozens
>>> (hundreds?) of other languages disagree with you.
>>>
>>
>> Sorry. Somehow I missed this post. Only realized now from the Skip
>> answer.
>>
>> This is simply not true!
>>
>> For most of the strongly typed languages (e.g. static typed languages)
> 
> Python is a strongly typed language. It checks types at runtime and
> does little implicit type conversion. Strong != static.
> 
>> in that list -- C, C++, C# and Scala, the ones I know best from that
>> list -- require little to no annotations in the code (and certainly no
>> new explicit function or class based syntax) in order for static
>> analysers to perform their thing, except perhaps on the most exotic
>> static analysers.
> 
> The languages you cite don't require extra type annotations because
> they already have the types in the function signatures. Here's an
> example function signature in Scala:
> 
>     def addInt( a:Int, b:Int ) : Int
> 
> How is that significantly different from a Python function that uses
> the proposed annotations?

Ian, that's obvious. Just open your eyes:

Scala
def addInt( a:Int, b:Int ) : Int

Python
def addInt( a:int, b:int ) -> int:


They're COMPLETELY different. In Scala they are *type declarations*, not
annotations. We're talking about annotations, not declarations. They're as
different as cheese and a very slightly different cheese. Do try to keep
up.

*wink*


-- 
Steven



From rosuav at gmail.com  Wed Jan 28 19:43:36 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 29 Jan 2015 11:43:36 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <54c980cd$0$12981$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
 <mailman.18224.1422466472.18130.python-list@python.org>
 <54c980cd$0$12981$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmpHud2U3vBX3Jyu6fOUqcD6KkPy67twnvrc7CJTob5K+w@mail.gmail.com>

On Thu, Jan 29, 2015 at 11:37 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> They're as
> different as cheese and a very slightly different cheese. Do try to keep
> up.

As different as brie and camembert?

ChrisA


From chat2jesse at gmail.com  Wed Jan 28 19:55:17 2015
From: chat2jesse at gmail.com (jesse)
Date: Wed, 28 Jan 2015 16:55:17 -0800
Subject: why zip64_limit defined as 1<<31 -1?
In-Reply-To: <CAPTjJmqBumcD_xWLBkxP1PxgaDixqWj-+Ra8vrSO50KsyWNbxA@mail.gmail.com>
References: <CAE6kErhvOus7igddqKMLaJ=NdqNT9b=EUfuPVk0NAH-5U0PiNA@mail.gmail.com>
 <CAPTjJmqBumcD_xWLBkxP1PxgaDixqWj-+Ra8vrSO50KsyWNbxA@mail.gmail.com>
Message-ID: <CAE6kErgzja2zS_fg6g0acQQpNVD_UCpmJQaNxbATSMyRoesznA@mail.gmail.com>

the official zip format spec states clearly that normal zip file should be
<= 4G size instead 2G.  I just can not believe Python has such an obvious
bug.

People suggested monkey patch the ZIP64_LIMIT value to pass 2G, I am not
sure what will be the ramifications.
On Jan 28, 2015 1:37 PM, "Chris Angelico" <rosuav at gmail.com> wrote:

> On Thu, Jan 29, 2015 at 5:53 AM, jesse <chat2jesse at gmail.com> wrote:
> > should not it be 1<<32 -1(4g)?
> >
> > normal zip archive format should be able to support 4g file.
> >
> > thanks
>
> 1<<31-1 is the limit for a signed 32-bit integer. You'd have to look
> into the details of the zip file format to see whether that's the
> official limit or not; it might simply be that some (un)archivers have
> problems with >2GB files, even if the official stance is that it's
> unsigned.
>
> ChrisA
> --
> https://mail.python.org/mailman/listinfo/python-list
>
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From rustompmody at gmail.com  Wed Jan 28 21:29:49 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Wed, 28 Jan 2015 18:29:49 -0800 (PST)
Subject: An object is an instance (or not)?
In-Reply-To: <mailman.18223.1422464917.18130.python-list@python.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <80a9f882-6b13-45a7-b514-8c47b3a4c37d@googlegroups.com>
 <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org>
 <1422423466.366357.219840709.1CB2D6D1@webmail.messagingengine.com>
 <CABicbJKM9xZmT+L4b=WxqXUpT60yS3sZGS56VzKt_NrZNaXbrg@mail.gmail.com>
 <1422424868.372353.219845333.5C2DDFCF@webmail.messagingengine.com>
 <85r3ufjspl.fsf@benfinney.id.au>
 <mailman.18223.1422464917.18130.python-list@python.org>
Message-ID: <b77efd62-6b15-4107-bee7-ceb59b9b17b6@googlegroups.com>

On Wednesday, January 28, 2015 at 10:39:34 PM UTC+5:30, rand... at fastmail.us wrote:
> On Wed, Jan 28, 2015, at 01:59, Ben Finney wrote:
> > You have no justification to claim that, and it's hostile and dismissive
> > to claim it so assertively.
> 
> Sorry about that - I was tired and had just read through the whole
> thread at once.

Heh Sweet!
The lost art of gracefully saying sorry


From torriem at gmail.com  Wed Jan 28 22:01:08 2015
From: torriem at gmail.com (Michael Torrie)
Date: Wed, 28 Jan 2015 20:01:08 -0700
Subject: unicode question
In-Reply-To: <1422483422.18222.BPMail_high_carrier@web163802.mail.gq1.yahoo.com>
References: <1422483422.18222.BPMail_high_carrier@web163802.mail.gq1.yahoo.com>
Message-ID: <54C9A274.6010609@gmail.com>

On 01/28/2015 03:17 PM, Albert-Jan Roskam wrote:
>> I do not know how complete the support is, but this is copied from 3.4.2, which uses tcl/tk 8.6.
>>>> t = "???????"
>>>> for c in t: print(c)  # Prints rightmost char above first
>> ?
>> ?
>> ?
>> ?
>> ?
>> ?
>> ?
> 
> Wow, I never knew this was so clever. Is that with or without an RTL marker?

I don't think this has anything to do with Python. Python is simply
spitting out unicode characters as it sees them, starting at string
position 0 and working to the end.  The magic is done by whatever is
displaying the utf-8 output from Python.  If I copy this text to the
clipboard,

t = "hi there, ???????!"

and paste it in my terminal (say to Python's shell), which is not BIDI
aware, I get the Arabic letters in reverse order. I tried to paste it
here but no matter what I do thunderbird goes into BIDI mode and makes
them appear right.



From greg.ewing at canterbury.ac.nz  Thu Jan 29 01:22:31 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Thu, 29 Jan 2015 19:22:31 +1300
Subject: An object is an instance (or not)?
In-Reply-To: <54c8cd8f$0$12975$c3e8da3$5496439d@news.astraweb.com>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
 <mailman.18195.1422405040.18130.python-list@python.org>
 <MPG.2f324d0d46ba9afc9896ac@nntp.aioe.org> <cirs87F1tdrU2@mid.individual.net>
 <54c8cd8f$0$12975$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <ciu1taFjekrU1@mid.individual.net>

Steven D'Aprano wrote:

> In fairness, "inherit" is standard terminology for the way instances get
> their behaviour from their class.

I'm not sure that's true, but even if it is, it's
not the same kind of inheritance relationship as
exists between a class and a base class, which was
my point.

> Also, you can override methods *on the instance*:

I wouldn't call that a method -- it's just an instance
attribute that happens to be a function. You can tell
it's not a method because it doesn't get a 'self' argument.

> In Python, obj.talk performs the following (grossly simplified)
> process:
> 
> * search the instance for an attribute "talk"
> * search the class
> * search all the base classes
> * fail
> 
> (simplified because I have ignored the roles of __getattr__ and
> __getattribute__, of metaclasses, and the descriptor protocol)

By ignoring the descriptor protocol, you're simplifying
away something very important. It's the main thing that
makes the instance-of relation different from the
subclass-of relation.

> The normal way of giving a class methods that are callable from the class is
> to define them on the class with the classmethod or staticmethod
> decorators. Using a metaclass is usually overkill :-)

True, but I was trying to illustrate the symmetry
between classes and instances, how the classic OOP
ideas of Smalltalk et al are manifest in Python,
and to show that classes *can* "participate fully
in OOP" just like any other objects if you want them
to. Python's "class methods" are strange beasts that
don't have an equivalent in the classic OOP model,
so they would only have confused matters.

And there are cases where you *do* need a metaclass,
such as giving a __dunder__ method to a class, so it's
useful to know how to do it just in case.

> An early essay on Python metaclasses was subtitled "The Killer-Joke".

Quick, translate this post into German before anyone
sees too much of it!

-- 
Greg


From breamoreboy at yahoo.co.uk  Thu Jan 29 01:26:01 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 29 Jan 2015 06:26:01 +0000
Subject: ANN: unpyc3 - a python bytecode decompiler for Python3
In-Reply-To: <CALvWhxvao6G0H3OjgPqqd-d6Qc0U1k6W8WHdipVPV0EUts9Nnw@mail.gmail.com>
References: <mailman.1084.1315945219.27778.python-list@python.org>
 <3dcc2862-bdd6-4a2a-8edb-1a9d51df26b3@googlegroups.com>
 <CABicbJKNs7uAWVBUSX6BV3OQJKJ5zTvmfOxHAucsH=VNJ5CfXw@mail.gmail.com>
 <CALvWhxuLSx-x8uMYTQyX5iHNpz38M7uOq+qTiibYrTmgmR33Sw@mail.gmail.com>
 <CAPTjJmqu9TqFK4uQaw+s-cuTMaJoatXRQ7iLsTch9aNDUfjnWw@mail.gmail.com>
 <CABicbJLEk3rhUd_8xRVZ59+wyuMrrVin9fOXhysjPxzoh86CKg@mail.gmail.com>
 <CAPTjJmp+uG6hnz6_S8b5wBLd3Sggw2F-W5Nvyc1=ikutHuHOpg@mail.gmail.com>
 <CABicbJJ7HhPJE68eJgaNKN7wAyXTSij4oZYTRB7T+tz9Txnz3w@mail.gmail.com>
 <CALvWhxvao6G0H3OjgPqqd-d6Qc0U1k6W8WHdipVPV0EUts9Nnw@mail.gmail.com>
Message-ID: <macjq2$3om$1@ger.gmane.org>

On 28/01/2015 23:12, Chris Kaynor wrote:
> On Wed, Jan 28, 2015 at 3:01 PM, Devin Jeanpierre
> <jeanpierreda at gmail.com> wrote:
>> On Wed, Jan 28, 2015 at 2:02 PM, Chris Angelico <rosuav at gmail.com> wrote:
>>> On Thu, Jan 29, 2015 at 8:52 AM, Devin Jeanpierre
>>> <jeanpierreda at gmail.com> wrote:
>>>> Git doesn't help if you lose your files in between commits, or if you
>>>> lose the entire directory between pushes.
>>>
>>> So you commit often and push immediately. Solved.
>> I distrust any backup strategy that requires explicit action by the
>> user. I've seen users fail too often. (Including myself.)
>
> That tends to be my opinion and experience as well :)
>

s/any backup strategy/anything/

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From steve+comp.lang.python at pearwood.info  Thu Jan 29 02:16:16 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Thu, 29 Jan 2015 18:16:16 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
 <mailman.18195.1422405040.18130.python-list@python.org>
 <MPG.2f324d0d46ba9afc9896ac@nntp.aioe.org> <cirs87F1tdrU2@mid.individual.net>
 <54c8cd8f$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <ciu1taFjekrU1@mid.individual.net>
Message-ID: <54c9de44$0$12915$c3e8da3$5496439d@news.astraweb.com>

Gregory Ewing wrote:

> Steven D'Aprano wrote:
> 
>> In fairness, "inherit" is standard terminology for the way instances get
>> their behaviour from their class.
> 
> I'm not sure that's true, but even if it is, it's
> not the same kind of inheritance relationship as
> exists between a class and a base class, which was
> my point.

I suspect that in Python it actually is, but I don't understand the 
implementation of attribute look-ups well enough to be sure.


>> Also, you can override methods *on the instance*:
> 
> I wouldn't call that a method -- it's just an instance
> attribute that happens to be a function. You can tell
> it's not a method because it doesn't get a 'self' argument.

Actually, if you look at my example, you will see that it is a method and it 
does get the self argument. Here is the critical code again:

from types import MethodType
polly.talk = MethodType(
    lambda self: print("Polly wants a spam sandwich!"), polly)


The MethodType constructor takes a function and an instance, and returns a 
method bound to that instance.


>> In Python, obj.talk performs the following (grossly simplified)
>> process:
>> 
>> * search the instance for an attribute "talk"
>> * search the class
>> * search all the base classes
>> * fail
>> 
>> (simplified because I have ignored the roles of __getattr__ and
>> __getattribute__, of metaclasses, and the descriptor protocol)
> 
> By ignoring the descriptor protocol, you're simplifying
> away something very important. It's the main thing that
> makes the instance-of relation different from the
> subclass-of relation.

That's certainly not correct, because Python had classes and instances 
before it had descriptors! Classes and instances go back to pre-1.5 days, 
while descriptors were only introduced in 2.2. Besides, descriptors are 
handled by the metaclass, so we could write a metaclass that doesn't handle 
them.


>> The normal way of giving a class methods that are callable from the class
>> is to define them on the class with the classmethod or staticmethod
>> decorators. Using a metaclass is usually overkill :-)
> 
> True, but I was trying to illustrate the symmetry
> between classes and instances, how the classic OOP
> ideas of Smalltalk et al are manifest in Python,
> and to show that classes *can* "participate fully
> in OOP" just like any other objects if you want them
> to. Python's "class methods" are strange beasts that
> don't have an equivalent in the classic OOP model,
> so they would only have confused matters.

Fair point about classmethods.

I think you're actually underestimating how close the symmetry between new-
style classes and instances actually is in Python.


> And there are cases where you *do* need a metaclass,
> such as giving a __dunder__ method to a class, so it's
> useful to know how to do it just in case.

I don't understand this. I write dunder methods all the time. Ah wait, I 
think I've got it. If you want (say) your class object itself to support 
(say) the + operator, it isn't enough to write a __add__ method on the 
class, you have to write it on the metaclass.


-- 
Steven



From lucaberto at libero.it  Thu Jan 29 02:44:40 2015
From: lucaberto at libero.it (luca72)
Date: Wed, 28 Jan 2015 23:44:40 -0800 (PST)
Subject: write file to a server
In-Reply-To: <6b5943a2-ab9d-4949-bfbe-7671740bb9fb@googlegroups.com>
References: <6b5943a2-ab9d-4949-bfbe-7671740bb9fb@googlegroups.com>
Message-ID: <1c833144-4113-4efe-9a00-2163781489f0@googlegroups.com>

thanks for the reply i have resolve with the r'.........'
i have another question on linux i write cp -Ruv source destination

There is one way to do it in python?
with shutil there is copythree but if the dest dir exist he give back an error.
Can you give me some ideas

Thanks

Luca


From marfig at gmail.com  Thu Jan 29 03:23:50 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Thu, 29 Jan 2015 09:23:50 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
 <mailman.18229.1422469034.18130.python-list@python.org>
Message-ID: <MPG.2f340c6ea39d9f3f9896b3@nntp.aioe.org>

In article <mailman.18229.1422469034.18130.python-list at python.org>, 
breamoreboy at yahoo.co.uk says...
> 
> C and C++ are weakly and statically typed languages.  Python is a 
> strongly and dynamically typed language.  Therefore anything following 
> based on the above paragraph alone is wrong.
> 

Indeed. I confused strongly/weakly with static. I feel a a bit 
embarrased by it. My apologies.

But no. Nothing that follows from that paragraph is wrong, just because 
of that mistake.

It still stands that list was artifically created to make it look like 
type annotations on top of executable code is a feature of nearly every 
language in the book. When it is not!

Most particularly when it comes to statically typed languages, wich 
Steven didn't feel guilty of including there.


From breamoreboy at yahoo.co.uk  Thu Jan 29 03:26:33 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 29 Jan 2015 08:26:33 +0000
Subject: why zip64_limit defined as 1<<31 -1?
In-Reply-To: <CAE6kErgzja2zS_fg6g0acQQpNVD_UCpmJQaNxbATSMyRoesznA@mail.gmail.com>
References: <CAE6kErhvOus7igddqKMLaJ=NdqNT9b=EUfuPVk0NAH-5U0PiNA@mail.gmail.com>
 <CAPTjJmqBumcD_xWLBkxP1PxgaDixqWj-+Ra8vrSO50KsyWNbxA@mail.gmail.com>
 <CAE6kErgzja2zS_fg6g0acQQpNVD_UCpmJQaNxbATSMyRoesznA@mail.gmail.com>
Message-ID: <macqs2$hdp$1@ger.gmane.org>

On 29/01/2015 00:55, jesse wrote:
> the official zip format spec states clearly that normal zip file should
> be <= 4G size instead 2G.  I just can not believe Python has such an
> obvious bug.
>
> People suggested monkey patch the ZIP64_LIMIT value to pass 2G, I am not
> sure what will be the ramifications.
>

There are numerous open issues on bugs.python.org regarding the zipfile 
and zipimport modules.  Perhaps you'd like to help fix a few of them?

As an aside please don't top post on this list, thanks.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From marfig at gmail.com  Thu Jan 29 03:34:52 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Thu, 29 Jan 2015 09:34:52 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
 <mailman.18224.1422466472.18130.python-list@python.org>
 <54c980cd$0$12981$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <MPG.2f340edca45427349896b4@nntp.aioe.org>

In article <54c980cd$0$12981$c3e8da3$5496439d at news.astraweb.com>, 
steve+comp.lang.python at pearwood.info says...
> 
> Ian, that's obvious. Just open your eyes:
> 
> Scala
> def addInt( a:Int, b:Int ) : Int
> 
> Python
> def addInt( a:int, b:int ) -> int:
> 
> 
> They're COMPLETELY different. In Scala they are *type declarations*, not
> annotations. We're talking about annotations, not declarations. They're as
> different as cheese and a very slightly different cheese. Do try to keep
> up.
> 
> *wink*

The sarcasm is unnecessary. They are different yes. Are you on purpose 
confusing the syntax of a feature with its meaning? Because while you 
have a very similar syntax between Julia, Scala and Python. Their 
meanings are very different.

I think it is obvious to anyone that if a feature like type annotations 
are meant to be EVALUATED AT RUNTIME (and I myself gave you another 
example of Julia), it makes every sense for that feature to be a part of 
the programming language syntax. I could never argue against Julia or 
Scala type annotations on that basis. The syntax is an integral part of 
the executable code.

But when a feature is not meant for runtime evaluation, why should it 
clutter your executable code? Make me understand your reasoning?

Your list of programming languages is just plain wrong. To my knowledge 
(there's a few languages there I don't know and never used), none of 
those languages implement anything like Python. Type annotations in 
python are entirely ignored by the interpreter except to make them 
available to external libraries. This is a feature that I have seen 
implemented in numerous languages as a part of doc-like comments. Never, 
ever, as a part ofthe language syntax.


From info at egenix.com  Thu Jan 29 03:49:29 2015
From: info at egenix.com (eGenix Team: M.-A. Lemburg)
Date: Thu, 29 Jan 2015 09:49:29 +0100
Subject: =?UTF-8?Q?ANN:_Python_Meeting_D=c3=bcsseldorf_-_New_Videos_?=
 =?UTF-8?Q?online?=
Message-ID: <54C9F419.6070706@egenix.com>

[This announcement is in German since it targets a local user group
 meeting in D?sseldorf, Germany]

________________________________________________________________________

WAS IST DAS PYTHON MEETING D?SSELDORF ?

Das Python Meeting D?sseldorf ist eine Veranstaltung, die alle drei
Monate in D?sseldorf stattfindet und sich an Python Begeisterte aus
der Region wendet:

                         http://pyddf.de/

Bei jedem Treffen werden Vortr?ge gehalten und anschlie?end in
Diskussionen vertieft. Die Meetings dauern ?blicherweise ca. 2 Stunden
und m?nden anschlie?end in eine Restaurant-Session.

Teilnehmer kommen aus ganz Nordrhein-Westfalen, haupts?chlich
allerdings aus der n?heren Umgebung.

Diese Nachricht ist auch online verf?gbar:
http://www.egenix.com/company/news/Python-Meeting-Duesseldorf-Videos

________________________________________________________________________

NEUE VIDEOS

Um die Vortr?ge auch f?r andere Python Enthusiasten zug?nglich zu
machen, nehmen wir die Vortr?ge auf, produzieren daraus Videos und
laden diese auf unseren PyDDF YouTube Channel hoch:

    https://youtube.com/pyddf/

In den letzten Tagen haben wir die Videos der letzten Treffen
aufgearbeitet. Insgesamt sind 34 neue Videos dazugekommen. Viel Spa?
damit:

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    https://www.youtube.com/watch?v=z_o6L5RkaiU&list=PLu2a6axgqUTzh81DNhnV2rTL6oCaKlZQr

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    https://www.youtube.com/watch?v=AHUKRoJwPCE&list=PLu2a6axgqUTylZtifjbOhvP0z1zIh7n_1

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    https://www.youtube.com/watch?v=y3BH9OBAn88&list=PLu2a6axgqUTwD7U3nFLhNiArHVLb17Y1Q

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    https://www.youtube.com/watch?v=1uJgXl4p9_I&list=PLu2a6axgqUTyDzIjWvz3NYQsqj8jT-G4J

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    https://www.youtube.com/watch?v=P3oD9EswbN8&list=PLu2a6axgqUTzRO1bUn62cUAwMkIxw8UrM

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    https://www.youtube.com/watch?v=Sd_fw8Ae49M&list=PLu2a6axgqUTz3PZfZowvKsZT3rTY2x7WO

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    https://www.youtube.com/watch?v=6pryEma7Ams&list=PLu2a6axgqUTyykq74j4ARFDfCMp7d3YsP


Die vollst?ndige Liste aller mehr als 70 Python Meeting Videos ist
?ber unsere Video Liste verf?gbar:

    http://www.egenix.com/library/pyddf/videos.html

________________________________________________________________________

WEITERE INFORMATIONEN

Weitere Informationen und Termine rund um das Python Meeting
D?sseldorf stehen auf unserer Webseite:

    http://pyddf.de/

Mit freundlichen Gr??en,
-- 
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eGenix.com

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    D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg
           Registered at Amtsgericht Duesseldorf: HRB 46611
               http://www.egenix.com/company/contact/


From breamoreboy at yahoo.co.uk  Thu Jan 29 03:49:50 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 29 Jan 2015 08:49:50 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <MPG.2f340c6ea39d9f3f9896b3@nntp.aioe.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
 <mailman.18229.1422469034.18130.python-list@python.org>
 <MPG.2f340c6ea39d9f3f9896b3@nntp.aioe.org>
Message-ID: <macs7n$6v5$1@ger.gmane.org>

On 29/01/2015 08:23, Mario Figueiredo wrote:
> In article <mailman.18229.1422469034.18130.python-list at python.org>,
> breamoreboy at yahoo.co.uk says...
>>
>> C and C++ are weakly and statically typed languages.  Python is a
>> strongly and dynamically typed language.  Therefore anything following
>> based on the above paragraph alone is wrong.
>>
>
> Indeed. I confused strongly/weakly with static. I feel a a bit
> embarrased by it. My apologies.

Accepted, from me anyhow. Please remember the only person who never 
makes a mistake never does anything :)

>
> But no. Nothing that follows from that paragraph is wrong, just because
> of that mistake.

I should have emphasied the word *alone*, sorry about that.

>
> It still stands that list was artifically created to make it look like
> type annotations on top of executable code is a feature of nearly every
> language in the book. When it is not!
>
> Most particularly when it comes to statically typed languages, wich
> Steven didn't feel guilty of including there.
>

I don't know enough about most other languages to comment, I'll leave 
that to the various gurus.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From cfkaran2 at gmail.com  Thu Jan 29 04:29:29 2015
From: cfkaran2 at gmail.com (Cem Karan)
Date: Thu, 29 Jan 2015 04:29:29 -0500
Subject: ANN: unpyc3 - a python bytecode decompiler for Python3
In-Reply-To: <CAPTjJmp+uG6hnz6_S8b5wBLd3Sggw2F-W5Nvyc1=ikutHuHOpg@mail.gmail.com>
References: <mailman.1084.1315945219.27778.python-list@python.org>
 <3dcc2862-bdd6-4a2a-8edb-1a9d51df26b3@googlegroups.com>
 <CABicbJKNs7uAWVBUSX6BV3OQJKJ5zTvmfOxHAucsH=VNJ5CfXw@mail.gmail.com>
 <CALvWhxuLSx-x8uMYTQyX5iHNpz38M7uOq+qTiibYrTmgmR33Sw@mail.gmail.com>
 <CAPTjJmqu9TqFK4uQaw+s-cuTMaJoatXRQ7iLsTch9aNDUfjnWw@mail.gmail.com>
 <CABicbJLEk3rhUd_8xRVZ59+wyuMrrVin9fOXhysjPxzoh86CKg@mail.gmail.com>
 <CAPTjJmp+uG6hnz6_S8b5wBLd3Sggw2F-W5Nvyc1=ikutHuHOpg@mail.gmail.com>
Message-ID: <4F485767-F2C8-4C56-BC82-D1B14C362B95@gmail.com>


On Jan 28, 2015, at 5:02 PM, Chris Angelico <rosuav at gmail.com> wrote:

> On Thu, Jan 29, 2015 at 8:52 AM, Devin Jeanpierre
> <jeanpierreda at gmail.com> wrote:
>> Git doesn't help if you lose your files in between commits, or if you
>> lose the entire directory between pushes.
> 
> So you commit often and push immediately. Solved.
> 
> ChrisA

Just to expand on what Chris is saying, learn to use branches.  I use git flow ([1][2]), but you don't need it, plain old branches are fine.  Then you can have a feature branch like 'Joes_current', or something similar which you and only you push/pull from.  Whenever you're done with it, you can merge the changes back into whatever you & your group see as the real branch.  That is the model I use at work, and it works fairly well, and its saved me once already when the laptop I was working on decided to die on me.

Thanks,
Cem Karan

[1] http://nvie.com/posts/a-successful-git-branching-model/
[2] https://github.com/nvie/gitflow

From zoneofbattle at yahoo.com  Thu Jan 29 06:29:12 2015
From: zoneofbattle at yahoo.com (Alex Potapenko)
Date: Thu, 29 Jan 2015 11:29:12 +0000 (UTC)
Subject: =?UTF-8?Q?=D0=9E=D1=82=D0=B2:_Python_on_armv7l_rou?=
 =?UTF-8?Q?ter:_C++_exceptions_issue?=
In-Reply-To: <1074278333.1184248.1422467092765.JavaMail.yahoo@mail.yahoo.com>
References: <1074278333.1184248.1422467092765.JavaMail.yahoo@mail.yahoo.com>
Message-ID: <119633865.1438155.1422530952127.JavaMail.yahoo@mail.yahoo.com>

Found a solution myself. It looks like you have to explicitly link python with libgcc_s during build time to solve this problem. This looks like a uClibc bug
Regards,Alex 

     ?????, 28 ?????? 2015 19:44 Alex Potapenko <zoneofbattle at yahoo.com> ?????(?):
   

 I run Python on an arm-brcm-linux-uclibcgnueabi router. Python was cross-compiled using hndtools-arm-linux-2.6.36-uclibc-4.5.3 toolchain. While trying to use deluge, I realised that there's something wrong with handling C++ exceptions in C++ extension modules: they're not being caught at all. I tested whether C++ exception handling works on my system in general, and concluded it does work fine. I then wrote a simple C++ extension module with a try-catch block in the init function, that has a "throw 1" in the try section and a "catch (...)" section (see module.cpp), and I got "terminate called after throwing an instance of 'int'" when trying to load the module. Tested this with Python 2.7.9 and 3.4.2, however I had similar issues with other versions, such as 2.7.3 and 2.6.9.
Does anyone happen to know what I can try here? Any help is greatly appreciated!


Thanks in advance,
Alex

   
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From jeanpierreda at gmail.com  Thu Jan 29 06:30:16 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Thu, 29 Jan 2015 03:30:16 -0800
Subject: ANN: unpyc3 - a python bytecode decompiler for Python3
In-Reply-To: <54c98027$0$12982$c3e8da3$5496439d@news.astraweb.com>
References: <mailman.1084.1315945219.27778.python-list@python.org>
 <3dcc2862-bdd6-4a2a-8edb-1a9d51df26b3@googlegroups.com>
 <CABicbJKNs7uAWVBUSX6BV3OQJKJ5zTvmfOxHAucsH=VNJ5CfXw@mail.gmail.com>
 <CALvWhxuLSx-x8uMYTQyX5iHNpz38M7uOq+qTiibYrTmgmR33Sw@mail.gmail.com>
 <CAPTjJmqu9TqFK4uQaw+s-cuTMaJoatXRQ7iLsTch9aNDUfjnWw@mail.gmail.com>
 <mailman.18244.1422481989.18130.python-list@python.org>
 <54c98027$0$12982$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CABicbJ+0AgT4YBGPPKJ7pvoc050Fp6mT72eo+yjoB+m3TcFyxA@mail.gmail.com>

On Wed, Jan 28, 2015 at 4:34 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Devin Jeanpierre wrote:
>> Git doesn't help if you lose your files in between commits,
>
> Sure it does? You just lose the changes made since the previous commit, but
> that's no different from restoring from backup. The restored file is only
> as up to date as the last time a backup was taken.

Yeah. My point here is that Drive/Dropbox take snapshots at much
shorter intervals than any reasonable person will commit with a DVCS,
so you lose much less.

-- Devin


From ninomaruzzeddu at gmx.com  Thu Jan 29 08:14:44 2015
From: ninomaruzzeddu at gmx.com (CHE SIA REVOLUCIOOON!!!)
Date: Thu, 29 Jan 2015 05:14:44 -0800 (PST)
Subject: -- redacted --
Message-ID: <7757dbc7-412a-4a42-8418-801a4d5d8fb4@googlegroups.com>

-- redacted --


From franssoa at email.invalid  Thu Jan 29 08:38:20 2015
From: franssoa at email.invalid (franssoa)
Date: Thu, 29 Jan 2015 14:38:20 +0100
Subject: Sort of Augmented Reality
Message-ID: <madd3b$u2l$1@dont-email.me>

Hello,

(please excuse my english as is not my primary language)

- I own a webcam that take a picture of outside of my house once per minute.
- With a DVB sticker, I know the latitude, longitude and altitude of the
planes in my area.

I would like to print the data of the planes visibles on the pictures
taken by the webcam, like "my sky view" from program "planeplotter" [1].

Does anybody know what kind of tools/library I can use, in Python as is
the language I know the best.
Last thing : I'm a dumb in math...

Fran?ois

[1] http://www.coaa.co.uk/planeplotter.htm


From 1989lzhh at gmail.com  Thu Jan 29 08:39:39 2015
From: 1989lzhh at gmail.com (1989lzhh)
Date: Thu, 29 Jan 2015 21:39:39 +0800
Subject: [OT] fortran lib which provide python like data type
Message-ID: <84BCA50E-DC66-40FF-8860-C86468F967EC@gmail.com>

Hi,
I am not sure here is the right place to ask this question, but I want to give it a shot:)
are there fortran libs providing python like data type, such as set, dict, list?
Thanks,
Yours liuzhenhai

From ginobusciarello at outlook.com  Thu Jan 29 08:51:22 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Thu, 29 Jan 2015 05:51:22 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <35861325-94c1-418c-ab89-e4ea967431da@googlegroups.com>
References: <35861325-94c1-418c-ab89-e4ea967431da@googlegroups.com>
Message-ID: <dd3e6122-1f19-463c-9075-7a2df513ee6b@googlegroups.com>

-- redacted --


From ginobusciarello at outlook.com  Thu Jan 29 08:55:47 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Thu, 29 Jan 2015 05:55:47 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
References: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
Message-ID: <7691947a-ea3b-4b6a-8c5c-7aa99eb7059e@googlegroups.com>

-- redacted --


From random832 at fastmail.us  Thu Jan 29 09:08:39 2015
From: random832 at fastmail.us (random832 at fastmail.us)
Date: Thu, 29 Jan 2015 09:08:39 -0500
Subject: Python is DOOMED! Again!
In-Reply-To: <mab931$qqu$1@ger.gmane.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org> <mab931$qqu$1@ger.gmane.org>
Message-ID: <1422540519.737721.220492505.1C641B3C@webmail.messagingengine.com>

On Wed, Jan 28, 2015, at 13:16, Mark Lawrence wrote:
> C and C++ are weakly and statically typed languages.

"strong typing" has no meaning at all, and "weak typing" means "anything
I don't like".

The fact that you can add an int and a float, or that you can use any
object as a boolean, would make python weakly typed in some people's
eyes.


From ian.g.kelly at gmail.com  Thu Jan 29 10:48:26 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 29 Jan 2015 08:48:26 -0700
Subject: An object is an instance (or not)?
In-Reply-To: <54c9de44$0$12915$c3e8da3$5496439d@news.astraweb.com>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
 <mailman.18195.1422405040.18130.python-list@python.org>
 <MPG.2f324d0d46ba9afc9896ac@nntp.aioe.org> <cirs87F1tdrU2@mid.individual.net>
 <54c8cd8f$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <ciu1taFjekrU1@mid.individual.net>
 <54c9de44$0$12915$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CALwzid=2YjtxhuDGW0aOBuodeZSp-ts_QthqQD2zB_wG_D7aFQ@mail.gmail.com>

On Thu, Jan 29, 2015 at 12:16 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Besides, descriptors are
> handled by the metaclass, so we could write a metaclass that doesn't handle
> them.

Maybe this doesn't affect your argument, but they're actually handled
by the class's __getattribute__, not by the metaclass.

>>> class MyMeta(type):
...   def __getattribute__(cls, attr):
...     raise AttributeError(attr)
...
>>> class MyClass(metaclass=MyMeta):
...   @property
...   def spam(self):
...     return 42
...
>>> MyClass().spam
42
>>> class MyClass:
...   def __getattribute__(self, attr):
...     return type(self).__dict__[attr]
...   @property
...   def spam(self):
...     return 42
...
>>> MyClass().spam
<property object at 0x7f0603e70598>


From steve+comp.lang.python at pearwood.info  Thu Jan 29 10:56:45 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 30 Jan 2015 02:56:45 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org> <mab931$qqu$1@ger.gmane.org>
 <mailman.18262.1422540523.18130.python-list@python.org>
Message-ID: <54ca583e$0$13005$c3e8da3$5496439d@news.astraweb.com>

random832 at fastmail.us wrote:

> On Wed, Jan 28, 2015, at 13:16, Mark Lawrence wrote:
>> C and C++ are weakly and statically typed languages.
> 
> "strong typing" has no meaning at all, and "weak typing" means "anything
> I don't like".

I see you've been reading Chris Smith's essay on typing :-)

https://cdsmith.wordpress.com/2011/01/09/an-old-article-i-wrote/

I think his essay is excellent, but his claim that strong and weak typing is
a meaningless distinction is excessive.

> The fact that you can add an int and a float, or that you can use any
> object as a boolean, would make python weakly typed in some people's
> eyes.

I think they would be wrong. Well, mostly wrong. But a little bit right.

We should agree that there is no universal, hard distinction between strong
and weak typing. But the names already suggest that -- there is no dividing
line between strong and weak. But we can certainly *rank* languages by
degrees of strength according to some standard, and if we agree on the
standard, we should agree on the rankings.

Even if we don't agree on a standard, we can surely agree on the two extreme
cases. Let's call them Foo and Bar language. They're both typed languages.

Foo language has no automatic coercions at all. Every type is utterly
distinct. The only way to convert a value of one type to another is with an
explicit XtoY function. Surely we can agree that Foo is a *very strongly
typed* language? (Perhaps even too strong?)

Bar language, on the other hand, tries extremely hard to ensure that every
type is automatically able to be coerced into every other type. The
coercion might not do what you expect, but it will do *something*:

{'a': 100, 'b': 300} + 5.0
=> 7.0

[1, 2, 3] + "hello"
=> [1, 2, 3, 'h', 'e', 'l', 'l', 'o']

"hello" + [1, 2, 3]
=> "hello[1, 2, 3]"

Bar will never give you a TypeError. I think we can agree that Bar is a
*very weakly typed* language.

There are degrees of strength, and I think that Python comes closer to the
Foo end than the Bar end. There are few automatic coercions, and most of
those are in the numeric tower according to the usual mathematical rules.


-- 
Steven



From steve+comp.lang.python at pearwood.info  Thu Jan 29 11:11:42 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 30 Jan 2015 03:11:42 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
 <mailman.18229.1422469034.18130.python-list@python.org>
 <MPG.2f340c6ea39d9f3f9896b3@nntp.aioe.org>
Message-ID: <54ca5bbf$0$12992$c3e8da3$5496439d@news.astraweb.com>

Mario Figueiredo wrote:

> In article <mailman.18229.1422469034.18130.python-list at python.org>,
> breamoreboy at yahoo.co.uk says...
>> 
>> C and C++ are weakly and statically typed languages.  Python is a
>> strongly and dynamically typed language.  Therefore anything following
>> based on the above paragraph alone is wrong.
>> 
> 
> Indeed. I confused strongly/weakly with static. I feel a a bit
> embarrased by it. My apologies.
> 
> But no. Nothing that follows from that paragraph is wrong, just because
> of that mistake.
> 
> It still stands that list was artifically created to make it look like
> type annotations on top of executable code is a feature of nearly every
> language in the book. When it is not!
> 
> Most particularly when it comes to statically typed languages, wich
> Steven didn't feel guilty of including there.

Why should I feel guilty? You wrote:


"Static analysis cannot and should not clutter executable code."


But what are type declarations in statically typed languages like C, Pascal,
Haskell, etc.? They are used by the compiler for static analysis. The same
applies to type declarations in dynamically typed languages like Cobra and
Julia. And yet, there they are, in the executable code.

So there are a whole lot of languages, going all the way back to 1950s
languages like Fortran, to some of the newest languages which are only a
few years old like Go, both dynamically typed and statically typed, which
do exactly what you say languages "cannot and should not" do: they put type
information used for static analysis there in the code.

As I said, these languages disagree with you. You are not just arguing
against Guido, but against the majority of programming language designers
for 60+ years.



-- 
Steven



From ian.g.kelly at gmail.com  Thu Jan 29 11:30:02 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 29 Jan 2015 09:30:02 -0700
Subject: Python is DOOMED! Again!
In-Reply-To: <MPG.2f340edca45427349896b4@nntp.aioe.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
 <mailman.18224.1422466472.18130.python-list@python.org>
 <54c980cd$0$12981$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f340edca45427349896b4@nntp.aioe.org>
Message-ID: <CALwzidmLEAb9Em1yMzqgWT=uUpQBJzEQM8+VXeP+-qzpZuU_vg@mail.gmail.com>

On Thu, Jan 29, 2015 at 1:34 AM, Mario Figueiredo <marfig at gmail.com> wrote:
> In article <54c980cd$0$12981$c3e8da3$5496439d at news.astraweb.com>,
> steve+comp.lang.python at pearwood.info says...
>>
>> Ian, that's obvious. Just open your eyes:
>>
>> Scala
>> def addInt( a:Int, b:Int ) : Int
>>
>> Python
>> def addInt( a:int, b:int ) -> int:
>>
>>
>> They're COMPLETELY different. In Scala they are *type declarations*, not
>> annotations. We're talking about annotations, not declarations. They're as
>> different as cheese and a very slightly different cheese. Do try to keep
>> up.
>>
>> *wink*
>
> The sarcasm is unnecessary. They are different yes. Are you on purpose
> confusing the syntax of a feature with its meaning? Because while you
> have a very similar syntax between Julia, Scala and Python. Their
> meanings are very different.
>
> I think it is obvious to anyone that if a feature like type annotations
> are meant to be EVALUATED AT RUNTIME (and I myself gave you another
> example of Julia), it makes every sense for that feature to be a part of
> the programming language syntax. I could never argue against Julia or
> Scala type annotations on that basis. The syntax is an integral part of
> the executable code.

Okay, I don't know enough about Scala's type system to discuss that
example in this context, so I won't try to. Let's instead focus on
another of the languages you listed: C. C includes types in its
syntax, which it uses for static analysis at compile time. At runtime,
it uses them for ... nothing. In fact, if you examine a compiled C
binary, you won't even find any type information in there. If you
dynamically load a C library containing a function that takes a
double, and you pass it a long, it won't even blink. It will just
assume that the data it received represents a double and proceed from
there.

Now with PEP 484 type annotations on the other hand, while the
suggested static analysis tools aren't used at runtime, the
annotations themselves are available to be evaluated at runtime. If
you want to write a decorator that examines the types of the arguments
of the function it decorates and does something nifty with them
(automatic registration of overloaded functions using PEP 443
generics, perhaps), there is absolutely nothing stopping you from
doing that.


From steve+comp.lang.python at pearwood.info  Thu Jan 29 11:41:45 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Fri, 30 Jan 2015 03:41:45 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
 <mailman.18224.1422466472.18130.python-list@python.org>
 <54c980cd$0$12981$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f340edca45427349896b4@nntp.aioe.org>
Message-ID: <54ca62ca$0$13000$c3e8da3$5496439d@news.astraweb.com>

Mario Figueiredo wrote:

> In article <54c980cd$0$12981$c3e8da3$5496439d at news.astraweb.com>,
> steve+comp.lang.python at pearwood.info says...
>> 
>> Ian, that's obvious. Just open your eyes:
>> 
>> Scala
>> def addInt( a:Int, b:Int ) : Int
>> 
>> Python
>> def addInt( a:int, b:int ) -> int:
>> 
>> 
>> They're COMPLETELY different. In Scala they are *type declarations*, not
>> annotations. We're talking about annotations, not declarations. They're
>> as different as cheese and a very slightly different cheese. Do try to
>> keep up.
>> 
>> *wink*
> 
> The sarcasm is unnecessary. They are different yes. Are you on purpose
> confusing the syntax of a feature with its meaning? Because while you
> have a very similar syntax between Julia, Scala and Python. Their
> meanings are very different.

No they aren't. Their primary meaning is to declare the type used by the
parameter.



> I think it is obvious to anyone that if a feature like type annotations
> are meant to be EVALUATED AT RUNTIME (and I myself gave you another
> example of Julia), it makes every sense for that feature to be a part of
> the programming language syntax. I could never argue against Julia or
> Scala type annotations on that basis. The syntax is an integral part of
> the executable code.

Ah, you mean just like Python, where annotations are evaluated at runtime,
just like Julia:

py> def spam(n:int)-> getattr(sys, 'version'):
...     return "spam"*n
...
py> spam.__annotations__
{'n': <class 'int'>, 'return': '3.3.0rc3 (default, Sep 27 2012, 18:44:58)
\n[GCC 4.1.2 20080704 (Red Hat 4.1.2-52)]'}


Python has had annotations for over five years. They are evaluated at
runtime. They will continue to be evaluated at runtime.

One of the benefits of this system is that people may write *runtime*
type-checkers that use the same annotations that the lexical analysis tools
will use.

It is possible that you aren't following the meaning of this. The idea
behind PEP 484 is that Python will standardise on a single expected syntax
for type-hints, so that all of the following tools can agree on a set of
basic rules for interpreting the annotations:

- lexical type-checkers (those that operate on only the source code, 
  with no runtime information)
- alternate Python compilers, like MyPy, which perform compile-time 
  type checking
- IDEs and text editors, which may use lexical type info available
  in the source code to flag errors and offer auto-completion
- stand-alone tools such as correctness provers
- documentation generators
- runtime type-checkers
- runtime introspection tools

and more.

One of the rules is that the *standard* type-hints have to be simple enough
that a purely lexical tool like an IDE or editor can understand it without
needing to run arbitrary code. But the annotations themselves can be
arbitrarily complex Python expressions. Its just that then the tools
expecting type-hints won't be able to process those annotations from the
source code alone. Runtime introspection tools will not care, because they
don't see the expression, they only see the result of evaluating that
expression.


> But when a feature is not meant for runtime evaluation, why should it
> clutter your executable code? Make me understand your reasoning?

Perhaps you should ask the designers of Pascal, Go, Scheme, C, D, F# and all
those dozens and hundreds of other languages. They have a feature which is
not evaluated at runtime -- the type declarations -- and they put it in the
source code.

And why shouldn't they? Type declarations are source code!


> Your list of programming languages is just plain wrong. To my knowledge
> (there's a few languages there I don't know and never used), none of
> those languages implement anything like Python. 

Not so.


> Type annotations in 
> python are entirely ignored by the interpreter except to make them 
> available to external libraries. 


That is incorrect.

Perhaps you are confusing by the fact that the Python interpreter doesn't
give any meaning to annotations? It still evaluates them at runtime, and
stores the result in the function object.



-- 
Steven



From info at wingware.com  Thu Jan 29 12:05:25 2015
From: info at wingware.com (Wingware)
Date: Thu, 29 Jan 2015 12:05:25 -0500
Subject: ANN: Wing IDE 5.1 released
Message-ID: <54CA6855.20002@wingware.com>

Hi,

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integrated development environment for the Python programming language.

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studio, and other key bindings, auto-completion, call tips, 
context-sensitive auto-editing, goto-definition, find uses, refactoring, 
a powerful debugger, version control, unit testing, search, project 
management, and many other features.

Wing IDE 5.1 adds multi-process and child process debugging, syntax 
highlighting in the shells, persistent time-stamped unit test results, 
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support for Flask and Django 1.7, and many other minor features and 
improvements.  For details see http://wingware.com/news/2015-01-22

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Upgrades: https://wingware.com/store/upgrade

Questions?  Don't hesitate to email us at support at wingware.com.

Thanks,

-- 

Stephan Deibel
Wingware | Python IDE

The Intelligent Development Environment for Python Programmers

wingware.com



From ian.g.kelly at gmail.com  Thu Jan 29 12:05:35 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 29 Jan 2015 10:05:35 -0700
Subject: why zip64_limit defined as 1<<31 -1?
In-Reply-To: <CAE6kErgzja2zS_fg6g0acQQpNVD_UCpmJQaNxbATSMyRoesznA@mail.gmail.com>
References: <CAE6kErhvOus7igddqKMLaJ=NdqNT9b=EUfuPVk0NAH-5U0PiNA@mail.gmail.com>
 <CAPTjJmqBumcD_xWLBkxP1PxgaDixqWj-+Ra8vrSO50KsyWNbxA@mail.gmail.com>
 <CAE6kErgzja2zS_fg6g0acQQpNVD_UCpmJQaNxbATSMyRoesznA@mail.gmail.com>
Message-ID: <CALwzidkoox8c2Vnp3dpyVby86STUnw85CetqTN1ZH7pHrE_ZsQ@mail.gmail.com>

On Wed, Jan 28, 2015 at 5:55 PM, jesse <chat2jesse at gmail.com> wrote:
> the official zip format spec states clearly that normal zip file should be
> <= 4G size instead 2G.  I just can not believe Python has such an obvious
> bug.
>
> People suggested monkey patch the ZIP64_LIMIT value to pass 2G, I am not
> sure what will be the ramifications.

Is the current value causing any actual problem? I'm not familiar with
the zipfile source, but from a brief scan it looks like all this does
is set the threshold at which it will output zip64 files instead of
classic zip files.


From breamoreboy at yahoo.co.uk  Thu Jan 29 12:17:09 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 29 Jan 2015 17:17:09 +0000
Subject: The Most Diabolical Python Antipattern
Message-ID: <madpuv$he7$1@ger.gmane.org>

The author is quite clear on his views here 
https://realpython.com/blog/python/the-most-diabolical-python-antipattern/ 
but what do you guys and gals think?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From ian.g.kelly at gmail.com  Thu Jan 29 12:25:53 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 29 Jan 2015 10:25:53 -0700
Subject: why zip64_limit defined as 1<<31 -1?
In-Reply-To: <CAPTjJmqBumcD_xWLBkxP1PxgaDixqWj-+Ra8vrSO50KsyWNbxA@mail.gmail.com>
References: <CAE6kErhvOus7igddqKMLaJ=NdqNT9b=EUfuPVk0NAH-5U0PiNA@mail.gmail.com>
 <CAPTjJmqBumcD_xWLBkxP1PxgaDixqWj-+Ra8vrSO50KsyWNbxA@mail.gmail.com>
Message-ID: <CALwzidkEUem2pEu-OP_RBV6yPZKCdQcTQZ9P86b6cPn0SVhf_Q@mail.gmail.com>

On Wed, Jan 28, 2015 at 2:36 PM, Chris Angelico <rosuav at gmail.com> wrote:
> On Thu, Jan 29, 2015 at 5:53 AM, jesse <chat2jesse at gmail.com> wrote:
>> should not it be 1<<32 -1(4g)?
>>
>> normal zip archive format should be able to support 4g file.
>>
>> thanks
>
> 1<<31-1 is the limit for a signed 32-bit integer. You'd have to look
> into the details of the zip file format to see whether that's the
> official limit or not; it might simply be that some (un)archivers have
> problems with >2GB files, even if the official stance is that it's
> unsigned.

The bug in which zip64 support was added indicates that the value was
indeed chosen as the limit of a signed 32-bit integer:

http://bugs.python.org/issue1446489


From python.list at tim.thechases.com  Thu Jan 29 12:32:38 2015
From: python.list at tim.thechases.com (Tim Chase)
Date: Thu, 29 Jan 2015 11:32:38 -0600
Subject: The Most Diabolical Python Antipattern
In-Reply-To: <madpuv$he7$1@ger.gmane.org>
References: <madpuv$he7$1@ger.gmane.org>
Message-ID: <20150129113238.7eaa986d@bigbox.christie.dr>

On 2015-01-29 17:17, Mark Lawrence wrote:
> The author is quite clear on his views here 
> https://realpython.com/blog/python/the-most-diabolical-python-antipattern/ 
> but what do you guys and gals think?

I just read that earlier today and agree for the most part.  The only
exception (pun only partially intended) I've found is in functions
that need to return a defined type.  I have one that I call int0()
that is my "give me a freakin' int" function which is something like

  def int0(val):
    try:
      return int(val)
    except:
      return 0

because I deal with a lot of CSV data from client/vendor that has
blanks, "NULL", "---", and plenty of other rubbish to suggest
something that, for my purposes is really just a 0.

Yes, I've been stung by it occasionally, but it's not much trouble to
see that I'm getting a 0 some place that should have a value I need
to extract.

-tkc




From skip.montanaro at gmail.com  Thu Jan 29 12:36:41 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Thu, 29 Jan 2015 11:36:41 -0600
Subject: The Most Diabolical Python Antipattern
In-Reply-To: <madpuv$he7$1@ger.gmane.org>
References: <madpuv$he7$1@ger.gmane.org>
Message-ID: <CANc-5Uy-B4GsUHbRX+KyH+uE06WXMDs5-Mf_S7uH0PYWiZ0HVw@mail.gmail.com>

On Thu, Jan 29, 2015 at 11:17 AM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
>
> ... but what do you guys and gals think?

I saw that blog referenced elsewhere a day or two ago. I think he's
correct. There are the occasional instance where I need to recover
from an exception no matter what caused it. In cases where I fail to
report the traceback somewhere, I'm often left scratching my head.

In my mind, this is approximately as bad as an external library
(silently) calling exit().

Skip


From aklee237 at gmail.com  Thu Jan 29 12:38:21 2015
From: aklee237 at gmail.com (3D artist)
Date: Thu, 29 Jan 2015 09:38:21 -0800 (PST)
Subject: 3d printing slicer
Message-ID: <f634e1d2-0b15-463d-829c-5c36b0dd55fc@googlegroups.com>

Hi everyone

I'm trying to run Nick Parker's 3d printing slicer.

https://github.com/nick-parker/python3Dplay/tree/master/Shift%20Method

I am using WinPython 2.7.9.1 to import scipy

https://winpython.github.io/

I get these errors when running main.py

Traceback (most recent call last):
  File "C:\Users\z003EE9Y\Desktop\WinPython-32bit-2.7.9.2\slicer\main.py", line 10, in <module>
    test = stl_importer.stl_import("model.stl")
  File "C:\Users\z003EE9Y\Desktop\WinPython-32bit-2.7.9.2\slicer\stl_importer.py", line 44, in stl_import
    output=mesh.mesh(currentTris)
  File "C:\Users\z003EE9Y\Desktop\WinPython-32bit-2.7.9.2\slicer\mesh.py", line 18, in __init__
    self.updateLims()
  File "C:\Users\z003EE9Y\Desktop\WinPython-32bit-2.7.9.2\slicer\mesh.py", line 28, in updateLims
    self.region[0][0]=[[max(Xs),max(Ys),max(Zs)],[min(Xs),min(Ys),min(Zs)]]
ValueError: setting an array element with a sequence.
>>> 

Error 1 test = stl_importer.stl_import("model.stl")

Error 2 output=mesh.mesh(currentTris)

Error 3    self.updateLims()

Error 4         self.region[0][0]=[[max(Xs),max(Ys),max(Zs)],[min(Xs),min(Ys),min(Zs)]]

Thanks in advance


From brunocauet at gmail.com  Thu Jan 29 12:49:16 2015
From: brunocauet at gmail.com (Bruno Cauet)
Date: Thu, 29 Jan 2015 18:49:16 +0100
Subject: Results of the python 2.x and 3.x use survey, 2014 edition
Message-ID: <CAMA3c49yP8C4MS50qsH7P3waKO49RPNtFXgd5WgYJQHk0VSbJw@mail.gmail.com>

Hi!
Finally, here are the results:
http://blog.frite-camembert.net/python-survey-2014.html
Here is the auto-generated Google Forms recap:
https://docs.google.com/forms/d/1DqxkNi4GvyTCu54usSdE1DjW29zw1tc52iMeH3z4heg/viewanalytics
(more elegant than my matplotlib graphs - I'd have no future as a
designer).

Overall people started writing more python 3: +15 points in "I ever
wrote python 3 code", +10 points in "I write more python 3 than 2".
Transition is still ongoing and I hope a tipping point will be soon be
attained.
Users definitely seem to want to switch to python 3, but dependencies
keep them with 2.7 (I weep for the few ones still on 2.5).

I also posted the results on HN
(https://news.ycombinator.com/item?id=8967645) and reddit
(http://www.reddit.com/r/Python/comments/2u3oh0/results_of_the_python_2x_and_3x_use_survey_2014/).
Have a nice day, and a year full of python 3!

Bruno Cauet


From ethan at stoneleaf.us  Thu Jan 29 12:49:54 2015
From: ethan at stoneleaf.us (Ethan Furman)
Date: Thu, 29 Jan 2015 09:49:54 -0800
Subject: The Most Diabolical Python Antipattern
In-Reply-To: <CANc-5Uy-B4GsUHbRX+KyH+uE06WXMDs5-Mf_S7uH0PYWiZ0HVw@mail.gmail.com>
References: <madpuv$he7$1@ger.gmane.org>
 <CANc-5Uy-B4GsUHbRX+KyH+uE06WXMDs5-Mf_S7uH0PYWiZ0HVw@mail.gmail.com>
Message-ID: <54CA72C2.9080903@stoneleaf.us>

On 01/29/2015 09:36 AM, Skip Montanaro wrote:
> On Thu, Jan 29, 2015 at 11:17 AM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
>>
>> ... but what do you guys and gals think?
> 
> I saw that blog referenced elsewhere a day or two ago. I think he's
> correct. There are the occasional instance where I need to recover
> from an exception no matter what caused it. In cases where I fail to
> report the traceback somewhere, I'm often left scratching my head.

I agree -- worst practice.


> In my mind, this is approximately as bad as an external library
> (silently) calling exit().

Yeah, I hate when that happens.  I hate it even more when it's my own library. :/  (yeah, I fixed that!)

--
~Ethan~

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From random832 at fastmail.us  Thu Jan 29 13:23:48 2015
From: random832 at fastmail.us (random832 at fastmail.us)
Date: Thu, 29 Jan 2015 13:23:48 -0500
Subject: Python is DOOMED! Again!
In-Reply-To: <54ca583e$0$13005$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org> <mab931$qqu$1@ger.gmane.org>
 <mailman.18262.1422540523.18130.python-list@python.org>
 <54ca583e$0$13005$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <1422555828.839301.220608921.416BDD33@webmail.messagingengine.com>

On Thu, Jan 29, 2015, at 10:56, Steven D'Aprano wrote:
> Bar language, on the other hand, tries extremely hard to ensure that
> every
> type is automatically able to be coerced into every other type. The
> coercion might not do what you expect, but it will do *something*:

See, this is where the concept falls apart. Many people will define a
dynamically-typed language as weakly-typed *only if* the result of the
automatic type coercion is unexpected/distasteful/fattening, even if it
is well-defined and predictable according to the rules of the language.
Which makes it a matter of personal taste.

> Bar will never give you a TypeError. I think we can agree that Bar is a
> *very weakly typed* language.

Statically typed lanugages by definition can never give you a TypeError
- there are no runtime conversions that can succeed or fail based on the
type of the arguments. What makes a statically typed language strong or
weak? Are statically typed languages always weak?

> 
> There are degrees of strength, and I think that Python comes closer to
> the
> Foo end than the Bar end. There are few automatic coercions, and most of
> those are in the numeric tower according to the usual mathematical rules.

Why is converting an int to a float when passed to a math function
better than converting any object to a string when passed to a string
function?


From automn at willow.org  Thu Jan 29 13:30:34 2015
From: automn at willow.org (Automn)
Date: 29 Jan 2015 18:30:34 GMT
Subject: joke
Message-ID: <slrnmckv8m.8cl.automn@sigtrans.org>

What about : 

- "The royal Python is Clean your highness." 
- "Thank you."



From wxjmfauth at gmail.com  Thu Jan 29 13:53:26 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Thu, 29 Jan 2015 10:53:26 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <54ca583e$0$13005$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org> <mab931$qqu$1@ger.gmane.org>
 <mailman.18262.1422540523.18130.python-list@python.org>
 <54ca583e$0$13005$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <509ce40c-0271-4a09-bbc7-ee91d92a291b@googlegroups.com>

Le jeudi 29 janvier 2015 16:56:59 UTC+1, Steven D'Aprano a ?crit?:
> 
> There are degrees of strength, and I think that Python comes closer to the
> Foo end than the Bar end. There are few automatic coercions, and most of
> those are in the numeric tower according to the usual mathematical rules.
> 
The set of elements N, Z, Q, I, R, C, ....
are, in mathematics, *not* building a tower.


From breamoreboy at yahoo.co.uk  Thu Jan 29 13:54:15 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 29 Jan 2015 18:54:15 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <1422555828.839301.220608921.416BDD33@webmail.messagingengine.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org> <mab931$qqu$1@ger.gmane.org>
 <mailman.18262.1422540523.18130.python-list@python.org>
 <54ca583e$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <1422555828.839301.220608921.416BDD33@webmail.messagingengine.com>
Message-ID: <madvl1$vai$1@ger.gmane.org>

On 29/01/2015 18:23, random832 at fastmail.us wrote:
>
> Statically typed lanugages by definition can never give you a TypeError
> - there are no runtime conversions that can succeed or fail based on the
> type of the arguments. What makes a statically typed language strong or
> weak? Are statically typed languages always weak?
>

They can give you lots of warnings about possible loss of data or 
similar.  Yes, you can silence these warnings if you know what you're 
doing.  You can also silence them if you don't know what you're doing. 
The end result could be a lovely, friendly segfault to debug.  What joy?

No, they're not always weakly typed.  The aim of the spreadsheet put up 
by Skip was to sort out (roughly) which languages belong in which camp. 
  I do not regard myself as suitably qualified to fill the thing out. 
Perhaps by now others have?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From sohcahtoa82 at gmail.com  Thu Jan 29 13:58:59 2015
From: sohcahtoa82 at gmail.com (sohcahtoa82 at gmail.com)
Date: Thu, 29 Jan 2015 10:58:59 -0800 (PST)
Subject: joke
In-Reply-To: <slrnmckv8m.8cl.automn@sigtrans.org>
References: <slrnmckv8m.8cl.automn@sigtrans.org>
Message-ID: <67446b65-76f9-4d81-864b-93b9edd610a8@googlegroups.com>

On Thursday, January 29, 2015 at 10:30:46 AM UTC-8, Automn wrote:
> What about : 
> 
> - "The royal Python is Clean your highness." 
> - "Thank you."

I don't get it.


From ethan at stoneleaf.us  Thu Jan 29 14:06:22 2015
From: ethan at stoneleaf.us (Ethan Furman)
Date: Thu, 29 Jan 2015 11:06:22 -0800
Subject: joke
In-Reply-To: <67446b65-76f9-4d81-864b-93b9edd610a8@googlegroups.com>
References: <slrnmckv8m.8cl.automn@sigtrans.org>
 <67446b65-76f9-4d81-864b-93b9edd610a8@googlegroups.com>
Message-ID: <54CA84AE.3010801@stoneleaf.us>

On 01/29/2015 10:58 AM, sohcahtoa82 at gmail.com wrote:
> On Thursday, January 29, 2015 at 10:30:46 AM UTC-8, Automn wrote:
>> What about : 
>>
>> - "The royal Python is Clean your highness." 
>> - "Thank you."
> 
> I don't get it.

I suspect it is a reference to an old Eddie Murphy (?) movie in which he is a prince and has attendants to bathe him.

If I am correct it is an immature joke and has no place on this list.

--
~Ethan~

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From chat2jesse at gmail.com  Thu Jan 29 14:12:23 2015
From: chat2jesse at gmail.com (jesse)
Date: Thu, 29 Jan 2015 11:12:23 -0800
Subject: why zip64_limit defined as 1<<31 -1?
In-Reply-To: <CALwzidkEUem2pEu-OP_RBV6yPZKCdQcTQZ9P86b6cPn0SVhf_Q@mail.gmail.com>
References: <CAE6kErhvOus7igddqKMLaJ=NdqNT9b=EUfuPVk0NAH-5U0PiNA@mail.gmail.com>
 <CAPTjJmqBumcD_xWLBkxP1PxgaDixqWj-+Ra8vrSO50KsyWNbxA@mail.gmail.com>
 <CALwzidkEUem2pEu-OP_RBV6yPZKCdQcTQZ9P86b6cPn0SVhf_Q@mail.gmail.com>
Message-ID: <CAE6kEriXAyuLjeHqt4LJLBeEpUVinYWyaHZ9D1XPgv1kEzADEw@mail.gmail.com>

On Jan 29, 2015 9:27 AM, "Ian Kelly" <ian.g.kelly at gmail.com> wrote:
>
> On Wed, Jan 28, 2015 at 2:36 PM, Chris Angelico <rosuav at gmail.com> wrote:
> > On Thu, Jan 29, 2015 at 5:53 AM, jesse <chat2jesse at gmail.com> wrote:
> >> should not it be 1<<32 -1(4g)?
> >>
> >> normal zip archive format should be able to support 4g file.
> >>
> >> thanks
> >
> > 1<<31-1 is the limit for a signed 32-bit integer. You'd have to look
> > into the details of the zip file format to see whether that's the
> > official limit or not; it might simply be that some (un)archivers have
> > problems with >2GB files, even if the official stance is that it's
> > unsigned.
>
> The bug in which zip64 support was added indicates that the value was
> indeed chosen as the limit of a signed 32-bit integer:
>
> http://bugs.python.org/issue1446489

ok,  then why signed 32-bit integer instead of unsigned 32 integer? any
technical limitation reason? the chosen 2G boundary does not conform to zip
standard specification.

> --
> https://mail.python.org/mailman/listinfo/python-list
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From ian.g.kelly at gmail.com  Thu Jan 29 15:26:14 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 29 Jan 2015 13:26:14 -0700
Subject: why zip64_limit defined as 1<<31 -1?
In-Reply-To: <CAE6kEriXAyuLjeHqt4LJLBeEpUVinYWyaHZ9D1XPgv1kEzADEw@mail.gmail.com>
References: <CAE6kErhvOus7igddqKMLaJ=NdqNT9b=EUfuPVk0NAH-5U0PiNA@mail.gmail.com>
 <CAPTjJmqBumcD_xWLBkxP1PxgaDixqWj-+Ra8vrSO50KsyWNbxA@mail.gmail.com>
 <CALwzidkEUem2pEu-OP_RBV6yPZKCdQcTQZ9P86b6cPn0SVhf_Q@mail.gmail.com>
 <CAE6kEriXAyuLjeHqt4LJLBeEpUVinYWyaHZ9D1XPgv1kEzADEw@mail.gmail.com>
Message-ID: <CALwzidkZ8YX6z_Z8eeErk25JUPSEa07az6VaTjgo8PKiCMPGjQ@mail.gmail.com>

On Thu, Jan 29, 2015 at 12:12 PM, jesse <chat2jesse at gmail.com> wrote:
>
> On Jan 29, 2015 9:27 AM, "Ian Kelly" <ian.g.kelly at gmail.com> wrote:
>>
>> On Wed, Jan 28, 2015 at 2:36 PM, Chris Angelico <rosuav at gmail.com> wrote:
>> > On Thu, Jan 29, 2015 at 5:53 AM, jesse <chat2jesse at gmail.com> wrote:
>> >> should not it be 1<<32 -1(4g)?
>> >>
>> >> normal zip archive format should be able to support 4g file.
>> >>
>> >> thanks
>> >
>> > 1<<31-1 is the limit for a signed 32-bit integer. You'd have to look
>> > into the details of the zip file format to see whether that's the
>> > official limit or not; it might simply be that some (un)archivers have
>> > problems with >2GB files, even if the official stance is that it's
>> > unsigned.
>>
>> The bug in which zip64 support was added indicates that the value was
>> indeed chosen as the limit of a signed 32-bit integer:
>>
>> http://bugs.python.org/issue1446489
>
> ok,  then why signed 32-bit integer instead of unsigned 32 integer? any
> technical limitation reason? the chosen 2G boundary does not conform to zip
> standard specification.

I don't know specifically, but as Chris said it may be to ensure
compatibility with unzip programs that use signed 32-bit integers.


From al.basili at gmail.com  Thu Jan 29 16:02:10 2015
From: al.basili at gmail.com (alb)
Date: 29 Jan 2015 21:02:10 GMT
Subject: parsing tree from excel sheet
References: <cirqviF15qtU1@mid.individual.net>
 <mailman.18217.1422454096.18130.python-list@python.org>
Message-ID: <civleiF21boU1@mid.individual.net>

Hi Peter,

Peter Otten <__peter__ at web.de> wrote:
[]
>    def show2(self):
>        yield str(self)
>        for child in self.children:
>            yield from child.show2()

here is what I get:

> SyntaxError: invalid syntax
> debian at debian:example$ python3 export_latex.py doctree.csv 
>   File "export_latex.py", line 36
>     yield from child.show2()
>              ^
> SyntaxError: invalid syntax

and I've tried with both python and python3 (see below versions).

debian at debian:example$ python
Python 2.6.6 (r266:84292, Dec 27 2010, 00:02:40) 
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> 
debian at debian:example$ python3
Python 3.1.3 (r313:86834, Nov 28 2010, 11:28:10) 
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> 

Is it an issue related to my installation? Shall I upgrade and/or 
downgrade?

Thanks for any hint,

Al


From andrew3 at r3dsolutions.com  Thu Jan 29 16:07:11 2015
From: andrew3 at r3dsolutions.com (Andrew Robinson)
Date: Thu, 29 Jan 2015 13:07:11 -0800
Subject: Fwd: Re: Comparisons and sorting of a numeric class....
In-Reply-To: <cip65eFah5qU1@mid.individual.net>
References: <54C6434E.1030101@r3dsolutions.com>
 <mailman.18147.1422279623.18130.python-list@python.org>
 <cip65eFah5qU1@mid.individual.net>
Message-ID: <54CAA0FF.7060800@r3dsolutions.com>


On 01/27/2015 02:04 AM, Gregory Ewing wrote:
> Andrew Robinson wrote:
>
>> The spelling caveat is great -- and in Python the object named in 
>> bool's honor is spelled bool (lowercase too). ;)
>
> That doesn't change the fact that the man was called
> George Boole (not Charles!). If you're going to refer
> to him by name, it's only courteous to make some effort
> to get it right.
I stand corrected.  Thank you.
>
> http://en.wikipedia.org/wiki/George_Boole
>



From rantingrickjohnson at gmail.com  Thu Jan 29 16:12:31 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 29 Jan 2015 13:12:31 -0800 (PST)
Subject: Python is DOOMED! Again!
In-Reply-To: <54ca5bbf$0$12992$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
 <mailman.18229.1422469034.18130.python-list@python.org>
 <MPG.2f340c6ea39d9f3f9896b3@nntp.aioe.org>
 <54ca5bbf$0$12992$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <0f28e2c1-55d2-41fa-b18b-c8d4ca474809@googlegroups.com>

On Thursday, January 29, 2015 at 10:11:56 AM UTC-6, Steven D'Aprano wrote:
>
> But what are type declarations in statically typed
> languages like C, Pascal, Haskell, etc.? They are used by
> the compiler for static analysis. The same applies to type
> declarations in dynamically typed languages like Cobra and
> Julia. And yet, there they are, in the executable code.
>
> So there are a whole lot of languages, going all the way
> back to 1950s languages like Fortran, to some of the
> newest languages which are only a few years old like Go,
> both dynamically typed and statically typed, which do
> exactly what you say languages "cannot and should not" do:
> they put type information used for static analysis there
> in the code.
>
> As I said, these languages disagree with you. You are not
> just arguing against Guido, but against the majority of
> programming language designers for 60+ years.

Are we really going to base our design decisions on the same
emotional "need to belong" that a 14 year girl bases clothing
purchases on? Following your logic, it's high time we adopt
braces, since they have been just as long!

===================================================================
 WELCOME TO COMPUTER LANGUAGE JEOPARDY!                            
===================================================================
|--------------------------|---------------|-doot------------|----|
|--------------------------|---------------|-----do----------|----|
|--------------------------|---------------|-------do--------|----|
|--dah-----------dah-------|----dah----dah-|---------do------|----|
|--------------------------|---------------|-----------do----|----|
|do---doo-----do-----dooooo|-do----do------|-------------do--|----|
|---------doo--------------|---------------|-----------------|doot|
===================================================================
                           @2nd skip------->             D.C.      

"And here is your host: Alex Trebek!

TREBEK: I swear i was not drunk when i sideswiped an array of mailboxes and ended up kissing a telephone pole in a ditch 45 feet away... so shut up about it already!

[snip: totally scripted introductions]

TREBEK: Okay let's begin!

PLAYER1: Alex, i'll take "Language Devolution" for 500 please.

TREBEK: Okay, and the answer is: "Python Type Hints"

(CHIME) PLAYER1: What does a book-licking contest look like?

*WAAAANK*

TREBEK: Sorry, while your answer certainly is a product of such a proposal, we're looking for something more specific to the category of: "Language Devolution".

(CHIME) PLAYER2: Python Insanity Proposal?

*WAAAANK*

TREBEK: Again, technically correct, but your answer must be in the form of a question!

(CHIME) PLAYER3: What happens after an emperor forsakes his clothing?

*DING-DING-DING*

TREBEK: Congrats, you're this weeks winner! Please stay tuned for a special episode of "Keeping Up With The Kewl Kids". Good night folks!

[This episode was sponsored by Alex's AA group]


From python at mrabarnett.plus.com  Thu Jan 29 16:16:57 2015
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 29 Jan 2015 21:16:57 +0000
Subject: parsing tree from excel sheet
In-Reply-To: <civleiF21boU1@mid.individual.net>
References: <cirqviF15qtU1@mid.individual.net>
 <mailman.18217.1422454096.18130.python-list@python.org>
 <civleiF21boU1@mid.individual.net>
Message-ID: <54CAA349.7070006@mrabarnett.plus.com>

On 2015-01-29 21:02, alb wrote:
> Hi Peter,
>
> Peter Otten <__peter__ at web.de> wrote:
> []
>>    def show2(self):
>>        yield str(self)
>>        for child in self.children:
>>            yield from child.show2()
>
> here is what I get:
>
>> SyntaxError: invalid syntax
>> debian at debian:example$ python3 export_latex.py doctree.csv
>>   File "export_latex.py", line 36
>>     yield from child.show2()
>>              ^
>> SyntaxError: invalid syntax
>
> and I've tried with both python and python3 (see below versions).
>
> debian at debian:example$ python
> Python 2.6.6 (r266:84292, Dec 27 2010, 00:02:40)
> [GCC 4.4.5] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
>>>>
> debian at debian:example$ python3
> Python 3.1.3 (r313:86834, Nov 28 2010, 11:28:10)
> [GCC 4.4.5] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
>>>>
>
> Is it an issue related to my installation? Shall I upgrade and/or
> downgrade?
>
"yield from" was introduced in Python 3.3.



From al.basili at gmail.com  Thu Jan 29 16:22:20 2015
From: al.basili at gmail.com (alb)
Date: 29 Jan 2015 21:22:20 GMT
Subject: parsing tree from excel sheet
References: <cirqviF15qtU1@mid.individual.net>
 <mailman.18220.1422455440.18130.python-list@python.org>
Message-ID: <civmkcF21boU2@mid.individual.net>

Hi Tim,

Tim Chase <python.list at tim.thechases.com> wrote:
[]
>> I know about the xlrd module to get data from excel
> 
> If I have to get my code to read Excel files, xlrd is usually my
> first and only stop.
> 

It provides quite a good interface to manipulating excel files and I 
find it pretty easy even for my entry level!

>> Does anyone recommend any other path other than scripting through
>> these two modules?
> 
> Well, if you export from Excel as CSV, you can use the "csv" module
> in the standard library.  This is actually my preferred route because
> it prevents people (coughclientscough) from messing up the CSV file
> with formatting, joined cells, and other weirdnesses that can choke
> my utilities.

In my case there's no such risk of manipulating the excel file. I'm in 
charge of it! :-) Sure it might at a later stage be misused and messed 
up inadvertedly, but we're just trying to validate an idea, i.e. writing 
specs without using any word processor.

I'm trying to bypass the need to go through a mark up language (to a 
certain point), in order to facilitate the transition from an 
unstructured approach to document writing to a more structured one.

I would have proposed SGML or XML and style sheets but unfortunately is 
hard to move from M$Word to XML (OMG I need to write code?!?!!). So to 
facilitate the transition to a structured approach I've come up with the 
idea to go through an automatic generation of documents using excel as a 
UI.

In a later stage with could move onto a full-fledged database and have 
simpler web access, but using the same backend for generating documents 
(i.e. some parser and latex).

>> Is there any more suitable module/example/project out there that
>> would achieve the same result?
> 
> I don't believe there's anything that will natively do the work for
> you.  Additionally, you'd have to clarify what should happen if two
> rows in the same section had different sub-trees but the same
> content/name.  Based on your use-case (LaTex export using these as
> headers) I suspect you'd want a warning so you can repair the input
> and re-run.  But it would be possible to default to either keeping or
> squashing the duplicates.

Sure, there are corner cases that might mess up the whole structure, 
which at the moment is not too fool proof, but I'm trying to test the 
idea and see what I can come up with. Once the flow is in place I could 
think over some more reliable approach as an interface to a database.
 
>> p.s.: I'm not extremely proficient in python, actually I'm just
>> starting with it!
> 
> Well, you've come to the right place. Most of us are pretty fond of
> Python here. :-)

I've never understood people discarding newsgroups in favor of more 
'recent' technologies like social networks. Long live the USENET!


From al.basili at gmail.com  Thu Jan 29 16:32:21 2015
From: al.basili at gmail.com (alb)
Date: 29 Jan 2015 21:32:21 GMT
Subject: parsing tree from excel sheet
References: <cirqviF15qtU1@mid.individual.net>
 <mailman.18217.1422454096.18130.python-list@python.org>
 <civleiF21boU1@mid.individual.net>
 <mailman.18282.1422566221.18130.python-list@python.org>
Message-ID: <civn75F21boU3@mid.individual.net>

Hi MRAB,

MRAB <python at mrabarnett.plus.com> wrote:
[]
>>> SyntaxError: invalid syntax
>>> debian at debian:example$ python3 export_latex.py doctree.csv
>>>   File "export_latex.py", line 36
>>>     yield from child.show2()
>>>              ^
>>> SyntaxError: invalid syntax
>>
>> and I've tried with both python and python3 (see below versions).
>>
>> debian at debian:example$ python
>> Python 2.6.6 (r266:84292, Dec 27 2010, 00:02:40)
>> [GCC 4.4.5] on linux2
>> Type "help", "copyright", "credits" or "license" for more information.
>>>>>
>> debian at debian:example$ python3
>> Python 3.1.3 (r313:86834, Nov 28 2010, 11:28:10)
>> [GCC 4.4.5] on linux2
>> Type "help", "copyright", "credits" or "license" for more information.
>>>>>
>>
>> Is it an issue related to my installation? Shall I upgrade and/or
>> downgrade?
>>
> "yield from" was introduced in Python 3.3.
> 

Ok, that either means I need to upgrade to 3.3 or need to modify the 
snippet to a suitable syntax that would work with other versions.

Considering that upgrading is something that I'm not keen to do on my 
production system I believe I've only have one available choice.

It seems I could use the generator and iterate with .next() in python 
2.6, at least from what I found here:
http://stackoverflow.com/questions/1756096/understanding-generators-in-python

Al


From breamoreboy at yahoo.co.uk  Thu Jan 29 16:59:47 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Thu, 29 Jan 2015 21:59:47 +0000
Subject: parsing tree from excel sheet
In-Reply-To: <civn75F21boU3@mid.individual.net>
References: <cirqviF15qtU1@mid.individual.net>
 <mailman.18217.1422454096.18130.python-list@python.org>
 <civleiF21boU1@mid.individual.net>
 <mailman.18282.1422566221.18130.python-list@python.org>
 <civn75F21boU3@mid.individual.net>
Message-ID: <maeagt$1of$1@ger.gmane.org>

On 29/01/2015 21:32, alb wrote:
> Hi MRAB,
>
> MRAB <python at mrabarnett.plus.com> wrote:
> []
>>>> SyntaxError: invalid syntax
>>>> debian at debian:example$ python3 export_latex.py doctree.csv
>>>>    File "export_latex.py", line 36
>>>>      yield from child.show2()
>>>>               ^
>>>> SyntaxError: invalid syntax
>>>
>>> and I've tried with both python and python3 (see below versions).
>>>
>>> debian at debian:example$ python
>>> Python 2.6.6 (r266:84292, Dec 27 2010, 00:02:40)
>>> [GCC 4.4.5] on linux2
>>> Type "help", "copyright", "credits" or "license" for more information.
>>>>>>
>>> debian at debian:example$ python3
>>> Python 3.1.3 (r313:86834, Nov 28 2010, 11:28:10)
>>> [GCC 4.4.5] on linux2
>>> Type "help", "copyright", "credits" or "license" for more information.
>>>>>>
>>>
>>> Is it an issue related to my installation? Shall I upgrade and/or
>>> downgrade?
>>>
>> "yield from" was introduced in Python 3.3.
>>
>
> Ok, that either means I need to upgrade to 3.3 or need to modify the
> snippet to a suitable syntax that would work with other versions.
>
> Considering that upgrading is something that I'm not keen to do on my
> production system I believe I've only have one available choice.
>
> It seems I could use the generator and iterate with .next() in python
> 2.6, at least from what I found here:
> http://stackoverflow.com/questions/1756096/understanding-generators-in-python
>
> Al
>

I'd be inclined to upgrade, see here 
https://www.python.org/dev/peps/pep-0380/#formal-semantics for why :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From rantingrickjohnson at gmail.com  Thu Jan 29 17:22:42 2015
From: rantingrickjohnson at gmail.com (Rick Johnson)
Date: Thu, 29 Jan 2015 14:22:42 -0800 (PST)
Subject: An object is an instance (or not)?
In-Reply-To: <mailman.18211.1422439270.18130.python-list@python.org>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
 <mailman.18199.1422411685.18130.python-list@python.org>
 <54c8a8fe$0$11125$c3e8da3@news.astraweb.com>
 <mailman.18211.1422439270.18130.python-list@python.org>
Message-ID: <e5f6abdc-13ed-4e1f-b853-f5224926c543@googlegroups.com>

On Wednesday, January 28, 2015 at 4:01:41 AM UTC-6, Chris Angelico wrote:
> On Wed, Jan 28, 2015 at 8:16 PM, Steven D'Aprano wrote:
> > Or perhaps that should be a sad face smiley :-( How much
> > time we would all save if academics and language
> > designers would only stick to a single consistent
> > terminology across all languages.
>
> That's like wishing that every human spoke the same
> language, instead of having English, French, Italian,
> Polish, Serbian, Korean, and a host of others. The problem
> isn't the languages; the variety of languages reflects a
> variety of concepts being communicated,

Yes guys, because everyone knows that "selfish adolescent
accessorizing" is the *KEY* to building a sane human
knowledge base! I mean, who needs a single word (or grunt)
to mean, say, "cat-herding", when infinitely more selfish
incarnations can be invented on the fly!!!

##########################
# Untested Code:
##########################

 def pollute_the_database(concept):
     for region in world.regions:
         # XXX: Avoid buffer overflows!
         grunt = region.generate_grunt(concept)
         database.setdefault(concept, {"aliases":[]})
         database[concept]["aliases"].append(str(grunt))

 if __game__ == "__existentialism__":
     concepts = humans.collectiveConciseness
     database = humans.collectiveDatabase
     while len(concepts) > 0:
         # XXX: Make thread safe!
         conceptN = concepts.pop()
         if is_selfishly_infantile(humans):
             pollute_the_database(conceptN)
         else:
             # Dead code follows :-'(
             word = world.generate_grunt(conceptN)
             database[concept] = word


From ckaynor at zindagigames.com  Thu Jan 29 17:30:08 2015
From: ckaynor at zindagigames.com (Chris Kaynor)
Date: Thu, 29 Jan 2015 14:30:08 -0800
Subject: parsing tree from excel sheet
In-Reply-To: <maeagt$1of$1@ger.gmane.org>
References: <cirqviF15qtU1@mid.individual.net>
 <mailman.18217.1422454096.18130.python-list@python.org>
 <civleiF21boU1@mid.individual.net>
 <mailman.18282.1422566221.18130.python-list@python.org>
 <civn75F21boU3@mid.individual.net> <maeagt$1of$1@ger.gmane.org>
Message-ID: <CALvWhxvV2o-S7b=rCcSqZdTWXimey+r-H6S0MrhcZPRrbvS0sw@mail.gmail.com>

On Thu, Jan 29, 2015 at 1:59 PM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> On 29/01/2015 21:32, alb wrote:
>>
>> Hi MRAB,
>>
>> MRAB <python at mrabarnett.plus.com> wrote:
>> []
>>>>>
>>>>> SyntaxError: invalid syntax
>>>>> debian at debian:example$ python3 export_latex.py doctree.csv
>>>>>    File "export_latex.py", line 36
>>>>>      yield from child.show2()
>>>>>               ^
>>>>> SyntaxError: invalid syntax
>>>>
>>>>
>>>> and I've tried with both python and python3 (see below versions).
>>>>
>>>> debian at debian:example$ python
>>>> Python 2.6.6 (r266:84292, Dec 27 2010, 00:02:40)
>>>> [GCC 4.4.5] on linux2
>>>> Type "help", "copyright", "credits" or "license" for more information.
>>>>>>>
>>>>>>>
>>>> debian at debian:example$ python3
>>>> Python 3.1.3 (r313:86834, Nov 28 2010, 11:28:10)
>>>> [GCC 4.4.5] on linux2
>>>> Type "help", "copyright", "credits" or "license" for more information.
>>>>>>>
>>>>>>>
>>>>
>>>> Is it an issue related to my installation? Shall I upgrade and/or
>>>> downgrade?
>>>>
>>> "yield from" was introduced in Python 3.3.
>>>
>>
>> Ok, that either means I need to upgrade to 3.3 or need to modify the
>> snippet to a suitable syntax that would work with other versions.
>>
>> Considering that upgrading is something that I'm not keen to do on my
>> production system I believe I've only have one available choice.
>>
>> It seems I could use the generator and iterate with .next() in python
>> 2.6, at least from what I found here:
>>
>> http://stackoverflow.com/questions/1756096/understanding-generators-in-python
>>
>> Al
>>
>
> I'd be inclined to upgrade, see here
> https://www.python.org/dev/peps/pep-0380/#formal-semantics for why :)

While that is true, most of that code is needed to handle the odd
corner cases and exceptions that could happen, as well as supporting
generator.throw and generator.send, while also ensuring proper and
quick clean-up of the objects.

>From what I could see at a quick glance, none of that is really needed
in the simple case in the posted code, and as such, it is LIKELY safe
to just replace "yield from ..." with "for item in ...: yield item".

Chris


From beliavsky at aol.com  Thu Jan 29 17:39:00 2015
From: beliavsky at aol.com (beliavsky at aol.com)
Date: Thu, 29 Jan 2015 14:39:00 -0800 (PST)
Subject: [OT] fortran lib which provide python like data type
In-Reply-To: <mailman.18264.1422543630.18130.python-list@python.org>
References: <mailman.18264.1422543630.18130.python-list@python.org>
Message-ID: <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>

On Thursday, January 29, 2015 at 10:01:00 AM UTC-5, Liu Zhenhai wrote:
> Hi,
> I am not sure here is the right place to ask this question, but I want to give it a shot:)
> are there fortran libs providing python like data type, such as set, dict, list?
> Thanks,
> Yours liuzhenhai

The "Fortran library" http://bigdft.org/Wiki/index.php?title=Fortran_library appears to have some of what you want. I have not tried the code.

"The flib library provides an object called dictionary which is -- strictly speaking -- more than just a dictionary. It is polymorphic and can be a list or a dictionary, as in the python language. The other difference is that it keeps the order of the elements, which is very useful if we want to dump its contents to the yaml output. It represents indeed a tree of data, and for these reasons it will most likely change name into f_tree in a future release of the module.

These dictionaries are also used in the other parts of the flib library and are thus essential for its proper use. There are many examples in the file dicts.f90."


From ian.g.kelly at gmail.com  Thu Jan 29 17:51:28 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Thu, 29 Jan 2015 15:51:28 -0700
Subject: The Most Diabolical Python Antipattern
In-Reply-To: <20150129113238.7eaa986d@bigbox.christie.dr>
References: <madpuv$he7$1@ger.gmane.org>
 <20150129113238.7eaa986d@bigbox.christie.dr>
Message-ID: <CALwzidnbQHayLRQU76YhXstF70HCC5bUBDG--yGn4U=pF0-uHA@mail.gmail.com>

On Thu, Jan 29, 2015 at 10:32 AM, Tim Chase
<python.list at tim.thechases.com> wrote:
> On 2015-01-29 17:17, Mark Lawrence wrote:
>> The author is quite clear on his views here
>> https://realpython.com/blog/python/the-most-diabolical-python-antipattern/
>> but what do you guys and gals think?
>
> I just read that earlier today and agree for the most part.  The only
> exception (pun only partially intended) I've found is in functions
> that need to return a defined type.  I have one that I call int0()
> that is my "give me a freakin' int" function which is something like
>
>   def int0(val):
>     try:
>       return int(val)
>     except:
>       return 0
>
> because I deal with a lot of CSV data from client/vendor that has
> blanks, "NULL", "---", and plenty of other rubbish to suggest
> something that, for my purposes is really just a 0.
>
> Yes, I've been stung by it occasionally, but it's not much trouble to
> see that I'm getting a 0 some place that should have a value I need
> to extract.

At least use "except Exception" instead of a bare except. Do you
really want things like SystemExit and KeyboardInterrupt to get turned
into 0?


From bc at freeuk.com  Thu Jan 29 17:57:01 2015
From: bc at freeuk.com (BartC)
Date: Thu, 29 Jan 2015 22:57:01 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <5Vyyw.472566$me1.406185@fx23.am4>

On 22/01/2015 04:30, Steven D'Aprano wrote:

> https://www.python.org/dev/peps/pep-0484/

> Here's a potential real-world example, from the statistics module in Python
> 3.4, before and after adding annotations:
>
> def median_grouped(data, interval=1): ...
>
> def median_grouped(data:Iterable[Real], interval:Real=1)->Real: ...

> So how does Python's proposed type-hints compared to that used by other
> languages?

> C:
>
>    double
>    median_grouped (IterableOfReal data, double interval)

> I think it is clear that Python's annotation syntax remains quite close to
> executable pseudo-code. Fears that type-hints will doom Python are not
> credible.

I've read most of the thread but haven't been able to figure out /why/ 
this is being proposed. What is the advantage, speed?

And how does it work in practice: is it necessary to use a special 
Python interpreter to gain the advantage, or do you only get a benefit 
after putting the source through some sort of compiler system?

I can understand many of the misgivings. I have a dynamic language of my 
own, to which I've tried adding type hinting a few times, but in the end 
decided to get rid of those type hints and keep things purer and simpler 
(and a hell of a lot easier to implement too).

There was also something unsatisfactory about having to help things 
along by putting in explicit hints, which also cause trouble: what 
happens when the promise you make are wrong? It would mean putting in 
extra checking code to make sure things are what you said.

So when assigning a non-hinted variable to a hinted one, it needs to be 
type-checked, otherwise things can go wrong internally. So far from 
making things faster, it starts by slowing them down!

Putting in hints, (as as I implemented them using primitive types), 
meant that functions and code no longer worked in a generic (or 
polymorphic) manner. Code also changes, but the type hints aren't 
maintained. I understand the Python proposal allows type hints to be a 
union of expected types, but that sounds complicated.

Depending on how it's implemented, it also seems to me that a program 
with type hints might work with a Python implementation that ignores the 
hints, but might not work with one that makes use of the hints (because 
of using a value that is not of the hinted type).

Also, how does it work with numeric types; is there just one numeric 
type, or two (integer and real) or more? With more than one numeric type 
hint, it's going to be a headache trying to determine what the result of 
a function can be. (And if you have to choose real because 1% of the 
time the result will be real, then you lose the advantage of being able 
to work with integers 99% of the time.)

-- 
Bartc


From rosuav at gmail.com  Thu Jan 29 18:17:14 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 30 Jan 2015 10:17:14 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <5Vyyw.472566$me1.406185@fx23.am4>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <5Vyyw.472566$me1.406185@fx23.am4>
Message-ID: <CAPTjJmrD+9jbYgPb7m61i2wVXMN8MyZKmdUchRm+R8zFpMaxnw@mail.gmail.com>

On Fri, Jan 30, 2015 at 9:57 AM, BartC <bc at freeuk.com> wrote:
> I've read most of the thread but haven't been able to figure out /why/ this
> is being proposed. What is the advantage, speed?

Have a read of the PEP:

https://www.python.org/dev/peps/pep-0484/

ChrisA


From rosuav at gmail.com  Thu Jan 29 18:25:33 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 30 Jan 2015 10:25:33 +1100
Subject: The Most Diabolical Python Antipattern
In-Reply-To: <20150129113238.7eaa986d@bigbox.christie.dr>
References: <madpuv$he7$1@ger.gmane.org>
 <20150129113238.7eaa986d@bigbox.christie.dr>
Message-ID: <CAPTjJmoEFM3PP6psU_ZDN3GWuRsddAvDjLekiX_Op46D=FcEAA@mail.gmail.com>

On Fri, Jan 30, 2015 at 4:32 AM, Tim Chase
<python.list at tim.thechases.com> wrote:
> I have one that I call int0()
> that is my "give me a freakin' int" function which is something like
>
>   def int0(val):
>     try:
>       return int(val)
>     except:
>       return 0
>
> because I deal with a lot of CSV data from client/vendor that has
> blanks, "NULL", "---", and plenty of other rubbish to suggest
> something that, for my purposes is really just a 0.

What's wrong with "except (TypeError, ValueError):" here? Or even just
"except ValueError:", which seems to be what you want? The bare except
is still a problem.

ChrisA


From ckaynor at zindagigames.com  Thu Jan 29 18:25:35 2015
From: ckaynor at zindagigames.com (Chris Kaynor)
Date: Thu, 29 Jan 2015 15:25:35 -0800
Subject: Python is DOOMED! Again!
In-Reply-To: <5Vyyw.472566$me1.406185@fx23.am4>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <5Vyyw.472566$me1.406185@fx23.am4>
Message-ID: <CALvWhxsobvpcwnRVdQJ=cmB+AVVkZUODZvfAS8byspQTRW04cw@mail.gmail.com>

On Thu, Jan 29, 2015 at 2:57 PM, BartC <bc at freeuk.com> wrote:
> I've read most of the thread but haven't been able to figure out /why/ this
> is being proposed. What is the advantage, speed?

Check out the rationale part of the PEP:
https://www.python.org/dev/peps/pep-0484/#rationale-and-goals. Other
parts of the PEP also answer many of the other questions you have.
I've put in my understandings and opinions below, however.


There are a few perceived advantages to adding type-hints, some of
which are more pie-in-the-sky while others are very likely:
- IDEs can use them to provide better auto-complete.
- Static checkers can do a better job of checking for program
correctness (by erroring if the type-hints are obviously broken).
- Possibility of performance improvements, although CPython (the
official Python interpreter) will still be required to work if the
type-hints are wrong.

> And how does it work in practice: is it necessary to use a special Python
> interpreter to gain the advantage, or do you only get a benefit after
> putting the source through some sort of compiler system?

CPython will, initially, do nothing special with the type-hints that
it does not currently do with the existing annotations, which is
merely parse them and ensure they meet the syntax requirements. My
understanding is that there will be a static checker (possibly derived
from MyPy) that will be endorsed, however, and possibly included in
the STD.

> I can understand many of the misgivings. I have a dynamic language of my
> own, to which I've tried adding type hinting a few times, but in the end
> decided to get rid of those type hints and keep things purer and simpler
> (and a hell of a lot easier to implement too).
>
> There was also something unsatisfactory about having to help things along by
> putting in explicit hints, which also cause trouble: what happens when the
> promise you make are wrong? It would mean putting in extra checking code to
> make sure things are what you said.

As a rule, breaking the type-hint promises will have no effect on the
run-time. Some implementations (Cython or PyPy) may decide to use the
type-hints to guide optimization, perhaps by creating a fast path for
if the promises are met, however conforming implementations cannot
rely on them being correct. PyPy, for example, could JIT the function
presuming the types are right, therefore front-loading the JIT time.
I'm not saying they WILL, just that they COULD.

> So when assigning a non-hinted variable to a hinted one, it needs to be
> type-checked, otherwise things can go wrong internally. So far from making
> things faster, it starts by slowing them down!

See above. The current plan is not to generally use the hinting at
run-time, but only during static checking of the code. For cases like
PyPy, they already have to do run-time type checking to ensure
correctness when running optimized paths.

> Putting in hints, (as as I implemented them using primitive types), meant
> that functions and code no longer worked in a generic (or polymorphic)
> manner. Code also changes, but the type hints aren't maintained. I
> understand the Python proposal allows type hints to be a union of expected
> types, but that sounds complicated.

Regarding the maintenance of type-hints, for people who heavily use
them, I would imagine they will have a static checker setup which will
regularly run and generally produce an error if the hints are not
updated. Most other people will likely only lightly use the type-hints
and may not use static checkers, and thus they probably will get out
of sync. With such a feature, my main use case would be to aid IDEs in
providing auto-complete, which I've done in the past by adding lines
like "if 0: assert isinstance(variable, type)". Most of the functions
I write do not have any such "hints" but instead I've only generally
used it in cases where the type is pretty much fixed, but is a custom
type with a more complicated API.

For the most part, I would almost never use the union types. From past
experience (from languages like C++ and C#), such tends to vastly over
complicate the definitions. The same applies to most cases of generic
types (think list, tuple, set, dict).

> Depending on how it's implemented, it also seems to me that a program with
> type hints might work with a Python implementation that ignores the hints,
> but might not work with one that makes use of the hints (because of using a
> value that is not of the hinted type).
>
> Also, how does it work with numeric types; is there just one numeric type,
> or two (integer and real) or more? With more than one numeric type hint,
> it's going to be a headache trying to determine what the result of a
> function can be. (And if you have to choose real because 1% of the time the
> result will be real, then you lose the advantage of being able to work with
> integers 99% of the time.)

My understanding is that you would generally use one of "int",
"float", "Decimal", "Rational", "complex", etc. - basically the name
of the classes themselves. There are some special rules for more
complicated cases, such as forward definitions or various union types.


Chris


From rosuav at gmail.com  Thu Jan 29 18:46:41 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 30 Jan 2015 10:46:41 +1100
Subject: parsing tree from excel sheet
In-Reply-To: <civn75F21boU3@mid.individual.net>
References: <cirqviF15qtU1@mid.individual.net>
 <mailman.18217.1422454096.18130.python-list@python.org>
 <civleiF21boU1@mid.individual.net>
 <mailman.18282.1422566221.18130.python-list@python.org>
 <civn75F21boU3@mid.individual.net>
Message-ID: <CAPTjJmo=z6fkcRz6osiN9fVY5_-JB-z9v38_nvzNsmAsk2ANpg@mail.gmail.com>

On Fri, Jan 30, 2015 at 8:32 AM, alb <al.basili at gmail.com> wrote:
> Ok, that either means I need to upgrade to 3.3 or need to modify the
> snippet to a suitable syntax that would work with other versions.

You could replace "yield from child.show2()" with:

for val in child.show2(): yield val

and it should work. However, you're running Python 3.1, and a *lot* of
improvements have been made since then, so it's well worth upgrading.

ChrisA


From ameyer2 at yahoo.com  Thu Jan 29 20:35:36 2015
From: ameyer2 at yahoo.com (Alan Meyer)
Date: Thu, 29 Jan 2015 20:35:36 -0500
Subject: Installling ADODB on an offline computer
Message-ID: <54CADFE8.8080505@yahoo.com>

I work on an application that uses the ActivePython compilation of 
Python from ActiveState.  It uses three Microsoft COM libraries that are 
needed for talking to SQL Server.  The libraries are:

     Microsoft Activex Data Objects
     Microsoft Activex Data Objects Recordset
     Microsoft ADO Ext

In the past, we have installed those libraries on numerous machines by 
running makepy.py.  It can be done from the ActivePython IDLE GUI, or 
from the command line.  makepy.py downloads and installs the packages 
for us, taking care of COM server or client registration, or whatever it 
is that has to be done (I don't really know much about this stuff.)

Now I've been asked to port the application to a computer that is not 
connected to the Internet.  I haven't found any way to get those 
packages.  I haven't found a way to, for example, download the packages 
to files, place the files on the target computer, and run makepy.py or a 
setup.py to install them.

Can someone suggest a way to do it?

Thank you very much.

     Alan


From rustompmody at gmail.com  Thu Jan 29 20:40:03 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Thu, 29 Jan 2015 17:40:03 -0800 (PST)
Subject: [OT] fortran lib which provide python like data type
In-Reply-To: <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
Message-ID: <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>

On Friday, January 30, 2015 at 4:09:19 AM UTC+5:30, beli... at aol.com wrote:
> On Thursday, January 29, 2015 at 10:01:00 AM UTC-5, Liu Zhenhai wrote:
> > Hi,
> > I am not sure here is the right place to ask this question, but I want to give it a shot:)
> > are there fortran libs providing python like data type, such as set, dict, list?
> > Thanks,
> > Yours liuzhenhai
> 
> The "Fortran library" http://bigdft.org/Wiki/index.php?title=Fortran_library appears to have some of what you want. I have not tried the code.
> 
> "The flib library provides an object called dictionary which is -- strictly speaking -- more than just a dictionary. It is polymorphic and can be a list or a dictionary, as in the python language. The other difference is that it keeps the order of the elements, which is very useful if we want to dump its contents to the yaml output. It represents indeed a tree of data, and for these reasons it will most likely change name into f_tree in a future release of the module.
> 
> These dictionaries are also used in the other parts of the flib library and are thus essential for its proper use. There are many examples in the file dicts.f90."

Interesting

Note the very first minimal example

FORTRAN

 use dictionary
 type(dictionary), pointer :: d
 d=>dict_new()
 call set(d//'toto',1)
 v = d//'toto'
 call dict_free(d)

The corresponding python

 d = dict()
 d['toto'] = 1
 v = d['toto']
 del(d)

In particular note the del in the python.

Should highlight the point that languages with gc, support data structures
in a way that gc-less languages - Fortran, C, C++ - do not and cannot.


From python at mrabarnett.plus.com  Thu Jan 29 21:11:40 2015
From: python at mrabarnett.plus.com (MRAB)
Date: Fri, 30 Jan 2015 02:11:40 +0000
Subject: Python is DOOMED! Again!
In-Reply-To: <CALvWhxsobvpcwnRVdQJ=cmB+AVVkZUODZvfAS8byspQTRW04cw@mail.gmail.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <5Vyyw.472566$me1.406185@fx23.am4>
 <CALvWhxsobvpcwnRVdQJ=cmB+AVVkZUODZvfAS8byspQTRW04cw@mail.gmail.com>
Message-ID: <54CAE85C.7060708@mrabarnett.plus.com>

On 2015-01-29 23:25, Chris Kaynor wrote:
> On Thu, Jan 29, 2015 at 2:57 PM, BartC <bc at freeuk.com> wrote:
[snip]
>> Putting in hints, (as as I implemented them using primitive types),
>> meant that functions and code no longer worked in a generic (or
>> polymorphic) manner. Code also changes, but the type hints aren't
>> maintained. I understand the Python proposal allows type hints to
>> be a union of expected types, but that sounds complicated.
>
> Regarding the maintenance of type-hints, for people who heavily use
> them, I would imagine they will have a static checker setup which
> will regularly run and generally produce an error if the hints are
> not updated. Most other people will likely only lightly use the
> type-hints and may not use static checkers, and thus they probably
> will get out of sync. With such a feature, my main use case would be
> to aid IDEs in providing auto-complete, which I've done in the past
> by adding lines like "if 0: assert isinstance(variable, type)". Most
> of the functions I write do not have any such "hints" but instead
> I've only generally used it in cases where the type is pretty much
> fixed, but is a custom type with a more complicated API.
>
I suppose you could check what types the arguments are by running the
code and outputting the types supplied, and then run a script that uses
the info to modify the source, and then you can diff the result.

Here's a simple example I've come up with:


#! python3.4
# -*- coding: utf-8 -*-
import inspect

def check_hints(func):

     def wrapper(*args, **kwargs):
         sig = inspect.signature(func)
         print('file      :', inspect.getfile(func))
         print('function  :', func.__name__)
         print('line      :', inspect.getsourcelines(func)[1] + 1)

         args_given = list(args)
         kwargs_given = dict(kwargs)

         for name in sig.parameters:
             param = sig.parameters[name]
             if param.kind == inspect.Parameter.POSITIONAL_OR_KEYWORD:
                 annotation = param.annotation
                 if args_given:
                     print('parameter : {} : {}'.format(name,
                       type(args_given.pop(0)).__name__))
                     if annotation != inspect.Parameter.empty:
                         print('annotation: {} : {}'.format(name,
                           annotation.__name__))
                 else:
                     try:
                         print('parameter : {} : {}'.format(name,
                           type(kwargs_given.pop(name)).__name__))
                         if annotation != inspect.Parameter.empty:
                             print('annotation: {} : {}'.format(name,
                               annotation.__name__))
                     except KeyError:
                         pass

         result = func(*args, **kwargs)

         print('return    : {}'.format(type(result).__name__))
         annotation = sig.return_annotation
         if annotation != inspect.Parameter.empty:
             print('annotation: {}'.format(annotation.__name__))

         print()

         return result

     return wrapper

@check_hints
def foo(arg1: int, arg2: str, arg3: float=2.0) -> int:
     pass

@check_hints
def bar(arg1, arg2, arg3=2.0):
     pass

foo(1, "bar")
foo("baz", 2, 3.0)

bar(1, "bar")
bar("baz", 2, 3.0)


From rustompmody at gmail.com  Thu Jan 29 21:55:33 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Thu, 29 Jan 2015 18:55:33 -0800 (PST)
Subject: Sort of Augmented Reality
In-Reply-To: <mailman.18292.1422584565.18130.python-list@python.org>
References: <madd3b$u2l$1@dont-email.me>
 <mailman.18292.1422584565.18130.python-list@python.org>
Message-ID: <9a1a0550-80f0-4947-9806-a605d451e8f1@googlegroups.com>

On Friday, January 30, 2015 at 7:52:58 AM UTC+5:30, Dennis Lee Bieber wrote:
> On Thu, 29 Jan 2015 14:38:20 +0100, franssoa
> declaimed the following:
> 
> >Hello,
> >
> >(please excuse my english as is not my primary language)
> >
> >- I own a webcam that take a picture of outside of my house once per minute.
> >- With a DVB sticker, I know the latitude, longitude and altitude of the
> >planes in my area.
> >
> >I would like to print the data of the planes visibles on the pictures
> >taken by the webcam, like "my sky view" from program "planeplotter" [1].
> >
> >Does anybody know what kind of tools/library I can use, in Python as is
> >the language I know the best.
> >Last thing : I'm a dumb in math...
> >
> 	Yet math is the main factor needed as you will need to know:

Saw this somewhere:

There are two Great Sins in the world - the Sin of Ignorance, 
and the Sin of Stupidity. Only the former may be overcome.

Is 'dumb' in the first or second category??
Your call...

Like smelly cheese and classical music, math is an acquired taste.
Actually enjoyable once you get past the initiation


From marko at pacujo.net  Fri Jan 30 01:16:23 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Fri, 30 Jan 2015 08:16:23 +0200
Subject: The Most Diabolical Python Antipattern
References: <madpuv$he7$1@ger.gmane.org>
 <20150129113238.7eaa986d@bigbox.christie.dr>
 <mailman.18286.1422571931.18130.python-list@python.org>
Message-ID: <87r3uchjyg.fsf@elektro.pacujo.net>

Ian Kelly <ian.g.kelly at gmail.com>:

> At least use "except Exception" instead of a bare except. Do you
> really want things like SystemExit and KeyboardInterrupt to get turned
> into 0?

How about:

==============================
    try:
        do_interesting_stuff()
    except ValueError:
        try:
            log_it()
        except:
            pass
        raise
==============================

Surprisingly this variant could raise an unexpected exception:

==============================
    try:
        do_interesting_stuff()
    except ValueError:
        try:
            log_it()
        finally:
            raise
==============================

A Python bug?


Marko


From motoom at xs4all.nl  Fri Jan 30 02:09:02 2015
From: motoom at xs4all.nl (Michiel Overtoom)
Date: Fri, 30 Jan 2015 08:09:02 +0100
Subject: The Most Diabolical Python Antipattern
In-Reply-To: <CANc-5Uy-B4GsUHbRX+KyH+uE06WXMDs5-Mf_S7uH0PYWiZ0HVw@mail.gmail.com>
References: <madpuv$he7$1@ger.gmane.org>
 <CANc-5Uy-B4GsUHbRX+KyH+uE06WXMDs5-Mf_S7uH0PYWiZ0HVw@mail.gmail.com>
Message-ID: <7B5DD954-EA09-4ECB-A23D-682594C3959B@xs4all.nl>


On Jan 29, 2015, at 18:36, Skip Montanaro wrote:

> There are the occasional instance where I need to recover
> from an exception no matter what caused it.

I had the same need, a while ago, when working on a CherryPy webapp which uses a BackgroundTask to parse user-uploaded data and image files (and that can throw a variety of exceptions). Any uncaught exception from a BackgroundTask will terminate the background thread, which is not good, because one rotten input file shouldn't spoil it for the rest. It was also unpredictable what kind of exceptions underlying modules would throw without going through all the sources with a fine comb. Thus, I wrote a decorator which will catch any exception (but not KeyboardInterrupt and SystemExit of course):


# alwayscatch.py - Software by Michiel Overtoom, motoom at xs4all.nl
#
# decorator to wrap an entire function in a try..except block
# to prevent any exception to reach the caller (except SystemExit and KeyboardInterrupt)
# because in that case some vital backgroundtask in a webframework will stop working.

def alwayscatch(logfunc=None, locus=None):
    def deco(wrappee):
        def wrapper(*args, **kwargs):
            try:
                return wrappee(*args, **kwargs)
            except KeyboardInterrupt, SystemExit:
                raise
            except Exception as e:
                if logfunc:
                    logfunc(locus, "Developer sloppyness and/or unrecognized situation", e)
                else:
                    print "No logging func defined"
        return wrapper
    return deco
    

def frameworklogfunc(locus, msg, exc):
    print "[%s] %s: '%s'" % (locus, msg, str(exc))

    
@alwayscatch(frameworklogfunc, "SUBSYSTEM")
def protectedfunc(x, y, color=23):
    return x / y / color


@alwayscatch()
def sillyfunc(a, b, c):
    return a / b / c
    

if __name__ == "__main__":
    print protectedfunc(900, 2, 0)
    print sillyfunc(900, 2, 0)


...and I used it like this, from the main program:

sizer = cherrypy.process.plugins.BackgroundTask(10, sizer.scan)
sizer.start()

...where the worker function is defined like this:

@alwayscatch(scanlogerror, "SIZE")
def scan():
    ...

...and the custom logging function: (cherrypy.log in its turn uses the standard logging framework)

def scanlogerror(locus, msg, exc):
    cherrypy.log("Uncaught exception: %s" % exc, locus, logging.ERROR)


Greetings,

-- 
"You can't actually make computers run faster, you can only make them do less." - RiderOfGiraffes



From admin at grails.asia  Fri Jan 30 02:25:42 2015
From: admin at grails.asia (jtan)
Date: Fri, 30 Jan 2015 15:25:42 +0800
Subject: The Most Diabolical Python Antipattern
In-Reply-To: <madpuv$he7$1@ger.gmane.org>
References: <madpuv$he7$1@ger.gmane.org>
Message-ID: <CAMu67MaXAw=tK_Te+U1q8zTq-Eqj8NjjggZn4=RKaPuTqjJqbQ@mail.gmail.com>

I would usually just log the stack trace so that I would still know that
something bad happened while the app looks okay.

On Fri, Jan 30, 2015 at 1:17 AM, Mark Lawrence <breamoreboy at yahoo.co.uk>
wrote:

> The author is quite clear on his views here https://realpython.com/blog/
> python/the-most-diabolical-python-antipattern/ but what do you guys and
> gals think?
>
> --
> My fellow Pythonistas, ask not what our language can do for you, ask
> what you can do for our language.
>
> Mark Lawrence
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>



-- 
Freelance Grails
<http://grails.asia/grails-tutorial-for-beginners-hql-queries> and Java
<http://javadevnotes.com/> developer
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From auriocus at gmx.de  Fri Jan 30 02:32:47 2015
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Fri, 30 Jan 2015 08:32:47 +0100
Subject: [OT] fortran lib which provide python like data type
In-Reply-To: <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
Message-ID: <mafc1u$n1l$1@dont-email.me>

Am 30.01.15 um 02:40 schrieb Rustom Mody:
> FORTRAN
> 
>  use dictionary
>  type(dictionary), pointer :: d
>  d=>dict_new()
>  call set(d//'toto',1)
>  v = d//'toto'
>  call dict_free(d)
> 
> The corresponding python
> 
>  d = dict()
>  d['toto'] = 1
>  v = d['toto']
>  del(d)
> 
> In particular note the del in the python.
> 
> Should highlight the point that languages with gc, support data structures
> in a way that gc-less languages - Fortran, C, C++ - do not and cannot.

For C++ this is not correct. Ususally a garbage collector is not used -
though possible - but the constructor/destructor/assignment op in C++
(usually called RAII) provide semantics very similar to the CPython
refcounting behaviour.

For example, I made a set of C++ interface methods to return nested
dicts/list to Python, which is far from complete, but allows to write
something like this:

SWList do_something(SWDict attrs) {
  SWList result;
  for (int i=0; i<5; i++) {
    SWDict entry;			
    entry.insert("count", i);
    entry.insert("name", "something");
    result.push_back(entry);
  }
  return result;
}


There is also Boost::Python which does the same, I think, and much more,
but only supports Python, whereas I use SWIG to interface these
dicts/lists to both CPython and Tcl.

You cannot, however, resolve certain cyclic dependencies with pure
reference counting.

	Christian



From breamoreboy at yahoo.co.uk  Fri Jan 30 03:10:58 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Fri, 30 Jan 2015 08:10:58 +0000
Subject: The Most Diabolical Python Antipattern
In-Reply-To: <87r3uchjyg.fsf@elektro.pacujo.net>
References: <madpuv$he7$1@ger.gmane.org>
 <20150129113238.7eaa986d@bigbox.christie.dr>
 <mailman.18286.1422571931.18130.python-list@python.org>
 <87r3uchjyg.fsf@elektro.pacujo.net>
Message-ID: <mafeat$bff$1@ger.gmane.org>

On 30/01/2015 06:16, Marko Rauhamaa wrote:
> Ian Kelly <ian.g.kelly at gmail.com>:
>
>> At least use "except Exception" instead of a bare except. Do you
>> really want things like SystemExit and KeyboardInterrupt to get turned
>> into 0?
>
> How about:
>
> ==============================
>      try:
>          do_interesting_stuff()
>      except ValueError:
>          try:
>              log_it()
>          except:
>              pass
>          raise
> ==============================
>
> Surprisingly this variant could raise an unexpected exception:
>
> ==============================
>      try:
>          do_interesting_stuff()
>      except ValueError:
>          try:
>              log_it()
>          finally:
>              raise
> ==============================
>
> A Python bug?
>
>
> Marko
>

It depends on the Python version that you're running - I think!!!  See 
https://www.python.org/dev/peps/pep-3134/ 
https://www.python.org/dev/peps/pep-0409/ 
https://www.python.org/dev/peps/pep-0415/ and finally try (groan :) 
https://pypi.python.org/pypi/pep3134/

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From chris at simplistix.co.uk  Fri Jan 30 03:15:37 2015
From: chris at simplistix.co.uk (Chris Withers)
Date: Fri, 30 Jan 2015 08:15:37 +0000
Subject: testfixtures 4.1.2 Released!
Message-ID: <54CB3DA9.7020805@simplistix.co.uk>

Hi All,

I'm pleased to announce the release of testfixtures 4.1.2. This is a 
bugfix release that fixes the following:

- Clarify documentation for name parameter to LogCapture.

- ShouldRaise now shows different output when two exceptions have
   the same representation but stiff differ.

- Fix bug that could result in a dict comparing equal to a
   list.

Thanks to Daniel Fortunov for the documentation clarification.

The package is on PyPI and a full list of all the links to docs, issue 
trackers and the like can be found here:

http://www.simplistix.co.uk/software/python/testfixtures

Any questions, please do ask on the Testing in Python list or on the 
Simplistix open source mailing list...

cheers,

Chris

-- 
Simplistix - Content Management, Batch Processing & Python Consulting
            - http://www.simplistix.co.uk


From marko at pacujo.net  Fri Jan 30 04:02:32 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Fri, 30 Jan 2015 11:02:32 +0200
Subject: The Most Diabolical Python Antipattern
References: <madpuv$he7$1@ger.gmane.org>
 <20150129113238.7eaa986d@bigbox.christie.dr>
 <mailman.18286.1422571931.18130.python-list@python.org>
 <87r3uchjyg.fsf@elektro.pacujo.net>
 <mailman.18296.1422605482.18130.python-list@python.org>
Message-ID: <87r3ucljyv.fsf@elektro.pacujo.net>

Mark Lawrence <breamoreboy at yahoo.co.uk>:

> On 30/01/2015 06:16, Marko Rauhamaa wrote:
>> How about:
>>
>> ==============================
>>      try:
>>          do_interesting_stuff()
>>      except ValueError:
>>          try:
>>              log_it()
>>          except:
>>              pass
>>          raise
>> ==============================
>>
>> Surprisingly this variant could raise an unexpected exception:
>>
>> ==============================
>>      try:
>>          do_interesting_stuff()
>>      except ValueError:
>>          try:
>>              log_it()
>>          finally:
>>              raise
>> ==============================
>>
>> A Python bug?
>
> It depends on the Python version that you're running - I think!!!  See
> https://www.python.org/dev/peps/pep-3134/

TL;DR

My Python did do exception chaining, but the problem is the surface
exception changes, which could throw off the whole error recovery.

So I'm thinking I might have found a valid use case for the "diabolical
antipattern."


Marko


From greg.ewing at canterbury.ac.nz  Fri Jan 30 04:07:57 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Fri, 30 Jan 2015 22:07:57 +1300
Subject: An object is an instance (or not)?
In-Reply-To: <54c9de44$0$12915$c3e8da3$5496439d@news.astraweb.com>
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
 <mailman.18195.1422405040.18130.python-list@python.org>
 <MPG.2f324d0d46ba9afc9896ac@nntp.aioe.org> <cirs87F1tdrU2@mid.individual.net>
 <54c8cd8f$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <ciu1taFjekrU1@mid.individual.net>
 <54c9de44$0$12915$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <cj0vveFck6dU1@mid.individual.net>

Steven D'Aprano wrote:
> Actually, if you look at my example, you will see that it is a method and it 
> does get the self argument. Here is the critical code again:
> 
> from types import MethodType
> polly.talk = MethodType(
>     lambda self: print("Polly wants a spam sandwich!"), polly)

Doing it by hand is cheating.

> That's certainly not correct, because Python had classes and instances 
> before it had descriptors!

Before the descriptor protocol, a subset of its functionality
was hard-wired into the interpreter. There has always been
some magic going on across the instance-class boundary that
doesn't occur across the class-baseclass boundary.

> Ah wait, I 
> think I've got it. If you want (say) your class object itself to support 
> (say) the + operator, it isn't enough to write a __add__ method on the 
> class, you have to write it on the metaclass.

That's right.

-- 
Greg


From ian.g.kelly at gmail.com  Fri Jan 30 04:11:36 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 30 Jan 2015 02:11:36 -0700
Subject: The Most Diabolical Python Antipattern
In-Reply-To: <87r3uchjyg.fsf@elektro.pacujo.net>
References: <madpuv$he7$1@ger.gmane.org>
 <20150129113238.7eaa986d@bigbox.christie.dr>
 <mailman.18286.1422571931.18130.python-list@python.org>
 <87r3uchjyg.fsf@elektro.pacujo.net>
Message-ID: <CALwzidn+oafsFM-0EZhfAB=tu4j3usoUnC22DQc5pdy=knKRhQ@mail.gmail.com>

On Thu, Jan 29, 2015 at 11:16 PM, Marko Rauhamaa <marko at pacujo.net> wrote:
> Ian Kelly <ian.g.kelly at gmail.com>:
>
>> At least use "except Exception" instead of a bare except. Do you
>> really want things like SystemExit and KeyboardInterrupt to get turned
>> into 0?
>
> How about:
>
> ==============================
>     try:
>         do_interesting_stuff()
>     except ValueError:
>         try:
>             log_it()
>         except:
>             pass
>         raise
> ==============================

Are you asking if I think this is better? It still swallows arbitrary
exceptions. Why would you want to re-raise the anticipated (and
logged) ValueError instead of the exception that could potentially be
unexpected?

> Surprisingly this variant could raise an unexpected exception:
>
> ==============================
>     try:
>         do_interesting_stuff()
>     except ValueError:
>         try:
>             log_it()
>         finally:
>             raise
> ==============================
>
> A Python bug?

This does what it is supposed to. "If no expressions are present,
raise re-raises the last exception that was active in the current
scope." In this case, what that exception is depends on whether the
finally clause was entered as a result of an exception or fall-through
from the try clause. If you only want to re-raise the ValueError, then
use the first form above. If you only want to re-raise the other
exception, then do so from an except block (or don't catch it in the
first place).


From fan.ding1 at kodak.com  Fri Jan 30 04:15:27 2015
From: fan.ding1 at kodak.com (fan.ding1 at kodak.com)
Date: Fri, 30 Jan 2015 17:15:27 +0800
Subject: python client call Java server by xmlrpc
In-Reply-To: <878uguklf3.fsf@handshake.de>
References: <OF59D4DFCB.6AA85FAB-ON48257DD5.002C7812-48257DD5.002D68BE@knotes.kodak.com>
 <878uguklf3.fsf@handshake.de>
Message-ID: <OFEA8E5121.C10F5A7F-ON48257DDD.00327700-48257DDD.0032DAA9@knotes.kodak.com>

Thanks dieter, The issue is solved.

I use SmartSniff to get the xml message send by java client, and python 
client, find the difference.

Define a new class:
class MyData(object):
    def __init__(self,myKey,myValue):
        self.Key = myKey
        self.Value = myValue

and use this object as parameter, then the server return correct reply.

para = MyData(0.5,0.01)

server.Fun([para ], [ ] )






From:
dieter <dieter at handshake.de>
To:
python-list at python.org
Date:
01/23/2015 03:26 PM
Subject:
Re: python client call Java server by xmlrpc
Sent by:
"Python-list" <python-list-bounces+fan.ding1=kodak.com at python.org>



fan.ding1 at kodak.com writes:

> I have xmlrpc server written in Java, and it has a method like
>
> Fun( vector, vector), the vector is array of user-defined object, which 
is 
> a class  extends HashMap.
>
> And I call it like:
>
> server = xmlrpclib.ServerProxy("http://myserver")
>
> server.Fun( [ {"0.5":0.1}], [ ] )
>
> It always fails with error
>
> 'No method matching arguments: , [Ljava.lang.Object;, 
[Ljava.lang.Object; 
> '
> Does anyone use this before? It troubles me some days.

The standard XML-RPC protocol knows only about a very small set
of types. Extensions are required to pass on more type information.

The (slightly confusing) error message (you got) indicates
that the XML-RPC framework on the server side has
not correctly recognized the types of the incoming parameters:
it should recognize the "[]" (as this is a standard type)
(and maybe the open "[" indicates that it has indeed)
but apparently, it got the content elements only as
generalized "Object"s not something specific (extending "HashMap").


The "xmlrpclib" in the Python runtime libary does not support
extensions to pass on additional type information (as far as I know).
This might indicate that you cannot use Python's "xmlrpclib" out
of the box to interact with your Java implemented XML-RPC service.


I would approach the problem as follows.

Implement a Java based XML-RPC client for your service. Should this
fail, then your service implementation has too complex types for
XML-RPC (and you must simplify them).

Should you succeed, you can use a tcp logger (or maybe debugging
tools of the Java libary implementing XML-RPC) to determine
the exact messages exchanged between client and server.
This way, you can learn how your Java libraries pass on non standard
type information. You can then derive a new class from Python's 
"xmlrpclib"
and implement there this type information passing extension (apparently
used by your Java libaries).

-- 
https://mail.python.org/mailman/listinfo/python-list


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From ian.g.kelly at gmail.com  Fri Jan 30 04:17:11 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 30 Jan 2015 02:17:11 -0700
Subject: The Most Diabolical Python Antipattern
In-Reply-To: <87r3ucljyv.fsf@elektro.pacujo.net>
References: <madpuv$he7$1@ger.gmane.org>
 <20150129113238.7eaa986d@bigbox.christie.dr>
 <mailman.18286.1422571931.18130.python-list@python.org>
 <87r3uchjyg.fsf@elektro.pacujo.net>
 <mailman.18296.1422605482.18130.python-list@python.org>
 <87r3ucljyv.fsf@elektro.pacujo.net>
Message-ID: <CALwzidnH7+ZMXLZ_MqVqgE6dBqHx0RT3Hk_CVjmNy89zUVXBBg@mail.gmail.com>

On Fri, Jan 30, 2015 at 2:02 AM, Marko Rauhamaa <marko at pacujo.net> wrote:
> Mark Lawrence <breamoreboy at yahoo.co.uk>:
>
>> On 30/01/2015 06:16, Marko Rauhamaa wrote:
>>> How about:
>>>
>>> ==============================
>>>      try:
>>>          do_interesting_stuff()
>>>      except ValueError:
>>>          try:
>>>              log_it()
>>>          except:
>>>              pass
>>>          raise
>>> ==============================
>>>
>>> Surprisingly this variant could raise an unexpected exception:
>>>
>>> ==============================
>>>      try:
>>>          do_interesting_stuff()
>>>      except ValueError:
>>>          try:
>>>              log_it()
>>>          finally:
>>>              raise
>>> ==============================
>>>
>>> A Python bug?
>>
>> It depends on the Python version that you're running - I think!!!  See
>> https://www.python.org/dev/peps/pep-3134/
>
> TL;DR
>
> My Python did do exception chaining, but the problem is the surface
> exception changes, which could throw off the whole error recovery.
>
> So I'm thinking I might have found a valid use case for the "diabolical
> antipattern."

I suppose, although it seems awfully contrived to me. In any case it
would still be better with "except Exception" rather than the bare
except. Unless re-raising that ValueError is more important to you
than letting the user hit Ctrl-C during the logging call.


From marko at pacujo.net  Fri Jan 30 05:00:58 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Fri, 30 Jan 2015 12:00:58 +0200
Subject: The Most Diabolical Python Antipattern
References: <madpuv$he7$1@ger.gmane.org>
 <20150129113238.7eaa986d@bigbox.christie.dr>
 <mailman.18286.1422571931.18130.python-list@python.org>
 <87r3uchjyg.fsf@elektro.pacujo.net>
 <mailman.18296.1422605482.18130.python-list@python.org>
 <87r3ucljyv.fsf@elektro.pacujo.net>
Message-ID: <87fvaslh9h.fsf@elektro.pacujo.net>

Marko Rauhamaa <marko at pacujo.net>:

>>> Surprisingly this variant could raise an unexpected exception:
>>>
>>> ==============================
>>>      try:
>>>          do_interesting_stuff()
>>>      except ValueError:
>>>          try:
>>>              log_it()
>>>          finally:
>>>              raise
>>> ==============================
>>>
>>> A Python bug?
> [...]
> My Python did do exception chaining, but the problem is the surface
> exception changes, which could throw off the whole error recovery.

BTW, the code above can be fixed:

==============================
  try:
      do_interesting_stuff()
  except ValueError as e:
      try:
          log_it()
      finally:
          raise e
==============================

Now the surface exception is kept and the subsidiary exception is
chained to it.

I'm a bit baffled why the two pieces of code are not equivalent.


Marko


From shinriyo at gmail.com  Fri Jan 30 05:26:32 2015
From: shinriyo at gmail.com (shinriyo at gmail.com)
Date: Fri, 30 Jan 2015 02:26:32 -0800 (PST)
Subject: about supervisor program doesn't show in web console
Message-ID: <ccafeaf7-2772-4a01-9fdc-345f537e13d2@googlegroups.com>

Hi there


I am trying to use supervisord.
I wrote some program in /etc/supervisord.conf file.

I wrote four programs in it.

However, one program can't show in the web console.

the program name is "myprogram_three".

My /etc/supervisord.conf file's snippet is below


I modified http_port.

[supervisord]
;http_port=/var/tmp/supervisor.sock ; (default is to run a UNIX domain socket server)
http_port=0.0.0.0:8888


And my programs registering is here

; App appname Program
; myprogram 1
[program:myprogram_one]
command=python /home/username/work/my_program.py start 3 appname /var/www/django/demo/appname/appname
startsecs = 5
user = root
redirect_stderr = true
stderr_logfile = /var/log/supervisor/Program/hoge_appname-stderr.log
stdout_logfile = /var/log/supervisor/Program/hoge_appname-stdout.log

; myprogram 2
[program:myprogram_two]
command=python /home/username/work/my_program.py start 4 appname /var/www/django/demo/appname/appname
startsecs = 5
user = root
redirect_stderr = true
stderr_logfile = /var/log/supervisor/Program/bar_appname-stderr.log
stdout_logfile = /var/log/supervisor/Program/bar_appname-stdout.log


; appnametwo Program
; myprogram 3
[program:myprogram_three]
command=python /home/username/work/my_program.py start 3 appnametwo /var/www/django/demo/appnametwo/appname
startsecs = 5
user = root
redirect_stderr = true
stderr_logfile = /var/log/supervisor/Program/hoge_appnametwo-stderr.log
stdout_logfile = /var/log/supervisor/Program/hoge_appnametwo-stdout.log


; myprogram 4
[program:myprogram_four]
command=python /home/username/work/my_program.py start 4 appnametwo /var/www/django/demo/appnametwo/appname
startsecs = 5
user = root
redirect_stderr = true
stderr_logfile = /var/log/supervisor/Program/bar_appnametwo-stderr.log
stdout_logfile = /var/log/supervisor/Program/bar_appnametwo-stdout.log


Why dows "myprogram_three" program work?

I would appreciate it if you could help me.


From mal at europython.eu  Fri Jan 30 06:00:36 2015
From: mal at europython.eu (M.-A. Lemburg)
Date: Fri, 30 Jan 2015 12:00:36 +0100
Subject: EuroPython 2015: New Code of Conduct
Message-ID: <54CB6454.2090801@europython.eu>

For EuroPython 2015 we have chosen to use a new code of conduct (CoC)
that is based on the PyCon UK Code of Conduct [1].

We think that it reads much nicer than the one we had before, while
serving the same purpose. In summary:


Be nice to each other
---------------------

We trust that attendees will treat each other in a way that reflects
the widely held view that diversity and friendliness are strengths of
our community to be celebrated and fostered.

Furthermore, we believe attendees have a right to:

 * be treated with courtesy, dignity and respect;

 * be free from any form of discrimination, victimization, harassment
   or bullying;

 * enjoy an environment free from unwelcome behavior, inappropriate
   language and unsuitable imagery.


Here?s the permanent link to the CoC for 2015:

    EuroPython 2015 - Code of Conduct
    http://ep2015.europython.eu/coc/

We?d like to thank the PyCon UK organizers for their work on the CoC
and for putting it under a CC license.

[1] http://pyconuk.net/CodeOfConduct

Thanks,
-?
EuroPython Society (EPS)
http://www.europython-society.org/


From ginobusciarello at outlook.com  Fri Jan 30 07:02:39 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Fri, 30 Jan 2015 04:02:39 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
References: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
Message-ID: <2b48e39a-90f7-4bc8-938c-53408f9505f3@googlegroups.com>

-- redacted --


From ginobusciarello at outlook.com  Fri Jan 30 07:02:56 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Fri, 30 Jan 2015 04:02:56 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <35861325-94c1-418c-ab89-e4ea967431da@googlegroups.com>
References: <35861325-94c1-418c-ab89-e4ea967431da@googlegroups.com>
Message-ID: <5e0eaa20-3ab9-4f38-ac41-3c0b493580fe@googlegroups.com>

-- redacted --


From ginobusciarello at outlook.com  Fri Jan 30 07:03:17 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Fri, 30 Jan 2015 04:03:17 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <7757dbc7-412a-4a42-8418-801a4d5d8fb4@googlegroups.com>
References: <7757dbc7-412a-4a42-8418-801a4d5d8fb4@googlegroups.com>
Message-ID: <2d633d1e-1abe-4486-8250-99a8cf7ecc33@googlegroups.com>

-- redacted --


From ginobusciarello at outlook.com  Fri Jan 30 07:03:52 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Fri, 30 Jan 2015 04:03:52 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <6a5767b4-ef13-4ee8-8f57-3964b109ca79@googlegroups.com>
References: <6a5767b4-ef13-4ee8-8f57-3964b109ca79@googlegroups.com>
Message-ID: <5f6b6654-af7c-4507-84c6-18db04234007@googlegroups.com>

-- redacted --


From ginobusciarello at outlook.com  Fri Jan 30 07:04:12 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Fri, 30 Jan 2015 04:04:12 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <9ea713a4-3e21-4522-b751-5d896c5ea31e@googlegroups.com>
References: <9ea713a4-3e21-4522-b751-5d896c5ea31e@googlegroups.com>
Message-ID: <239f0f82-584f-4cc4-be42-a8d6b5688129@googlegroups.com>

-- redacted --


From ginobusciarello at outlook.com  Fri Jan 30 07:05:02 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Fri, 30 Jan 2015 04:05:02 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <932064e4-d5b5-410a-990c-15a20def69a5@googlegroups.com>
References: <932064e4-d5b5-410a-990c-15a20def69a5@googlegroups.com>
Message-ID: <5e799d46-8964-44d5-a5ea-03e39aec639f@googlegroups.com>

-- redacted --


From ginobusciarello at outlook.com  Fri Jan 30 07:14:32 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Fri, 30 Jan 2015 04:14:32 -0800 (PST)
Subject: -- redacted --
Message-ID: <83af10d1-4ece-4480-b42d-270d6263bf7d@googlegroups.com>

-- redacted --


From cirillobolello at mail.com  Fri Jan 30 07:23:21 2015
From: cirillobolello at mail.com (COLLABORATORE DI MICHELE RAGAZZI ODEY GIANO)
Date: Fri, 30 Jan 2015 04:23:21 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <9ea713a4-3e21-4522-b751-5d896c5ea31e@googlegroups.com>
References: <9ea713a4-3e21-4522-b751-5d896c5ea31e@googlegroups.com>
Message-ID: <1d58f3a3-eef5-46e0-83fa-0f08b594c1b3@googlegroups.com>

-- redacted --


From shannonlab.saiyou at gmail.com  Fri Jan 30 08:38:39 2015
From: shannonlab.saiyou at gmail.com (shannonlab.saiyou at gmail.com)
Date: Fri, 30 Jan 2015 05:38:39 -0800 (PST)
Subject: about supervisor program doesn't show in web console
In-Reply-To: <ccafeaf7-2772-4a01-9fdc-345f537e13d2@googlegroups.com>
References: <ccafeaf7-2772-4a01-9fdc-345f537e13d2@googlegroups.com>
Message-ID: <88b17d6a-4347-4f1d-9aa5-c8d10ebc5214@googlegroups.com>

I resolved

I tried and reseted
echo_supervisord_conf > /etc/supervisord.conf

2015?1?30???? 19?26?45? UTC+9 shin... at gmail.com:
> Hi there
> 
> 
> I am trying to use supervisord.
> I wrote some program in /etc/supervisord.conf file.
> 
> I wrote four programs in it.
> 
> However, one program can't show in the web console.
> 
> the program name is "myprogram_three".
> 
> My /etc/supervisord.conf file's snippet is below
> 
> 
> I modified http_port.
> 
> [supervisord]
> ;http_port=/var/tmp/supervisor.sock ; (default is to run a UNIX domain socket server)
> http_port=0.0.0.0:8888
> 
> 
> And my programs registering is here
> 
> ; App appname Program
> ; myprogram 1
> [program:myprogram_one]
> command=python /home/username/work/my_program.py start 3 appname /var/www/django/demo/appname/appname
> startsecs = 5
> user = root
> redirect_stderr = true
> stderr_logfile = /var/log/supervisor/Program/hoge_appname-stderr.log
> stdout_logfile = /var/log/supervisor/Program/hoge_appname-stdout.log
> 
> ; myprogram 2
> [program:myprogram_two]
> command=python /home/username/work/my_program.py start 4 appname /var/www/django/demo/appname/appname
> startsecs = 5
> user = root
> redirect_stderr = true
> stderr_logfile = /var/log/supervisor/Program/bar_appname-stderr.log
> stdout_logfile = /var/log/supervisor/Program/bar_appname-stdout.log
> 
> 
> ; appnametwo Program
> ; myprogram 3
> [program:myprogram_three]
> command=python /home/username/work/my_program.py start 3 appnametwo /var/www/django/demo/appnametwo/appname
> startsecs = 5
> user = root
> redirect_stderr = true
> stderr_logfile = /var/log/supervisor/Program/hoge_appnametwo-stderr.log
> stdout_logfile = /var/log/supervisor/Program/hoge_appnametwo-stdout.log
> 
> 
> ; myprogram 4
> [program:myprogram_four]
> command=python /home/username/work/my_program.py start 4 appnametwo /var/www/django/demo/appnametwo/appname
> startsecs = 5
> user = root
> redirect_stderr = true
> stderr_logfile = /var/log/supervisor/Program/bar_appnametwo-stderr.log
> stdout_logfile = /var/log/supervisor/Program/bar_appnametwo-stdout.log
> 
> 
> Why dows "myprogram_three" program work?
> 
> I would appreciate it if you could help me.


From shannonlab.saiyou at gmail.com  Fri Jan 30 08:42:38 2015
From: shannonlab.saiyou at gmail.com (shannonlab.saiyou at gmail.com)
Date: Fri, 30 Jan 2015 05:42:38 -0800 (PST)
Subject: How to show Tail -f in supervisor's web console.
Message-ID: <40cc66e4-e714-40e8-9a3a-a24e77a0fa4d@googlegroups.com>

Hello

I use supervisor's web console.

I touched "Tail -f" button.
But, it can't show the log page.

I researched the log file

tail -f /tmp/supervisord.log

but, it doesn't show about the bug.

I would appreciate it if you help me.


From franssoa at email.invalid  Fri Jan 30 08:53:47 2015
From: franssoa at email.invalid (franssoa)
Date: Fri, 30 Jan 2015 14:53:47 +0100
Subject: Sort of Augmented Reality
In-Reply-To: <mailman.18292.1422584565.18130.python-list@python.org>
References: <madd3b$u2l$1@dont-email.me>
 <mailman.18292.1422584565.18130.python-list@python.org>
Message-ID: <mag2c9$e6v$1@dont-email.me>

Le 30. 01. 15 03:22, Dennis Lee Bieber a ?crit :

>
> 	Given the first, and the aircraft data, you would need to compute the
> rays (azimuth/elevation) from camera to each target and map those to pixels
> in the image... a lot of spherical trigonometry there...
>
> http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CB4QFjAA&url=http%3A%2F%2Fccar.colorado.edu%2FASEN5070%2Fhandouts%2FComp_of_Azimuth_Ele.ppt&ei=gerKVN-nOsSxyATMwoKQDw&usg=AFQjCNEVx_Yf8QtGYwJ2wH7OU5LRaqQJEA&bvm=bv.84607526,d.aWw
>
> (satellite based, but may be applicable; do a search for "convert lat long
> to azimuth elevation")
>
Hum not so simple I was thinking :-)
I think I'll have some hours of reading in internet...

Thank you for the seed

franssoa


From bkline at rksystems.com  Fri Jan 30 09:45:10 2015
From: bkline at rksystems.com (bkline at rksystems.com)
Date: Fri, 30 Jan 2015 06:45:10 -0800 (PST)
Subject: Installling ADODB on an offline computer
In-Reply-To: <54CADFE8.8080505@yahoo.com>
References: <54CADFE8.8080505@yahoo.com>
Message-ID: <ad0eecf8-c18a-4318-867d-1f6bb08bbd6e@googlegroups.com>

On Thursday, January 29, 2015 at 8:35:50 PM UTC-5, Alan Meyer wrote:
> I work on an application that uses the ActivePython compilation of 
> Python from ActiveState.  It uses three Microsoft COM libraries that are 
> needed for talking to SQL Server.  The libraries are:
> 
>      Microsoft Activex Data Objects
>      Microsoft Activex Data Objects Recordset
>      Microsoft ADO Ext
> 
> In the past, we have installed those libraries on numerous machines by 
> running makepy.py.  It can be done from the ActivePython IDLE GUI, or 
> from the command line.  makepy.py downloads and installs the packages 
> for us, taking care of COM server or client registration, or whatever it 
> is that has to be done (I don't really know much about this stuff.)
> 
> Now I've been asked to port the application to a computer that is not 
> connected to the Internet.  I haven't found any way to get those 
> packages.  I haven't found a way to, for example, download the packages 
> to files, place the files on the target computer, and run makepy.py or a 
> setup.py to install them.
> 
> Can someone suggest a way to do it?
> 
> Thank you very much.
> 
>      Alan

I don't think makepy.py needs to download anything. It's just extracting information from the registry about COM services which are available and building a Python wrapper around those services. I've used it successfully myself on a machine completely cut off from the outside world.

Cheers,
Bob


From unknown3000 at gmail.com  Fri Jan 30 09:56:18 2015
From: unknown3000 at gmail.com (unknown3000 at gmail.com)
Date: Fri, 30 Jan 2015 06:56:18 -0800 (PST)
Subject: multiprocessing.Queue & vim python interpreter
In-Reply-To: <mailman.18072.1422071975.18130.python-list@python.org>
References: <d4aeba08-023d-4e57-8a30-367a128a8e50@googlegroups.com>
 <mailman.18072.1422071975.18130.python-list@python.org>
Message-ID: <ccfaeb09-4555-44d9-b314-3f95341e2443@googlegroups.com>

On Friday, January 23, 2015 at 10:59:46 PM UTC-5, Cameron Simpson wrote:
> On 18Jan2015 16:20, unknown3000 at gmail.com <unknown3000 at gmail.com> wrote:
> >I am experimenting on a fork of vim-plug for managing vim plugins. I wanted to add parallel update support for python since ruby isn't nearly as common. I've come across a weird bug that only seems to happen when I'm inside vim, I'm wondering if someone could tell me why.
> >
> >This problem can be reproduced by sourcing a vim file with the following snippet. Then execute the command PyCrash.
> >command! -nargs=0 PyCrash call s:py_crash()
> >function! s:py_crash()
> >    python << EOF
> >import multiprocessing as multi
> >queue = multi.Queue()
> >queue.put('a')
> >queue.close()
> >EOF
> >endfunction
> >
> >This prints to messages the following:
> >Traceback (most recent call last):
> >  File "/usr/lib/python2.7/multiprocessing/queues.py", line 266, in _feed
> >    send(obj)
> >IOError: [Errno 32] Broken pipe
> 
> Please include the entire traceback in errors.
> 
> I would guess this is because you have made a Queue but have not got subprocess 
> to read from it. So when you .put onto it, you get a broken pipe.
> 
> Cheers,
> Cameron Simpson <cs at zip.com.au>
> 
> Nothing is impossible for the man who doesn't have to do it.

Hi there. Thanks for getting back to me. I don't really need an answer to this issue anymore as I went with threads instead since multiprocessing. The latter doesn't work well on Windows and worse inside an embedded context like GVim ON Windows. Not having fork is a real pain.

This bug was probably related to the embedded python nature of the code rather than python as I never experienced it outside of Vim using the same multiprocessing/Queue code. Also, I don't remember which commit it was so since I'm working on other stuff I'm just gonna leave this unfixed/investigated. Thanks anyway.

Regards,

Jeremy


From al.basili at gmail.com  Fri Jan 30 10:05:13 2015
From: al.basili at gmail.com (alb)
Date: 30 Jan 2015 15:05:13 GMT
Subject: parsing tree from excel sheet
References: <cirqviF15qtU1@mid.individual.net>
 <mailman.18217.1422454096.18130.python-list@python.org>
Message-ID: <cj1kt9Fi3e0U1@mid.individual.net>

Hi Peter, I'll try to comment the code below to verify if I understood 
it correctly or missing some major parts. Comments are just below code 
with the intent to let you read the code first and my understanding 
afterwards.

Peter Otten <__peter__ at web.de> wrote:
[]
> $ cat parse_column_tree.py
> import csv
> 
> def column_index(row):
>    for result, cell in enumerate(row, 0):
>        if cell:
>            return result
>    raise ValueError

Here you get the depth of your first node in this row.

> class Node:
>    def __init__(self, name, level):
>        self.name = name
>        self.level = level
>        self.children = []
> 
>    def append(self, child):
>        self.children.append(child)
> 
>    def __str__(self):
>        return "\%s{%s}" % (self.level, self.name)

Up to here everything is fine, essentially defining the basic methods 
for the node object. A node is represented univocally with its name and 
the level. Here I could say that two nodes with the same name cannot be 
on the same level but this is cosmetic.

The important part would be that 'Name' can be also 'Attributes', with a 
dictionary instead. This would allow to store more information on each 
node.

>    def show(self):
>        yield [self.name]

Here I'm lost in translation! Why using yield in the first place?
What this snippet is used for?


>        for i, child in enumerate(self.children):
>            lastchild = i == len(self.children)-1
>            first = True
>            for c in child.show():
>                if first:
>                    yield ["\---> " if lastchild else "+---> "] + c
>                    first = False
>                else:
>                    yield ["      " if lastchild else "|     "] + c

Here I understand more, essentially 'yield' returns a string that would 
be used further down in the show(root) function. Yet I doubt that I 
grasp the true meaning of the code. It seems those 'show' functions have 
lots of iterations that I'm not quite able to trace. Here you loop over 
children, as well as in the main()...

>    def show2(self):
>        yield str(self)
>        for child in self.children:
>            yield from child.show2()

ok, this as well requires some explanation. Kinda lost again. From what 
I can naively deduce is that it is a generator that returns the str 
defined in the node as __str__ and it shows it for the whole tree.

> def show(root):
>    for row in root.show():
>        print("".join(row))
> 
> def show2(root):
>    for line in root.show2():
>        print(line)

Here we implement the functions to print a node, but I'm not sure I 
understand why do I have to iterate if the main() iterates again over the 
nodes.

> 
> def read_tree(rows, levelnames):
>    root = Node("#ROOT", "#ROOT")
>    old_level = 0
>    stack = [root]
>    for i, row in enumerate(rows, 1):

I'm not quite sure I understand what is the stack for. As of now is a 
list whose only element is root.

>        new_level = column_index(row)
>        node = Node(row[new_level], levelnames[new_level])

here you are getting the node based on the current row, with its level.

>        if new_level == old_level:
>            stack[-1].append(node)

I'm not sure I understand here. Why the end of the list and not the 
beginning?

>        elif new_level > old_level:
>            if new_level - old_level != 1:
>                raise ValueError

here you avoid having a node which is distant more than one level from 
its parent.

>            stack.append(stack[-1].children[-1])

here I get a crash: IndexError: list index out of range!

>            stack[-1].append(node)
>            old_level = new_level
>        else:
>            while new_level < old_level:
>                stack.pop(-1)
>                old_level -= 1
>            stack[-1].append(node)

Why do I need to pop something from the stack??? Here you are saying 
that if current row has a depth (new_level) that is smaller than the 
previous one (old_level) I decrement by one the old_level (even if I may 
have a bigger jump) and pop something from the stack...???

>    return root

once filled, the tree is returned. I thought the tree would have been 
the stack, but instead is root...nice surprise.

> 
> def main():
[strip arg parsing]

>    with open(args.infile) as f:
>        rows = csv.reader(f)
>        levelnames = next(rows) # skip header
>        tree = read_tree(rows, levelnames)

filling the tree with the data in the csv.

> 
>        show_tree = show2 if args.latex else show
>        for node in tree.children:
>            show_tree(node)
>            print("")

It's nice to define show_tree as a function of the argument. The for 
loop now is more than clear, traversing each node of the tree.

As I said earlier in the thread there's a lot of food for a newbie, but 
better going through these sort of exercises than dumb tutorial which 
don't teach you much.

Al


From ian.g.kelly at gmail.com  Fri Jan 30 10:21:09 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 30 Jan 2015 08:21:09 -0700
Subject: The Most Diabolical Python Antipattern
In-Reply-To: <87fvaslh9h.fsf@elektro.pacujo.net>
References: <madpuv$he7$1@ger.gmane.org>
 <20150129113238.7eaa986d@bigbox.christie.dr>
 <mailman.18286.1422571931.18130.python-list@python.org>
 <87r3uchjyg.fsf@elektro.pacujo.net>
 <mailman.18296.1422605482.18130.python-list@python.org>
 <87r3ucljyv.fsf@elektro.pacujo.net>
 <87fvaslh9h.fsf@elektro.pacujo.net>
Message-ID: <CALwzidn+cgbt4FvyXyv4OCbxxF5R15cuPy4-_jiOWzcy0wpHDA@mail.gmail.com>

On Fri, Jan 30, 2015 at 3:00 AM, Marko Rauhamaa <marko at pacujo.net> wrote:
> Marko Rauhamaa <marko at pacujo.net>:
>
>>>> Surprisingly this variant could raise an unexpected exception:
>>>>
>>>> ==============================
>>>>      try:
>>>>          do_interesting_stuff()
>>>>      except ValueError:
>>>>          try:
>>>>              log_it()
>>>>          finally:
>>>>              raise
>>>> ==============================
>>>>
>>>> A Python bug?
>> [...]
>> My Python did do exception chaining, but the problem is the surface
>> exception changes, which could throw off the whole error recovery.
>
> BTW, the code above can be fixed:
>
> ==============================
>   try:
>       do_interesting_stuff()
>   except ValueError as e:
>       try:
>           log_it()
>       finally:
>           raise e
> ==============================
>
> Now the surface exception is kept and the subsidiary exception is
> chained to it.
>
> I'm a bit baffled why the two pieces of code are not equivalent.

The bare raise re-raises the most recent exception that is being
handled. The "raise e" raises that exception specifically, which is
not the most recent in the case of a secondary exception.

Note that the exceptions are actually chained *in reverse*; the
message falsely indicates that the secondary exception was raised
first, and the primary exception was raised while handling it, e.g.:

Traceback (most recent call last):
  File "<stdin>", line 5, in <module>
TypeError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 7, in <module>
  File "<stdin>", line 2, in <module>
ValueError

That's because "raise e" causes the exception e to be freshly raised,
whereas the bare "raise" merely makes the existing exception context
active again.

It's interesting to note here that although the exception retains its
original traceback information (note the two separate lines in the
traceback), it is not chained again from the TypeError. One might
expect to actually see the ValueError, followed by the TypeError,
followed by the ValueError in the chain. That doesn't happen because
the two ValueErrors raised are actually the same object, and Python is
apparently wise enough to break the chain to avoid an infinite cycle.


From marko at pacujo.net  Fri Jan 30 10:30:08 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Fri, 30 Jan 2015 17:30:08 +0200
Subject: The Most Diabolical Python Antipattern
References: <madpuv$he7$1@ger.gmane.org>
 <20150129113238.7eaa986d@bigbox.christie.dr>
 <mailman.18286.1422571931.18130.python-list@python.org>
 <87r3uchjyg.fsf@elektro.pacujo.net>
 <mailman.18296.1422605482.18130.python-list@python.org>
 <87r3ucljyv.fsf@elektro.pacujo.net>
 <87fvaslh9h.fsf@elektro.pacujo.net>
 <mailman.18306.1422631319.18130.python-list@python.org>
Message-ID: <87zj90jngf.fsf@elektro.pacujo.net>

Ian Kelly <ian.g.kelly at gmail.com>:

> The bare raise re-raises the most recent exception that is being
> handled. The "raise e" raises that exception specifically, which is
> not the most recent in the case of a secondary exception.

Scary. That affects all finally clauses. Must remember that.

The pitfall is avoided by using the "except: pass" antipattern but then
you lose exception chaining.


Marko


From ian.g.kelly at gmail.com  Fri Jan 30 10:42:04 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 30 Jan 2015 08:42:04 -0700
Subject: The Most Diabolical Python Antipattern
In-Reply-To: <87zj90jngf.fsf@elektro.pacujo.net>
References: <madpuv$he7$1@ger.gmane.org>
 <20150129113238.7eaa986d@bigbox.christie.dr>
 <mailman.18286.1422571931.18130.python-list@python.org>
 <87r3uchjyg.fsf@elektro.pacujo.net>
 <mailman.18296.1422605482.18130.python-list@python.org>
 <87r3ucljyv.fsf@elektro.pacujo.net>
 <87fvaslh9h.fsf@elektro.pacujo.net>
 <mailman.18306.1422631319.18130.python-list@python.org>
 <87zj90jngf.fsf@elektro.pacujo.net>
Message-ID: <CALwzid=htmO2A1TW7UXJzFkbXgypgm5h6XLM2zNL2Mzw1uQUuA@mail.gmail.com>

On Fri, Jan 30, 2015 at 8:30 AM, Marko Rauhamaa <marko at pacujo.net> wrote:
> Ian Kelly <ian.g.kelly at gmail.com>:
>
>> The bare raise re-raises the most recent exception that is being
>> handled. The "raise e" raises that exception specifically, which is
>> not the most recent in the case of a secondary exception.
>
> Scary. That affects all finally clauses. Must remember that.
>
> The pitfall is avoided by using the "except: pass" antipattern but then
> you lose exception chaining.

Like I suggested earlier, just don't catch the inner exception at all.
The result will be both exceptions propagated, chained in the proper
order.


From ian.g.kelly at gmail.com  Fri Jan 30 10:46:35 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 30 Jan 2015 08:46:35 -0700
Subject: Python tracker manual password reset
Message-ID: <CALwzidk0jF1GWWC70PobWsHPrVsuDMrinVdBuJ_tJ-H-3U93vw@mail.gmail.com>

I just tried to use the password recovery tool for the Python tracker.
I entered my personal email. It sent me the confirmation email with
the password reset link, which I followed. It then reset my password
and sent an email to a different address, an old work address that I
no longer have, so I have no idea what the new password is.

Is there someone I can contact to have my password manually reset?


From rosuav at gmail.com  Fri Jan 30 10:55:57 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 31 Jan 2015 02:55:57 +1100
Subject: The Most Diabolical Python Antipattern
In-Reply-To: <CALwzid=htmO2A1TW7UXJzFkbXgypgm5h6XLM2zNL2Mzw1uQUuA@mail.gmail.com>
References: <madpuv$he7$1@ger.gmane.org>
 <20150129113238.7eaa986d@bigbox.christie.dr>
 <mailman.18286.1422571931.18130.python-list@python.org>
 <87r3uchjyg.fsf@elektro.pacujo.net>
 <mailman.18296.1422605482.18130.python-list@python.org>
 <87r3ucljyv.fsf@elektro.pacujo.net>
 <87fvaslh9h.fsf@elektro.pacujo.net>
 <mailman.18306.1422631319.18130.python-list@python.org>
 <87zj90jngf.fsf@elektro.pacujo.net>
 <CALwzid=htmO2A1TW7UXJzFkbXgypgm5h6XLM2zNL2Mzw1uQUuA@mail.gmail.com>
Message-ID: <CAPTjJmqGmU-JhTb8-+dZZxp2rnCTG_+4cOJ1dGz=EuHRwgcNnw@mail.gmail.com>

On Sat, Jan 31, 2015 at 2:42 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> Like I suggested earlier, just don't catch the inner exception at all.
> The result will be both exceptions propagated, chained in the proper
> order.

So many MANY times, the best thing to do with unrecognized exceptions
is simply to not catch them.

ChrisA


From marko at pacujo.net  Fri Jan 30 10:56:41 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Fri, 30 Jan 2015 17:56:41 +0200
Subject: The Most Diabolical Python Antipattern
References: <madpuv$he7$1@ger.gmane.org>
 <20150129113238.7eaa986d@bigbox.christie.dr>
 <mailman.18286.1422571931.18130.python-list@python.org>
 <87r3uchjyg.fsf@elektro.pacujo.net>
 <mailman.18296.1422605482.18130.python-list@python.org>
 <87r3ucljyv.fsf@elektro.pacujo.net>
 <87fvaslh9h.fsf@elektro.pacujo.net>
 <mailman.18306.1422631319.18130.python-list@python.org>
 <87zj90jngf.fsf@elektro.pacujo.net>
 <mailman.18307.1422632572.18130.python-list@python.org>
Message-ID: <87vbjojm86.fsf@elektro.pacujo.net>

Ian Kelly <ian.g.kelly at gmail.com>:

> Like I suggested earlier, just don't catch the inner exception at all.
> The result will be both exceptions propagated, chained in the proper
> order.

Depends on the situation.


Marko


From robertchen117 at gmail.com  Fri Jan 30 11:09:15 2015
From: robertchen117 at gmail.com (Robert Chen)
Date: Fri, 30 Jan 2015 08:09:15 -0800 (PST)
Subject: how to parse sys.argv as dynamic parameters to another function?
Message-ID: <baa4011f-0745-4f8b-a6f5-fc242a886d78@googlegroups.com>

how to parse sys.argv as dynamic parameters to another function? 


fun(sys.argv)

in perl, this is very easy. please help. 


From skip.montanaro at gmail.com  Fri Jan 30 11:16:24 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Fri, 30 Jan 2015 10:16:24 -0600
Subject: how to parse sys.argv as dynamic parameters to another function?
In-Reply-To: <baa4011f-0745-4f8b-a6f5-fc242a886d78@googlegroups.com>
References: <baa4011f-0745-4f8b-a6f5-fc242a886d78@googlegroups.com>
Message-ID: <CANc-5Uwt3o+1V8xjhXpFDVrcZb-KJ+FW4P8Bs_hr3P7O336zPw@mail.gmail.com>

On Fri, Jan 30, 2015 at 10:09 AM, Robert Chen <robertchen117 at gmail.com> wrote:
>
> how to parse sys.argv as dynamic parameters to another function?
>
>
> fun(sys.argv)


Not sure what you mean by "dynamic", but I think you already have it,
assuming fun is a function which accepts a single list of strings as
its argument.

Skip


From rustompmody at gmail.com  Fri Jan 30 11:27:02 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 30 Jan 2015 08:27:02 -0800 (PST)
Subject: [OT] fortran lib which provide python like data type
In-Reply-To: <mafc1u$n1l$1@dont-email.me>
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
Message-ID: <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>

On Friday, January 30, 2015 at 1:03:03 PM UTC+5:30, Christian Gollwitzer wrote:
> Am 30.01.15 um 02:40 schrieb Rustom Mody:
> > FORTRAN
> > 
> >  use dictionary
> >  type(dictionary), pointer :: d
> >  d=>dict_new()
> >  call set(d//'toto',1)
> >  v = d//'toto'
> >  call dict_free(d)
> > 
> > The corresponding python
> > 
> >  d = dict()
> >  d['toto'] = 1
> >  v = d['toto']
> >  del(d)
> > 
> > In particular note the del in the python.
> > 
> > Should highlight the point that languages with gc, support data structures
> > in a way that gc-less languages - Fortran, C, C++ - do not and cannot.
> 
> For C++ this is not correct. Ususally a garbage collector is not used -
> though possible - but the constructor/destructor/assignment op in C++
> (usually called RAII) provide semantics very similar to the CPython
> refcounting behaviour.

You may be right... Dont claim to be able to wrap my head round C++
However...

> 
> For example, I made a set of C++ interface methods to return nested
> dicts/list to Python, which is far from complete, but allows to write
> something like this:
> 
> SWList do_something(SWDict attrs) {
>   SWList result;
>   for (int i=0; i<5; i++) {
>     SWDict entry;			
>     entry.insert("count", i);
>     entry.insert("name", "something");
>     result.push_back(entry);
>   }
>   return result;
> }
> 
> 
> There is also Boost::Python which does the same, I think, and much more,
> but only supports Python, whereas I use SWIG to interface these
> dicts/lists to both CPython and Tcl.
> 
> You cannot, however, resolve certain cyclic dependencies with pure
> reference counting.

... if I restate that in other words it says that sufficiently
complex data structures will be beyond the reach of the standard
RAII infrastructure.

Of course this only brings up one side of memory-mgmt problems
viz. unreclaimable memory.

What about dangling pointers?
C++ apps are prone to segfault. Seems to suggest
(to me at least) that the memory-management infrastructure
is not right.

Stroustrup talks of the fact that C++ is suitable for lightweight
abstractions. In view of the segfault-proneness I'd say they 
are rather leaky abstractions.

But as I said at the outset I dont understand C++


From ian.g.kelly at gmail.com  Fri Jan 30 11:28:42 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 30 Jan 2015 09:28:42 -0700
Subject: how to parse sys.argv as dynamic parameters to another function?
In-Reply-To: <baa4011f-0745-4f8b-a6f5-fc242a886d78@googlegroups.com>
References: <baa4011f-0745-4f8b-a6f5-fc242a886d78@googlegroups.com>
Message-ID: <CALwzid=2xNRdfCkJY9terZoZ1Ep385Y7-ESmoBLBKPQw0ZEgYA@mail.gmail.com>

On Fri, Jan 30, 2015 at 9:09 AM, Robert Chen <robertchen117 at gmail.com> wrote:
> how to parse sys.argv as dynamic parameters to another function?
>
>
> fun(sys.argv)
>
> in perl, this is very easy. please help.

Do you mean that you want each item of sys.argv to be passed as a
separate parameter to the function? If so, then:

fun(*sys.argv)


From ameyer2 at yahoo.com  Fri Jan 30 11:38:15 2015
From: ameyer2 at yahoo.com (Alan Meyer)
Date: Fri, 30 Jan 2015 11:38:15 -0500
Subject: Installling ADODB on an offline computer
In-Reply-To: <ad0eecf8-c18a-4318-867d-1f6bb08bbd6e@googlegroups.com>
References: <54CADFE8.8080505@yahoo.com>
 <ad0eecf8-c18a-4318-867d-1f6bb08bbd6e@googlegroups.com>
Message-ID: <magc0m$26e$1@dont-email.me>

On 01/30/2015 09:45 AM, bkline at rksystems.com wrote:
> On Thursday, January 29, 2015 at 8:35:50 PM UTC-5, Alan Meyer wrote:
>> I work on an application that uses the ActivePython compilation of
>> Python from ActiveState.  It uses three Microsoft COM libraries that are
>> needed for talking to SQL Server.  The libraries are:
>>
>>       Microsoft Activex Data Objects
>>       Microsoft Activex Data Objects Recordset
>>       Microsoft ADO Ext
>>
>> In the past, we have installed those libraries on numerous machines by
>> running makepy.py.  It can be done from the ActivePython IDLE GUI, or
>> from the command line.  makepy.py downloads and installs the packages
>> for us, taking care of COM server or client registration, or whatever it
>> is that has to be done (I don't really know much about this stuff.)
>>
>> Now I've been asked to port the application to a computer that is not
>> connected to the Internet.  I haven't found any way to get those
>> packages.  I haven't found a way to, for example, download the packages
>> to files, place the files on the target computer, and run makepy.py or a
>> setup.py to install them.
>>
>> Can someone suggest a way to do it?
>>
>> Thank you very much.
>>
>>       Alan
>
> I don't think makepy.py needs to download anything. It's just extracting information from the registry about COM services which are available and building a Python wrapper around those services. I've used it successfully myself on a machine completely cut off from the outside world.
>
> Cheers,
> Bob
>
Well, son of a gun.

Thanks Bob.

    Alan


From ian.g.kelly at gmail.com  Fri Jan 30 11:38:53 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 30 Jan 2015 09:38:53 -0700
Subject: The Most Diabolical Python Antipattern
In-Reply-To: <87vbjojm86.fsf@elektro.pacujo.net>
References: <madpuv$he7$1@ger.gmane.org>
 <20150129113238.7eaa986d@bigbox.christie.dr>
 <mailman.18286.1422571931.18130.python-list@python.org>
 <87r3uchjyg.fsf@elektro.pacujo.net>
 <mailman.18296.1422605482.18130.python-list@python.org>
 <87r3ucljyv.fsf@elektro.pacujo.net>
 <87fvaslh9h.fsf@elektro.pacujo.net>
 <mailman.18306.1422631319.18130.python-list@python.org>
 <87zj90jngf.fsf@elektro.pacujo.net>
 <mailman.18307.1422632572.18130.python-list@python.org>
 <87vbjojm86.fsf@elektro.pacujo.net>
Message-ID: <CALwzidm4o4c-HnUYEzUPw7Eh=40iVAq+17HehkAtKC6Ee+GdfA@mail.gmail.com>

On Fri, Jan 30, 2015 at 8:56 AM, Marko Rauhamaa <marko at pacujo.net> wrote:
> Ian Kelly <ian.g.kelly at gmail.com>:
>
>> Like I suggested earlier, just don't catch the inner exception at all.
>> The result will be both exceptions propagated, chained in the proper
>> order.
>
> Depends on the situation.

Like what? If you want to specifically propagate the original
exception in order to be caught again elsewhere, then I think there's
a code smell to that. If this inner exception handler doesn't
specifically know how to handle a ValueError, then why should some
outer exception handler be able to handle an exception that could have
come from virtually anywhere?

A better approach to that would be to create a specific exception
class that narrowly identifies what went wrong, and raise *that* with
the other exceptions chained to it. E.g.:

  try:
      do_interesting_stuff()
  except ValueError as e:
      try:
          log_it()
      except Exception:
          # Chain both exceptions as __context__
          raise SpecificException
      else:
          # Chain the original exception as __cause__
          raise SpecificException from e

Or if you don't care about distinguishing __cause__ from __context__:

  try:
      do_interesting_stuff()
  except ValueError:
      try:
          log_it()
      finally:
          raise SpecificException


From torriem at gmail.com  Fri Jan 30 12:08:35 2015
From: torriem at gmail.com (Michael Torrie)
Date: Fri, 30 Jan 2015 10:08:35 -0700
Subject: [OT] fortran lib which provide python like data type
In-Reply-To: <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
Message-ID: <54CBBA93.9020404@gmail.com>

On 01/30/2015 09:27 AM, Rustom Mody wrote:
> ... if I restate that in other words it says that sufficiently
> complex data structures will be beyond the reach of the standard
> RAII infrastructure.
> 
> Of course this only brings up one side of memory-mgmt problems
> viz. unreclaimable memory.
> 
> What about dangling pointers?
> C++ apps are prone to segfault. Seems to suggest
> (to me at least) that the memory-management infrastructure
> is not right.
> 
> Stroustrup talks of the fact that C++ is suitable for lightweight
> abstractions. In view of the segfault-proneness I'd say they 
> are rather leaky abstractions.
> 
> But as I said at the outset I dont understand C++

Yes I can tell you haven't used C++.  Compared to C, I've always found
memory management in C++ to be quite a lot easier. The main reason is
that C++ guarantees objects will be destroyed when going out of scope.
So when designing a class, you put any allocation routines in the
constructor, and put deallocation routines in the destructor.  And it
just works.  This is something I miss in other languages, even Python.

And for many things, though it's not quite as efficient, when dealing
with objects you can forgo pointers altogether and just use copy
constructors, instead of the

blah *a = new blah_with_label("hello") //allocate on heap
//forget to "delete a" and it leaks the heap *and* anything
//that class blah allocated on construction.

just simply declare objects directly and use them:

blah a("hello") //assuming there's a constructor that takes a string
                //deletes everything when it goes out of scope

So for the lightweight abstractions Stroustrup talks about, this works
very well. And you'll rarely have a memory leak (only in the class
itself) and no "dangling pointers."

For other things, though, you have to dynamically create objects.  But
the C++ reference-counting smart pointers offer much of the same
destruction semantics as using static objects.  It's really a slick
system.  Almost makes memory management a non-issue.  Circular
references will still leak (just like they do on Python).  But it
certainly makes life a lot more pleasant than in C from a memory
management perspective.



From __peter__ at web.de  Fri Jan 30 12:11:28 2015
From: __peter__ at web.de (Peter Otten)
Date: Fri, 30 Jan 2015 18:11:28 +0100
Subject: parsing tree from excel sheet
References: <cirqviF15qtU1@mid.individual.net>
 <mailman.18217.1422454096.18130.python-list@python.org>
 <cj1kt9Fi3e0U1@mid.individual.net>
Message-ID: <mage01$dd2$1@ger.gmane.org>

alb wrote:

> Hi Peter, I'll try to comment the code below to verify if I understood
> it correctly or missing some major parts. Comments are just below code
> with the intent to let you read the code first and my understanding
> afterwards.

Let's start with the simplest:
 
> Peter Otten <__peter__ at web.de> wrote:

>>    def show2(self):
>>        yield str(self)
>>        for child in self.children:
>>            yield from child.show2()
> 
> ok, this as well requires some explanation. Kinda lost again. From what
> I can naively deduce is that it is a generator that returns the str
> defined in the node as __str__ and it shows it for the whole tree.

Given a tree

A --> A1
      A2 --> A21
             A22
      A3

assume a slightly modified show2():

def append_nodes(node, nodes):
    nodes.append(node)
    for child in node.children:
        append_nodes(child, nodes)

When you invoke this with the root node in the above sample tree and an 
empty list

nodes = []
append_nodes(A, nodes)

the first thing it will do is append the root node to the nodes list

[A]

Then it iterates over A's children:

append_nodes(A1, nodes) will append A1 and return immediately because A1 
itself has not children.

[A, A1]

append_nodes(A2, nodes) will append A2 and then iterate over A2's children.
As A21 and A22 don't have any children append_nodes(A21, nodes) and 
append_nodes(A22, nodes) will just append the respective node with no 
further nested ("recursive") invocation, and thus the list is now

[A, A1, A21, A22]

Finally the append_nodes(A3, nodes) will append A3 and then return because 
it has no children, and we end up with

nodes = [A, A1, A21, A22, A3]

Now why the generator? For such a small problem it doesn't matter, for large 
datasets it is convenient that you can process the first item immmediately, 
when the following ones may not yet be available. It also becomes easier to 
implement different treatment of the items or to stop in the process:

for deer in hunt():
    kill(deer)
    if have_enough_food():
        break

for animal in hunt():
    take_photograph(animal)
    if not_enough_light():
        break

Also, you never need more than one item in memory instead of the whole list 
for many problems.

Ok, how to get from the recursive list building to yielding nodes as they 
are encountered? The basic process is always the same:

def f(items)
   items.append(3)
   items.append(6)
   for i in range(10):
       items.append(i)

items = []
f(items)
for item in items:
   print(item)

becomes

def g():
    yield 3
    yield 6
    for i in range(10):
        yield i

for item in g():
    print(items)

In Python 3.3 there was added some syntactic sugar so that you can write

def g():
    yield 3
    yield 6
    yield from range(10)


Thus

def append_nodes(node, nodes):
    nodes.append(node)
    for child in node.children:
        append_nodes(child, nodes)


becomes

def generate_nodes(node):
    yield node
    for child in node.children:
        yield from generate_nodes(child)

This looks a lot like show2() except that it's not a method and thus the 
node not called self and that the node itself is yielded rather than 
str(node). The latter makes the function a bit more flexible and is what I 
should have done in the first place.

The show() method is basically the the same, but there are varying prefixes 
before the node name. Here's a simpler variant that just adds some 
indentation. We start with generate_nodes() without the syntactic sugar. 
This is because we need a name for the nodes yielded from the nested 
generator call so that we can modify them:

def indented_nodes(node):
    yield node
    for child in node.children:
        for desc in from indented_nodes(child):
            yield desc

Now let's modify the yielded nodes:

def indented_nodes(node):
    yield [node]
    for child in node.children:
        for desc in indented_nodes(child):
            yield ["***"] + desc

How does it fare on the example tree? 

A --> A1
      A2 --> A21
             A22
      A3

The lists will have an "***" entry for every nesting level, so we get

[A]
["***", A1]
["***", A2]
["***", "***", A21]
["***", "***", A22]
["***", A3]

With "".join() we can print it nicely:

for item in indented_nodes(tree):
    print("".join(item))

But wait, "".join() only accepts strings so let's change

    yield [node]

to 
    yield [node.name] # str(node) would also work

A
***A1
***A2
******A21
******A22
***A3

>> def show2(root):
>>    for line in root.show2():
>>        print(line)

> Here we implement the functions to print a node, but I'm not sure I 
> understand why do I have to iterate if the main() iterates again over the 
> nodes.

Your example had the structure

A
 A1
   A11
   A12
 A2

and I was unsure if there could be data files that have multiple root nodes, 
e. g.

A
 A1
   A11
   A12
 A2
B
 B1
 B2

To simplify the handling of these I introduced an artificial root R

R
 A
  A1
    A11
    A12
  A2
 B
  B1
  B2

which makes all toplevel nodes in the data file children of R. In the
main() function I iterate over R's children to hide R from the user.

You can replace

        for node in tree.children:
            show_tree(node)
            print("")

in my original code with

        show_tree(tree)

to see the hidden node.

I may address the rest of your post later unless someone else does. In the 
mean time, can you please provide the data file that triggers the IndexError 
to help me with the debugging?




From __peter__ at web.de  Fri Jan 30 12:24:55 2015
From: __peter__ at web.de (Peter Otten)
Date: Fri, 30 Jan 2015 18:24:55 +0100
Subject: parsing tree from excel sheet
References: <cirqviF15qtU1@mid.individual.net>
 <mailman.18217.1422454096.18130.python-list@python.org>
 <cj1kt9Fi3e0U1@mid.individual.net> <mage01$dd2$1@ger.gmane.org>
Message-ID: <magep8$rdj$1@ger.gmane.org>

Peter Otten wrote:

> [A, A1, A21, A22]
> 
> Finally the append_nodes(A3, nodes) will append A3 and then return because
> it has no children, and we end up with
> 
> nodes = [A, A1, A21, A22, A3]
 
Yay, proofreading! Both lists should contain A2:

[A, A1, A2, A21, A22]

nodes = [A, A1, A2, A21, A22, A3]



From rustompmody at gmail.com  Fri Jan 30 12:31:34 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 30 Jan 2015 09:31:34 -0800 (PST)
Subject: [OT] fortran lib which provide python like data type
In-Reply-To: <mailman.18313.1422637734.18130.python-list@python.org>
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <mailman.18313.1422637734.18130.python-list@python.org>
Message-ID: <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>

On Friday, January 30, 2015 at 10:39:12 PM UTC+5:30, Michael Torrie wrote:
> On 01/30/2015 09:27 AM, Rustom Mody wrote:
> > ... if I restate that in other words it says that sufficiently
> > complex data structures will be beyond the reach of the standard
> > RAII infrastructure.
> > 
> > Of course this only brings up one side of memory-mgmt problems
> > viz. unreclaimable memory.
> > 
> > What about dangling pointers?
> > C++ apps are prone to segfault. Seems to suggest
> > (to me at least) that the memory-management infrastructure
> > is not right.
> > 
> > Stroustrup talks of the fact that C++ is suitable for lightweight
> > abstractions. In view of the segfault-proneness I'd say they 
> > are rather leaky abstractions.
> > 
> > But as I said at the outset I dont understand C++
> 
> Yes I can tell you haven't used C++.  Compared to C, I've always found
> memory management in C++ to be quite a lot easier. The main reason is
> that C++ guarantees objects will be destroyed when going out of scope.

I hear you and I trust you as a gentleman but I dont trust C++ :-)

The only time in some near 15 years of python use that
I got it to segfault was when Ranting Rick gave some wx code to try
[at that time he was in rant-against-tk mode]
Sure enough it was related to the fact that wx is written in C++
and some expectations were not being followed.

> So when designing a class, you put any allocation routines in the
> constructor, and put deallocation routines in the destructor.  And it
> just works.  This is something I miss in other languages, even Python.
> 
> And for many things, though it's not quite as efficient, when dealing
> with objects you can forgo pointers altogether and just use copy
> constructors, instead of the
> 
> blah *a = new blah_with_label("hello") //allocate on heap
> //forget to "delete a" and it leaks the heap *and* anything
> //that class blah allocated on construction.
> 
> just simply declare objects directly and use them:
> 
> blah a("hello") //assuming there's a constructor that takes a string
>                 //deletes everything when it goes out of scope
> 
> So for the lightweight abstractions Stroustrup talks about, this works
> very well. And you'll rarely have a memory leak (only in the class
> itself) and no "dangling pointers."

And what about the grey area between lightweight and heavyweight?

You say just use copy constructors and no pointers.
Can you (ie C++) guarantee that no pointer is ever copied out of 
scope of these copy-constructed objects?

> 
> For other things, though, you have to dynamically create objects.  But
> the C++ reference-counting smart pointers offer much of the same
> destruction semantics as using static objects.  It's really a slick
> system.  Almost makes memory management a non-issue.  Circular
> references will still leak (just like they do on Python).  But it
> certainly makes life a lot more pleasant than in C from a memory
> management perspective.



From rustompmody at gmail.com  Fri Jan 30 13:02:55 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Fri, 30 Jan 2015 10:02:55 -0800 (PST)
Subject: RAII vs gc (was fortran lib which provide python like data type)
In-Reply-To: <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <mailman.18313.1422637734.18130.python-list@python.org>
 <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
Message-ID: <8ff4c8aa-a858-481f-8964-7c794f848de2@googlegroups.com>

On Friday, January 30, 2015 at 11:01:50 PM UTC+5:30, Rustom Mody wrote:
> On Friday, January 30, 2015 at 10:39:12 PM UTC+5:30, Michael Torrie wrote:
> > On 01/30/2015 09:27 AM, Rustom Mody wrote:
> > > ... if I restate that in other words it says that sufficiently
> > > complex data structures will be beyond the reach of the standard
> > > RAII infrastructure.
> > > 
> > > Of course this only brings up one side of memory-mgmt problems
> > > viz. unreclaimable memory.
> > > 
> > > What about dangling pointers?
> > > C++ apps are prone to segfault. Seems to suggest
> > > (to me at least) that the memory-management infrastructure
> > > is not right.
> > > 
> > > Stroustrup talks of the fact that C++ is suitable for lightweight
> > > abstractions. In view of the segfault-proneness I'd say they 
> > > are rather leaky abstractions.
> > > 
> > > But as I said at the outset I dont understand C++
> > 
> > Yes I can tell you haven't used C++.  Compared to C, I've always found
> > memory management in C++ to be quite a lot easier. The main reason is
> > that C++ guarantees objects will be destroyed when going out of scope.
> 
> I hear you and I trust you as a gentleman but I dont trust C++ :-)
> 
> The only time in some near 15 years of python use that
> I got it to segfault was when Ranting Rick gave some wx code to try
> [at that time he was in rant-against-tk mode]
> Sure enough it was related to the fact that wx is written in C++
> and some expectations were not being followed.
> 
> > So when designing a class, you put any allocation routines in the
> > constructor, and put deallocation routines in the destructor.  And it
> > just works.  This is something I miss in other languages, even Python.
> > 
> > And for many things, though it's not quite as efficient, when dealing
> > with objects you can forgo pointers altogether and just use copy
> > constructors, instead of the
> > 
> > blah *a = new blah_with_label("hello") //allocate on heap
> > //forget to "delete a" and it leaks the heap *and* anything
> > //that class blah allocated on construction.
> > 
> > just simply declare objects directly and use them:
> > 
> > blah a("hello") //assuming there's a constructor that takes a string
> >                 //deletes everything when it goes out of scope
> > 
> > So for the lightweight abstractions Stroustrup talks about, this works
> > very well. And you'll rarely have a memory leak (only in the class
> > itself) and no "dangling pointers."
> 
> And what about the grey area between lightweight and heavyweight?
> 
> You say just use copy constructors and no pointers.
> Can you (ie C++) guarantee that no pointer is ever copied out of 
> scope of these copy-constructed objects?
> 
> > 
> > For other things, though, you have to dynamically create objects.  But
> > the C++ reference-counting smart pointers offer much of the same
> > destruction semantics as using static objects.  It's really a slick
> > system.  Almost makes memory management a non-issue.  Circular
> > references will still leak (just like they do on Python).  But it
> > certainly makes life a lot more pleasant than in C from a memory
> > management perspective.

The case of RAII vs gc is hardly conclusive:

http://stackoverflow.com/questions/228620/garbage-collection-in-c-why


From torriem at gmail.com  Fri Jan 30 13:15:12 2015
From: torriem at gmail.com (Michael Torrie)
Date: Fri, 30 Jan 2015 11:15:12 -0700
Subject: [OT] fortran lib which provide python like data type
In-Reply-To: <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <mailman.18313.1422637734.18130.python-list@python.org>
 <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
Message-ID: <54CBCA30.5050700@gmail.com>

On 01/30/2015 10:31 AM, Rustom Mody wrote:
> And what about the grey area between lightweight and heavyweight?

That's what the smart pointers are for.

> You say just use copy constructors and no pointers.
> Can you (ie C++) guarantee that no pointer is ever copied out of 
> scope of these copy-constructed objects?

If that happened, then it's because you the programmer wanted it to
happen.  It's not just going to happen all by itself.  Yes anytime
pointers are allowed, things are potentially unsafe in the hands of a
programmer.  I'm just saying it's not nearly so bad as you make it out
to be.  Follow basic rules and 99% of segfaults will never happen and
the majority of leaks will not happen either.

Python can still leak badly if a programmer causes it to.  As for
segfaulting, no your python code should not itself segfault.  C++ code
certainly could.  Exposing pointers to the programmer can be very
powerful (and necessary... cannot write a bare-metal OS in common
Python) but the programmer can screw it up too on occasion.


From no.email at nospam.invalid  Fri Jan 30 13:23:21 2015
From: no.email at nospam.invalid (Paul Rubin)
Date: Fri, 30 Jan 2015 10:23:21 -0800
Subject: [OT] fortran lib which provide python like data type
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <mailman.18313.1422637734.18130.python-list@python.org>
 <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
 <mailman.18316.1422641719.18130.python-list@python.org>
Message-ID: <87fvas3z6u.fsf@jester.gateway.sonic.net>

Michael Torrie <torriem at gmail.com> writes:
> Follow basic [C++] rules and 99% of segfaults will never happen and
> the majority of leaks will not happen either.

That is a safe and simple approach, but it works by copying data all
over the place instead of passing pointers, resulting in performance
loss.  Alex Martelli used to post a good riff here about how the main
reason to use C++ in the first place was for when you needed to
explicitly control resources for performance.  So the "data copying"
style seems to somewhat miss the point.

Smart pointers have similar issues to Python's reference-counted
allocation, e.g. cache and thread unfriendliness, and no compaction
mechanism AFAIK.  Plus I always found them scary in terms of subtle bug
potential due to abstraction leaks.  But I haven't used them so far.


From marfig at gmail.com  Fri Jan 30 13:36:33 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Fri, 30 Jan 2015 19:36:33 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
 <mailman.18229.1422469034.18130.python-list@python.org>
 <MPG.2f340c6ea39d9f3f9896b3@nntp.aioe.org>
 <54ca5bbf$0$12992$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <MPG.2f34ebd12b42ff6f9896b5@nntp.aioe.org>

In article <54ca5bbf$0$12992$c3e8da3$5496439d at news.astraweb.com>, 
steve+comp.lang.python at pearwood.info says...
> 
> Why should I feel guilty? You wrote:
> 
> 
> "Static analysis cannot and should not clutter executable code."
> 
> 
> But what are type declarations in statically typed languages like C, Pascal,
> Haskell, etc.? They are used by the compiler for static analysis. The same
> applies to type declarations in dynamically typed languages like Cobra and
> Julia. And yet, there they are, in the executable code.
> 
> So there are a whole lot of languages, going all the way back to 1950s
> languages like Fortran, to some of the newest languages which are only a
> few years old like Go, both dynamically typed and statically typed, which
> do exactly what you say languages "cannot and should not" do: they put type
> information used for static analysis there in the code.

You are confusing static analysis with compile time checking which 
produces side-effects like implicit conversion for instance and that 
affects the resulting binary code. Something that Python won't do with 
type annotations. And something that Julia, Scala or C does.

This is also the first time I hear compilation time mentioned as static 
analysis.

To be clear, type declarations in Julia, Scala, C have the potential to 
produce side-effects, can result in optimized code and can result in 
compile time errors or warnings. Type annotations in Python are instead 
completely ignored by the interpreter. They do nothing of the above. 
They do not participate in code execution.

> As I said, these languages disagree with you. You are not just arguing
> against Guido, but against the majority of programming language designers
> for 60+ years.

You are right. I'm not arguing against Guido. I have yet to hear his 
opinion on your or mine arguments. I'm not arguing against the majority 
of programming languages either, because they agree with me.

I'm arguing with you.


From marfig at gmail.com  Fri Jan 30 13:42:31 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Fri, 30 Jan 2015 19:42:31 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
 <mailman.18229.1422469034.18130.python-list@python.org>
 <MPG.2f340c6ea39d9f3f9896b3@nntp.aioe.org>
 <54ca5bbf$0$12992$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <MPG.2f35eef1cc884a1b9896b6@nntp.aioe.org>

In article <54ca5bbf$0$12992$c3e8da3$5496439d at news.astraweb.com>, 
steve+comp.lang.python at pearwood.info says...
> 
> 
> Why should I feel guilty? You wrote:
> 
> 
> "Static analysis cannot and should not clutter executable code."
> 
> 
> But what are type declarations in statically typed languages like C, Pascal,
> Haskell, etc.? They are used by the compiler for static analysis. The same
> applies to type declarations in dynamically typed languages like Cobra and
> Julia. And yet, there they are, in the executable code.
> 
> So there are a whole lot of languages, going all the way back to 1950s
> languages like Fortran, to some of the newest languages which are only a
> few years old like Go, both dynamically typed and statically typed, which
> do exactly what you say languages "cannot and should not" do: they put type
> information used for static analysis there in the code.

(Sorry if I'm late...)

You are comparing static analysis with compile time checking which 
can result in implicit conversions and that can affect the resulting
binary code. Something that Python won't do with type annotations. And
something that Julia, Scala or C does.

This is also the first time I hear compilation mentioned as static 
analysis. But I suppose... After all it does perform a crude form of 
static analysis as a natural consequence of compile time checks, besides 
doing a whole bunch of other things that aren't static analysis. A dog 
has four legs and two eyes. So does an elephant. I suppose you are going 
to argue with me that a dog is an elephant after all.

To be clear, type declarations in Julia, Scala, C have the potential to 
produce side-effects, can result in optimized code and can result in 
compile time errors or warnings. They also affect runtime evaluation as 
you could easily attest if you input a float into a function expecting 
an int, whereas in Python the float will be gladly accepted and will 
only fail at the point in code where its interface won't match the 
statement.

Meanwhile, type annotations in Python are instead completely ignored by 
the interpreter. They do nothing of the above. They do not participate 
in code generation and execution.

> As I said, these languages disagree with you. You are not just arguing
> against Guido, but against the majority of programming language designers
> for 60+ years.

You are right. I'm not arguing against Guido. I have yet to hear his 
opinion on what you are saying, so I don't even know if I should want to
argue with him. And I'm not arguing against the majority of programming
languages either, because as much as you try I have yet to hear an 
argument from you that convinces me they don't agree with me.

No. I'm arguing with you.





From p.f.moore at gmail.com  Fri Jan 30 13:45:09 2015
From: p.f.moore at gmail.com (Paul Moore)
Date: Fri, 30 Jan 2015 10:45:09 -0800 (PST)
Subject: Multiplexing 2 streams with asyncio
Message-ID: <a0f4ef01-fcdb-4442-b874-b62004d624e6@googlegroups.com>

I'm trying to get to grips with asyncio. I *think* it's a reasonable fit for my problem, but I'm not really sure - so if the answer is "you shouldn't be doing that, then that's fair enough :-)

What I am trying to do is, given 2 files (the stdout and stderr from a subprocess.Popen object, as it happens), I want to wait on data coming in from either file, and write it to the appropriate one of sys.stdout or sys.stderr, process the data somehow, and then go back to waiting. Sorry if that description's a little vague. Basically I'm trying to write a version of Popen.communicate() that echoes the output to the standard streams *as well* as capturing it.

This would normally be handled on Unix with something like a select loop, and with threads on Windows. But is it something I could use an asyncio event loop for? It seems like I could set up reader callbacks on the 2 streams, and then run the event loop, but I can't work out from the documentation how to do this. Can anyone help with some pointers?

The reasons I want to try this rather than use the traditional approach are:

1. To learn about asyncio, which looks really cool but I've no idea how to start with even something simple using it :-(
2. Because on Windows I'd have to use threads, whereas asyncio uses IO completion ports behind the scenes (I think) which are probably a lot more lightweight.

I know there's a Process abstraction in asyncio, but I don't want to use that directly, because I need my code to be interoperable with existing code that uses Popen.

Thanks for any help.
Paul


From marfig at gmail.com  Fri Jan 30 13:50:36 2015
From: marfig at gmail.com (Mario Figueiredo)
Date: Fri, 30 Jan 2015 19:50:36 +0100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org> <mab931$qqu$1@ger.gmane.org>
 <mailman.18262.1422540523.18130.python-list@python.org>
 <54ca583e$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <1422555828.839301.220608921.416BDD33@webmail.messagingengine.com>
 <mailman.18277.1422557674.18130.python-list@python.org>
Message-ID: <MPG.2f35f0cce3d003db9896b7@nntp.aioe.org>

In article <mailman.18277.1422557674.18130.python-list at python.org>, 
breamoreboy at yahoo.co.uk says...
> 
> No, they're not always weakly typed.  The aim of the spreadsheet put up 
> by Skip was to sort out (roughly) which languages belong in which camp. 
>   I do not regard myself as suitably qualified to fill the thing out. 
> Perhaps by now others have?


It would help that if instead of weakly typed or strongly typed box, 
they could be classified comparatively to each other. The terms are 
better suited to describe two languages as they stand to each other.

Weakly Typed ------------------------------------------> Strongly Typed

>From C to Lisp (arguably) with languages closer to each other indicating 
a more similar type system model.


From skip.montanaro at gmail.com  Fri Jan 30 14:00:56 2015
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Fri, 30 Jan 2015 13:00:56 -0600
Subject: Python is DOOMED! Again!
In-Reply-To: <MPG.2f35f0cce3d003db9896b7@nntp.aioe.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
 <mab931$qqu$1@ger.gmane.org>
 <mailman.18262.1422540523.18130.python-list@python.org>
 <54ca583e$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <1422555828.839301.220608921.416BDD33@webmail.messagingengine.com>
 <mailman.18277.1422557674.18130.python-list@python.org>
 <MPG.2f35f0cce3d003db9896b7@nntp.aioe.org>
Message-ID: <CANc-5Ux=JBafBZnzmVE9n6_49NDkFqytNeWaEcU_rq+HVafa-g@mail.gmail.com>

On Fri, Jan 30, 2015 at 12:50 PM, Mario Figueiredo <marfig at gmail.com> wrote:

> It would help that if instead of weakly typed or strongly typed box,
> they could be classified comparatively to each other. The terms are
> better suited to describe two languages as they stand to each other.
>
> Weakly Typed ------------------------------------------> Strongly Typed
>

The spreadsheet should be world-writable. Knock yourself out. :-)

http://preview.tinyurl.com/kcrcq4y

Skip
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From ned at nedbatchelder.com  Fri Jan 30 14:05:11 2015
From: ned at nedbatchelder.com (Ned Batchelder)
Date: Fri, 30 Jan 2015 14:05:11 -0500
Subject: how to parse sys.argv as dynamic parameters to another function?
In-Reply-To: <CALwzid=2xNRdfCkJY9terZoZ1Ep385Y7-ESmoBLBKPQw0ZEgYA@mail.gmail.com>
References: <baa4011f-0745-4f8b-a6f5-fc242a886d78@googlegroups.com>
 <CALwzid=2xNRdfCkJY9terZoZ1Ep385Y7-ESmoBLBKPQw0ZEgYA@mail.gmail.com>
Message-ID: <magkl7$ue5$1@ger.gmane.org>

On 1/30/15 11:28 AM, Ian Kelly wrote:
> On Fri, Jan 30, 2015 at 9:09 AM, Robert Chen <robertchen117 at gmail.com> wrote:
>> how to parse sys.argv as dynamic parameters to another function?
>>
>>
>> fun(sys.argv)
>>
>> in perl, this is very easy. please help.
>
> Do you mean that you want each item of sys.argv to be passed as a
> separate parameter to the function? If so, then:
>
> fun(*sys.argv)
>

Robert, this will work, but keep in mind that sys.argv is a list of 
strings, always.  If your function is expecting integers, you will have 
to do an explicit conversion somewhere.

-- 
Ned Batchelder, http://nedbatchelder.com



From ian.g.kelly at gmail.com  Fri Jan 30 14:39:14 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 30 Jan 2015 12:39:14 -0700
Subject: Multiplexing 2 streams with asyncio
In-Reply-To: <a0f4ef01-fcdb-4442-b874-b62004d624e6@googlegroups.com>
References: <a0f4ef01-fcdb-4442-b874-b62004d624e6@googlegroups.com>
Message-ID: <CALwzid==E-mDg6rM-H8rU0LMFdE=mvzD4ZT++b6j6=TBK5odiA@mail.gmail.com>

On Fri, Jan 30, 2015 at 11:45 AM, Paul  Moore <p.f.moore at gmail.com> wrote:
> 2. Because on Windows I'd have to use threads, whereas asyncio uses IO completion ports behind the scenes (I think) which are probably a lot more lightweight.

I have no idea whether that's true, but note that add_reader() on
Windows doesn't work with pipes:

https://docs.python.org/3/library/asyncio-eventloops.html#windows


From sturla.molden at gmail.com  Fri Jan 30 16:11:22 2015
From: sturla.molden at gmail.com (Sturla Molden)
Date: Fri, 30 Jan 2015 21:11:22 +0000 (UTC)
Subject: multiprocessing module backport from 3 to 2.7 - spawn feature
References: <CA+1Rt66fb5zFwKiBG=tkHzURfiYFX_xKo=XxUKvWO4CdySX0_Q@mail.gmail.com>
 <CANc-5UyZZNkTjrVUt1M2zAUCeJGr_RffXcO_E4FiY5gZhSOD1A@mail.gmail.com>
Message-ID: <1840874457444343902.582322sturla.molden-gmail.com@news.gmane.org>

Skip Montanaro <skip.montanaro at gmail.com> wrote:

> Can you explain what you see as the difference between "spawn" and "fork"
> in this context? Are you using Windows perhaps? I don't know anything
> obviously different between the two terms on Unix systems.

spawn is fork + exec.

Only a handful of POSIX functions are required to be "fork safe", i.e.
callable on each side of a fork without an exec. 

An example of an API which is not safe to use on both sides of a fork is
Apple's GCD. The default builds of NumPy and SciPy depend on it on OSX
because it is used in Accelerate Framework. You can thus get problems if
you use numpy.dot in a process started with multiprocessing. What will
happen is that the call to numpy.dot never returns, given that you called
any BLAS or LAPACK function at least once before the instance of
multiprocessing.Process was started. This is not a bug in NumPy or in
Accelerate Framework, it is a bug in multiprocessing because it assumes
that BLAS is fork safe. The correct way of doing this is to start processes
with spawn (fork + exec), which multiprocessing does on Python 3.4. 

Sturla



From sturla.molden at gmail.com  Fri Jan 30 16:15:05 2015
From: sturla.molden at gmail.com (Sturla Molden)
Date: Fri, 30 Jan 2015 21:15:05 +0000 (UTC)
Subject: multiprocessing module backport from 3 to 2.7 - spawn feature
References: <CA+1Rt66fb5zFwKiBG=tkHzURfiYFX_xKo=XxUKvWO4CdySX0_Q@mail.gmail.com>
 <CANc-5UyZZNkTjrVUt1M2zAUCeJGr_RffXcO_E4FiY5gZhSOD1A@mail.gmail.com>
 <CA+1Rt67KWpmqw_iLfu+0qYs9QGRvXjPA76FhJQ4mpWpOtz6eVA@mail.gmail.com>
Message-ID: <1259194424444345107.780033sturla.molden-gmail.com@news.gmane.org>

Andres Riancho <andres.riancho at gmail.com> wrote:

> Spawn, and I took that from the multiprocessing 3 documentation, will
> create a new process without using fork(). 

> This means that no memory
> is shared between the MainProcess and the spawn'ed sub-process created
> by multiprocessing.

If you memory map a segment with MAP_SHARED it will be shared, even after a
spawn. 

File descriptors are also shared.



From sturla.molden at gmail.com  Fri Jan 30 16:28:28 2015
From: sturla.molden at gmail.com (Sturla Molden)
Date: Fri, 30 Jan 2015 21:28:28 +0000 (UTC)
Subject: RAII vs gc (was fortran lib which provide python like data type)
References: <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
 <8ff4c8aa-a858-481f-8964-7c794f848de2@googlegroups.com>
Message-ID: <1553594603444345533.649938sturla.molden-gmail.com@news.gmane.org>

Rustom Mody <rustompmody at gmail.com> wrote:

> The case of RAII vs gc is hardly conclusive:
> 
> http://stackoverflow.com/questions/228620/garbage-collection-in-c-why

The purpose of RAII is not to be an alternative to garbage collection
(which the those answers imply), but to ensure  deterministc execution of
setup and tear-down code. The Python equivalent of RAII is not garbage
collection but context managers.

Those answers is a testimony to how little the majority of C++ users
actually understand about the language.



A C++ statement with RAII like

{
   Foo bar(); 
   // suite
}

is not equivalent to

    bar = Foo()

in Python. It actually corresponds to

with Foo() as bar:
    <suite>



Sturla



From ian.g.kelly at gmail.com  Fri Jan 30 16:50:23 2015
From: ian.g.kelly at gmail.com (Ian Kelly)
Date: Fri, 30 Jan 2015 14:50:23 -0700
Subject: Python is DOOMED! Again!
In-Reply-To: <MPG.2f35eef1cc884a1b9896b6@nntp.aioe.org>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
 <mailman.18229.1422469034.18130.python-list@python.org>
 <MPG.2f340c6ea39d9f3f9896b3@nntp.aioe.org>
 <54ca5bbf$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f35eef1cc884a1b9896b6@nntp.aioe.org>
Message-ID: <CALwzidmfCm2fL=3E9oHbM2Jx8DZcVdaDnCf2OJQyTCDUda_VRg@mail.gmail.com>

On Fri, Jan 30, 2015 at 11:42 AM, Mario Figueiredo <marfig at gmail.com> wrote:
> To be clear, type declarations in Julia, Scala, C have the potential to
> produce side-effects, can result in optimized code and can result in
> compile time errors or warnings. They also affect runtime evaluation as
> you could easily attest if you input a float into a function expecting
> an int, whereas in Python the float will be gladly accepted and will
> only fail at the point in code where its interface won't match the
> statement.

At least for C, as I noted in a previous post, it is simply not true
that they are used for runtime evaluation. For example:

>>> import ctypes
>>> libc = ctypes.CDLL("libc.so.6")
>>> libc.abs(ctypes.c_double(123.456))
2093824448

The C compiler may complain about it, but that's a compile-time static
check, no different from the sort of checks that PEP 484 seeks to add
to Python.

> Meanwhile, type annotations in Python are instead completely ignored by
> the interpreter. They do nothing of the above. They do not participate
> in code generation and execution.

But unlike C, Python lets you easily implement this yourself if you want to.

>>> def runtime_type_check(f):
...   @functools.wraps(f)
...   def wrapper(**args):
...     for arg, value in args.items():
...       if arg in f.__annotations__:
...         if not isinstance(value, f.__annotations__[arg]):
...           raise TypeError("Arg %s expected %s, got %s"
...               % (arg, f.__annotations__[arg].__name__, type(arg).__name__))
...     return f(**args)
...   return wrapper
...
>>> @runtime_type_check
... def add(x:int, y:int) -> int:
...   return x + y
...
>>> add(x="hello", y="world")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 8, in wrapper
TypeError: Arg y expected int, got str

(This could of course be extended for positional arguments and more
complex annotations, but I wanted to keep it simple for the purpose of
the example.)


From marko at pacujo.net  Fri Jan 30 17:25:18 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sat, 31 Jan 2015 00:25:18 +0200
Subject: multiprocessing module backport from 3 to 2.7 - spawn feature
References: <CA+1Rt66fb5zFwKiBG=tkHzURfiYFX_xKo=XxUKvWO4CdySX0_Q@mail.gmail.com>
 <CANc-5UyZZNkTjrVUt1M2zAUCeJGr_RffXcO_E4FiY5gZhSOD1A@mail.gmail.com>
 <mailman.18320.1422652292.18130.python-list@python.org>
Message-ID: <87h9v7hpo1.fsf@elektro.pacujo.net>

Sturla Molden <sturla.molden at gmail.com>:

> Only a handful of POSIX functions are required to be "fork safe", i.e.
> callable on each side of a fork without an exec.

That is a pretty surprising statement. Forking without an exec is a
routine way to do multiprocessing.

I understand there are things to consider, but all system calls are
available and safe.


Marko


From greg.ewing at canterbury.ac.nz  Fri Jan 30 17:51:16 2015
From: greg.ewing at canterbury.ac.nz (Gregory Ewing)
Date: Sat, 31 Jan 2015 11:51:16 +1300
Subject: [OT] fortran lib which provide python like data type
In-Reply-To: <mailman.18316.1422641719.18130.python-list@python.org>
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <mailman.18313.1422637734.18130.python-list@python.org>
 <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
 <mailman.18316.1422641719.18130.python-list@python.org>
Message-ID: <cj2g77Fpbv8U1@mid.individual.net>

Michael Torrie wrote:
> On 01/30/2015 10:31 AM, Rustom Mody wrote:
> 
>>And what about the grey area between lightweight and heavyweight?
> 
> That's what the smart pointers are for.

I'd say it's what higher-level languages are for. :-)

I'm completely convinced nowadays that there is
*no* use case for C++. If you need to program the
bare metal, use C. For anything more complicated,
use a language that has proper memory-management
abstractions built in.

-- 
Greg


From sturla.molden at gmail.com  Fri Jan 30 18:12:29 2015
From: sturla.molden at gmail.com (Sturla Molden)
Date: Fri, 30 Jan 2015 23:12:29 +0000 (UTC)
Subject: [OT] fortran lib which provide python like data type
References: <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <54CBBA93.9020404@gmail.com>
Message-ID: <1841390178444352281.903812sturla.molden-gmail.com@news.gmane.org>

Michael Torrie <torriem at gmail.com> wrote:
 
> Yes I can tell you haven't used C++.  Compared to C, I've always found
> memory management in C++ to be quite a lot easier. The main reason is
> that C++ guarantees objects will be destroyed when going out of scope.
> So when designing a class, you put any allocation routines in the
> constructor, and put deallocation routines in the destructor.  And it
> just works.  This is something I miss in other languages, even Python.

Python has context managers for that.



From steve+comp.lang.python at pearwood.info  Fri Jan 30 18:45:44 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 31 Jan 2015 10:45:44 +1100
Subject: An object is an instance (or not)?
References: <MPG.2f320f923eedd5a69896a1@nntp.aioe.org>
 <mailman.18191.1422400930.18130.python-list@python.org>
 <MPG.2f3248ebaccae0069896a9@nntp.aioe.org>
 <mailman.18195.1422405040.18130.python-list@python.org>
 <MPG.2f324d0d46ba9afc9896ac@nntp.aioe.org> <cirs87F1tdrU2@mid.individual.net>
 <54c8cd8f$0$12975$c3e8da3$5496439d@news.astraweb.com>
 <ciu1taFjekrU1@mid.individual.net>
 <54c9de44$0$12915$c3e8da3$5496439d@news.astraweb.com>
 <cj0vveFck6dU1@mid.individual.net>
Message-ID: <54cc17a9$0$13002$c3e8da3$5496439d@news.astraweb.com>

Gregory Ewing wrote:

> Steven D'Aprano wrote:
>> Actually, if you look at my example, you will see that it is a method and
>> it does get the self argument. Here is the critical code again:
>> 
>> from types import MethodType
>> polly.talk = MethodType(
>>     lambda self: print("Polly wants a spam sandwich!"), polly)
> 
> Doing it by hand is cheating.

Smile when you say that, pardner :-)

I don't see why you think I'm cheating. What rule do you think is being
broken? I want to add a method to the instance itself, so I create a method
object and put it on the instance. What should I have done?

The default metaclass ("type") only applies the descriptor protocol to
attributes retrieved from the class itself, not those retrieved from the
instance. For instance, you can add a property object onto the instance,
but it won't behave as a property:

py> class K(object):
...     pass
...
py> x = K()
py> x.spam = property(lambda self: 23)
py> x.spam
<property object at 0xb7bbcb44>


But if I add it to the class, the descriptor magic happens:

py> K.eggs = x.spam
py> x.eggs
23

Functions are descriptors, just like property objects! So an alternative to
manually making a method object would be to use a metaclass that extended
the descriptor protocol to instance attributes. I suppose you would call
that "cheating" too?

But all of this is a side-show that distracts from my point, which is that
the lookup rules for instances and classes are such that you can override
behaviour defined in the class on a per-instance basis. The mechanics of
such aren't really relevant.


>> That's certainly not correct, because Python had classes and instances
>> before it had descriptors!
> 
> Before the descriptor protocol, a subset of its functionality
> was hard-wired into the interpreter. There has always been
> some magic going on across the instance-class boundary that
> doesn't occur across the class-baseclass boundary.

Yes, but that magic is effectively "implementation, not interface". I put
that in scare quotes because in actual pedantic fact, the descriptor
protocol is an interface: we can write our own custom descriptors. I don't
dispute that's important.

But from a birds eye view, and looking at just method and regular attribute
access, the relationship between instance-class and class-baseclass is very
similar, as is that between class-metaclass, and descriptor magic is merely
part of the implementation to make things work.

I daresay you are right that there are a few places where the interpreter
treats classes as a distinct and different kind of thing than non-class
instances. One obvious place is that dunder methods are not looked up on
the instance, unlike pretty much everything else. But I did preface my
comments about attribute lookup order as being simplified, so you can
probably find a lot more to criticise if you wish :-)



-- 
Steven



From steve+comp.lang.python at pearwood.info  Fri Jan 30 18:49:13 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 31 Jan 2015 10:49:13 +1100
Subject: [OT] fortran lib which provide python like data type
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <mailman.18313.1422637734.18130.python-list@python.org>
 <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
 <mailman.18316.1422641719.18130.python-list@python.org>
 <cj2g77Fpbv8U1@mid.individual.net>
Message-ID: <54cc187a$0$13002$c3e8da3$5496439d@news.astraweb.com>

Gregory Ewing wrote:

> I'm completely convinced nowadays that there is
> no use case for C++.


I can think of one use-case for C++.

You walk up to somebody in the street, say "I wrote my own C++ parser!", and
while they are gibbering and shaking in shock, you rifle through their
pockets and steal any valuables you find.



-- 
Steven



From steve+comp.lang.python at pearwood.info  Fri Jan 30 18:50:45 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 31 Jan 2015 10:50:45 +1100
Subject: [OT] fortran lib which provide python like data type
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <mailman.18313.1422637734.18130.python-list@python.org>
 <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
 <mailman.18316.1422641719.18130.python-list@python.org>
Message-ID: <54cc18d5$0$13002$c3e8da3$5496439d@news.astraweb.com>

Michael Torrie wrote:

> If that happened, then it's because you the programmer wanted it to
> happen. ?It's not just going to happen all by itself. ?Yes anytime
> pointers are allowed, things are potentially unsafe in the hands of a
> programmer. ?I'm just saying it's not nearly so bad as you make it out
> to be. ?Follow basic rules and 99% of segfaults will never happen and
> the majority of leaks will not happen either.


Oh great. So if the average application creates a hundred thousand pointers
of the course of a session, you'll only have a thousand or so seg faults
and leaks.

Well, that certainly explains this:

https://access.redhat.com/articles/1332213

Manual low-level pointer manipulation is an anti-pattern. What you glibly
describe as programmers following "basic rules" has proven to be beyond the
ability of the programming community as a whole.



-- 
Steven



From steve+comp.lang.python at pearwood.info  Fri Jan 30 19:01:57 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 31 Jan 2015 11:01:57 +1100
Subject: Python tracker manual password reset
References: <mailman.18308.1422632844.18130.python-list@python.org>
Message-ID: <54cc1b76$0$12977$c3e8da3$5496439d@news.astraweb.com>

Ian Kelly wrote:

> I just tried to use the password recovery tool for the Python tracker.
> I entered my personal email. It sent me the confirmation email with
> the password reset link, which I followed. It then reset my password
> and sent an email to a different address, an old work address that I
> no longer have, so I have no idea what the new password is.

o_O

If you are right in your diagnosis, that's an impressive bug. Why does the
bug tracker even remember old email addresses?

> Is there someone I can contact to have my password manually reset?

Have you reported this on the tracker meta tracker?

http://psf.upfronthosting.co.za/roundup/meta

If you are subscribed to python-dev, you could ask for help there (with an
appropriate apology-in-advance if its the wrong place). If you're not
subscribed, let me know and I can do so for you.



-- 
Steven



From breamoreboy at yahoo.co.uk  Fri Jan 30 20:28:51 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 31 Jan 2015 01:28:51 +0000
Subject: The Most Diabolical Python Antipattern
In-Reply-To: <mafeat$bff$1@ger.gmane.org>
References: <madpuv$he7$1@ger.gmane.org>
 <20150129113238.7eaa986d@bigbox.christie.dr>
 <mailman.18286.1422571931.18130.python-list@python.org>
 <87r3uchjyg.fsf@elektro.pacujo.net> <mafeat$bff$1@ger.gmane.org>
Message-ID: <mahb4i$se8$1@ger.gmane.org>

On 30/01/2015 08:10, Mark Lawrence wrote:
> On 30/01/2015 06:16, Marko Rauhamaa wrote:
>> Ian Kelly <ian.g.kelly at gmail.com>:
>>
>>> At least use "except Exception" instead of a bare except. Do you
>>> really want things like SystemExit and KeyboardInterrupt to get turned
>>> into 0?
>>
>> How about:
>>
>> ==============================
>>      try:
>>          do_interesting_stuff()
>>      except ValueError:
>>          try:
>>              log_it()
>>          except:
>>              pass
>>          raise
>> ==============================
>>
>> Surprisingly this variant could raise an unexpected exception:
>>
>> ==============================
>>      try:
>>          do_interesting_stuff()
>>      except ValueError:
>>          try:
>>              log_it()
>>          finally:
>>              raise
>> ==============================
>>
>> A Python bug?
>>
>>
>> Marko
>>
>
> It depends on the Python version that you're running - I think!!!  See
> https://www.python.org/dev/peps/pep-3134/
> https://www.python.org/dev/peps/pep-0409/
> https://www.python.org/dev/peps/pep-0415/ and finally try (groan :)
> https://pypi.python.org/pypi/pep3134/
>

http://bugs.python.org/issue23353 looks like fun and references PEP3134 
for anybody who's interested.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From sturla.molden at gmail.com  Fri Jan 30 21:01:17 2015
From: sturla.molden at gmail.com (Sturla Molden)
Date: Sat, 31 Jan 2015 03:01:17 +0100
Subject: multiprocessing module backport from 3 to 2.7 - spawn feature
In-Reply-To: <87h9v7hpo1.fsf@elektro.pacujo.net>
References: <CA+1Rt66fb5zFwKiBG=tkHzURfiYFX_xKo=XxUKvWO4CdySX0_Q@mail.gmail.com>
 <CANc-5UyZZNkTjrVUt1M2zAUCeJGr_RffXcO_E4FiY5gZhSOD1A@mail.gmail.com>
 <mailman.18320.1422652292.18130.python-list@python.org>
 <87h9v7hpo1.fsf@elektro.pacujo.net>
Message-ID: <mahd1b$p7j$1@ger.gmane.org>

On 30/01/15 23:25, Marko Rauhamaa wrote:
> Sturla Molden <sturla.molden at gmail.com>:
>
>> Only a handful of POSIX functions are required to be "fork safe", i.e.
>> callable on each side of a fork without an exec.
>
> That is a pretty surprising statement. Forking without an exec is a
> routine way to do multiprocessing.
>
> I understand there are things to consider, but all system calls are
> available and safe.

POSIX says this:


- No asynchronous input or asynchronous output operations shall be 
inherited by the child process.

- A process shall be created with a single thread. If a multi-threaded 
process calls fork(), the new process shall contain a replica of the 
calling thread and its entire address space, possibly including the 
states of mutexes and other resources. Consequently, to avoid errors, 
the child process may only execute async-signal-safe operations until 
such time as one of the exec functions is called.

- Fork handlers may be established by means of the pthread_atfork() 
function in order to maintain application invariants across fork() calls.

- When the application calls fork() from a signal handler and any of the 
fork handlers registered by pthread_atfork() calls a function that is 
not asynch-signal-safe, the behavior is undefined.


Hence you must be very careful which functions you use after calling 
forking before you have called exec. Generally never use an API above 
POSIX, e.g. BLAS or Apple's CoreFoundation.



Apple said this when the problem with multiprocessing and Accelerate 
Framework first was discovered:


---------- Forwarded message ----------
From:  <devbugs at apple.com>
Date: 2012/8/2
Subject: Bug ID 11036478: Segfault when calling dgemm with Accelerate
/ GCD after in a forked process
To: ******@******


Hi Olivier,

Thank you for contacting us regarding Bug ID# 11036478.

Thank you for filing this bug report.

This usage of fork() is not supported on our platform.

For API outside of POSIX, including GCD and technologies like
Accelerate, we do not support usage on both sides of a fork(). For
this reason among others, use of fork() without exec is discouraged in
general in processes that use layers above POSIX.

We recommend that you either restrict usage of blas to the parent or
the child process but not both, or that you switch to using GCD or
pthreads rather than forking to create parallelism.



Also see this:

http://bugs.python.org/issue8713

https://mail.python.org/pipermail/python-ideas/2012-November/017930.html





Sturla



From rajanbond at gmail.com  Fri Jan 30 21:27:19 2015
From: rajanbond at gmail.com (rajanbond at gmail.com)
Date: Fri, 30 Jan 2015 18:27:19 -0800 (PST)
Subject: Create dictionary based of x items per key from two lists
Message-ID: <0dddee06-233b-436a-be48-3c16e62c1718@googlegroups.com>

I have two lists 

l1 =  ["a","b","c","d","e","f","g","h","i","j"]
l2 = ["aR","bR","cR"]

l2 will always be smaller or equal to l1

numL1PerL2 = len(l1)/len(l2)

I want to create a dictionary that has key from l1 and value from l2 based on numL1PerL2

So

{
a:aR,
b:aR,
c:aR,
d:bR,
e:bR,
f:bR,
g:cR,
h:cR,
i:cR,
j:cR
}

So last item from l2 is key for remaining items from l1


From rosuav at gmail.com  Fri Jan 30 21:38:40 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 31 Jan 2015 13:38:40 +1100
Subject: Create dictionary based of x items per key from two lists
In-Reply-To: <0dddee06-233b-436a-be48-3c16e62c1718@googlegroups.com>
References: <0dddee06-233b-436a-be48-3c16e62c1718@googlegroups.com>
Message-ID: <CAPTjJmoJmr6PUwGEtpOZ=i2Kff=AMEuuK2kvzuT23fefJg1j8g@mail.gmail.com>

On Sat, Jan 31, 2015 at 1:27 PM,  <rajanbond at gmail.com> wrote:
> l1 =  ["a","b","c","d","e","f","g","h","i","j"]
> l2 = ["aR","bR","cR"]
>
> l2 will always be smaller or equal to l1
>
> numL1PerL2 = len(l1)/len(l2)
>
> I want to create a dictionary that has key from l1 and value from l2 based on numL1PerL2
>
> So
>
> {
> a:aR,
> b:aR,
> c:aR,
> d:bR,
> e:bR,
> f:bR,
> g:cR,
> h:cR,
> i:cR,
> j:cR
> }
>
> So last item from l2 is key for remaining items from l1

So the Nth element of l1 will always be paired with the
(N/numL1PerL2)th element of l2 (with the check at the end)? Seems easy
enough.

dups = len(l1)/len(l2)
l2.append(l2[-1])
result = {x:l2[i/dups] for i,x in enumerate(l1)}

This mutates l2 for convenience, but you could also adjust the index
to take care of the excess. As a one-liner:

result = {x:l2[min(i/(len(l1)/len(l2)),len(l2)-1)] for i,x in enumerate(l1)}

But the one-liner is not better code :)

ChrisA


From orgnut at yahoo.com  Fri Jan 30 22:31:37 2015
From: orgnut at yahoo.com (Larry Hudson)
Date: Fri, 30 Jan 2015 19:31:37 -0800
Subject: Sort of Augmented Reality
In-Reply-To: <9a1a0550-80f0-4947-9806-a605d451e8f1@googlegroups.com>
References: <madd3b$u2l$1@dont-email.me>
 <mailman.18292.1422584565.18130.python-list@python.org>
 <9a1a0550-80f0-4947-9806-a605d451e8f1@googlegroups.com>
Message-ID: <gdCdnbmUcYQH0VHJnZ2dnUU7-UWdnZ2d@giganews.com>

On 01/29/2015 06:55 PM, Rustom Mody wrote:
[snip...]
> Like smelly cheese and classical music, math is an acquired taste.
> Actually enjoyable once you get past the initiation
>

This comment is OT, irrelevant and only about myself...

I found the appreciation of classical music instinctive and immediate as soon as I started 
listening to it (in my mid to late teens -- I'm now 77).  OTH, I still don't care for opera...  ;-)

      -=- Larry -=-



From torriem at gmail.com  Fri Jan 30 22:35:09 2015
From: torriem at gmail.com (Michael Torrie)
Date: Fri, 30 Jan 2015 20:35:09 -0700
Subject: [OT] fortran lib which provide python like data type
In-Reply-To: <1841390178444352281.903812sturla.molden-gmail.com@news.gmane.org>
References: <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <54CBBA93.9020404@gmail.com>
 <1841390178444352281.903812sturla.molden-gmail.com@news.gmane.org>
Message-ID: <54CC4D6D.8080907@gmail.com>

On 01/30/2015 04:12 PM, Sturla Molden wrote:
> Michael Torrie <torriem at gmail.com> wrote:
>  
>> Yes I can tell you haven't used C++.  Compared to C, I've always found
>> memory management in C++ to be quite a lot easier. The main reason is
>> that C++ guarantees objects will be destroyed when going out of scope.
>> So when designing a class, you put any allocation routines in the
>> constructor, and put deallocation routines in the destructor.  And it
>> just works.  This is something I miss in other languages, even Python.
> 
> Python has context managers for that.

Right I had forgotten about that.  That's a good solution for dynamic,
GC languages.



From torriem at gmail.com  Fri Jan 30 22:49:14 2015
From: torriem at gmail.com (Michael Torrie)
Date: Fri, 30 Jan 2015 20:49:14 -0700
Subject: [OT] fortran lib which provide python like data type
In-Reply-To: <54cc18d5$0$13002$c3e8da3$5496439d@news.astraweb.com>
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <mailman.18313.1422637734.18130.python-list@python.org>
 <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
 <mailman.18316.1422641719.18130.python-list@python.org>
 <54cc18d5$0$13002$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <54CC50BA.7050100@gmail.com>

On 01/30/2015 04:50 PM, Steven D'Aprano wrote:
> Oh great. So if the average application creates a hundred thousand pointers
> of the course of a session, you'll only have a thousand or so seg faults
> and leaks.
> 
> Well, that certainly explains this:
> 
> https://access.redhat.com/articles/1332213

I fail to see the connection. GLibc is a low-level library written in C,
not C++.  By its nature requires a lot of pointer use, and is prone to
having errors.  But not that many, seeing as *all* Linux software
depends on it and uses at least part of it *all* the time.  Pretty
remarkable if you ask me.  Wonder how they do it.  Perhaps they try to
follow "basic rules."

> Manual low-level pointer manipulation is an anti-pattern. What you glibly
> describe as programmers following "basic rules" has proven to be beyond the
> ability of the programming community as a whole.

I don't see how you would write system code without this "anti-pattern"
as you describe.  Python is a great language for everything else, but I
certainly wouldn't call it a system language.  Couldn't write a kernel
in it without providing it with some sort of unsafe memory access
(pointers!).  Or even write a Python interpreter (Yes there's PyPy, but
with a jit it's still working with pointers).

What I call glibly "basic rules" are in fact shown to more or less work
out, as Glibc proves.  Pointer use does lead to potential
vulnerabilities.  And they must be corrected as they are found.  Still
not sure what your point is.

Is there a reason to use C or C++ for many of us?  Nope.  I'm not
arguing that we should find them of use.  It's easy for us to sit on
Python and look with contempt at C or C++, but they really do have their
place (C more than C++ IMO).  This is so far off the original topic that
it probably is construed that I am arguing for C++ vs Python or
something.  But I am not.  I'm quite content with Python.  There are a
host of languages I find interesting including D, Google Go, Vala,
FreeBASIC, Mozilla Rust, etc.  But Python fits my needs so well, I can't
be bothered to invest much time in these other languages.


From shinriyo at gmail.com  Sat Jan 31 00:01:07 2015
From: shinriyo at gmail.com (shinriyo at gmail.com)
Date: Fri, 30 Jan 2015 21:01:07 -0800 (PST)
Subject: inet_http_server is only one username and passowrd in supervisor
Message-ID: <3bdda3d8-d419-4f9e-a2c1-0032377219c5@googlegroups.com>

Hi there

I use supervisor.

in the [inet_http_server] section, there are only one username and password

username=user
password=pass

Do you know how to add more than two users.

Thank you.


From tjreedy at udel.edu  Sat Jan 31 03:00:56 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Sat, 31 Jan 2015 03:00:56 -0500
Subject: Python tracker manual password reset
In-Reply-To: <CALwzidk0jF1GWWC70PobWsHPrVsuDMrinVdBuJ_tJ-H-3U93vw@mail.gmail.com>
References: <CALwzidk0jF1GWWC70PobWsHPrVsuDMrinVdBuJ_tJ-H-3U93vw@mail.gmail.com>
Message-ID: <mai23r$obp$1@ger.gmane.org>

On 1/30/2015 10:46 AM, Ian Kelly wrote:
> I just tried to use the password recovery tool for the Python tracker.
> I entered my personal email. It sent me the confirmation email with
> the password reset link, which I followed. It then reset my password
> and sent an email to a different address, an old work address that I
> no longer have, so I have no idea what the new password is.
>
> Is there someone I can contact to have my password manually reset?

Answered offline.


-- 
Terry Jan Reedy



From jacob at blindza.co.za  Sat Jan 31 03:17:56 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Sat, 31 Jan 2015 10:17:56 +0200
Subject: help() function screen output
Message-ID: <119606D35A474010A5746243A54F7836@JakesPC>

Using python 3.4 32 bit on windows 7 64 bit machine, and when, for example, type in something like the following in interpreter window:
help(str)

It will populate the screen with one full screen of information, with a prompt of --more-- to hit enter, or something to continue displaying information, but, when, for example, hit enter key, it merely populates one more line of info, each time - under pythn 2.7, it seemed to render one full screen of info each time.

Is there rather a different keystroke should use to invoke that, or is this a python 3.4 feature/issue?

TIA

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."
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From auriocus at gmx.de  Sat Jan 31 03:27:11 2015
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Sat, 31 Jan 2015 09:27:11 +0100
Subject: [OT] fortran lib which provide python like data type
In-Reply-To: <87fvas3z6u.fsf@jester.gateway.sonic.net>
References: <mailman.18264.1422543630.18130.python-list@python.org>	<4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>	<3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>	<mafc1u$n1l$1@dont-email.me>	<3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>	<mailman.18313.1422637734.18130.python-list@python.org>	<0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>	<mailman.18316.1422641719.18130.python-list@python.org>
 <87fvas3z6u.fsf@jester.gateway.sonic.net>
Message-ID: <mai3js$o47$1@dont-email.me>

Am 30.01.15 um 19:23 schrieb Paul Rubin:
> Michael Torrie <torriem at gmail.com> writes:
>> Follow basic [C++] rules and 99% of segfaults will never happen and
>> the majority of leaks will not happen either.
> 
> That is a safe and simple approach, but it works by copying data all
> over the place instead of passing pointers, resulting in performance
> loss.  

This "performance loss" is partly a myth. Consider the following code,
assuming it is compiled using a recent (C++11) compiler

====================
#include <vector>

std::vector<double> compute() {
	const size_t N=100000;
	std::vector<double> result(N);
	for (size_t i=0; i<N; i++) {
		result[i]=2*i;
	}
	return result;
}

int main() {
	auto s = compute();
	// print it or whatever
	return 0;
}

=========================


At first, it may seem that this code copies the big vector twice: Once
into a temporary return value, once into the automatic variable s. This
is not the case, once for the move constructors in C++11 and second for
return value optimization, some years already in the compilers. Instead,
the vector is constructed directly into the place where the main
functinos expects it to be.

	Christian



From fatihbazman at gmail.com  Sat Jan 31 03:51:58 2015
From: fatihbazman at gmail.com (fatihbazman at gmail.com)
Date: Sat, 31 Jan 2015 00:51:58 -0800 (PST)
Subject: A python coder needed
Message-ID: <0eb69caf-6db1-400b-9bbe-5f197384065f@googlegroups.com>

Hello. I am looking for a python coder. Please find the details which are in the below:

A bittorrent client will be coded in order to share files in a private group. The private tracker server was coded by me (PHP & MySQL) and bittorrent client will be communicated with this tracker server via REST API. File meta data and peer information will be stored on this private tracker server. Files will be stored on peers computers and shared in each others by peers.

For this project, Python coder will use libtorrent library and produce a software with a simple and user friendly UI. During the file sharing, all bittorent features will be used (for example segmented file transfer, cryptographic hash etc.).

At the end of project, all source will be furnished as open and will be complied for WINDOWS and Linux as well.

If you want more details for my project, please send an email to me: faithbazman at gmail.

Regards,
Fatih.



From wxjmfauth at gmail.com  Sat Jan 31 04:02:22 2015
From: wxjmfauth at gmail.com (wxjmfauth at gmail.com)
Date: Sat, 31 Jan 2015 01:02:22 -0800 (PST)
Subject: Sort of Augmented Reality
In-Reply-To: <gdCdnbmUcYQH0VHJnZ2dnUU7-UWdnZ2d@giganews.com>
References: <madd3b$u2l$1@dont-email.me>
 <mailman.18292.1422584565.18130.python-list@python.org>
 <9a1a0550-80f0-4947-9806-a605d451e8f1@googlegroups.com>
 <gdCdnbmUcYQH0VHJnZ2dnUU7-UWdnZ2d@giganews.com>
Message-ID: <dc2da397-cee4-4ed1-837c-d34e24f057fd@googlegroups.com>

Rustom
"... math is an acquired taste.
Actually enjoyable once you get past the initiation  ..."

On that side, the Flexible String Representation is a jewel.
Simply unbelievable.

Dennis
"... Given the first, and the aircraft data, you would need to compute the
rays (azimuth/elevation) from camera to each target and map those to pixels
in the image... a lot of spherical trigonometry there... "

It seem you are confusing 'spherical trigonometry' and
'trigonometry in a euclidean space' when one works
with a spherical coordinates system.

jmf


From __peter__ at web.de  Sat Jan 31 04:07:55 2015
From: __peter__ at web.de (Peter Otten)
Date: Sat, 31 Jan 2015 10:07:55 +0100
Subject: parsing tree from excel sheet
References: <cirqviF15qtU1@mid.individual.net>
 <mailman.18217.1422454096.18130.python-list@python.org>
 <cj1kt9Fi3e0U1@mid.individual.net>
Message-ID: <mai61r$fkh$1@ger.gmane.org>

alb wrote:

> > 
> > def read_tree(rows, levelnames):
> >    root = Node("#ROOT", "#ROOT")
> >    old_level = 0
> >    stack = [root]
> >    for i, row in enumerate(rows, 1):
> 
> I'm not quite sure I understand what is the stack for. As of now is a 
> list whose only element is root.

The stack is used to emulate the function call stack in a recursive 
solution. Every nested call produces a new set of local variables and the 
innermost call corresponds to the top of the stack or the end of the `stack` 
list in my code.

Given a tree

A
  A1
    A11
    A12
  A2

or in another notation

0 A
1 A1
2 A11
2 A12
1 A2

we start with a stack (with the node's children in parens)

[A()]

then look at A1 and see that the level is one deeper than that of A and 
append it to A, the current TOS (top of stack)

[A(A1)]

Next is A11 which is two levels deeper than A, so we take the last child of 
A and put it on the stack, 

[A(A1), A1()]

then add A11 as a child to the new TOS

[A(A1), A1(A11)]

Next is A12 which is one level deeper than A1, so we add it to the current 
TOS

[A(A1), A1(A11, A12)]

Next is A2 which is one level higher than A1, so we keep removing nodes from 
the stack until the current TOS is one level higher than A2. Here we only 
have to remove A1 from the stack to get

[A(A1)]

and after adding A2 to the TOS

[A(A1, A2)]

I have ommitted the children of the children so far, but the actual 
structure is now

[A(A1(A11(), A12()), A2())]

Therefore I just need to return A which contains the complete layout of the 
tree.
 
> >        new_level = column_index(row)
> >        node = Node(row[new_level], levelnames[new_level])
> 
> here you are getting the node based on the current row, with its level.
> 
> >        if new_level == old_level:
> >            stack[-1].append(node)
> 
> I'm not sure I understand here. Why the end of the list and not the 
> beginning?
> 
> >        elif new_level > old_level:
> >            if new_level - old_level != 1:
> >                raise ValueError
> 
> here you avoid having a node which is distant more than one level from 
> its parent.
> 
> >            stack.append(stack[-1].children[-1])
> 
> here I get a crash: IndexError: list index out of range!
> 
> >            stack[-1].append(node)
> >            old_level = new_level
> >        else:
> >            while new_level < old_level:
> >                stack.pop(-1)
> >                old_level -= 1
> >            stack[-1].append(node)
> 
> Why do I need to pop something from the stack??? Here you are saying 
> that if current row has a depth (new_level) that is smaller than the 
> previous one (old_level) I decrement by one the old_level (even if I may 
> have a bigger jump) and pop something from the stack...???
> 
> >    return root
> 
> once filled, the tree is returned. I thought the tree would have been 
> the stack, but instead is root...nice surprise.


> Why do I need to pop something from the stack???

That got me thinking, and I found that my code is indeed much more complex 
than necessary. Sorry for that ;)

As a compensation here is the simplified non-popping version of read_tree():

def read_tree(rows, levelnames):
    root = Node("#ROOT", "#ROOT")
    parents = [root] + [None] * len(levelnames)

    for row in rows:
        level = column_index(row)
        node = Node(row[level], levelnames[level])

        parents[level].append(node)
        parents[level+1] = node

    return root





From __peter__ at web.de  Sat Jan 31 04:07:55 2015
From: __peter__ at web.de (Peter Otten)
Date: Sat, 31 Jan 2015 10:07:55 +0100
Subject: parsing tree from excel sheet
References: <cirqviF15qtU1@mid.individual.net>
 <mailman.18217.1422454096.18130.python-list@python.org>
 <cj1kt9Fi3e0U1@mid.individual.net>
Message-ID: <mai6bm$fmu$1@ger.gmane.org>

alb wrote:

> > 
> > def read_tree(rows, levelnames):
> >    root = Node("#ROOT", "#ROOT")
> >    old_level = 0
> >    stack = [root]
> >    for i, row in enumerate(rows, 1):
> 
> I'm not quite sure I understand what is the stack for. As of now is a 
> list whose only element is root.

The stack is used to emulate the function call stack in a recursive 
solution. Every nested call produces a new set of local variables and the 
innermost call corresponds to the top of the stack or the end of the `stack` 
list in my code.

Given a tree

A
  A1
    A11
    A12
  A2

or in another notation

0 A
1 A1
2 A11
2 A12
1 A2

we start with a stack (with the node's children in parens)

[A()]

then look at A1 and see that the level is one deeper than that of A and 
append it to A, the current TOS (top of stack)

[A(A1)]

Next is A11 which is two levels deeper than A, so we take the last child of 
A and put it on the stack, 

[A(A1), A1()]

then add A11 as a child to the new TOS

[A(A1), A1(A11)]

Next is A12 which is one level deeper than A1, so we add it to the current 
TOS

[A(A1), A1(A11, A12)]

Next is A2 which is one level higher than A1, so we keep removing nodes from 
the stack until the current TOS is one level higher than A2. Here we only 
have to remove A1 from the stack to get

[A(A1)]

and after adding A2 to the TOS

[A(A1, A2)]

I have ommitted the children of the children so far, but the actual 
structure is now

[A(A1(A11(), A12()), A2())]

Therefore I just need to return A which contains the complete layout of the 
tree.
 
> >        new_level = column_index(row)
> >        node = Node(row[new_level], levelnames[new_level])
> 
> here you are getting the node based on the current row, with its level.
> 
> >        if new_level == old_level:
> >            stack[-1].append(node)
> 
> I'm not sure I understand here. Why the end of the list and not the 
> beginning?
> 
> >        elif new_level > old_level:
> >            if new_level - old_level != 1:
> >                raise ValueError
> 
> here you avoid having a node which is distant more than one level from 
> its parent.
> 
> >            stack.append(stack[-1].children[-1])
> 
> here I get a crash: IndexError: list index out of range!
> 
> >            stack[-1].append(node)
> >            old_level = new_level
> >        else:
> >            while new_level < old_level:
> >                stack.pop(-1)
> >                old_level -= 1
> >            stack[-1].append(node)
> 
> Why do I need to pop something from the stack??? Here you are saying 
> that if current row has a depth (new_level) that is smaller than the 
> previous one (old_level) I decrement by one the old_level (even if I may 
> have a bigger jump) and pop something from the stack...???
> 
> >    return root
> 
> once filled, the tree is returned. I thought the tree would have been 
> the stack, but instead is root...nice surprise.


> Why do I need to pop something from the stack???

That got me thinking, and I found that my code is indeed much more complex 
than necessary. Sorry for that ;)

As a compensation here is the simplified non-popping version of read_tree():

def read_tree(rows, levelnames):
    root = Node("#ROOT", "#ROOT")
    parents = [root] + [None] * len(levelnames)

    for row in rows:
        level = column_index(row)
        node = Node(row[level], levelnames[level])

        parents[level].append(node)
        parents[level+1] = node

    return root





From rosuav at gmail.com  Sat Jan 31 04:10:09 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 31 Jan 2015 20:10:09 +1100
Subject: A python coder needed
In-Reply-To: <0eb69caf-6db1-400b-9bbe-5f197384065f@googlegroups.com>
References: <0eb69caf-6db1-400b-9bbe-5f197384065f@googlegroups.com>
Message-ID: <CAPTjJmpwATB=m_ht53uxOA8VqGwZ685zdntUKp-Ojg8QbNbv_A@mail.gmail.com>

On Sat, Jan 31, 2015 at 7:51 PM,  <fatihbazman at gmail.com> wrote:
> Hello. I am looking for a python coder. Please find the details which are in the below:
>
> A bittorrent client will be coded in order to share files in a private group. The private tracker server was coded by me (PHP & MySQL) and bittorrent client will be communicated with this tracker server via REST API. File meta data and peer information will be stored on this private tracker server. Files will be stored on peers computers and shared in each others by peers.
>
> For this project, Python coder will use libtorrent library and produce a software with a simple and user friendly UI. During the file sharing, all bittorent features will be used (for example segmented file transfer, cryptographic hash etc.).
>

There are various job posting sites; I believe the Stack Overflow
family of sites has one, for instance. The Python Job Board is
currently down, or I'd point you there.

However, this sounds like something that must surely exist. Can't you
just take one of the existing torrent clients and maybe have a tiny
script to signal it to start using a particular torrent file?

ChrisA


From steve+comp.lang.python at pearwood.info  Sat Jan 31 04:13:45 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 31 Jan 2015 20:13:45 +1100
Subject: help() function screen output
References: <mailman.18331.1422692290.18130.python-list@python.org>
Message-ID: <54cc9cc9$0$12981$c3e8da3$5496439d@news.astraweb.com>

Jacob Kruger wrote:

> Using python 3.4 32 bit on windows 7 64 bit machine, and when, for
> example, type in something like the following in interpreter window:
> help(str)
> 
> It will populate the screen with one full screen of information, with a
> prompt of --more-- to hit enter, or something to continue displaying
> information, but, when, for example, hit enter key, it merely populates
> one more line of info, each time - under pythn 2.7, it seemed to render
> one full screen of info each time.

Are you sure? 

I don't have Windows to try, but in Linux using both Python 2.7 and 3.3,
pressing Enter advances by a single line.

> Is there rather a different keystroke should use to invoke that, or is
> this a python 3.4 feature/issue?

Try using the Space key to advance an entire page.

You can also try Page Up and Page Down keys.

The exact keys will depend on the pager program used by help. The help
function depends on the pydoc module, which tries to use your operating
system's "pager" program for displaying pages of text. On Linux, that may
be the external programs "more" or "less". I don't know what Windows uses.
If there is no external pager program available, pydoc may end up using its
own internal pager. So the exact keys used will differ.


-- 
Steven



From fatihbazman at gmail.com  Sat Jan 31 04:17:39 2015
From: fatihbazman at gmail.com (Fatih Bazman)
Date: Sat, 31 Jan 2015 01:17:39 -0800 (PST)
Subject: A python coder needed
In-Reply-To: <mailman.18333.1422695417.18130.python-list@python.org>
References: <0eb69caf-6db1-400b-9bbe-5f197384065f@googlegroups.com>
 <mailman.18333.1422695417.18130.python-list@python.org>
Message-ID: <d660ca9d-82fa-4ca8-9d52-604f7714350f@googlegroups.com>

On Saturday, January 31, 2015 at 11:11:02 AM UTC+2, Chris Angelico wrote:
> On Sat, Jan 31, 2015 at 7:51 PM,  <fatihbazman> wrote:
> > Hello. I am looking for a python coder. Please find the details which are in the below:
> >
> > A bittorrent client will be coded in order to share files in a private group. The private tracker server was coded by me (PHP & MySQL) and bittorrent client will be communicated with this tracker server via REST API. File meta data and peer information will be stored on this private tracker server. Files will be stored on peers computers and shared in each others by peers.
> >
> > For this project, Python coder will use libtorrent library and produce a software with a simple and user friendly UI. During the file sharing, all bittorent features will be used (for example segmented file transfer, cryptographic hash etc.).
> >
> 
> There are various job posting sites; I believe the Stack Overflow
> family of sites has one, for instance. The Python Job Board is
> currently down, or I'd point you there.
> 
> However, this sounds like something that must surely exist. Can't you
> just take one of the existing torrent clients and maybe have a tiny
> script to signal it to start using a particular torrent file?
> 
> ChrisA

Thank you for your response ChrisA. I have checked deluge-torrent. But it is very complicated. However, I need a simple client for just one purpose but I dont have enough experience for Pyhton. In my project, REST API, GUI and torrent classes shall be used. Therefore, I am looking for a coder.

Fatih.


From mail at timgolden.me.uk  Sat Jan 31 04:46:20 2015
From: mail at timgolden.me.uk (Tim Golden)
Date: Sat, 31 Jan 2015 09:46:20 +0000
Subject: help() function screen output
In-Reply-To: <119606D35A474010A5746243A54F7836@JakesPC>
References: <119606D35A474010A5746243A54F7836@JakesPC>
Message-ID: <54CCA46C.8040302@timgolden.me.uk>

On 31/01/2015 08:17, Jacob Kruger wrote:
> Using python 3.4 32 bit on windows 7 64 bit machine, and when, for
> example, type in something like the following in interpreter window:
> help(str)
> It will populate the screen with one full screen of information, with a
> prompt of --more-- to hit enter, or something to continue displaying
> information, but, when, for example, hit enter key, it merely populates
> one more line of info, each time - under pythn 2.7, it seemed to render
> one full screen of info each time.
> Is there rather a different keystroke should use to invoke that, or is
> this a python 3.4 feature/issue?

The help() function uses (by default, on Windows) the built-in 
"more.com" command. There's some hand-waving going on there because it 
can/will be overridden if you have a different "more" executable 
available before the system-provided more.com or if you have a PAGER env 
var set.

If you, at the Windows command prompt (ie *not* in Python), type:

more /?

You can see the various keystrokes which the program responds to. 
Specifically, the last two lines show:

<space> Display next page
<ret>   Display next line

which is, I suspect, what you're after here.

(If you're interested, the code for all this is in the pydoc module 
(Lib\pydoc.py) in the getpager() function.

TJG


From jacob at blindza.co.za  Sat Jan 31 04:49:30 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Sat, 31 Jan 2015 11:49:30 +0200
Subject: help() function screen output
In-Reply-To: <54cc9cc9$0$12981$c3e8da3$5496439d@news.astraweb.com>
References: <mailman.18331.1422692290.18130.python-list@python.org>
 <54cc9cc9$0$12981$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <A02C42721D924033BF592C0C0D506D25@JakesPC>

----- Original Message ----- 
From: "Steven D'Aprano" <steve+comp.lang.python at pearwood.info>
Newsgroups: comp.lang.python
To: <python-list at python.org>
Sent: Saturday, January 31, 2015 11:13 AM
Subject: Re: help() function screen output


> Jacob Kruger wrote:
>
>> Using python 3.4 32 bit on windows 7 64 bit machine, and when, for
>> example, type in something like the following in interpreter window:
>> help(str)
>>
>> It will populate the screen with one full screen of information, with a
>> prompt of --more-- to hit enter, or something to continue displaying
>> information, but, when, for example, hit enter key, it merely populates
>> one more line of info, each time - under pythn 2.7, it seemed to render
>> one full screen of info each time.
>
> Are you sure?
>
> I don't have Windows to try, but in Linux using both Python 2.7 and 3.3,
> pressing Enter advances by a single line.
>
>> Is there rather a different keystroke should use to invoke that, or is
>> this a python 3.4 feature/issue?
>
> Try using the Space key to advance an entire page.
>
> You can also try Page Up and Page Down keys.
Ok, strangely, while am relatively sure 2.7 rendered a screen at a time 
before when hitting enter key, it now also seems to advance one line at a 
time, but, yes, seems like space bar does advance a whole screen in both 
versions, and page up/down doesn't react, but, space bar will do for 
now...<smile>

And, I generally let it render a screen full, and then review the screen 
contents using screen-reader screen review functionality, but, in this case 
it pretty much matches what people see.

Thanks

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..." 



From jacob at blindza.co.za  Sat Jan 31 04:56:04 2015
From: jacob at blindza.co.za (Jacob Kruger)
Date: Sat, 31 Jan 2015 11:56:04 +0200
Subject: help() function screen output
In-Reply-To: <54CCA46C.8040302@timgolden.me.uk>
References: <119606D35A474010A5746243A54F7836@JakesPC>
 <54CCA46C.8040302@timgolden.me.uk>
Message-ID: <65353AC027724F91873AA815A4773E89@JakesPC>

----- Original Message ----- > Specifically, the last two lines show:
>
> <space> Display next page
> <ret>   Display next line
>
> which is, I suspect, what you're after here.
>
> (If you're interested, the code for all this is in the pydoc module 
> (Lib\pydoc.py) in the getpager() function.
>
> TJG
> -- 
> https://mail.python.org/mailman/listinfo/python-list
>
Yes, that makes sense/works - wonder what changed recently in my overall 
configuration/setup - suppose might have something to do with screen 
reader's system wide interference - maybe it was passing a different 
effective keystroke through to command line prompt before, or something, 
since am 99.9% sure always just used <ret> key to advance one screen at a 
time before - who knows, but, main thing is, yes, space bar does what I want 
it to.

Thanks

Jacob Kruger
Blind Biker
Skype: BlindZA
"Roger Wilco wants to welcome you...to the space janitor's closet..."



From tjreedy at udel.edu  Sat Jan 31 05:19:04 2015
From: tjreedy at udel.edu (Terry Reedy)
Date: Sat, 31 Jan 2015 05:19:04 -0500
Subject: help() function screen output
In-Reply-To: <54cc9cc9$0$12981$c3e8da3$5496439d@news.astraweb.com>
References: <mailman.18331.1422692290.18130.python-list@python.org>
 <54cc9cc9$0$12981$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <maia6q$aik$1@ger.gmane.org>

On 1/31/2015 4:13 AM, Steven D'Aprano wrote:
> Jacob Kruger wrote:
>
>> Using python 3.4 32 bit on windows 7 64 bit machine, and when, for
>> example, type in something like the following in interpreter window:
>> help(str)
>>
>> It will populate the screen with one full screen of information, with a
>> prompt of --more-- to hit enter, or something to continue displaying
>> information, but, when, for example, hit enter key, it merely populates
>> one more line of info, each time - under pythn 2.7, it seemed to render
>> one full screen of info each time.

> I don't have Windows to try, but in Linux using both Python 2.7 and 3.3,
> pressing Enter advances by a single line.

Same on Windows, 2.7 and 3.4.

>> Is there rather a different keystroke should use to invoke that, or is
>> this a python 3.4 feature/issue?
>
> Try using the Space key to advance an entire page.

This works on Windows.

> You can also try Page Up and Page Down keys.

Nada

In Idle Shell, help displays entire text and one can scroll up and down 
as desired with scrollbar or PageUp/Down or arrows.

-- 
Terry Jan Reedy



From steve+comp.lang.python at pearwood.info  Sat Jan 31 06:04:00 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 31 Jan 2015 22:04:00 +1100
Subject: [OT] fortran lib which provide python like data type
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <mailman.18313.1422637734.18130.python-list@python.org>
 <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
 <mailman.18316.1422641719.18130.python-list@python.org>
 <54cc18d5$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18329.1422676162.18130.python-list@python.org>
Message-ID: <54ccb6a2$0$12985$c3e8da3$5496439d@news.astraweb.com>

Michael Torrie wrote:

> On 01/30/2015 04:50 PM, Steven D'Aprano wrote:
>> Oh great. So if the average application creates a hundred thousand
>> pointers of the course of a session, you'll only have a thousand or so
>> seg faults and leaks.
>> 
>> Well, that certainly explains this:
>> 
>> https://access.redhat.com/articles/1332213
> 
> I fail to see the connection. 

The connection is that you made a comment about eliminating "99%" of
segfaults, as if that was something to be proud of. It's not. Like 99%
uptime (which means you are down for over three and a half days per year),
it's not very impressive. All it takes is *one* mishandled pointer, and you
can have a seg fault, leak, buffer overflow, security exploit, or other
serious bug. Which leads to vulnerabilities like Ghost.

Yesterday, as I wrote that message, my web browser crashed *eight times* in
a matter of half an hour. There are thousands of serious security
vulnerabilities due to mishandled pointers. Anyone who thinks that Linux
is "secure" is deluding themselves. It's only secure in comparison to
nightmares like Windows. The fact is, the security of computer systems is
best described as "with care and attention to detail, we can make it merely
awful".

And the manual use of pointers in low-level languages like C is a huge
factor in that.


> GLibc is a low-level library written in C, 
> not C++.  By its nature requires a lot of pointer use, and is prone to
> having errors.  But not that many, seeing as *all* Linux software 
> depends on it and uses at least part of it *all* the time.  Pretty
> remarkable if you ask me.  Wonder how they do it.  Perhaps they try to
> follow "basic rules."

Exactly. And as Ghost demonstrates, that is *not good enough*.


>> Manual low-level pointer manipulation is an anti-pattern. What you glibly
>> describe as programmers following "basic rules" has proven to be beyond
>> the ability of the programming community as a whole.
> 
> I don't see how you would write system code without this "anti-pattern"
> as you describe.  Python is a great language for everything else, but I
> certainly wouldn't call it a system language.

I didn't actually mention Python.

> Couldn't write a kernel 
> in it without providing it with some sort of unsafe memory access
> (pointers!).  Or even write a Python interpreter (Yes there's PyPy, but
> with a jit it's still working with pointers).

Systems languages now are, in a sense, in the same position that programming
was back in the days before the invention of Fortran. The programmer,
writing in a low-level assembly, was responsible for pushing items onto the
stack, jumping to a sub-routine, popping the arguments off, then jumping
back to the return address. Before Fortran, there were a number of
proto-languages that aimed to make that safer, but Fortran was the first
language where the compiler itself could completely handle all the
book-keeping needed to use functions easily and safely.

The problem is not *pointers*, but "manual low-level pointer manipulation",
as I said. We programmers are expected to work out how much memory we need
before allocating a pointer, remember to check whether it is nil or not
before dereferencing it, don't forget to release the memory when you're
done, oh you just wrote past the end of the buffer and now the Russian mob
owns your computer... 

Where are the systems languages that will do to pointer access what Fortran
did to the stack?

They do exist: Rust claims to be a blazing fast systems language that is
memory-safe and eliminates dangling pointers and buffer overflows at
compile time. Assuming this is true, that means that the Rust compiler
could generate code that is just as fast and efficient as C but without all
the unsafe memory accesses of C.

http://doc.rust-lang.org/nightly/intro.html#ownership

I've never used Rust. I don't know whether it is ready for kernel
development, or whether it lives up to its claims. Rust itself is not the
point: there are other approaches to memory-safety, some of them are
suitable for application development and some are suitable for systems
languages.

C is now four decades old. It took a single decade to go from hand-writing
machine code in binary to Fortran, and here we are sixty years later still
having buffer overflows. The fact that C is still one of the top three
*application development languages* is a shameful indictment on the
conservatism, resistance to change, intellectual laziness and hubris of the
programming community as a whole.

I won't go so far as to say that C must die. But it must become a niche
language, used for the tiny (and growing ever more tiny as time goes on)
segment of code that modern, memory-safe languages *provably* cannot
handle.


> What I call glibly "basic rules" are in fact shown to more or less work
> out, as Glibc proves.  Pointer use does lead to potential
> vulnerabilities.  And they must be corrected as they are found.  Still
> not sure what your point is.

No. They must be prevented from existing in the first place.

We know that the NSA and other hostile government organisations are engaged
in a concerted effort to weaponise software bugs. Criminal organisations
mass deploy malware at random against hundreds of millions of machines at a
time. Other groups write "advanced persistent threats", effectively custom
malware targeted specifically at a single person or organisation. All these
things have something in common: they rely on bugs in the targeted
software.

Eliminate insecure and buggy software, and you eliminate these threats.

(Buffer overflows are not the only source of exploitable bugs. Today,
they're not even the number one such source. But they are number two.)


> Is there a reason to use C or C++ for many of us?  Nope.  I'm not
> arguing that we should find them of use.  It's easy for us to sit on
> Python and look with contempt at C or C++, but they really do have their
> place (C more than C++ IMO).  This is so far off the original topic that
> it probably is construed that I am arguing for C++ vs Python or
> something.  But I am not.  I'm quite content with Python.  There are a
> host of languages I find interesting including D, Google Go, Vala,
> FreeBASIC, Mozilla Rust, etc.  But Python fits my needs so well, I can't
> be bothered to invest much time in these other languages.

I cannot disagree with that.




-- 
Steven



From steve+comp.lang.python at pearwood.info  Sat Jan 31 06:56:43 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sat, 31 Jan 2015 22:56:43 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org> <mab931$qqu$1@ger.gmane.org>
 <mailman.18262.1422540523.18130.python-list@python.org>
 <54ca583e$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18276.1422555831.18130.python-list@python.org>
Message-ID: <54ccc2fc$0$13009$c3e8da3$5496439d@news.astraweb.com>

random832 at fastmail.us wrote:

> On Thu, Jan 29, 2015, at 10:56, Steven D'Aprano wrote:
>> Bar language, on the other hand, tries extremely hard to ensure that
>> every
>> type is automatically able to be coerced into every other type. The
>> coercion might not do what you expect, but it will do *something*:
> 
> See, this is where the concept falls apart. Many people will define a
> dynamically-typed language as weakly-typed *only if* the result of the
> automatic type coercion is unexpected/distasteful/fattening, 

Oh, the curse of the discontinuous mind! :-)

https://richarddawkins.net/2013/01/the-tyranny-of-the-discontinuous-mind-christmas-2011/

A concept doesn't fall apart just because a few people are unable to use it
correctly. We may not be able to distinguish the exact moment when a child
becomes an adult (except, of course, by picking some arbitrary culturally
sanctioned age) but the concepts of child and adult are meaningful. And so
it is with strong and weak typing: people of good faith may nevertheless
disagree where the dividing line should be draw, or even whether a dividing
line is meaningful, but the concept of typing strength remains meaningful.


> even if it 
> is well-defined and predictable according to the rules of the language.
> Which makes it a matter of personal taste.


Some degree of weakness in a type system is not necessarily bad. Even the
strongest of languages usually allow a few exceptions, such as numeric
coercions. I've never come across a language that has pointers which
insists on having a separate Nil pointer for ever pointer type: the
compiler will allow Nil to be used for any pointer type. Anything else
would be impractical.

Unfortunately, weakly typed languages get a bad reputation because so few of
them have well-defined rules that can be derived without having to learn a
bunch of arbitrary rules. Consider Javascript. What happens when you add
two arrays?

js> [1, 2, 3] + [4]
1,2,34

If it makes no sense to you, consider this:

js> typeof([1, 2, 3] + [4])
string

If it still makes no sense to you, you're not alone.

How about an array and an object?

js> [] + {}  //empty array plus empty object
[object Object]
js> {} + [] //empty object plus empty array
0

What if you add two empty objects?

js> {} + {}
NaN

More here:

https://www.destroyallsoftware.com/talks/wat


>> Bar will never give you a TypeError. I think we can agree that Bar is a
>> *very weakly typed* language.
> 
> Statically typed lanugages by definition can never give you a TypeError

They can't give you a *runtime* TypeError, but the compiler can give you a
compile-time type error. (Sorry for the misleading use of "TypeError" as in
the Python exception, I was thinking more broadly than just runtime
exceptions.)


> - there are no runtime conversions that can succeed or fail based on the
> type of the arguments. What makes a statically typed language strong or
> weak? Are statically typed languages always weak?

Statically typed languages tend to be strong. The point of doing static type
analysis is to prohibit ill-defined operations at compile-time, rather than
have the compiler mindlessly (say) write a 16-byte struct where a 2-byte
int is expected. But I don't think that it is necessarily the case that
statically-typed languages *must* be strongly typed, or dynamically-typed
languages weak.


>> There are degrees of strength, and I think that Python comes closer to
>> the
>> Foo end than the Bar end. There are few automatic coercions, and most of
>> those are in the numeric tower according to the usual mathematical rules.
> 
> Why is converting an int to a float when passed to a math function
> better than converting any object to a string when passed to a string
> function?

Both ints and floats are models of the same abstract thing, namely "number".
Ideally, from a mathematically standpoint, there should be no difference
between 23 and 23.0. Automatic coercions allow us to get a little closer to
that ideal.

Arbitrary objects, on the other hand, are rarely related to strings. Given
that we need to be able to display arbitrary objects to the human
programmer, if only for debugging, we need to be able to *explicitly*
convert into a string:


py> import nntplib
py> SERVER = "news.gmane.org"
py> server = nntplib.NNTP(SERVER)
py> str(server)
'<nntplib.NNTP instance at 0xb7bc76ec>'

but doing so *implicitly* gains us nothing except the saving of a few
keystrokes, while risking serious bugs. Forcing all arbitrary objects to
support string operations would be pointless and confusing. What could this
possibly mean?

server.replace('7', 'FOO')


We shouldn't insist that server objects support string methods, since that
would preempt them using methods of the same name for their own purposes,
and would needlessly clutter their API. We shouldn't want server objects to
automatically coerce into a string (why a string? why not a list or a dict
or a float?) because there is no real benefit to doing so. It can only
cause confusion.


-- 
Steven



From marko at pacujo.net  Sat Jan 31 07:22:44 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sat, 31 Jan 2015 14:22:44 +0200
Subject: [OT] fortran lib which provide python like data type
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <mailman.18313.1422637734.18130.python-list@python.org>
 <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
 <mailman.18316.1422641719.18130.python-list@python.org>
 <cj2g77Fpbv8U1@mid.individual.net>
Message-ID: <87zj8zf8bv.fsf@elektro.pacujo.net>

Gregory Ewing <greg.ewing at canterbury.ac.nz>:

> I'm completely convinced nowadays that there is *no* use case for C++.

While I wouldn't go quite that far (my most recent creation was written
in C++; why? because the legacy support libraries were written in C++).

However, C++ is like putting lipstick on a pig. In fact, C++ has so much
makeup on you wouldn't even no there's a pig underneath it. The guiding
principle in C++ language development is to take static type safety to
the extreme. That overriding principle has sacrificed other objectives
and made working with the language painful. And despite all that
machinery, C++ omitted the simplest of things that Delphi/C# got right:
delegates. Stroustrup apparently has never had to deal with callbacks;
his thick books never made a mention of them last time I checked.

Java was a masterful simplification of C++ although it, too, has taken
on unnecessary weight in the form of annotations, generics and closures.
I was exposed to Java very late in the game and was very positively
impressed by the programming model. Too bad Java's ecosystem and
stringent portability requirements make it difficult to integrate Java
with other software. At any rate, Java makes for a great production
server backend language with its high-level programming features coupled
with great performance.

Currently, my main programming languages are bash, Python and C. They
work beautifully together and cover the whole gamut of programming needs
from interrupt routines all the way to test automation. Over time, I've
shifted more and more weight from bash to Python because Python's
predictable, flexible semantics has turned out to be worth its clunky
multiprocessing facilities. Python exposes the OS facilities so doing
the "right thing" in the linux ecosystem is very possible (unlike in
Java). Python, too, is fast picking up Stroustrup-esque features so I'm
a bit concerned for losing Python as the no-nonsense swiss-army knife.

Esthetically, I'm most impressed with Scheme. One day it might give
Python a run for its money.


Marko


From marko at pacujo.net  Sat Jan 31 07:24:02 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sat, 31 Jan 2015 14:24:02 +0200
Subject: Python tracker manual password reset
References: <CALwzidk0jF1GWWC70PobWsHPrVsuDMrinVdBuJ_tJ-H-3U93vw@mail.gmail.com>
 <mailman.18330.1422691268.18130.python-list@python.org>
Message-ID: <87vbjnf89p.fsf@elektro.pacujo.net>

Terry Reedy <tjreedy at udel.edu>:

> On 1/30/2015 10:46 AM, Ian Kelly wrote:
>> Is there someone I can contact to have my password manually reset?
>
> Answered offline.

Spoilsport.


Marko


From antoine at python.org  Sat Jan 31 09:24:38 2015
From: antoine at python.org (Antoine Pitrou)
Date: Sat, 31 Jan 2015 14:24:38 +0000 (UTC)
Subject: AssertionError (3.X only) when calling
 =?utf-8?b?UHlfRmluYWxpemU=?= with threads
References: <0d97bf89-9cc3-4253-885b-54c0bfd2cd37@googlegroups.com>
Message-ID: <loom.20150131T152358-629@post.gmane.org>


Hi Tom,

Tom Kent <teeks99 <at> gmail.com> writes:
> 
> I'm getting an error output when I call the C-API's Py_Finalize() from a
different C-thread than I made a
> python call on.

Can you please post a bug on https://bugs.python.org ?
Be sure to upload your example there.

Thank you

Antoine.




From rosuav at gmail.com  Sat Jan 31 09:53:17 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 1 Feb 2015 01:53:17 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <54ccc2fc$0$13009$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
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Message-ID: <CAPTjJmrb3SQTFmsTU3iDfJeYW9+jyjLqrf33rC-S9j=Yu6g6rw@mail.gmail.com>

On Sat, Jan 31, 2015 at 10:56 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Both ints and floats are models of the same abstract thing, namely "number".
> Ideally, from a mathematically standpoint, there should be no difference
> between 23 and 23.0. Automatic coercions allow us to get a little closer to
> that ideal.

So far, I'm mostly with you. (Though if your float type is not a
perfect superset of your integer type - as in Python - then the
default "up-cast" from int to float, while disallowing a corresponding
implicit "down-cast", seems flawed. But in concept, yes, automatic
coercion allows us to treat 23 and 23.0 as the same.)

> Arbitrary objects, on the other hand, are rarely related to strings. Given
> that we need to be able to display arbitrary objects to the human
> programmer, if only for debugging, we need to be able to *explicitly*
> convert into a string:
>
>
> py> import nntplib
> py> SERVER = "news.gmane.org"
> py> server = nntplib.NNTP(SERVER)
> py> str(server)
> '<nntplib.NNTP instance at 0xb7bc76ec>'

Here, though, I'm not so sure. Why should you be able to *type-cast*
anything to string? Python has another, and perfectly serviceable,
function for converting arbitrary objects into strings, and that's
repr(). It would make perfect sense for a language to make this
distinction much more stark:

1) str() attempts to convert something into a string. It can do this
automatically in the case of "string-like" objects (eg buffers, maybe
some magical things that come from databases), and can convert others
with help (eg bytes->string using an encoding parameter), but anything
else will raise an error.

2) repr() guarantees to convert anything into a string. It does this
in a relatively arbitrary fashion; you can write a helper method for
your class to make this more useful to the human.

#2 is how Python's repr already functions, so explicitly converting
arbitrary objects into strings is covered. The idea that we can str()
them as well isn't necessarily part of a sane typing system.

(Note that I'm not saying that Python got it wrong, here; just that
taking the alternate choice would also be not-wrong.)

> but doing so *implicitly* gains us nothing except the saving of a few
> keystrokes, while risking serious bugs.

Complete and automatic casting to string, I would agree. However, I
would suggest that there are a few *binary operations* which could be
more convenient if they allowed some non-strings. For instance, Pike
allows addition of strings and integers: "1" + 2 == "12", where Python
requires "1" + str(2) for the same operation. (But Pike does *not*
allow just any object there. Only a few, like numbers, can be quietly
cast on being added to strings.)

> Forcing all arbitrary objects to
> support string operations would be pointless and confusing. What could this
> possibly mean?
>
> server.replace('7', 'FOO')

Well duh, you would go to the server and replace the 7th stored post
with the new body 'FOO' :)

Strings have *tons* of methods. There's no way you'd want them all on
every object, and it wouldn't make sense. You definitely don't up-cast
everything to string just to use methods on them... I can't imagine
any (sane) language ever doing that.

ChrisA


From ginobusciarello at outlook.com  Sat Jan 31 10:03:11 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Sat, 31 Jan 2015 07:03:11 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <7757dbc7-412a-4a42-8418-801a4d5d8fb4@googlegroups.com>
References: <7757dbc7-412a-4a42-8418-801a4d5d8fb4@googlegroups.com>
Message-ID: <eb6d610d-6512-43bf-9f10-c92cbd12bc4a@googlegroups.com>

-- redacted --


From ginobusciarello at outlook.com  Sat Jan 31 10:03:28 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Sat, 31 Jan 2015 07:03:28 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <9ea713a4-3e21-4522-b751-5d896c5ea31e@googlegroups.com>
References: <9ea713a4-3e21-4522-b751-5d896c5ea31e@googlegroups.com>
Message-ID: <44d5156b-94d7-410c-9735-b5ba2d063b88@googlegroups.com>

-- redacted --


From ginobusciarello at outlook.com  Sat Jan 31 10:03:58 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Sat, 31 Jan 2015 07:03:58 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <932064e4-d5b5-410a-990c-15a20def69a5@googlegroups.com>
References: <932064e4-d5b5-410a-990c-15a20def69a5@googlegroups.com>
Message-ID: <ad50469e-3414-402b-a4e3-528ef3a0797b@googlegroups.com>

-- redacted --


From ginobusciarello at outlook.com  Sat Jan 31 10:04:14 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Sat, 31 Jan 2015 07:04:14 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <6a5767b4-ef13-4ee8-8f57-3964b109ca79@googlegroups.com>
References: <6a5767b4-ef13-4ee8-8f57-3964b109ca79@googlegroups.com>
Message-ID: <157caeb2-2aa7-4b43-8f59-43a9b56a1e85@googlegroups.com>

-- redacted --


From ginobusciarello at outlook.com  Sat Jan 31 10:04:30 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Sat, 31 Jan 2015 07:04:30 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <35861325-94c1-418c-ab89-e4ea967431da@googlegroups.com>
References: <35861325-94c1-418c-ab89-e4ea967431da@googlegroups.com>
Message-ID: <0f7cbe0f-08fb-4ded-b0a5-dad8a29b6a86@googlegroups.com>

-- redacted --


From ginobusciarello at outlook.com  Sat Jan 31 10:05:06 2015
From: ginobusciarello at outlook.com (CHE SIA REVOLUCIOOON!!!)
Date: Sat, 31 Jan 2015 07:05:06 -0800 (PST)
Subject: -- redacted --
In-Reply-To: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
References: <f1b45ebe-669d-4b7d-a63b-7944b403e6cc@googlegroups.com>
Message-ID: <652f4567-cdc5-436b-b78c-fd71b40c8442@googlegroups.com>

-- redacted --


From rustompmody at gmail.com  Sat Jan 31 10:50:29 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Sat, 31 Jan 2015 07:50:29 -0800 (PST)
Subject: [OT] fortran lib which provide python like data type
In-Reply-To: <87zj8zf8bv.fsf@elektro.pacujo.net>
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <mailman.18313.1422637734.18130.python-list@python.org>
 <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
 <mailman.18316.1422641719.18130.python-list@python.org>
 <cj2g77Fpbv8U1@mid.individual.net>
 <87zj8zf8bv.fsf@elektro.pacujo.net>
Message-ID: <ff1ad9ad-94a0-476e-a148-3c1f46906fce@googlegroups.com>

On Saturday, January 31, 2015 at 5:52:58 PM UTC+5:30, Marko Rauhamaa wrote:
> Esthetically, I'm most impressed with Scheme. One day it might give
> Python a run for its money.
> 
> 
> Marko

Aren't you getting this backwards?

http://www.wisdomandwonder.com/link/2110/why-mit-switched-from-scheme-to-python

Dont get me wrong: Ive had more fun with scheme than any other language.
[And APL for very different reasons]
Its just that its 2015 now not 1985...
People did not 'settle' the question: "How many angels can dance on the head 
of a pin". It just stopped being relevant.

Likewise, which is the 'best' programming language is a question without the 
edge it had when I was a student


From rustompmody at gmail.com  Sat Jan 31 11:18:31 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Sat, 31 Jan 2015 08:18:31 -0800 (PST)
Subject: [OT] fortran lib which provide python like data type
In-Reply-To: <54ccb6a2$0$12985$c3e8da3$5496439d@news.astraweb.com>
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <mailman.18313.1422637734.18130.python-list@python.org>
 <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
 <mailman.18316.1422641719.18130.python-list@python.org>
 <54cc18d5$0$13002$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18329.1422676162.18130.python-list@python.org>
 <54ccb6a2$0$12985$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <3f60b63d-d4f3-474b-9290-0d87948a7af2@googlegroups.com>

On Saturday, January 31, 2015 at 4:34:14 PM UTC+5:30, Steven D'Aprano wrote:
> 
> Yesterday, as I wrote that message, my web browser crashed *eight times* in
> a matter of half an hour. There are thousands of serious security
> vulnerabilities due to mishandled pointers. Anyone who thinks that Linux
> is "secure" is deluding themselves. It's only secure in comparison to
> nightmares like Windows. The fact is, the security of computer systems is
> best described as "with care and attention to detail, we can make it merely
> awful".

Beware that may be closer to ghost than you may think
http://blog.trendmicro.com/trendlabs-security-intelligence/analyzing-cve-2015-0311-flash-zero-day-vulnerability/


From marko at pacujo.net  Sat Jan 31 12:43:15 2015
From: marko at pacujo.net (Marko Rauhamaa)
Date: Sat, 31 Jan 2015 19:43:15 +0200
Subject: [OT] fortran lib which provide python like data type
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <mailman.18313.1422637734.18130.python-list@python.org>
 <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
 <mailman.18316.1422641719.18130.python-list@python.org>
 <cj2g77Fpbv8U1@mid.individual.net> <87zj8zf8bv.fsf@elektro.pacujo.net>
 <ff1ad9ad-94a0-476e-a148-3c1f46906fce@googlegroups.com>
Message-ID: <87bnlekfrg.fsf@elektro.pacujo.net>

Rustom Mody <rustompmody at gmail.com>:

> On Saturday, January 31, 2015 at 5:52:58 PM UTC+5:30, Marko Rauhamaa wrote:
>> Esthetically, I'm most impressed with Scheme. One day it might give
>> Python a run for its money.
>
> Aren't you getting this backwards?

Deep down I'm a minimalist romantic.

> Its just that its 2015 now not 1985...

"Python was conceived in the late 1980s" ["Python", Wikipedia]
Scheme was conceived in the 1920s.       ["Combinatory Logic", Wikipedia]

> People did not 'settle' the question: "How many angels can dance on
> the head of a pin". It just stopped being relevant.

Speak for yourself. It's just that the answer was found:

    ? = ?f.((fS)K)                       ["Iota and Jot", Wikipedia]

Donc Dieu existe, r?pondez!


Marko


From breamoreboy at yahoo.co.uk  Sat Jan 31 12:59:24 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sat, 31 Jan 2015 17:59:24 +0000
Subject: [OT] fortran lib which provide python like data type
In-Reply-To: <ff1ad9ad-94a0-476e-a148-3c1f46906fce@googlegroups.com>
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <mailman.18313.1422637734.18130.python-list@python.org>
 <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
 <mailman.18316.1422641719.18130.python-list@python.org>
 <cj2g77Fpbv8U1@mid.individual.net> <87zj8zf8bv.fsf@elektro.pacujo.net>
 <ff1ad9ad-94a0-476e-a148-3c1f46906fce@googlegroups.com>
Message-ID: <maj55s$6ra$1@ger.gmane.org>

On 31/01/2015 15:50, Rustom Mody wrote:
> On Saturday, January 31, 2015 at 5:52:58 PM UTC+5:30, Marko Rauhamaa wrote:
>> Esthetically, I'm most impressed with Scheme. One day it might give
>> Python a run for its money.
>>
>>
>> Marko
>
> Aren't you getting this backwards?
>
> http://www.wisdomandwonder.com/link/2110/why-mit-switched-from-scheme-to-python
>
> Dont get me wrong: Ive had more fun with scheme than any other language.
> [And APL for very different reasons]
> Its just that its 2015 now not 1985...
> People did not 'settle' the question: "How many angels can dance on the head
> of a pin". It just stopped being relevant.
>
> Likewise, which is the 'best' programming language is a question without the
> edge it had when I was a student
>

The answer is beautifully put here 
https://mail.python.org/pipermail/python-list/2002-November/154258.html 
so I have no hesitation in reposting for the umpteenth time.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From al.basili at gmail.com  Sat Jan 31 17:45:15 2015
From: al.basili at gmail.com (alb)
Date: 31 Jan 2015 22:45:15 GMT
Subject: parsing tree from excel sheet
References: <cirqviF15qtU1@mid.individual.net>
 <mailman.18217.1422454096.18130.python-list@python.org>
 <cj1kt9Fi3e0U1@mid.individual.net>
 <mailman.18314.1422637907.18130.python-list@python.org>
Message-ID: <cj547rFfl2sU1@mid.individual.net>

Hi Peter,

Peter Otten <__peter__ at web.de> wrote:
[]
> Let's start with the simplest:
> 
>> Peter Otten <__peter__ at web.de> wrote:
> 
>>>    def show2(self):
>>>        yield str(self) 
>>>        for child in self.children:
>>>            yield from child.show2()
[]
> 
> Given a tree
> 
> A --> A1
>      A2 --> A21
>             A22
>      A3
> 
> assume a slightly modified show2():
> 
> def append_nodes(node, nodes):
>    nodes.append(node)
>    for child in node.children:
>        append_nodes(child, nodes)

I'm assuming you are referring to the method in the Node class.

> 
> When you invoke this with the root node in the above sample tree and 
> an empty list
> 
> nodes = [] append_nodes(A, nodes)
> 
> the first thing it will do is append the root node to the nodes list
> 
> [A]
> 
> Then it iterates over A's children:
> 
> append_nodes(A1, nodes) will append A1 and return immediately because 
> A1 itself has not children.
> 
> [A, A1]
> 
> append_nodes(A2, nodes) will append A2 and then iterate over A2's 
> children. As A21 and A22 don't have any children append_nodes(A21, 
> nodes) and append_nodes(A22, nodes) will just append the respective 
> node with no further nested ("recursive") invocation, and thus the 
> list is now
> 
> [A, A1, A21, A22]
> 
> Finally the append_nodes(A3, nodes) will append A3 and then return 
> because it has no children, and we end up with
> 
> nodes = [A, A1, A21, A22, A3]

So the recursive function will append children as long as there are any, 
traversing the whole tree structure (yep, I saw the missing A2 in the 
list as you mentioned already).
 
> Now why the generator? For such a small problem it doesn't matter, for 
> large datasets it is convenient that you can process the first item 
> immmediately, when the following ones may not yet be available.

I've read something about generators and they are a strong concept 
(especially for a C-minded guy like me!).

[]
> Ok, how to get from the recursive list building to yielding nodes as 
> they are encountered? The basic process is always the same:
> 
> def f(items)
>   items.append(3)
>   items.append(6)
>   for i in range(10):
>       items.append(i)
> 
> items = []
> f(items)
> for item in items:
>   print(item)
> 
> becomes
> 
> def g():
>    yield 3
>    yield 6
>    for i in range(10):
>        yield i
> 
> for item in g():
>    print(items)
---------------^ should be item and not items.

> 
> In Python 3.3 there was added some syntactic sugar so that you can 
> write
> 
> def g():
>    yield 3
>    yield 6
>    yield from range(10)
> 
> 
> Thus
> 
> def append_nodes(node, nodes):
>    nodes.append(node)
>    for child in node.children:
>        append_nodes(child, nodes)
> 
> 
> becomes
> 
> def generate_nodes(node):
>    yield node
>    for child in node.children:
>        yield from generate_nodes(child)

I'm with you now! I guess it would have been nearly impossible to see 
the real picture behind.

> This looks a lot like show2() except that it's not a method and thus 
> the node not called self and that the node itself is yielded rather 
> than str(node). The latter makes the function a bit more flexible and 
> is what I should have done in the first place.

Indeed returning the node might be more useful than just yielding its 
string.

> 
> The show() method is basically the the same, but there are varying 
> prefixes before the node name. Here's a simpler variant that just adds 
> some indentation. We start with generate_nodes() without the syntactic 
> sugar. This is because we need a name for the nodes yielded from the 
> nested generator call so that we can modify them:
> 
> def indented_nodes(node):
>    yield node
>    for child in node.children:
>        for desc in from indented_nodes(child):
>            yield desc
> 
> Now let's modify the yielded nodes:
> 
> def indented_nodes(node):
>    yield [node]

why this line has changed from 'yield node'?

>    for child in node.children:
>        for desc in indented_nodes(child):
>            yield ["***"] + desc

Ok, the need for manipulation does not allow to use the syntax sugar of 
above.

> 
> How does it fare on the example tree? 
> 
> A --> A1
>      A2 --> A21
>             A22
>      A3
> 
> The lists will have an "***" entry for every nesting level, so we get
> 
> [A]
> ["***", A1]
> ["***", A2]
> ["***", "***", A21]
> ["***", "***", A22]
> ["***", A3]
> 
> With "".join() we can print it nicely:
> 
> for item in indented_nodes(tree):
>    print("".join(item))
> 
> But wait, "".join() only accepts strings so let's change
> 
>    yield [node]
> 
> to 
>    yield [node.name] # str(node) would also work

Again my question, why not simply yield node.name?

> A
> ***A1
> ***A2
> ******A21
> ******A22
> ***A3
> 
>>> def show2(root):
>>>    for line in root.show2():
>>>        print(line)
> 
>> Here we implement the functions to print a node, but I'm not sure I 
>> understand why do I have to iterate if the main() iterates again over the 
>> nodes.
> 
> Your example had the structure
> 
> A
> A1
>   A11
>   A12
> A2
> 
> and I was unsure if there could be data files that have multiple root 
> nodes, e. g.
> 
> A
> A1
>   A11
>   A12
> A2
> B
> B1
> B2
> 
> To simplify the handling of these I introduced an artificial root R
> 
> R
> A
>  A1
>    A11
>    A12
>  A2
> B
>  B1
>  B2
> 
> which makes all toplevel nodes in the data file children of R. In the
> main() function I iterate over R's children to hide R from the user.
> 
> You can replace
> 
>        for node in tree.children:
>            show_tree(node)
>            print("")
> 
> in my original code with
> 
>        show_tree(tree)
> 
> to see the hidden node.

That makes it more clear indeed. Indeed this is what it going to happen 
in reality since I'll have several subsystems at the very same level, 
therefore all children of a #ROOT node.

> 
> I may address the rest of your post later unless someone else does. In 
> the mean time, can you please provide the data file that triggers the 
> IndexError to help me with the debugging?

There was a mistake in my file indeed, now that I fixed it everything 
works!

Al


From breamoreboy at yahoo.co.uk  Sat Jan 31 20:56:57 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 01 Feb 2015 01:56:57 +0000
Subject: [OT]very high tech humour
Message-ID: <mak15a$brk$1@ger.gmane.org>

https://www.youtube.com/watch?v=kAG39jKi0lI

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From ethan at stoneleaf.us  Sat Jan 31 21:18:03 2015
From: ethan at stoneleaf.us (Ethan Furman)
Date: Sat, 31 Jan 2015 18:18:03 -0800
Subject: [OT]very high tech humour
In-Reply-To: <mak15a$brk$1@ger.gmane.org>
References: <mak15a$brk$1@ger.gmane.org>
Message-ID: <54CD8CDB.8060308@stoneleaf.us>

LOL!

--
~Ethan~

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From steve+comp.lang.python at pearwood.info  Sat Jan 31 21:27:41 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 01 Feb 2015 13:27:41 +1100
Subject: [OT] fortran lib which provide python like data type
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <mailman.18313.1422637734.18130.python-list@python.org>
 <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
 <mailman.18316.1422641719.18130.python-list@python.org>
 <cj2g77Fpbv8U1@mid.individual.net> <87zj8zf8bv.fsf@elektro.pacujo.net>
Message-ID: <54cd8f1e$0$12986$c3e8da3$5496439d@news.astraweb.com>

Marko Rauhamaa wrote:

> I'm most impressed with Scheme. One day it might give
> Python a run for its money.

Scheme is forty years old, having come out in 1975. Python is 24 years old,
having come out in 1991. If Scheme hasn't caught up with Python by now, it
never will.



-- 
Steven



From rustompmody at gmail.com  Sat Jan 31 21:30:33 2015
From: rustompmody at gmail.com (Rustom Mody)
Date: Sat, 31 Jan 2015 18:30:33 -0800 (PST)
Subject: [OT] fortran lib which provide python like data type
In-Reply-To: <87bnlekfrg.fsf@elektro.pacujo.net>
References: <mailman.18264.1422543630.18130.python-list@python.org>
 <4822a519-5814-433b-88ad-9bea8a2f83e3@googlegroups.com>
 <3c31aec4-0c0a-4eb9-aff4-e7b7aa76da21@googlegroups.com>
 <mafc1u$n1l$1@dont-email.me>
 <3d3ef587-a62d-4024-964c-0ac8be023ca3@googlegroups.com>
 <mailman.18313.1422637734.18130.python-list@python.org>
 <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
 <mailman.18316.1422641719.18130.python-list@python.org>
 <cj2g77Fpbv8U1@mid.individual.net>
 <87zj8zf8bv.fsf@elektro.pacujo.net>
 <ff1ad9ad-94a0-476e-a148-3c1f46906fce@googlegroups.com>
 <87bnlekfrg.fsf@elektro.pacujo.net>
Message-ID: <561ab49b-890e-4c95-9cf2-6cbbac5b3c93@googlegroups.com>

On Saturday, January 31, 2015 at 11:13:29 PM UTC+5:30, Marko Rauhamaa wrote:
> Rustom Mody:
> 
> > On Saturday, January 31, 2015 at 5:52:58 PM UTC+5:30, Marko Rauhamaa wrote:
> >> Esthetically, I'm most impressed with Scheme. One day it might give
> >> Python a run for its money.
> >
> > Aren't you getting this backwards?
> 
> Deep down I'm a minimalist romantic.
> 
> > Its just that its 2015 now not 1985...
> 
> "Python was conceived in the late 1980s" ["Python", Wikipedia]
> Scheme was conceived in the 1920s.       ["Combinatory Logic", Wikipedia]
> 
> > People did not 'settle' the question: "How many angels can dance on
> > the head of a pin". It just stopped being relevant.
> 
> Speak for yourself. It's just that the answer was found:
> 
>     ? = ?f.((fS)K)                       ["Iota and Jot", Wikipedia]
> 
> Donc Dieu existe, r?pondez!



My r?pondez:

Marvin Minsky's Turing award lecture
http://web.media.mit.edu/~minsky/papers/TuringLecture/TuringLecture.html

There is a real conflict between the logician's goal and the
educator's. The logician wants to minimize the variety of ideas,
and doesn't mind a long, thin path. The educator (rightly) wants
to make the paths short and doesn't mind?in fact,
prefers?connections to many other ideas. And he cares almost not
at all about the directions of the links.

Anyway?  Thanks for those links or rather the pointer to
http://en.wikipedia.org/wiki/Iota_and_Jot


From jsf80238 at gmail.com  Sat Jan 31 21:38:48 2015
From: jsf80238 at gmail.com (Jason Friedman)
Date: Sat, 31 Jan 2015 19:38:48 -0700
Subject: Create dictionary based of x items per key from two lists
In-Reply-To: <0dddee06-233b-436a-be48-3c16e62c1718@googlegroups.com>
References: <0dddee06-233b-436a-be48-3c16e62c1718@googlegroups.com>
Message-ID: <CANy1k1iTMpiUdXaFRqfvt_P=jLk08yVohKxGtY8rXVcwUxiCKw@mail.gmail.com>

> I have two lists
>
> l1 =  ["a","b","c","d","e","f","g","h","i","j"]
> l2 = ["aR","bR","cR"]
>
> l2 will always be smaller or equal to l1
>
> numL1PerL2 = len(l1)/len(l2)
>
> I want to create a dictionary that has key from l1 and value from l2 based on numL1PerL2
>
> So
>
> {
> a:aR,
> b:aR,
> c:aR,
> d:bR,
> e:bR,
> f:bR,
> g:cR,
> h:cR,
> i:cR,
> j:cR
> }

Another possibility is:
import itertools
my_dict = {x:y for x,y in zip(list1, itertools.cycle(list2))}


From steve+comp.lang.python at pearwood.info  Sat Jan 31 22:00:05 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 01 Feb 2015 14:00:05 +1100
Subject: RAII vs gc (was fortran lib which provide python like data type)
References: <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
 <8ff4c8aa-a858-481f-8964-7c794f848de2@googlegroups.com>
 <mailman.18322.1422653315.18130.python-list@python.org>
Message-ID: <54cd96b5$0$12994$c3e8da3$5496439d@news.astraweb.com>

Sturla Molden wrote:

> Rustom Mody <rustompmody at gmail.com> wrote:
> 
>> The case of RAII vs gc is hardly conclusive:
>> 
>> http://stackoverflow.com/questions/228620/garbage-collection-in-c-why
> 
> The purpose of RAII is not to be an alternative to garbage collection
> (which the those answers imply), but to ensure  deterministc execution of
> setup and tear-down code. The Python equivalent of RAII is not garbage
> collection but context managers.
> 
> Those answers is a testimony to how little the majority of C++ users
> actually understand about the language.
> 
> 
> 
> A C++ statement with RAII like
> 
> {
>    Foo bar();
>    // suite
> }
> 
> is not equivalent to
> 
>     bar = Foo()
> 
> in Python. It actually corresponds to
> 
> with Foo() as bar:
>     <suite>


Nice answer! I'm not qualified to tell whether you are right or not, but
what you say has the ring of truth about it.



-- 
Steven



From breamoreboy at yahoo.co.uk  Sat Jan 31 22:06:21 2015
From: breamoreboy at yahoo.co.uk (Mark Lawrence)
Date: Sun, 01 Feb 2015 03:06:21 +0000
Subject: Create dictionary based of x items per key from two lists
In-Reply-To: <CAPTjJmoJmr6PUwGEtpOZ=i2Kff=AMEuuK2kvzuT23fefJg1j8g@mail.gmail.com>
References: <0dddee06-233b-436a-be48-3c16e62c1718@googlegroups.com>
 <CAPTjJmoJmr6PUwGEtpOZ=i2Kff=AMEuuK2kvzuT23fefJg1j8g@mail.gmail.com>
Message-ID: <mak57e$3pd$1@ger.gmane.org>

On 31/01/2015 02:38, Chris Angelico wrote:
> On Sat, Jan 31, 2015 at 1:27 PM,  <rajanbond at gmail.com> wrote:
>> l1 =  ["a","b","c","d","e","f","g","h","i","j"]
>> l2 = ["aR","bR","cR"]
>>
>> l2 will always be smaller or equal to l1
>>
>> numL1PerL2 = len(l1)/len(l2)
>>
>> I want to create a dictionary that has key from l1 and value from l2 based on numL1PerL2
>>
>> So
>>
>> {
>> a:aR,
>> b:aR,
>> c:aR,
>> d:bR,
>> e:bR,
>> f:bR,
>> g:cR,
>> h:cR,
>> i:cR,
>> j:cR
>> }
>>
>> So last item from l2 is key for remaining items from l1
>
> So the Nth element of l1 will always be paired with the
> (N/numL1PerL2)th element of l2 (with the check at the end)? Seems easy
> enough.
>
> dups = len(l1)/len(l2)
> l2.append(l2[-1])
> result = {x:l2[i/dups] for i,x in enumerate(l1)}
>
> This mutates l2 for convenience, but you could also adjust the index
> to take care of the excess. As a one-liner:
>
> result = {x:l2[min(i/(len(l1)/len(l2)),len(l2)-1)] for i,x in enumerate(l1)}
>
> But the one-liner is not better code :)
>
> ChrisA
>

The one-liner might not be better code, but it must be better speed wise 
precisely because it's on one line, right? :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence



From steve+comp.lang.python at pearwood.info  Sat Jan 31 22:06:36 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 01 Feb 2015 14:06:36 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <1939680766443642112.878725sturla.molden-gmail.com@news.gmane.org>
 <CANc-5Uy3as3J=_h7oJiG4xY9kwSzchmxt=6bKZoEQhc4HHvePA@mail.gmail.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
 <mailman.18229.1422469034.18130.python-list@python.org>
 <MPG.2f340c6ea39d9f3f9896b3@nntp.aioe.org>
 <54ca5bbf$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f34ebd12b42ff6f9896b5@nntp.aioe.org>
Message-ID: <54cd983c$0$13002$c3e8da3$5496439d@news.astraweb.com>

Mario Figueiredo wrote:

> In article <54ca5bbf$0$12992$c3e8da3$5496439d at news.astraweb.com>,
> steve+comp.lang.python at pearwood.info says...
>> 
>> Why should I feel guilty? You wrote:
>> 
>> 
>> "Static analysis cannot and should not clutter executable code."
>> 
>> 
>> But what are type declarations in statically typed languages like C,
>> Pascal, Haskell, etc.? They are used by the compiler for static analysis.
>> The same applies to type declarations in dynamically typed languages like
>> Cobra and Julia. And yet, there they are, in the executable code.
>> 
>> So there are a whole lot of languages, going all the way back to 1950s
>> languages like Fortran, to some of the newest languages which are only a
>> few years old like Go, both dynamically typed and statically typed, which
>> do exactly what you say languages "cannot and should not" do: they put
>> type information used for static analysis there in the code.
> 
> You are confusing static analysis with compile time checking which
> produces side-effects like implicit conversion for instance and that
> affects the resulting binary code. Something that Python won't do with
> type annotations. And something that Julia, Scala or C does.

I'm not confusing anything. I'm fully aware of the differences between what
C or Pascal does and what Python does. But I'm also aware of the
similarities.


> This is also the first time I hear compilation time mentioned as static
> analysis.

Compilation consists of many different tasks. They may be explicitly handled
by different tools, or implicitly handled by a single tool. That tool may
combine them into a single phase, or keep them separate. These are all
implementation details: different compilers for the same language could do
this differently.

Typical tasks for a compiler, in no particular order:

- lexing and parsing of source code
- type analysis and checking
- code generation
- linking to external libraries
- optimisation

For languages like C and Pascal, the type checking is typically done
statically at compile-time. So of course they include static analysis. The
compiler hasn't compiled the code yet, so it only has the source code to
work with! A type error will halt the compiler and stop the program from
compiling.


> To be clear, type declarations in Julia, Scala, C have the potential to
> produce side-effects, can result in optimized code and can result in
> compile time errors or warnings. Type annotations in Python are instead
> completely ignored by the interpreter. They do nothing of the above.
> They do not participate in code execution.

As as been pointed out repeatedly, Python annotations DO participate in the
code execution: the annotations are created and stored in the function
object at runtime, and one could easily create a library to use those
annotations at runtime for runtime type-checks.


>> As I said, these languages disagree with you. You are not just arguing
>> against Guido, but against the majority of programming language designers
>> for 60+ years.
> 
> You are right. I'm not arguing against Guido. I have yet to hear his
> opinion on your or mine arguments. I'm not arguing against the majority
> of programming languages either, because they agree with me.

Do you really expect us to believe that the majority of programming
languages put type declarations in docstrings, or a second file separate
from the source of the function? Okay, let's see some examples. Here is a
list of languages still well-known enough that people use them:

http://rosettacode.org/wiki/Category:Programming_Languages


How many of them use docstrings as the only way to declare the type of a
variable? How many use header files as the sole way to declare the type of
variables?

I'm feeling generous. You don't even need to show a *majority* (50%). I'd be
amazed if you can find *ten percent* of those languages that agree with
you.



-- 
Steven



From steve+comp.lang.python at pearwood.info  Sat Jan 31 22:16:09 2015
From: steve+comp.lang.python at pearwood.info (Steven D'Aprano)
Date: Sun, 01 Feb 2015 14:16:09 +1100
Subject: Python is DOOMED! Again!
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org> <mab931$qqu$1@ger.gmane.org>
 <mailman.18262.1422540523.18130.python-list@python.org>
 <54ca583e$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18276.1422555831.18130.python-list@python.org>
 <54ccc2fc$0$13009$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18340.1422716000.18130.python-list@python.org>
Message-ID: <54cd9a7a$0$12984$c3e8da3$5496439d@news.astraweb.com>

Chris Angelico wrote:

> On Sat, Jan 31, 2015 at 10:56 PM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> Both ints and floats are models of the same abstract thing, namely
>> "number". Ideally, from a mathematically standpoint, there should be no
>> difference between 23 and 23.0. Automatic coercions allow us to get a
>> little closer to that ideal.
> 
> So far, I'm mostly with you. (Though if your float type is not a
> perfect superset of your integer type - as in Python - then the
> default "up-cast" from int to float, while disallowing a corresponding
> implicit "down-cast", seems flawed. But in concept, yes, automatic
> coercion allows us to treat 23 and 23.0 as the same.)

In principle, we might have a real-number type that is a perfect superset of
ints, and we might even have int versions of NAN and INF. But down-casting
real-to-integer is ambiguous, due to the need to handle any fractional
parts:

- raise an exception if the fractional part is non-zero
- truncate (round towards zero)
- round down towards -infinity
- round up toward +infinity
- round to nearest, ties to odd numbers
- round to nearest, ties to even numbers
- round to nearest, ties split randomly
- something else

One might semi-arbitrarily pick one (say, truncation) as the default when
you cast using int(x) but you need to support at least the most common
rounding modes, perhaps as separate functions.


>> Arbitrary objects, on the other hand, are rarely related to strings.
>> Given that we need to be able to display arbitrary objects to the human
>> programmer, if only for debugging, we need to be able to *explicitly*
>> convert into a string:
>>
>>
>> py> import nntplib
>> py> SERVER = "news.gmane.org"
>> py> server = nntplib.NNTP(SERVER)
>> py> str(server)
>> '<nntplib.NNTP instance at 0xb7bc76ec>'
> 
> Here, though, I'm not so sure. Why should you be able to *type-cast*
> anything to string? Python has another, and perfectly serviceable,
> function for converting arbitrary objects into strings, and that's
> repr().

Which *also* converts to a string. (Note I didn't say *cast* to a string. I
cannot imagine any meaningful definition of what casting a NNTP server
object to a str might be.)


> It would make perfect sense for a language to make this 
> distinction much more stark:
> 
> 1) str() attempts to convert something into a string. It can do this
> automatically in the case of "string-like" objects (eg buffers, maybe
> some magical things that come from databases), and can convert others
> with help (eg bytes->string using an encoding parameter), but anything
> else will raise an error.
> 
> 2) repr() guarantees to convert anything into a string. It does this
> in a relatively arbitrary fashion; you can write a helper method for
> your class to make this more useful to the human.
> 
> #2 is how Python's repr already functions, so explicitly converting
> arbitrary objects into strings is covered. The idea that we can str()
> them as well isn't necessarily part of a sane typing system.
> 
> (Note that I'm not saying that Python got it wrong, here; just that
> taking the alternate choice would also be not-wrong.)

I agree with all of that. And for what it is worth, a class can refuse to
convert to str while still supporting repr:

py> class K(object):
...     def __str__(self): raise TypeError
...     def __repr__(self): return "Stuff and things. Mostly stuff."
...
py> k = K()
py> str(k)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 2, in __str__
TypeError
py> repr(k)
'Stuff and things. Mostly stuff.'


But by default, Python will fallback on __repr__ if __str__ doesn't exist,
or __str__ if __repr__ doesn't exist, or both. Or something. (I always
forget what the rules are exactly.)


>> but doing so *implicitly* gains us nothing except the saving of a few
>> keystrokes, while risking serious bugs.
> 
> Complete and automatic casting to string, I would agree. However, I
> would suggest that there are a few *binary operations* which could be
> more convenient if they allowed some non-strings. For instance, Pike
> allows addition of strings and integers: "1" + 2 == "12", where Python
> requires "1" + str(2) for the same operation. (But Pike does *not*
> allow just any object there. Only a few, like numbers, can be quietly
> cast on being added to strings.)

I'm surprised you're not into Perl, with an attitude like that. A sick,
disgusting, despicably perverted attitude. *wink*

But seriously, I can see some uses there, but frankly why bother to make an
exception for ints when you require all other types to have an explicit
coercion?

The problem with string/int automatic coercions is that there are lots of
answers but none of them are obviously the right answer:

"1" + 1 --> "11" or 2?

"1a" + 1 --> 2 like Perl does, or "1a1" like Javascript does?

Do you strip out all non-numeric characters, or truncate at the first
non-numeric character?

Should you perhaps be a little more flexible and allow common mistypings
like O for 0 and l for 1? How about whitespace?



-- 
Steven



From rosuav at gmail.com  Sat Jan 31 22:21:22 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 1 Feb 2015 14:21:22 +1100
Subject: RAII vs gc (was fortran lib which provide python like data type)
In-Reply-To: <54cd96b5$0$12994$c3e8da3$5496439d@news.astraweb.com>
References: <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
 <8ff4c8aa-a858-481f-8964-7c794f848de2@googlegroups.com>
 <mailman.18322.1422653315.18130.python-list@python.org>
 <54cd96b5$0$12994$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmr7b9wYxffJQ2cnLPf=60CiyJQyc8vbSPCm-Ovjuh8CJw@mail.gmail.com>

On Sun, Feb 1, 2015 at 2:00 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
>> A C++ statement with RAII like
>>
>> {
>>    Foo bar();
>>    // suite
>> }
>>
>> is not equivalent to
>>
>>     bar = Foo()
>>
>> in Python. It actually corresponds to
>>
>> with Foo() as bar:
>>     <suite>
>
>
> Nice answer! I'm not qualified to tell whether you are right or not, but
> what you say has the ring of truth about it.

I would say that this is indeed correct, with the caveat that RAII is
most often used for memory allocation, in which case the correct
transformation into Python _would_ be a constructor call. But when you
use this kind of thing to set up state and clean up afterwards, then
yes, Python's equivalent would be a context manager.

So a C++ way to release and reacquire the GIL might look like this
(borrowing from https://docs.python.org/3.5/c-api/init.html):

class ReleaseGIL
{
    //Internal state
    PyThreadState *_save;
public:
    //Constructor
    ReleaseGIL() {_save = PyEval_SaveThread();}
    //Destructor
    ~ReleaseGIL() {PyEval_RestoreThread(_save);}
};

//Usage example:
int do_work()
{
    while (1)
    {
        //use the Python C API to figure out what we need to do
        ReleaseGIL heavy_processing_coming;
        //do the heavy computational work
    } //GIL is reacquired here
}


The Python equivalent would be something like:

@contextlib.contextmanager
def release_gil():
    """Why the <bleep> are we manipulating the
    GIL from Python code anyway???"""
    _save = PyEval_SaveThread()
    yield
    PyEval_RestoreThread(_save)

def do_work()
    while True:
        # get some work
        with release_gil() as heavy_processing_coming:
            # do the heavy computational work
        # GIL is reacquired here

In each case, you have a guarantee that code following the suite will
not be executed without first performing the appropriate cleanup.

ChrisA


From rosuav at gmail.com  Sat Jan 31 22:22:16 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 1 Feb 2015 14:22:16 +1100
Subject: Create dictionary based of x items per key from two lists
In-Reply-To: <mak57e$3pd$1@ger.gmane.org>
References: <0dddee06-233b-436a-be48-3c16e62c1718@googlegroups.com>
 <CAPTjJmoJmr6PUwGEtpOZ=i2Kff=AMEuuK2kvzuT23fefJg1j8g@mail.gmail.com>
 <mak57e$3pd$1@ger.gmane.org>
Message-ID: <CAPTjJmr4dFVOchN7VRq7HWgJzyQmwbvo2KG0FgU5G-od8=xNOg@mail.gmail.com>

On Sun, Feb 1, 2015 at 2:06 PM, Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
> The one-liner might not be better code, but it must be better speed wise
> precisely because it's on one line, right? :)

Well of course it is. Python code speed is always measured in lines
per minute. That's why you should eliminate blank lines from your
code.

ChrisA


From jeanpierreda at gmail.com  Sat Jan 31 22:27:22 2015
From: jeanpierreda at gmail.com (Devin Jeanpierre)
Date: Sat, 31 Jan 2015 19:27:22 -0800
Subject: RAII vs gc (was fortran lib which provide python like data type)
In-Reply-To: <1553594603444345533.649938sturla.molden-gmail.com@news.gmane.org>
References: <0b8db0f6-75c5-4a8f-a9a5-51fa936b306e@googlegroups.com>
 <8ff4c8aa-a858-481f-8964-7c794f848de2@googlegroups.com>
 <1553594603444345533.649938sturla.molden-gmail.com@news.gmane.org>
Message-ID: <CABicbJ+T=zffqZeTiB7auwAg9M=s=H-8AFZqndQU5ZORCiTrFw@mail.gmail.com>

On Fri, Jan 30, 2015 at 1:28 PM, Sturla Molden <sturla.molden at gmail.com> wrote:
> in Python. It actually corresponds to
>
> with Foo() as bar:
>     <suite>

The problem with with statements is that they only handle the case of
RAII with stack allocated variables, and can't handle transfer of
ownership cleanly.

Consider the case of a function that opens a file and returns it:

def myfunction(name, stuff):
    f = open(name)
    f.seek(stuff) # or whatever
    return f

def blahblah():
    with myfunction('hello', 12) as f:
         ....

This code is wrong, because if an error occurs during seek in
myfunction, the file is leaked.

The correct myfunction is as follows:

def myfunction(name, stuff)
    f = open(name)
    try:
        f.seek(stuff)
    except:
        f.close()
        raise

Or whatever. (I would love a close_on_error context manager, BTW.)

With RAII, the equivalent C++ looks nearly exactly like the original
(bad) Python approach, except it uses unique_ptr to store the file,
and isn't broken. ("Modern") C++ makes this easy to get right. But
then, this isn't the common case.

-- Devin


From rosuav at gmail.com  Sat Jan 31 22:46:15 2015
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 1 Feb 2015 14:46:15 +1100
Subject: Python is DOOMED! Again!
In-Reply-To: <54cd9a7a$0$12984$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org>
 <mab931$qqu$1@ger.gmane.org>
 <mailman.18262.1422540523.18130.python-list@python.org>
 <54ca583e$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18276.1422555831.18130.python-list@python.org>
 <54ccc2fc$0$13009$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18340.1422716000.18130.python-list@python.org>
 <54cd9a7a$0$12984$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <CAPTjJmq_juW7dVCeTV_7=ReKSJhieJZUcL1sDeQ+2XDUfC2B7A@mail.gmail.com>

On Sun, Feb 1, 2015 at 2:16 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Chris Angelico wrote:
>
>> On Sat, Jan 31, 2015 at 10:56 PM, Steven D'Aprano
>> <steve+comp.lang.python at pearwood.info> wrote:
>>> Both ints and floats are models of the same abstract thing, namely
>>> "number". Ideally, from a mathematically standpoint, there should be no
>>> difference between 23 and 23.0. Automatic coercions allow us to get a
>>> little closer to that ideal.
>>
>> So far, I'm mostly with you. (Though if your float type is not a
>> perfect superset of your integer type - as in Python - then the
>> default "up-cast" from int to float, while disallowing a corresponding
>> implicit "down-cast", seems flawed. But in concept, yes, automatic
>> coercion allows us to treat 23 and 23.0 as the same.)
>
> In principle, we might have a real-number type that is a perfect superset of
> ints, and we might even have int versions of NAN and INF. But down-casting
> real-to-integer is ambiguous, due to the need to handle any fractional
> parts:
>
> - raise an exception if the fractional part is non-zero
> - truncate (round towards zero)
> - round down towards -infinity
> - round up toward +infinity
> - round to nearest, ties to odd numbers
> - round to nearest, ties to even numbers
> - round to nearest, ties split randomly
> - something else
>
> One might semi-arbitrarily pick one (say, truncation) as the default when
> you cast using int(x) but you need to support at least the most common
> rounding modes, perhaps as separate functions.

Agreed; but the trap here is that there are equivalent problems when
converting integers to floating point - just more subtle, because they
don't happen in the low ranges of values. In the same way that a
UTF-16 string representation has more subtle problems than an ASCII
string representation (because it's easy to test your code on "foreign
text" and still not realize that it has issues with astral
characters), casting int to float is subtle because you'll probably do
all your testing on numbers less than 2**53. It might take a lot of
tracking-down work before you finally discover that there's one place
in your code where you do division with / instead of //, and you get
back a float, and then only when your integers are really huge (maybe
you encode an eight-digit date, four-digit time, then a three-digit
country code, and finally a two-digit incrementing number) do you
actually start losing precision. The bulk of Python programs will
never run into this; yet we do have an arbitrary-precision integer
type, we're not like ECMAScript with a single "Number" type.

>>> Arbitrary objects, on the other hand, are rarely related to strings.
>>> Given that we need to be able to display arbitrary objects to the human
>>> programmer, if only for debugging, we need to be able to *explicitly*
>>> convert into a string:
>>>
>>>
>>> py> import nntplib
>>> py> SERVER = "news.gmane.org"
>>> py> server = nntplib.NNTP(SERVER)
>>> py> str(server)
>>> '<nntplib.NNTP instance at 0xb7bc76ec>'
>>
>> Here, though, I'm not so sure. Why should you be able to *type-cast*
>> anything to string? Python has another, and perfectly serviceable,
>> function for converting arbitrary objects into strings, and that's
>> repr().
>
> Which *also* converts to a string. (Note I didn't say *cast* to a string. I
> cannot imagine any meaningful definition of what casting a NNTP server
> object to a str might be.)

Sure, but Python doesn't really have a way to spell "convert this to a
string if it's already basically stringy, otherwise raise TypeError".
You can do that for other types like int, but not for string, because
you can always call str() on something.

> I agree with all of that. And for what it is worth, a class can refuse to
> convert to str while still supporting repr:
>
> py> class K(object):
> ...     def __str__(self): raise TypeError
> ...     def __repr__(self): return "Stuff and things. Mostly stuff."
> ...
> py> k = K()
> py> str(k)
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
>   File "<stdin>", line 2, in __str__
> TypeError
> py> repr(k)
> 'Stuff and things. Mostly stuff.'

Hmm. Sure you can do that, but is that just part of the freedom you
have to shoot yourself in the foot? Would that be considered an
ill-behaved class?

>> Complete and automatic casting to string, I would agree. However, I
>> would suggest that there are a few *binary operations* which could be
>> more convenient if they allowed some non-strings. For instance, Pike
>> allows addition of strings and integers: "1" + 2 == "12", where Python
>> requires "1" + str(2) for the same operation. (But Pike does *not*
>> allow just any object there. Only a few, like numbers, can be quietly
>> cast on being added to strings.)
>
> I'm surprised you're not into Perl, with an attitude like that. A sick,
> disgusting, despicably perverted attitude. *wink*
>
> But seriously, I can see some uses there, but frankly why bother to make an
> exception for ints when you require all other types to have an explicit
> coercion?

Ints, floats, and any user-defined type that chooses to ask for it;
but not arrays, mappings, files, or other types that don't make sense.
It's the same feature that allows you to add a float and an int; the +
operator is defined as accepting certain pairs of dissimilar types,
and has well-defined behaviour around those types.

> The problem with string/int automatic coercions is that there are lots of
> answers but none of them are obviously the right answer:
>
> "1" + 1 --> "11" or 2?

If that's 2, then you have a classic "sloppy typing" system that has
to spell addition and concatenation differently (cf PHP and REXX). The
one obvious answer here is "11".

> "1a" + 1 --> 2 like Perl does, or "1a1" like Javascript does?
>
> Do you strip out all non-numeric characters, or truncate at the first
> non-numeric character?

You don't strip out anything from the string when you add an integer
to it, because you convert the integer to a string.

(Now, what the rules are for converting a string to an integer, well,
that's a completely different question. Fresh new argument as to
whether casting "1z" to integer should be 1 or TypeError.)

> Should you perhaps be a little more flexible and allow common mistypings
> like O for 0 and l for 1? How about whitespace?

Definitely not O/0 or I/1, but ignoring whitespace when converting
string to integer is often helpful, and seldom a problem. But none of
this has anything to do with adding strings and non-strings; you
*always* convert to string (or throw an error), never the other way.

ChrisA


From ethan at stoneleaf.us  Sat Jan 31 23:31:17 2015
From: ethan at stoneleaf.us (Ethan Furman)
Date: Sat, 31 Jan 2015 20:31:17 -0800
Subject: Python is DOOMED! Again!
In-Reply-To: <54cd9a7a$0$12984$c3e8da3$5496439d@news.astraweb.com>
References: <54c07d04$0$13012$c3e8da3$5496439d@news.astraweb.com>
 <mailman.17982.1421951313.18130.python-list@python.org>
 <6eb91c4b-92ff-44a8-b5a9-6ef04c71f4cb@googlegroups.com>
 <MPG.2f2b9739d70d7220989688@nntp.aioe.org>
 <35a40ec6-3763-448b-9ea4-4a233a04979b@googlegroups.com>
 <54c1ccc8$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18150.1422284487.18130.python-list@python.org>
 <54c6d7c2$0$12992$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18178.1422380228.18130.python-list@python.org>
 <MPG.2f31f0482d3837cb98969f@nntp.aioe.org>
 <54c83ab4$0$12982$c3e8da3$5496439d@news.astraweb.com>
 <MPG.2f3318cb4d02fd059896b2@nntp.aioe.org> <mab931$qqu$1@ger.gmane.org>
 <mailman.18262.1422540523.18130.python-list@python.org>
 <54ca583e$0$13005$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18276.1422555831.18130.python-list@python.org>
 <54ccc2fc$0$13009$c3e8da3$5496439d@news.astraweb.com>
 <mailman.18340.1422716000.18130.python-list@python.org>
 <54cd9a7a$0$12984$c3e8da3$5496439d@news.astraweb.com>
Message-ID: <54CDAC15.9050709@stoneleaf.us>

On 01/31/2015 07:16 PM, Steven D'Aprano wrote:
> 
> But by default, Python will fallback on __repr__ if __str__ doesn't exist,
> or __str__ if __repr__ doesn't exist, or both. Or something. (I always
> forget what the rules are exactly.)

If __str__ is missing, __repr__ is called.

If __repr__ is missing, object.__repr__ (or some intermediate base class' __repr__) is called.

--
~Ethan~

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From 2281570025 at qq.com  Sat Jan 31 23:51:27 2015
From: 2281570025 at qq.com (=?gb18030?B?aU1hdGg=?=)
Date: Sun, 1 Feb 2015 12:51:27 +0800
Subject: cx_Freeze:Fatal Python error: Py_Initialize: Unable to get the locale
 encoding ImportError: No module named 'encodings'
Message-ID: <tencent_4143EC48083924EF32B7D695@qq.com>

I downloaded cx_Freeze from here, installed it successfully on Ubuntu following this thread .

After run python3 setup.py build in cx_Freeze/samples/simple,then change the dir to cx_Freeze/samples/simple/build/exe.linux-i686-3.4,run the following command ,I got the error

?  exe.linux-i686-3.4  ./hello

Fatal Python error: Py_Initialize: Unable to get the locale encoding

ImportError: No module named 'encodings'

[1]    3950 abort      ./hello

?  exe.linux-i686-3.4  

any idea on fixing this issue ?
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